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Sample records for tooth extraction

  1. Reasons for permanent tooth extractions in Taiwan.

    Science.gov (United States)

    Lee, Chen-Yi; Chang, Yong-Yuan; Shieh, Tien-Yu; Chang, Chin-Shun

    2015-03-01

    There has been no study in Taiwan on reasons for extraction of permanent teeth. This study aimed to determine the reasons for permanent teeth extraction in Taiwan. This study performed a secondary data analysis based on the National Health Insurance Research Database. The 2009 database was adopted and there are 131 104 records of dental visits in the database; among them, 4958 visits (from 4811 patients) have a coding of extraction. The results showed that dental caries (55.3%) was the main reason for tooth extraction, followed by periodontal disease (22.1%). Extraction because of dental caries was commonly observed in all age-groups, and extractions because of periodontal disease increased in those older than 35 years. Maxillary and mandibular third molar were the most frequently removed tooth types, and most were extracted because of dental caries and impaction respectively. PMID:22743854

  2. Necessity of analgesics prescription after tooth extraction

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    Tozoglu Sinan

    2009-01-01

    Full Text Available Introduction. For patients and surgeons, pain and discomfort associated with dento-alveolar surgery can be a frightening prospect. This study was aimed to check whether prescription of analgesics is necessary or not after simple extraction of the mandibular third molars. Material and methods. Seventy-six dental outpatients undergoing uncomplicated extraction of both mandibular third molars teeth served as subjects. After extraction on the first side, patients received either naproxen sodium 550 mg orally or a placebo. The order of the drugs was reversed during extraction on side two. The postoperative pain was scored with a six-point category rating scala. The obtained data were analyzed with Mann-Whitney U-test. Results. The sum of the pain intensity for hours 2 through 8 was less for the group that received sodium naproxen. For hours 8-24, the sum of the pain intensity was less for the placebo group but this difference was not statistically different. Conclusion. This study shows that uncomplicated tooth extraction did not cause a significant postoperative pain and there was no need to prescribe analgesics for such cases.

  3. Endoscopic Extraction of the Impacted Wisdom Tooth from Maxillary Sinus

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    Larin R.A.

    2013-03-01

    Full Text Available We described a case of laterally situated impacted wisdom tooth extraction in maxillary sinus using an endoscopic endonasal approach. The technique was shown to be an adequate alternative to a traumatic transmaxillary approach earlier applied in such cases.

  4. Necessity of analgesics prescription after tooth extraction

    OpenAIRE

    Tozoglu Sinan; Gungormus Metin; Buyukkurt Cemil M.; Yavuz Selim M.

    2009-01-01

    Introduction. For patients and surgeons, pain and discomfort associated with dento-alveolar surgery can be a frightening prospect. This study was aimed to check whether prescription of analgesics is necessary or not after simple extraction of the mandibular third molars. Material and methods. Seventy-six dental outpatients undergoing uncomplicated extraction of both mandibular third molars teeth served as subjects. After extraction on the first side, patients received either naproxen sodium 5...

  5. Wisdom tooth--complications in extraction.

    Science.gov (United States)

    Agrawal, Amiya; Yadav, Arvind; Chandel, Siddhartha; Singh, Nishi; Singhal, Ankita

    2014-01-01

    The purpose of this study is to analyze the incidence of complications in a group of 171 patients in whom extractions of impacted mandibular third molar have been performed by two oral surgeons between the period April 2010 and March 2012. This retrospective study comprises evaluation of 270 impacted mandibular third molars which were classified into two groups A and B on the basis of procedure of osteotomy only and osteotomy and odontotomy both respectively. Total no of complications reported were 40 (14.81%). Maximum no of cases reported alveolar osteitis (AO) (11.11%) while other complications reported root tip fractures (2.22%), lingual nerve parasthesia and TMJ problems (each 0.74%) in descending frequency. Conclusion drawn is that the risk of complications in extractions of impacted mandibular third molars always exists, and extractions associated with both osteotomy and odontotomy are associated with higher risk of complications. PMID:24939262

  6. Subcutaneous emphysema as a complication of tooth extraction

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    Vaci? Aca

    2004-01-01

    Full Text Available Subcutaneous emphysema is a rare complication in dentistry, which may lead to diagnostic errors and inadequate therapy. A 17 years old female patient, in whom the separation of tooth roots was performed by the use of air-powered drill during the extraction of the first right lower molar, is presented in this paper. During the intervention, swelling of the right half of the face and the lower eyelid suddenly occurred, accompanied with simultaneous feeling of choking, and pressure in the neck and chest. Because of the suspicion of the allergic reaction, the patient was administered antihistaminic agent, together with parenteral corticosteroid, and was sent to an institution where she was treated as an in-patient. During hospitalization, subcutaneous emphysema of the face and neck was diagnosed by physical and x-ray examination. The emphysema completely disappeared after the use of oxygen and antibiotics.

  7. A Case of Recurrent Neuro-Behçet's Disease after Tooth Extraction

    OpenAIRE

    Choi, Seong-Min; Choi, Yun-Ju; Kim, Joon-Tae; Lee, Seung-Han; Park, Man-Seok; Kim, Byeong-Chae; Kim, Myeong-Kyu; Cho, Ki-hyun

    2009-01-01

    We report a 39-yr-old man with neuro-Behçet's disease (NBD) in remission who developed left-sided ataxia with a sensory deficit about 10 days after tooth extraction. Several years ago, he experienced a similar episode of relapse after tooth extraction. Brain magnetic resonance imaging showed a newly developed right thalamic lesion. In cerebrospinal fluid, lymphocyte-dominant pleocytosis and mild elevation of IgG were found. Immunologic factors may be important in the pathogenesis of NBD becau...

  8. Application of Coenzyme Q10 for Accelerating Soft Tissue Wound Healing after Tooth Extraction in Rats

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    Toshiki Yoneda

    2014-12-01

    Full Text Available Accelerating wound healing after tooth extraction is beneficial in dental treatment. Application of antioxidants, such as reduced coenzyme Q10 (rCoQ10, may promote wound healing after tooth extraction. In this study, we examined the effects of topical application of rCoQ10 on wound healing after tooth extraction in rats. After maxillary first molars were extracted, male Fischer 344 rats (8 weeks old (n = 27 received topical application of ointment containing 5% rCoQ10 (experimental group or control ointment (control group to the sockets for 3 or 8 days (n = 6–7/group. At 3 days after extraction, the experimental group showed higher collagen density and lower numbers of polymorphonuclear leukocytes in the upper part of socket, as compared to the control group (p < 0.05. Gene expression of interleukin-1?, tumor necrosis factor-? and nuclear factor-?B were also lower in the experimental group than in the control group (p < 0.05. At 8 days after tooth extraction, there were no significant differences in collagen density, number of polymorphonuclear leukocytes and bone fill between the groups. Our results suggest that topical application of rCoQ10 promotes wound healing in the soft tissue of the alveolar socket, but that rCoQ10 has a limited effect on bone remodeling in rats.

  9. The role of traditional healers in tooth extractions in Lekie Division, Cameroon

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    Naidoo Sudeshni

    2011-05-01

    Full Text Available Abstract Background The extraction of the teeth by traditional healers in Cameroon is an established cultural practice in the central region of the Cameroon. Traditional healers (TH use herbs and crude un-sterilized instruments and tools for the tooth extraction procedure. The present study investigates the knowledge and practices of traditional healers regarding tooth extraction and the management of its complications. Methods A cross sectional design utilizing semi-structured questionnaires was used to collect the data from traditional healers and their patients. Results Sixteen traditional healers (TH were interviewed. All were male and the majority were between 25-35 years old. The most important reason given for the removal of a tooth was "if it has a hole". All reported using herbs to control bleeding and pain after extractions. Only 20% used gloves between patients when extracting a tooth and just over a third (31.3% gave post-operative instructions. Eighty seven percent managed complications with herbs and 62.5% reported that they would refer their patients to a dentist whenever there are complications. Only a third (31.3% was familiar with the basic anatomy of a tooth and more than half (56.3% reported that tooth extractions are the only treatment for dental problems. One hundred and fifty patients were interviewed with a mean age of 29 years. More than two thirds were in the 21-30 year age group and just over half were male. Sixty six percent reported that they visited the TH because it is cheap, 93.3% were satisfied with the treatment they received while 95.3% reported said they never had a problem after an extraction. Conclusions Tooth extractions using medicinal plants is well established in Lekie division, Cameroon. Infection control during extraction is not the norm. Traditional healers are willing to co-operate with oral health workers in improving the oral health of their patients. Mutual cooperation, collaboration and integrating TH into primary oral health care services need to be increased.

  10. Fate of the buccal bone at implants placed early, delayed, or late after tooth extraction analyzed by cone beam CT

    DEFF Research Database (Denmark)

    Schropp, Lars; Wenzel, Ann; Spin-Neto, Rubens; Stavropoulos, Andreas

    2015-01-01

    AIM: To present 10-year cone beam CT (CBCT) data on the fate of buccal bone at single-tooth implants placed early, delayed, or late after tooth extraction. MATERIAL AND METHODS: Sixty-three of 72 patients, originally randomly allocated to three equal-size groups, received a single-tooth implant on average 10 days (Ea; N = 22), 3 months (De; N = 22), or 1.5 years (La; N = 19) after tooth extraction. Healing abutments were mounted after a 3-month period of submerged healing and metalceramic crowns...

  11. Effect of irradiation on wound healing after tooth extraction in the rachitic rats

    International Nuclear Information System (INIS)

    To observe the histopathological changes following irradiation on the wound healing after tooth extraction in the rachitic rats. In order to carry out this study, the rats were divided into four groups: Group 1 (normal diet/non-irradiation group), Group 2 (normal diet/irradiation group), Group 3 (rachitogenic diet/non-irradiation group), and Group 4 (rachitogenic diet/irradiation group). Rachitic changes were induced with rachitogenic diet No. 2 (high calcium, low phosphorus, and Vitamin D deficient diet) for 5 weeks. After the extraction of both maxillary first molars of the rats in Group 2 and 4, the head and neck of the rats were irradiated with single absorbed dose of 10 Gy. The rats were sacrificed at the 1st, 5th, 10th, and 15th day after tooth extraction. The specimens including the extraction wound were sectioned, stained with the hematoxylin-eosin and Masson's trichrome method and examined under the light microscope. In the Group 2, the amount of newly formed bone trabeculae on the periphery of extraction socket and osteoblastic activity were reduced. In the Group 3, epithelial fusion was not revealed on the 5th day after toothe extraction and growth rate of osteoid formation was reduced. In the Group 4, necrotized tissue at the outer surface of extraction socket and destructive changes on the alveolar bones were noted on the 10th day. Epithelial fusion was not revealed and large amounts of osteoclast were noted on alveolar bone on the 15th day. The healing process of wound after tooth extraction was retarded by irradiation and especially in the rachitic rats.

  12. Preventing wrong tooth extraction: experience in development and implementation of an outpatient safety checklist.

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    Saksena, A; Pemberton, M N; Shaw, A; Dickson, S; Ashley, M P

    2014-10-01

    Extraction of the wrong tooth or teeth is a serious and avoidable clinical error causing harm to the patient. All NHS Trusts in England are required to use a surgical safety checklist in operating theatres to prevent incorrect site surgery and ensure safe management of patients. However, the majority of patients have dental extractions and other oral surgical procedures undertaken on an outpatient basis and these patients are also at risk of having an incorrect site surgical procedure such as a wrong tooth extraction. We describe our experience in developing, introducing and refining a surgical safety checklist for outpatient oral surgery along with the key strategic actions needed to ensure effective cultural change and optimum patient safety in the outpatient setting. PMID:25303583

  13. Histometric study of socket healing after tooth extraction in rats treated with diclofenac

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    Yugoshi Luciana Ibara

    2002-01-01

    Full Text Available The purpose of the present study was to investigate if diclofenac administration interferes with the time course of alveolar wound healing in rats. Forty-two Wistar rats were used, 21 rats received 10 mg/kg/day of diclofenac one day before and 4 days after extraction of the right maxillary incisors and 21 rats received saline. The animals were sacrificed 7, 14 and 21 days after tooth extraction. Progressive new bone formation and a decrease in the volume fraction of blood clot and connective tissue from 1 to 3 weeks after tooth extraction was quantified using the histometric point-counting method. Diclofenac treatment caused a significant delay in new bone formation in association with an impairment of blood clot remission/organization.

  14. Evaluation of Amoxicillin & Cephalexin concentrations in dental alveolar sockets after tooth extraction

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    Fakhraei AH.

    2005-06-01

    Full Text Available Statement of Problem: One of the most important complications after tooth extraction and oral and maxillofacial surgery is transient bacteraemia and prescription of prophylactic antibiotic is necessary to prevent postoperative infections in immunocompromised patients. Purpose: The aim of this study was the evaluation of cephalexin and amoxicillin concentrations in dental alveolar sockets following tooth extraction. Materials and Methods: In this interventional study, 80 healthy patients subjected to tooth extraction were divided into two groups. Each group received 1 gr amoxicillin or cephalexin and teeth were extracted 30-60-90-120-180 minutes after antibiotic intake. Blood sampling was performed immediately after extraction and concentrations of two antibiotics were measured in microbiology laboratory. ANOVA test and Post-hoc (Duncan test were used for statistical analysis with P<0.05 as the limit of significance. Results: The maximum serum concentration was 10.1006 ?g/ml for amoxicillin at 120 minutes and 41.5467 ?g/ml for cephalexin at 90 minutes after drug intake. The minimum inhibitory concentration (MIC of cephalexin and amoxicillin for Streptococcus sanguis was 2 ?g/ml and 1 ?g/ml respectively. Conclusion: The mean concentration for amoxicillin was 10 times and for cephalexin was 20 times higher than MIC.

  15. A Comparison of Equivalent Doses of Lidocaine and Articaine in Maxillary Posterior Tooth Extractions: Case Series

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    Christopher C. Friedl

    2012-06-01

    Full Text Available Objectives: Local anaesthesia is the standard of care during dental extractions. With the advent of newer local anesthetic agents, it is often difficult for the clinician to decide which agent would be most efficacious in a given clinical scenario. This study assessed the efficacy of equal-milligram doses of lidocaine and articaine in achieving surgical anaesthesia of maxillary posterior teeth diagnosed with irreversible pulpitis. Material and Methods: This case-series evaluated a total of 41 patients diagnosed with irreversible pulpitis in a maxillary posterior tooth. Patients randomly received an infiltration of either 3.6 mL (72 mg 2% lidocaine with 1:100,000 epinephrine or 1.8 mL (72 mg 4% articaine with 1:100,000 epinephrine in the buccal fold and palatal soft tissue adjacent to the tooth. After 10 minutes, initial anaesthesia of the tooth was assessed by introducing a sterile 27-gauge needle into the gingival tissue adjacent to the tooth, followed by relief of the gingival cuff. Successful treatment was considered to have occurred when the tooth was extracted with no reported pain. Data was analyzed with the Fisher’s exact test, unpaired t-test and normality test. Results: Twenty-one patients received lidocaine and 20 received articaine. Forty of the 41 patients achieved initial anaesthesia 10 minutes after injection: 21 after lidocaine and 19 after articaine (P = 0.488. Pain-free extraction was accomplished in 33 patients: 19 after lidocaine and 14 after articaine buccal and palatal infiltrations (P = 0.226. Conclusions: There was no significant difference in efficacy between equivalent doses of lidocaine and articaine in the anaesthesia of maxillary posterior teeth with irreversible pulpitis.

  16. Prevention of medication-related osteonecrosis of the jaws secondary to tooth extractions. A systematic review

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    Limeres, Jacobo

    2016-01-01

    Background A study was made to identify the most effective protocol for reducing the risk of osteonecrosis of the jaws (ONJ) following tooth extraction in patients subjected to treatment with antiresorptive or antiangiogenic drugs. Material and Methods A MEDLINE and SCOPUS search (January 2003 - March 2015) was made with the purpose of conducting a systematic literature review based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. All articles contributing information on tooth extractions in patients treated with oral or intravenous antiresorptive or antiangiogenic drugs were included. Results Only 13 of the 380 selected articles were finally included in the review: 11 and 5 of them offered data on patients treated with intravenous and oral bisphosphonates, respectively. No randomized controlled trials were found – all publications corresponding to case series or cohort studies. The prevalence of ONJ in the patients treated with intravenous and oral bisphosphonates was 6,9% (range 0-34.7%) and 0.47% (range 0-2.5%), respectively. The main preventive measures comprised local and systemic infection control. Conclusions No conclusive scientific evidence is available to date on the efficacy of ONJ prevention protocols in patients treated with antiresorptive or antiangiogenic drugs subjected to tooth extraction. Key words:Bisphosphonates, angiogenesis inhibitors, antiresorptive drugs, extraction, osteonecrosis. PMID:26827065

  17. Mandibular anesthesia and tooth extraction in the bottlenosed dolphin.

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    Ridgway, S H; Green, R F; Sweeney, J C

    1975-07-01

    Anatomical dissections were done to show the innervation of the teeth and mandible of the bottlenosed dolphin (Turslops truncatus). Using structural landmarks, a method has been devised for anesthetizing the lower jaw. With this procedure teeth can be extracted and age determined by counting dentine layers in sections of etched teeth. Animals of the most desirable ages can thus be selected and the ages of animals already in captivity can be determined. PMID:1152182

  18. High-Frequency Acceleration: Therapeutic Tool to Preserve Bone following Tooth Extractions.

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    Alikhani, M; Lopez, J A; Alabdullah, H; Vongthongleur, T; Sangsuwon, C; Alikhani, M; Alansari, S; Oliveira, S M; Nervina, J M; Teixeira, C C

    2016-03-01

    A common problem in clinical dentistry is the significant and rapid bone loss that occurs after tooth extraction. Currently there is no solution for the long-term preservation of alveolar bone. Previously, we showed that high-frequency acceleration (HFA) has an osteogenic effect on healthy alveolar bone. However, it is not known if HFA can preserve alveolar bone after extraction without negatively affecting wound healing. The purpose of this study was to evaluate the effect of HFA on alveolar bone loss and the rate of bone formation after tooth extraction. Eighty-five adult Sprague-Dawley rats were divided into 3 groups: control, static (static load), and HFA. In all groups, the maxillary right third molar was extracted. The HFA group received HFA for 5 min/d, applied through the second molar. The static group received the same magnitude of static load. The control group did not receive any stimulation. Some animals received fluorescent dyes at 26 and 54 d. Samples were collected on days 0, 7, 14, 28, and 56 for fluorescence microscopy, micro-computed tomography, histology, RNA, and protein analyses. We found that HFA increased bone volume in the extraction site and surrounding alveolar bone by 44% when compared with static, while fully preserving alveolar bone height and width long-term. These effects were accompanied by increased expression of osteogenic markers and intramembranous bone formation and by decreased expression of osteoclastic markers and bone resorption activity, as well as decreased expression of many inflammatory markers. HFA is a noninvasive safe treatment that can be used to prevent alveolar bone loss and/or accelerate bone healing after tooth extraction. PMID:26672126

  19. Effect of Alendronate on Bone Formation during Tooth Extraction Wound Healing.

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    Tanoue, R; Koi, K; Yamashita, J

    2015-09-01

    Alendronate (ALN) is an antiresorptive agent widely used for the treatment of osteoporosis. Its suppressive effect on osteoclasts has been extensively studied. However, the effect of ALN on bone formation is not as clear as its effect on resorption. The objective was to determine the effect of short-term ALN on bone formation and tooth extraction wound healing. Molar tooth extractions were performed in mice. ALN, parathyroid hormone (PTH), or saline (vehicle control) was administered. PTH was used as the bone anabolic control. Mice were euthanized at 3, 5, 7, 10, and 21 d after extractions. Hard tissue healing was determined histomorphometrically. Neutrophils and lymphatic and blood vessels were quantified to evaluate soft tissue healing. Gene expression in the wounds was assessed at the RNA level. Furthermore, the vossicle bone transplant system was used to verify findings from extraction wound analysis. Alkaline phosphatase (ALP) was visualized in the vossicles to assess osteoblast activity. ALN exhibited no negative effect on bone formation. In intact tibiae, ALN increased bone mass significantly more than PTH did. Consistently, significantly elevated osteoblast numbers were noted. In the extraction sockets, bone fill in the ALN-treated mice was equivalent to the control. Genes associated with bone morphogenetic protein signaling, such as bmp2, nog, and dlx5, were activated in the extraction wounds of the ALN-treated animals. Bone formation in vossicles was significantly enhanced in the ALN versus PTH group. In agreement with this, ALN upregulated ALP activity considerably in vossicles. Neutrophil aggregation and suppressed lymphangiogenesis were evident in the soft tissue at 21 d after extraction, although gross healing of extraction wounds was uneventful. Bone formation was not impeded by short-term ALN treatment. Rather, short-term ALN treatment enhanced bone formation. ALN did not alter bone fill in extraction sockets. PMID:26124220

  20. Effects of local and whole body irradiation on appearance of osteoclasts during wound healing of tooth extraction sockets in rats

    International Nuclear Information System (INIS)

    We examined effects of local and whole body irradiation before tooth extraction on appearance and differentiation of osteoclasts in the alveolar bone of rat maxillary first molars. Wistar rats weighting 100 g were divided into three groups: non-irradiation group, local irradiation group, and whole body irradiation group. In the local irradiation group, a field made with lead blocks was placed over the maxillary left first molar tooth. In the whole body irradiation group, the animals were irradiated in cages. Both groups were irradiated at 8 Gy. The number of osteoclasts around the interradicular alveolar bone showed chronological changes common to non-irradiated and irradiated animals. Several osteoclasts appeared one day after tooth extraction, and the maximal peak was observed 3 days after extraction. Local irradiation had no difference from non-irradiated controls. In animals receiving whole body irradiation, tooth extraction one day after irradiation caused smaller number of osteoclasts than that 7 day after irradiation during the experimental period. Whole body-irradiated rats had small osteoclasts with only a few nuclei and narrow resorption lacunae, indicating deficiency of radioresistant osteoclast precursor cells. Injection of intact bone marrow cells to whole body-irradiated animals immediately after tooth extraction recovered to some content the number of osteoclasts. These findings suggest that bone resorption in the wound healing of alveolar socket requires radioresistant, postmitotic osteoclast precursor cells from hematopoietic organs, but not from local sources around the alveolar socket, at the initial phase of wound healing. (author)

  1. Ibuprofen versus Acetaminophen in Controlling Postoperative Impacted Third Molar Tooth Extraction Pain

    International Nuclear Information System (INIS)

    Objectives: To compare the efficacy of ibuprofen and acetaminophen in reducing postoperative third molar extraction pain in patients reporting to Armed Forces Institute of Dentistry. Study design: Randomized controlled trial. Place and duration of study: The study was carried out on patients who presented for surgical removal of impacted teeth at Armed Forces Institute of Dentistry Rawalpindi (AFID) from February 2008 to March 2--9 at the Department of Oral Surgery, Armed Forces Institute of Dentistry Rawalpindi. Patients and methods: One hundred and forty patients requiring surgical removal of mandibular impacted teeth were equally divided into two groups. Surgical extraction of third molar tooth was performed under local anesthesia. Patients in group A were given ibuprofen and in group B were given acetaminophen at 6 hourly intervals. First dose was given 3 hours postoperatively. Each patient rated pain on a visual analog scale at baseline and then at 12, 24, 48 and 72 hours postoperatively. Results: There was statistically significant difference (p=0.025) during first 12 hours with ibuprofen group showing better efficacy but afterwards there was no significant difference in the efficacy of both drugs. Conclusions: Ibuprofen is more effective in controlling severe third molar extraction pain as compared to acetaminophen but has similar efficacy in controlling moderate pain. (author)

  2. The Use of Aloe Vera Extract as a Novel Storage Media for the Avulsed Tooth

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    Samaneh Badakhsh

    2014-07-01

    Full Text Available Background: Tooth avulsion is one of the most severe dental traumas which most often occur in children. When immediate replantation is not possible, storage in a proper media may lead to a prolonged survival rate. Aloe Vera is a cactus like plant with green, tapered leaves that are filled with a transparent viscous gel. This medicinal plant has significant anti-inflammatory, antioxidant, antibacterial and antifungal effects. The purpose of this study was to assess the effectiveness of different concentrations of Aloe Vera extract compared to DMEM (cell culture medium and egg white. Methods: The periodontal ligament (PDL cells were cultured and certain number of cells were treated with Aloe Vera extract (in four different concentrations, egg white and culture media for 1, 3, 6, and 9 hours. Cell viability was determined by using the (3-[4, 5-dimethylthiazolyl-2]-2, 5-diphenyltetrazolium bromide assay. Moreover, One-way ANOVA and post hoc (LSD test were used for analyzing the study groups. Results: The results indicate that culture media and Aloe Vera extract (10, 30, and 50% concentration were statistically similar and significantly preserved more PDL cells compared to other experimental storage media. Conclusion: Aloe Vera 10, 30, and 50% may be recommended as a suitable storage media for avulsed teeth.

  3. An innovative approach to chair side provisional replacement of an extracted anterior tooth with Fiber Reinforced Ribbon Composite for space maintenance

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    Srinivas N CH

    2011-04-01

    Full Text Available An immediate replacement of an extracted anterior tooth may contribute to patients comfort, treatment acceptance and expectations of future treatment. However, fabrication of custom made restoration in the anterior region of the mouth through a removable or fixed may result in an esthetic compromise for patients during fabrication period. Chair side tooth replacement is an excellent short term option and one of the method is application of fiber reinforced composite resin technology. Though this method is used for reinforcing permanent tooth its use for primary teeth has not been reported. This article presents an innovative, affordable chair side procedure in which ribbon multipurpose bondable reinforcement ribbon is used to replace a single extracted tooth using patients own tooth.

  4. Fabrication and anti-microbial evaluation of drug loaded polylactide space filler intended for ridge preservation following tooth extraction

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    Nebu George Thomas

    2011-01-01

    Full Text Available Background: The preservation or reduction of alveolar ridge resorption following tooth extraction is important in patients especially for those intended for implants at a later stage. One way to achieve this is by using membranes, graft materials, and biodegradable space fillers to prevent alveolar bone resorption and promote regeneration. A major attraction for using biodegradable and biocompatible polymers as space fillers for ridge preservation is their safety profile in comparison to xenograft materials like lyophilized bone and collagen. Materials and Methods: Biocompatible polylactide space fillers were fabricated by fusing porous polylactide particles. The sponges were loaded with drugs by placing them in the respective solutions. Pseudomonas aeruginosa was isolated from a chronic periodontitis patient and in vitro anti-microbial evaluation was done with the drug loaded sponges. Results: Chlorhexidine loaded space filler showed significant anti microbial effect against multiple drug resistant Pseudomonas aeruginosa isolated from a patient with chronic periodontitis. Conclusion: The results of this study indicate that biodegradable drug releasing polylactide space fillers has the potential to be used for ridge preservation following tooth extraction. Release of drugs in the socket may prove useful in preventing development of alveolar osteitis post extraction which can interfere with normal healing of the socket. Synthetic biodegradable polymers also exhibit a controlled degradation rate to achieve complete resorption within the intended time.

  5. The Use of Aloe Vera Extract as a Novel Storage Media for the Avulsed Tooth

    OpenAIRE

    Samaneh Badakhsh; Tahereh Eskandarian; Tahereh Esmaeilpour

    2014-01-01

    Background: Tooth avulsion is one of the most severe dental traumas which most often occur in children. When immediate replantation is not possible, storage in a proper media may lead to a prolonged survival rate. Aloe Vera is a cactus like plant with green, tapered leaves that are filled with a transparent viscous gel. This medicinal plant has significant anti-inflammatory, antioxidant, antibacterial and antifungal effects. The purpose of this study was to assess the effectiveness of differe...

  6. Distinct subcutaneous emphysema following surgical wisdom tooth extraction in a patient suffering from 'Gilles de la Tourette syndrome'.

    Science.gov (United States)

    Tomasetti, Patrick; Kuttenberger, Johannes; Bassetti, Renzo

    2015-01-01

    Subcutaneous emphysema is a rare complication in oral surgery. In most cases, it resolves spontaneously. However, air might disperse into deeper facial spaces causing life-threatening complications such as compression of the tracheobronchial tree or the development of pneumomediastinum. Moreover, microorganisms might spread from the oral cavity into deeper spaces. Hence, rapid diagnosis of subcutaneous emphysema is important. Characteristic signs are both a shiftable swelling and crepitation. In this case report, a 30-year-old man, suffering from the Gilles de la Tourette Syndrome, with a distinct subcutaneous emphysema after bilateral surgical wisdom tooth extraction is presented. Induced by a specific motor tic, air accumulated from the periorbital through to the parapharyngeal region. Applying a 10-cm-long Redon drainage tube as air valve, 10 days after wisdom teeth extraction, the patient was asymptomatic with complete resolution of the emphysema. PMID:26077530

  7. Dentinal Tubule Disinfection with Propolis & Two Extracts of Azadirachta indica Against Candida albicans Biofilm Formed on Tooth Substrate

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    Joy Sinha, Dakshita; Garg, Paridhi; Verma, Anurag; Malik, Vibha; Maccune, Edgar Richard; Vasudeva, Agrima

    2015-01-01

    Aim: This study evaluates the disinfection of dentinal tubules using Propolis, Azadirachta indica (alcoholic and aqueous extracts), 2% chlorhexidine gel and calcium hydroxide against Candida albicans biofilm formed on tooth substrate. Materials & Method: One hundred and five human teeth were infected with Candida albicans for 2 days. Samples were divided into 7 groups. Group I- Propolis, Group II- Alcoholic extract of Azadirachta indica, Group III- Aqueous extract of Azadirachta indica, Group IV- 2% Chlorhexidine, Group V- Calcium hydroxide, Group VI- Ethanol and Group VII- Saline (negative control). At the end of 1,3 and 5 days, the antimicrobial efficacy of medicaments against Candida albicans was assessed at the depths of 200 µm and 400 µm. Results: The overall percentage inhibition of fungal growth (at 200 µm and 400 µm depth) was 99.2% with 2% chlorhexidine gel. There was no statistical difference between propolis, alcoholic extract of Azadirachta indica (neem) and 2% chlorhexidine. Conclusion: Propolis and alcoholic extract of Azadirachta indica performed equally well as that of 2% Chlorhexidine.

  8. The evaluation of the changes in blood pressure and pulse rate of hypertensive patients during tooth extraction.

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    Gungormus, M; Buyukkurt, M C

    2003-01-01

    The purpose of this investigation was to evaluate the changes in blood pressure and the pulse rate of hypertensive patients having dental extraction under a local anesthetic containing a vasopressor. The study included 64 patients (42 female and 22 male), 38 to 78 years of age. Twenty-six of the patients were normotensive, 38 were hypertensive patients. The hypertensive patients were identified as those patients who had histories of medically diagnosed high blood pressure and baseline recordings of blood pressures higher than 140/90 mm Hg. Articain HCl with 0.012 mg epinephrine hydrochloride, was used as the local anesthetic for all patients and one tooth was extracted from each patient. Blood pressure and pulse rate measurements were recorded immediately prior to anesthesia, just before extraction and 5 minutes after extraction. The data were analyzed by a two-way ANOVA with repeated measures. Analysis of the data indicated no statistically significant changes in the systolic and diastolic blood pressures and pulse rate for all interval measurements in both normotensive and hypertensive patients (P > 0.05). In this study, it was determined that there were no significant changes in the blood pressures and the pulse rate of hypertensive patients during surgical procedure, and one cartridge local anesthetic with articain HCl containing 0.012 mg pinephrine may be used safely in hypertensive patients with blood pressure equal or smaller than 154/99 mm Hg. PMID:15055158

  9. Oral health-related quality of life following non-surgical (routine tooth extraction: A pilot study

    Directory of Open Access Journals (Sweden)

    Wasiu L Adeyemo

    2012-01-01

    Full Text Available Aim: The study was designed to explore the changes in oral health-related quality of life (QoL in the immediate postoperative period following routine (non-surgical dental extraction. Setting and Design: A prospective study carried out at the Oral and Maxillofacial Surgery clinic of the Lagos University Teaching Hospital, Nigeria. Materials and Methods: Subjects attending who required non-surgical removal of one or two teeth under local anesthesia were included in the study. A baseline QoL questionnaire (oral health impact profile-14 [OHIP-14] was filled by each patient just before surgery, and only those who were considered to have their QoL "not affected" (total score 14 or less were included in the study. After the extraction, each subject was given a modified form of "health related QoL" [OHIP-14]-instrument to be completed by the 3 rd day-after surgery, and were given the opportunity to review the questionnaire on the 7 th day postoperative review. Results: Total OHIP-14 scores ranged between 14 and 48 (mean ± SD, 26.2 ± 8.3. Majority of the subjects (60% reported, "a little affected." Only few subjects (5.8% reported, "not at all affected," and about 32% reported, "quite a lot." Summation of OHIP-14 scores revealed that QoL was "affected" in 41 subjects (34.2% and "not affected" in 79 subjects (65.8%. More than 30% of subjects reported that their ability to chew, ability to open the mouth and enjoyment of food were affected following tooth extraction. Few subjects (14-34% reported deterioration in their speech and less than 20% of subjects reported that change in their appearance was "affected." Only few subjects (12.5-15.1% reported sleep and duty impairment. Thirty-percent of subjects reported their inability to keep social activities, and 41% were not able to continue with their favorite sports and hobbies. Multiple regression analysis revealed no significant association between age, sex, indications for extraction, duration of extraction, intra-operative complications, and deterioration in QoL ( P < 0.05. Consumption of analgesics beyond postoperative day 1 (POD1 was more common in subjects with socket healing complications than those without ( P = 0.000. About 33% of subjects reported, "inability to work" (1-3 days. Conclusion: About a third of subjects experienced significant deterioration in QoL. The most affected domains were eating/diet variation and speech variation. Therefore, patients should be informed of possible deterioration in their QoL following non-surgical tooth extraction.

  10. The Wisdom Tooth

    OpenAIRE

    Speck, John E.

    1981-01-01

    Physicians may often wonder about the basis on which dentists advocate removal of third molars. This article outlines indications for removal and for leaving the tooth in place. It also describes postoperative experiences according to the nature of the extractions.

  11. Root resection under the surgical field employed for extraction of impacted tooth and management of external resorption

    Directory of Open Access Journals (Sweden)

    A R Vivekananda Pai

    2012-01-01

    Full Text Available This case report illustrates determination of prognosis and immediate resection carried out, before completing the endodontic therapy, during the surgery employed for managing a nonperiodontal problem. This case showed external pressure resorption in the distobuccal root of maxillary second molar caused by the impingement of impacted third molar. Extraction of third molar was decided when healing was not seen, despite initiating endodontic therapy in second molar. Following elevation of flap and extraction of third molar, the poor prognosis due to severe bone loss around the resorbed root was evident. But due to strategic value of second molar, it was found beneficial to employ resection. Therefore, immediate resection was carried out in the same surgical field before the completion of endodontic therapy. This prevented the need for another surgical entry with its associated trauma to carry out resection separately later. Resection followed by the completion of endodontic therapy and full crown assisted in salvaging the remaining functional portion of the tooth and prevented the occurrence of distal extension with its potential drawbacks.

  12. Correlation between the Appearance of Neuropeptides in the Rat Trigeminal Ganglion and Reinnervation of the Healing Root Socket after Tooth Extraction

    International Nuclear Information System (INIS)

    The neuropeptide substance P (SP) modulates bone metabolism. This study examined the temporal appearance of the neuropeptides SP and brain-derived nerve growth factor (BDNF) and their receptors (neurokinin-1 receptor (NK1-R) and Trk B, respectively) in the rat trigeminal ganglion to investigate the role of neuropeptides in healing after tooth extraction. Rats were anesthetized and their upper right first molars were extracted; the rats were sacrificed 3 hours and 1–21 days after extraction. Their trigeminal ganglion and maxilla were removed, and cryosections were prepared and immunostained using specific antibodies against SP, BDNF, NK1-R, and Trk B. In the tooth sockets after extraction, new bone and a few SP-immunoreactive nerve fibers were first seen at day 7, and bone completely filled the sockets at day 21. In the trigeminal ganglion, the proportions of NK1-R-, BDNF-, and Trk B-immunoreactive neurons changed similarly, i.e., they initially decreased, increased rapidly to maximum levels by day 3, and then decreased gradually to control levels until 21 days. These findings suggest that the appearance of neuropeptides in the trigeminal ganglion, the reinnervation of SP-immunoreactive nerve fibers, and bone repair in the tooth socket during healing after extraction were correlated

  13. The Effectiveness of a New Hemostatic Agent (Ankaferd Blood Stopper for the Control of Bleeding following Tooth Extraction in Hemophilia: A Controlled Clinical Trial

    Directory of Open Access Journals (Sweden)

    Hakk? O?uz Kazanc?o?lu

    2013-03-01

    Full Text Available Objective: To assess the hemostatic efficacy of a new local hemostatic agent, Ankaferd Blood Stopper (ABS, for the control of bleeding following tooth extraction in hemophiliacs. Materials and Methods: Simple tooth extractions were performed in 27 hemophilia A patients. In the treatment group (n=17 local hemostasis was achieved via application of ABS to the extraction sockets, whereas in the control group (n=10 local hemostasis was achieved via direct packing with gauze. Results: In all, 57 (21 primary and 36 permanent teeth extractions were performed in 27 hemophilia A patients. There were no significant differences in age or factor VIII level distribution between the 2 groups (p>0.05. The most significant clinical difference between the groups was associated with the use of ABS; those in the treatment group had significantly shorter duration of bleeding (p=0.002. Conclusion: This is the first study to evaluate the efficacy of ABS for the control of bleeding following tooth extraction in hemophiliacs. ABS can be considered an alternative local hemostatic agent for reducing clotting factor concentrates in hemophilia patients.

  14. Ophthalmic Complication Following Posterior Superior Alveolar Nerve Block for Tooth Extraction! A Rare Occurrence.

    Science.gov (United States)

    Ghosh, Abhishek; Vaibhav, N; Raut, Rohan; Venkatesh, Anchita

    2015-09-01

    One of the most commonly asked question by a patient who comes for extraction especially in the rural areas is whether the procedure will cause problems to the eye!! In reality however, ophthalmic complications following routine maxillary molar extractions are practically unheard of. When they occur they can be extremely unnerving not just to the patient but also to the surgeon. Patients generally panic which makes it tougher for the clinician to assess the situation. We present a case of a 26 year old female patient developing ophthalmic complication following local anesthesia administration during extraction of upper left maxillary third molar. In this article, ophthalmic complications arising from posterior superior alveolar nerve block are discussed and management guidelines are highlighted. PMID:26225091

  15. Rare Occurrence of Herpes Zoster of Trigeminal Nerve following Extraction of Tooth

    Science.gov (United States)

    Christy, A. Winnifred; Raja Deva Thanmbi, T. Jones; Leelavathy, J.; Rhema Louis, Antoinette

    2015-01-01

    Herpes Zoster also known as Shingles is an acute viral infection which is an extremely painful and incapacitating ailment. It results from the reactivation of the varicella zoster virus. The triggering factors for the onset of an attack of Herpes Zoster include some form of immunosuppression. The diagnosis of Herpes Zoster can be made on proper medical history and a thorough clinical examination. Here is the report of a male patient affected by Herpes Zoster infection which followed after extraction of a lower first molar. PMID:26819783

  16. Calcium dynamics in the healing of tooth extraction sockets in mice evaluated using 45Ca-autoradiography and Electron Probe Micro Analysis

    International Nuclear Information System (INIS)

    The calcium distribution in tooth extraction sockets of mice was examined using 45-Calcium autoradiography (ARG) and Electron Probe Micro Analysis (EPMA). Mice were divided into 8 groups (n=8) according to the number of days (1, 2, 3, 4, 5, 7, 10, 20 respectively) after extraction. Frozen sections were taken from mice on each experimental day after injection of 45-Calcium (RI). The process of formation of new bone was observed using ARG. An ultimate analysis was performed by EPMA. Histological analysis was performed with toluidine blue- and alizarin red S-staining. In toluidine blue-staining, an osteoblast was found along the socket wall at 4 days and non-calcified periodontal ligament was recognized until 5 days after extraction. In alizarin red S-staining, new bone was recognized separated from the socket wall at 4 days after extraction. 45Ca-labeling was detected strongly in the periosteum of the mandible, the surface of cement and periodontal ligament in control animals. 45Ca-labeling was moved from the bottom to the top of the tooth extraction socket during the period from 1 to 5 days after extraction, but in the periodontal ligament lower than in the granulation tissue. 45Ca-labeling was detected in the socket at 7, 10 and 20 days. At 4 days, calcium phosphate was observed in the central portion of the socket using EPMA. 45Ca-labeling showed deposition of calcium phosphate for alveolar bone and new bone. These results suggest that the granulation tissue may be involved in the initial calcification in the tooth extraction socket and lead to the formation of new bone in it. (author)

  17. Sobredentadura: alternativa terapéutica para disminuir las extracciones dentarias / Overdenture: therapeutic alternative to decrease tooth extractions

    Scientific Electronic Library Online (English)

    Mario, Castañeda Deroncelé.

    2014-11-01

    Full Text Available Se describe el caso clínico de una paciente de 45 años de edad, atendida en la Clínica Estomatológica Docente "José Luis Tassende" de Santiago de Cuba porque refería que en innumerables ocasiones se le fracturaban los dientes artificiales de la prótesis y la porción coronaria de la espiga del incisi [...] vo central superior derecho; también presentaba algunos dientes remanentes con facetas de desgastes en las caras palatinas, incisales y vestibulares, por lo cual se le realizó una prótesis parcial metálica (superior e inferior), con sobredentadura sobre dientes naturales. Con el proceder aplicado se evitaron las extracciones dentarias y se logró una adecuada rehabilitación estética y funcional Abstract in english The case report of a 45 year-old patient, assisted in "José Luis Tassende" Stomatological Clinic from Santiago de Cuba is described. She complained of fractures in countless occasions of the artificial teeth from her denture and the coronary portion of the pin of the central right superior incisor t [...] ooth; she also presented some residual teeth with facets of waste in the palatine, incisal and vestibular faces, reason why a metallic partial prosthesis (superior and inferior), with overdenture on her natural teeth was made. With this procedure, the teeth extractions were avoided and an appropriate aesthetic and functional rehabilitation was achieved

  18. Immediate Placement of Implants in Tooth Extraction Sockets in the Presence of Periapical Lesions with or without Er:YAG Laser Irradiation

    Directory of Open Access Journals (Sweden)

    Reza Birang

    2012-06-01

    Full Text Available Background and aims. Immediate placement of implant into fresh extraction sockets has become a common and accept-able clinical method. Different clinical studies have reported great success and survival rates in immediate implant placement in extraction sockets with periapical lesions. Theaim of this study was to investigate the effect of Er:YAG laser irradiation on success rate of immediate implant placement in tooth extraction sockets with chronic periapical lesions.Materials and methods. Thirty patients requiring a single-root tooth extraction with chronic periapical lesions were in-cluded in this prospective, randomized, clinical trial and divided into control (n=15 and test (n=15 groups. After tooth extrac-tion, the implant were placed with guided bone regeneration in the control group after periapical curettage and socket irrigation and in the test group, irrigation of the periapical region was accompaniedwith Er:YAG laser for 1 min at 100 mJ, 10 Hz, 12.73 J/cm2. Radiographic (using standard long-cone parallel and clinical parameters (plaque index [PI], modified bleeding index [mBI], probing depth [PD], keratinized mucosa [KM], Periotest values [PTV] were assessed at baseline and 1, 3 and 6 months after implant placement. Data was analyzed with t-test and chi-squared test. The level of significance was set at 5%.Results. A survival rate of 100% was observed for all the implants placed at the sixth-month follow-up, with no significant differences between clinical and radiographic parameters of the control and test groups at different time intervals (P>0.05.Conclusion. At 6-month follow-up, there were no complications in soft and hard tissue healing processes after immediate placement of implants into fresh extraction sockets with chronic periapical lesions, regardless of Er:YAG laser irradiation.

  19. Histometric study of socket healing after tooth extraction in rats treated with diclofenac / Estudo histométrico do reparo alveolar após extração dental em ratos tratados com diclofenaco

    Scientific Electronic Library Online (English)

    Luciana Ibara, Yugoshi; Miguel Angel, Sala; Luiz Guilherme, Brentegani; Teresa Lúcia Lamano, Carvalho.

    Full Text Available O objetivo do presente trabalho foi investigar se a administração de diclofenaco interfere no processo de reparo alveolar em ratos. Foram utilizados 42 ratos Wistar, dos quais 21 receberam 10mg/kg/dia de diclofenaco e o restante solução salina. Os animais foram submetidos a extração dos incisivos su [...] periores direito, e sacrificados 7, 14 e 21 dias após a avulsão dental. A formação progressiva de osso e a redução do volume de coágulo sangüíneo e tecido conjuntivo no período de 1 a 3 semanas após a extração dental foram quantificadas através do método histométrico de contagem de pontos. O tratamento com o diclofenaco causou significante atraso na neo-formação óssea, associado a um atraso na organização e remissão do coágulo sangüíneo. Abstract in english The purpose of the present study was to investigate if diclofenac administration interferes with the time course of alveolar wound healing in rats. Forty-two Wistar rats were used, 21 rats received 10 mg/kg/day of diclofenac one day before and 4 days after extraction of the right maxillary incisors [...] and 21 rats received saline. The animals were sacrificed 7, 14 and 21 days after tooth extraction. Progressive new bone formation and a decrease in the volume fraction of blood clot and connective tissue from 1 to 3 weeks after tooth extraction was quantified using the histometric point-counting method. Diclofenac treatment caused a significant delay in new bone formation in association with an impairment of blood clot remission/organization.

  20. Does Extraction or Retention of the Wisdom Tooth at the Time of Surgery for Open Reduction and Internal Fixation of the Mandible Alter the Patient Outcome?

    Science.gov (United States)

    Hammond, Douglas; Parmar, Sat; Whitty, Justin; Pigadas, Nick

    2015-12-01

    Whether to extract or retain wisdom teeth present in a fracture line is a controversial topic. This study reviewed the records of all patients who had mandibular wisdom teeth at the time of the injury, and had an open reduction and internal fixation procedure between January 2009 and January 2012. The cohort of patients who concomitantly had their wisdom tooth extracted at the time of fixation had a greater complication rate (24.3%) compared with patients who did not (14.9%). This suggests that if third molars in the line of a fracture have caries, are fractured, show signs of pericoronitis, are periodontally involved, or are interfering with the occlusion are extracted at the time of fixation, this will increase the incidence of complications. PMID:26576231

  1. The effect of red wine extract, resveratrol, on the degree and rate of orthodontic tooth movement in guinea pigs

    Directory of Open Access Journals (Sweden)

    Isidro Alex C Urriquia

    2015-01-01

    Full Text Available Objective: An animal trial, its protocol approved by the Institutional Animal Care and Use Committee of the U.P. National Institutes of Health (IACUC Protocol No. 2010-008, was employed to investigate the effects of resveratrol on the degree and rate of orthodontic tooth movement in guinea pigs. Materials and Methods: Eighteen male adult guinea pigs were randomly allocated into 3 groups: low dose, high dose, and control groups. A 0.016" titanium molybdenum alloy wire formed into a helical torsion spring with a coil, with the loops cemented onto the maxillary incisors of the animals, served as the orthodontic appliance. Daily oral administration of resveratrol was provided to the low dose (0.047 mg/kg and high dose (0.47 mg/kg groups, while water was provided to the control group. Measurements were taken everyday at the interproximal area at the level of the incisal edge using a measuring caliper. Results: The results of the ANOVA showed no statistically significant differences in the mean measurements of tooth separation among the three groups from day 2 (P=0.966 to day 8 (P=0.056. However, starting from day 9 (P=0.049 until day 18 (P=0.000, there was a significant difference in the mean tooth separation among the test groups. Conclusion: Using the LSD, it was noted that the low dose and the high dose groups have similar degrees of mean tooth separation, with the control group being significantly different from the two.

  2. Tooth - abnormal shape

    Science.gov (United States)

    Hutchinson incisors; Abnormal tooth shape; Peg teeth; Mulberry teeth; Conical teeth ... many different conditions. Specific diseases can affect tooth shape, tooth color, time of appearance, or absence of ...

  3. Efeito comparativo entre clonixinato de lisina e paracetamol no controle da dor pós-exodontia / Comparison between lysine and paracetamol for post tooth extraction pain control

    Scientific Electronic Library Online (English)

    Klinger de Souza, Amorim; Lucas Celestino Guerzet, Ayres; Rafael Soares da, Cunha; Liane Maciel de Almeida, Souza; Mônica Silveira, Paixao; Francisco, Groppo.

    2012-12-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A exodontia é praticada desde os primórdios da humanidade como forma de resolver cirurgicamente os problemas dentários. Porém, como todo procedimento cirúrgico, ela promove um processo inflamatório reacional que se apresenta clinicamente com dor. Muitos fármacos têm sido u [...] sados no intuito de minimizar o desconforto pós-operatório, porém um protocolo para o seu controle ainda não está estabelecido. Este estudo teve como objetivo avaliar o efeito analgésico do clonixinato de lisina e paracetamol no controle de dor pós-exodontia. MÉTODO: Estudo duplamente encoberto e randomizado com 40 pacientes atendidos no Ambulatório de Cirurgia I no Departamento de Odontologia da Universidade Federal de Sergipe (DOD/UFS) que necessitaram de extrações por via alveolar em hemiarcadas diferentes utilizando clonixinato de lisina (125 mg) três vezes ao dia ou paracetamol (750 mg) quatro vezes ao dia, ambos por três dias no pós-operatório. A dor foi avaliada nas primeiras 24 e 48h com o uso da escala analógica visual. Os dados foram submetidos aos testes estatísticos t de Student e de Friedman. RESULTADOS: Não houve diferenças estatisticamente significantes entre idade, em relação aos gêneros e em relação à intensidade da dor. CONCLUSÃO: Tanto o clonixinato de lisina como o paracetamol foi eficaz para o controle da dor pós-exodontia. Abstract in english BACKGROUND AND OBJECTIVES: Tooth extraction is practiced since the early days of mankind to surgically solve dental problems. However, as any surgical procedure, it promotes an inflammatory reaction with clinical presentation of pain. Several drugs have been used to minimize postoperative discomfort [...] ; however there is still no established protocol for its control. This study aimed at evaluating the analgesic effect of lysine and paracetamol to control post tooth extraction pain. METHOD: Double blind randomized study with 40 patients seen by the Surgical Outpatient Setting I, Dentistry Department, Federal University of Sergipe (DOD/UFS), who needed alveolar extractions in different hemiarcades using lysine (125 mg) three times a day or paracetamol (750 mg) four times a day, both during three postoperative days. Pain was evaluated at 24 and 48 hours with the visual analog scale. Data were submitted to Student's t and Friedman statistical tests. RESULTS: There have been no statistically significant differences in age, gender and pain intensity. CONCLUSION: Both lysine and paracetamol were effective to control post tooth extraction pain.

  4. Intentional replantation of periodontally compromised hopeless tooth

    Directory of Open Access Journals (Sweden)

    G Nagappa

    2013-01-01

    Full Text Available Aesthetic considerations have influenced the management of dental maladies in varying degrees for many years. Even single tooth mal-alignment makes the patient to approach a dentist. Intentional replantation is a procedure in which an intentional tooth extraction is performed followed by reinsertion of the extracted tooth. Many authors agree that it should be reserved as the last resort to save a tooth after other procedures have failed or would likely to fail. The main reason of failure in replanted teeth is root resorption, specifically ankylosis or replacement resorption. Although the success rate is not always high, intentional replantation may be a treatment alternative that deserves consideration to maintain the natural dentition and avoid extraction of the tooth. Here is case report of a patient desiring alignment of malpositioned periodontally involved anterior single tooth due to various causes treated by intentional replantation.

  5. Dental Caries (Tooth Decay)

    Science.gov (United States)

    ... Find Data by Topic > Dental Caries (Tooth Decay) Dental Caries (Tooth Decay) Main Content Dental caries (tooth decay) remains the most prevalent chronic ... important source of information on oral health and dental care in the United States since the early ...

  6. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Contact InfoBites Quick Reference Learn more Children's Oral Health How Do I Care for My Child's Baby Teeth? When Should My Child First See a Dentist? Check Menstrual Calendar for Tooth Extraction What is Orofacial Pain? What is Baby Bottle Tooth ... | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  7. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Menstrual Calendar for Tooth Extraction Why is Oral Health Important for Men? How Do I Care for My Child's Baby Teeth? Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  8. Cigarette smoke inhalation influences bone healing of post-extraction tooth socket: a histometric study in rats

    Scientific Electronic Library Online (English)

    Ana Paula Oliveira, Giorgetti; João Batista, César Neto; Márcio Zaffalon, Casati; Enílson Antonio, Sallum; Francisco Humberto, Nociti Júnior.

    Full Text Available O objetivo do estudo foi avaliar a influência da inalação da fumaça de cigarros (IFC) sobre os períodos iniciais de reparo ósseo alveolar. Quarenta ratos Wistar foram aleatoriamente divididos em teste: animais expostos à IFC, que se iniciou 3 dias antes das extrações mantendo-se até o sacrifício (n= [...] 20)e controle (animais que não foram expostos à IFC; n=20). Os animais tiveram seus segundos molares inferiores extraídos bilateralmente (n=5/grupo/período) e foram sacrificados nos dias 3, 7, 10 e 14 dias após a cirurgia. Imagens digitalizadas foram analisadas de acordo com os seguintes parâmetros histométricos: tecido osteóide (OT), área remanescente (RA), tecido mineralizado (MT) e tecido não mineralizado (NMT) em cada alvéolo. Análise intergrupo mostrou que não houve diferença estatisticamente significante aos 3 dias (p>0,05) para todos os parâmetros. Aos 7 dias, a IFC influenciou negativamente (p?0,05) o preenchimento ósseo mostrando diferença estatisticamente significante para os parâmetros tecido não mineralizado e defeito remanescente (MT: 36%, NMT: 53%, RA: 12%; and MT: 39%, NMT: 29%, RA: 32%, para controle e teste, respectivamente). No entanto, não houve diferença estatisticamente significante (p>0,05) aos 10 e 14 dias. Conclui-se que a IFC pode afetar o reparo ósseo alveolar inicial, o que pode ser crítico para a quantidade e qualidade da nova formação óssea em fumantes. Abstract in english The aim of this study was to evaluate, histometrically, the bone healing of the molar extraction socket just after cigarette smoke inhalation (CSI). Forty male Wistar rats were randomly assigned to a test group (animals exposed to CSI, starting 3 days before teeth extraction and maintained until sac [...] rifice; n=20) and a control group (animals never exposed to CSI; n=20). Second mandibular molars were bilaterally extracted and the animals (n=5/group/period) were sacrificed at 3, 7, 10 and 14 days after surgery. Digital images were analyzed according to the following histometric parameters: osteoid tissue (OT), remaining area (RA), mineralized tissue (MT) and non-mineralized tissue (NMT) in the molar socket. Intergroup analysis showed no significant differences at day 3 (p>0.05) for all parameters. On the 7th day, CSI affected negatively (p0.05) were found at days 10 and 14. It may be concluded that CSI may affect socket healing from the early events involved in the healing process, which may be critical for the amount and quality of new-bone formation in smokers.

  9. Exsanguinating bleeding following tooth extraction in a 12-year-old girl: a rare case of acquired haemophilia A.

    Science.gov (United States)

    Todo, Kimito; Ohmae, Tadaki; Osamura, Toshio; Kiyosawa, Nobuyuki; Sugimoto, Mitsuhiko; Shima, Midori; Imamura, Toshihiko; Imashuku, Shinsaku

    2015-12-01

    Acquired haemophilia A (AHA) is a life-threatening haemorrhagic disorder that occurs with various underlying conditions such as autoimmune disease, drug reactions, lymphoproliferative diseases, solid tumours and pregnancy/postpartum status. However, in half of all reported cases, the underlying disease is unknown. Most AHA cases develop in adults; paediatric/adolescent cases are extremely rare. The main clinical symptom is bleeding into the skin, muscles, soft tissues and/or mucous membranes. Here, we report the case of an otherwise healthy 12-year-old girl who presented with prolonged bleeding postexodontia. After being diagnosed with AHA, she was successfully treated with recombinant activated factor VII infusion and oral prednisolone. To avoid such unanticipated bleeding when performing dental extraction, preoperative haemostatic screening tests are recommended. PMID:26397882

  10. Fate of the buccal bone at implants placed early, delayed, or late after tooth extraction analyzed by cone beam CT : 10-year results from a randomized, controlled, clinical study

    DEFF Research Database (Denmark)

    Schropp, Lars; Wenzel, Ann

    2015-01-01

    AIM: To present 10-year cone beam CT (CBCT) data on the fate of buccal bone at single-tooth implants placed early, delayed, or late after tooth extraction. MATERIAL AND METHODS: Sixty-three of 72 patients, originally randomly allocated to three equal-size groups, received a single-tooth implant on average 10 days (Ea; N = 22), 3 months (De; N = 22), or 1.5 years (La; N = 19) after tooth extraction. Healing abutments were mounted after a 3-month period of submerged healing and metalceramic crowns were cemented after one additional month. At the second stage surgery, presence of buccal bone defects (dehiscences or intrabony) and their dimensions were registered. CBCT scans recorded with a Scanora(®) 3D unit and standardized periapical (PA) radiographs of the implants were obtained at the 10-year control. Interproximal bone levels (i.e., the distance from the implant platform to the first bone-to-implant contact; BIC) measured in CBCT image sections and PA were compared, and the buccal bone level was determinedin the CBCT images. RESULTS: Two Ea and one De implants failed to osseointegrate. Forty-nine patients attended the 10-year control and due to poor quality of 5 CBCT scans, useful CBCT images were available from 44 patients (Ea:12, De:17, La:15). No significant differences between CBCT and PA images in measurements of the interproximal bone levels were observed. Ten years after implant placement, BIC at the buccal aspect was located on average 2 mm apically to the implant platform (2.39 ± 1.06 mm [median = 2.36] for Ea, 2.22 ± 0.99 mm [median = 2.16] for De, and 1.85 ± 0.65 mm [median = 1.95] for La implants) with no significant difference among the groups (P = 0.20). Mean buccal bone level (bBL) for implants with an intrabony or a dehiscence defect at second stage surgery was 2.51 ± 1.12 mm [median = 2.70] and 2.84 ± 0.70 mm [median = 2.79], respectively, while 1.78 ± 0.74 mm [median = 1.93] for the implants with no defect. The difference in bBL between the implants without a defect and those with a dehiscence was significant at 10 years (P = 0.0005). CONCLUSION: Time of placement of single-tooth implants after tooth extraction did not significantly influence the peri-implant buccal bone level, while presence of a buccal bone dehiscence at second stage surgery resulted in significantly more apically located BIC buccally at 10 years.

  11. Preemptive analgesia of dexamethasone as compared to ketorolac tromethamine in simple tooth extractions / Analgesia preemptiva da dexametasona em relação ao cetorolaco de trometamol em extrações dentárias simples

    Scientific Electronic Library Online (English)

    Rodrigo Mathias Freire de Menezes, Carneiro; Rafael Soares da, Cunha; Liane Maciel de Almeida, Souza; Francisco, Groppo.

    2014-04-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Entendendo que a dor é o maior transtorno pós-operatório, diante da necessidade de estabelecer um protocolo terapêutico do seu controle pós-exodontias e dos poucos estudos comparando esses fármacos é que se justifica o trabalho. O objetivo deste estudo foi avaliar e compa [...] rar o efeito analgésico preemptivo de dois fármacos, ambos administrados em dose única. MÉTODOS: A pesquisa tem caráter experimental a partir de um ensaio clínico com seres humanos. Trata-se de um estudo duplamente encoberto, cruzado e randomizado, com 51 pacientes atendidos no Ambulatório de Cirurgia Oral do Departamento de Odontologia da Universidade Federal de Sergipe (DOD/UFS), entre setembro de 2011 e setembro de 2012, que necessitaram de extrações simples por via alveolar em hemiarcadas diferentes utilizando dexametasona (4mg) e cetorolaco de trometamol (10mg), uma hora antes da cirurgia distintamente. A dor foi avaliada nas primeiras 24 e 48h, com o uso da escala analógica visual. O intervalo de 8 dias foi estabelecido entre as exodontias. RESULTADOS: Não houve diferenças estatisticamente significantes no teste Exato de Fisher (p>0,05) e Friedman (p>0,05), nem entre os fármacos (considerando um mesmo período) nem entre os períodos (considerando o mesmo fármaco). CONCLUSÃO: Não existem diferenças significativas entre os fármacos e os períodos observados. Abstract in english BACKGROUND AND OBJECTIVES: Understanding that pain is the most important postoperative problem, in face to the need of establishing a therapeutic protocol to control post-tooth extraction pain and due to few studies comparing these drugs is that our study is justified. This study aimed at evaluatin [...] g and at comparing the preemptive analgesic effect of two drugs, both administered in bolus. METHODS: This is an experimental research as from a clinical trial with human beings. It is a double-blind, crossover and randomized trial with 51 patients seen by the Oral Surgery Ambulatory of the Dentistry Department, Federal University of Sergipe (DOD/UFS), between September 2011 and September 2012, who needed simple alveolar extractions in different hemiarcades, using dexamethasone (4mg) or ketorolac tromethamine (10mg), one hour before surgery distinctively. Pain was evaluated in the first 24 and 48 hours with the visual analog scale. The interval of eight days was established between extractions. RESULTS: There have been no statistically significant differences by Fisher (p>0.05) and Friedman (p>0.05) Exact tests, or between drugs (considering a same period) or between periods (considering the same drug). CONCLUSION: There are no significant differences between drugs and observed periods.

  12. Tooth formation - delayed or absent

    Science.gov (United States)

    Delayed or absent tooth formation; Teeth - delayed or absent formation ... appearance, or tooth absence. Delayed or absent tooth formation can result from many different conditions, including: Apert ...

  13. Tooth Eruption without Roots

    OpenAIRE

    Wang, X.-P.

    2013-01-01

    Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development accompanies rapid tooth eruption, but roots are required for the movement of teeth into the oral cavity. It has been shown that the dental follicle and bone remodeling are essential for tooth eruption. So far, only limited genes have been associated with root formation and tooth eruption. This may be due to the diffic...

  14. Tooth Retained Implant: No More an Oxymoron

    Directory of Open Access Journals (Sweden)

    Divya Bhat

    2011-03-01

    Full Text Available Introduction: Periodontally af-fected teeth are treated in one of the two ways. (1 Tooth retention after periodontal surgery, in which the degree of regeneration achieved is unpredictable. (2 Tooth extrac-tion and implant placement. Implants have an osseointegrated surface which does not provide adequate shock absorption. Regeneration can be achieved by resecting the crown of the affected tooth and submerging the root. This technique has not had a clinical application so far as the tooth becomes difficult to restore. Placing an implant within the root can make the retained root restorable. At the same time, as the implant is placed within the root surface it achieves a periodontal integration which dampens occlusal forces better than osseointegration. Therefore, such a “tooth retained implant” may serve as an additional treatment option with significant benefits over tooth retention and implant placement alone. The hypothesis: Implants placed within retained roots have shown cementum deposition and attachment of periodontal ligament fibers over their surface. This periodontal attachment may be able to dam-pen forces better than in an osseointegrated implant. Moreover, since an implant is being placed, the crown of the tooth can be resected and submerged. This prevents epithelial migration, allows for the periodontal ligament cells to populate the wound and favors regeneration.Evaluation of the hypothesis: The technique of placing implants within cavities prepared in the root and then submerging them are simple for any practitioner placing implants routinely.

  15. Robust tooth surface reconstruction by iterative deformation.

    Science.gov (United States)

    Jiang, Xiaotong; Dai, Ning; Cheng, Xiaosheng; Wang, Jun; Peng, Qingjin; Liu, Hao; Cheng, Cheng

    2016-01-01

    Digital design technologies have been applied extensively in dental medicine, especially in the field of dental restoration. The all-ceramic crown is an important restoration type of dental CAD systems. This paper presents a robust tooth surface reconstruction algorithm for all-ceramic crown design. The algorithm involves three necessary steps: standard tooth initial positioning and division; salient feature point extraction using Morse theory; and standard tooth deformation using iterative Laplacian Surface Editing and mesh stitching. This algorithm can retain the morphological features of the tooth surface well. It is robust and suitable for almost all types of teeth, including incisor, canine, premolar, and molar. Moreover, it allows dental technicians to use their own preferred library teeth for reconstruction. The algorithm has been successfully integrated in our Dental CAD system, more than 1000 clinical cases have been tested to demonstrate the robustness and effectiveness of the proposed algorithm. PMID:26638148

  16. Diagnosis of toothed gears

    Energy Technology Data Exchange (ETDEWEB)

    Bartelmus, W. (Poltegor Instytut, Wroclaw (Poland))

    1991-01-01

    Evaluates factors that influence wear of toothed gears used on equipment for mining and mine haulage in brown coal surface mines in Poland and methods for monitoring and diagnosing gear condition. The following aspects are analyzed: loads acting on toothed gears and interaction of gear elements, tooth durability, effects of design, technology and operating conditions on vibrations generated by gear systems, sources of mechanical vibrations and acoustic emission in toothed gears, characteristics of vibration signals, diagnostic methods, use of ferrography for diagnosis of gear condition, classification of wear phenomena and manifestations of gear wear, monitoring systems of gear condition, recommendations for monitoring and diagnostic systems. 37 refs.

  17. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Contact InfoBites Quick Reference Learn more Children's Oral Health Check Menstrual Calendar for Tooth Extraction What is ... Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  18. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Saturday, January 09, 2016 About | Contact InfoBites Quick Reference ... Learn more Children's Oral Health Check Menstrual Calendar for Tooth Extraction What is a Composite Resin (White Filling)? How Do I Care for My Child's Baby Teeth? Men: Looking for ...

  19. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Menstrual Calendar for Tooth Extraction Why is Oral Health Important for Men? How Do I Care for My Child's Baby Teeth? Headaches and Jaw Pain? Check Your Posture! Learn what those dental words mean. The Life of a ... | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  20. Single-Tooth Modeling for 3D Dental Model

    Directory of Open Access Journals (Sweden)

    Xiaosheng Cheng

    2010-01-01

    Full Text Available An integrated single-tooth modeling scheme is proposed for the 3D dental model acquired by optical digitizers. The cores of the modeling scheme are fusion regions extraction, single tooth shape restoration, and single tooth separation. According to the “valley” shape-like characters of the fusion regions between two adjoining teeth, the regions of the 3D dental model are analyzed and classified based on the minimum curvatures of the surface. The single tooth shape is restored according to the bioinformation along the hole boundary, which is generated after the fusion region being removed. By using the extracted boundary from the blending regions between the teeth and soft tissues as reference, the teeth can be separated from the 3D dental model one by one correctly. Experimental results show that the proposed method can achieve satisfying modeling results with high-degree approximation of the real tooth and meet the requirements of clinical oral medicine.

  1. Overview of Tooth Disorders

    Science.gov (United States)

    ... expose their teeth to staining substances, such as coffee, tea, and cigarette smoke. Graying of a tooth ... class, we learned how to take a patient’s history of present illness, past medical history, family history, ...

  2. Seal Out Tooth Decay

    Science.gov (United States)

    ... Besides sealants, are there other ways to prevent tooth decay? How can I get dental sealants for my children? What are dental sealants? Sealants are thin, plastic coatings painted on the chewing surfaces of the back ...

  3. Alveolar Ridge Conservation by Early Bone Formation After Tooth Extraction in Rabbits: A Histomorphological Study / Conservación de la Cresta Alveolar por Formación Ósea Temprana después de la Extracción Dentaria en Conejos: Un Estudio Histomorfológico

    Scientific Electronic Library Online (English)

    Mario, Cantín; Sergio, Olate; Ramón, Fuentes; Bélgica, Vásquez.

    2015-03-01

    Full Text Available La pérdida de volumen cresta alveolar, es un proceso irreversible. Para evitar este evento fisiológico, que típicamente resulta en cambios anatómicos locales significativos, tanto en la dimensión horizontal y vertical, existen algunos procedimienos para reducir al mínimo la pérdida de volumen óseo q [...] ue sigue típicamente a la extracción del diente. El propósito de este estudio fue evaluar si tres injertos óseos diferentes podrían promover la formación de hueso en el alveolo tras la extracción del diente para la conservación de la cresta alveolar. Los primeros molares mandibulares de conejos machos adultos fueron extraídos y los alvéolos post extracción fueron rellenados aleatoriamente con tres injertos óseos diferentes, uno de xenoinjerto y dos injertos aloplásticos, más un grupo que no recibió tratamiento (coágulo de sangre). Los alvéolos post extracción en los conejos seleccionados de cada grupo fueron evaluados a las 4, 6, o 8 semanas post-extracción. Los resultados indicaron que los alvéolos tratados con injerto aloplástico mostraron formación de hueso lamelar (6,5%) ya a las 4 semanas post extracción. Por otra parte, el grado de formación de hueso nuevo fue significativamente mayor (P Abstract in english Alveolar ridge volume loss is an irreversible process. To prevent this physiological event, which typically result in significant local anatomical changes in both the horizontal and the vertical dimension, some strategies are indicated to minimize the loss of ridge volume that typically follows toot [...] h extraction. The purpose of this study was to evaluate if three different bone grafts could promote new bone formation in the alveolar socket following tooth extraction for the alveolar ridge conservation. First mandibular molars of male adults rabbits were extracted and the extraction sockets were randomly treated with three different bone grafts, one xenograft and two alloplastic grafts, and a group that received no treatment (blood clot). The extraction sockets of selected rabbits from each group were evaluated at 4, 6, or 8-week post-extraction. The results indicated that the extraction sockets treated with alloplastic graft (biphasic calcium phosphate) exhibited lamellar bone formation (6.5%) as early as four weeks after the extraction was performed. Moreover, the degree of new bone formation was significantly higher (P

  4. The effect of permanent grafting materials on the preservation of the buccal bone plate after tooth extraction: an experimental study in the dog.

    LENUS (Irish Health Repository)

    Bashara, Haitham

    2012-08-01

    The aim of the present study was to evaluate the effects of a novel bone substitute system (Natix(®)), consisting of porous titanium granules (PTG) and a bovine-derived xenograft (Bio-Oss(®)), on hard tissue remodelling following their placement into fresh extraction sockets in dogs.

  5. Tooth regeneration: Current status

    Directory of Open Access Journals (Sweden)

    Dadu Shifali

    2009-01-01

    Full Text Available Regeneration of a functional tooth has the potential to be a promising therapeutic strategy. Experiments have shown that with the use of principles of bioengineering along with adult stem cells, scaffold material, and signaling molecules, tooth regeneration is possible. Research work is in progress on creating a viable bioroot with all its support. A new culture needs to be created that can possibly provide all the nutrients to the stem cells. With the ongoing research, tissue engineering is likely to revolutionize dental health and well-being of people by regenerating teeth over the next decade.

  6. Acoustic tooth cleaner

    Science.gov (United States)

    Heyman, J. S. (Inventor)

    1982-01-01

    An acoustic oral hygiene unit is described that uses acoustic energy to oscillate mild abrasive particles in a water suspension which is then directed in a low pressure stream onto the teeth. The oscillating abrasives scrub the teeth clean removing food particles, plaque, calculous, and other foreign material from tooth surfaces, interproximal areas, and tooth-gingiva interface more effectively than any previous technique. The relatively low power output and the basic design makes the invention safe and convenient for everyday use in the home without special training. This invention replaces all former means of home dental prophylaxis, and requires no augmentation to fulfill all requirements for daily oral hygienic care.

  7. Tooth movements in foxhounds after one or two alveolar corticotomies.

    Science.gov (United States)

    Sanjideh, Payam A; Rossouw, P Emile; Campbell, Phillip M; Opperman, Lynne A; Buschang, Peter H

    2010-02-01

    The aim of this split-mouth experimental study was to determine (1) whether corticotomy procedures increase tooth movement and (2) the effects of a second corticotomy procedure after 4 weeks on the rate of tooth movement. The mandibular third and maxillary second premolars of five skeletally mature male foxhounds, approximately 2 years of age, were extracted. One randomly selected mandibular quadrant had buccal and lingual flaps and corticotomies performed around the second premolar; the other quadrant served as the control. Both maxillary quadrants had initial buccal flaps and corticotomies; one randomly selected quadrant had a second buccal flap surgery and corticotomy after 28 days. Coil springs (200 g force), along with a 0.045 mm diameter tube on a 0.040 mm diameter guiding wire, were used to move the mandibular second and maxillary third premolars. Records, including digital calliper measurements and radiographs, were taken on days 0, 10, 14, 28, 42, and 56. Multilevel statistical procedures were used to model longitudinal tooth movements. The radiographic measurements initially showed increasing mandibular tooth movement rates, peaking between 22 and 25 days, and then decelerating. Total mandibular tooth movements were significantly (P corticotomy procedure. Alveolar corticotomy significantly increases orthodontic tooth movement. Performing a second corticotomy procedure after 4 weeks maintained higher rates of tooth movement over a longer duration and produced greater overall tooth movement than performing just one initial corticotomy, but the difference was small. PMID:19736219

  8. Radiation dosimetry of tooth enamels with electron spin resonance (ESR)

    International Nuclear Information System (INIS)

    Electron spin resonance (ESR) dosimetry method using tooth enamel was developed as to detect the minimum radiation dose of around 10 mGy. The main broad signal component must be subtracted from the ESR spectrum to get the signal induced by radiation. Dosimetry of residents close to Chernobyl reactor accident was made using eight tooth pieces with ESR. The obtained dose ranges from about 20 mSv to about 70 mSv including the effect of natural radiation and the dental X-rays. The ESR dosimetry system was developed to measure, the cumulative radiation dose in a tooth without extraction. (author)

  9. TOOTHED-CHAIN DRIVE

    Directory of Open Access Journals (Sweden)

    Berezhnoy S. B.

    2014-03-01

    Full Text Available The article presents a new design of the drive which includes chain and toothed developed geometric and kinematic calculations. Feature of chain gears is that the sprocket pins have involute profile. The drive has a high load capacity, higher kinematic accuracy with reduced dynamic loads

  10. An electron spin resonance system for in-vivo human tooth dosimetry

    International Nuclear Information System (INIS)

    An electron spin resonance (ESR) dosimetry system for an in-vivo human tooth has been developed to measure, without extraction, the cumulative radiation dose in a tooth. The system consists of a TE102 cavity with an aperture at the end plate, a Nd-B-Fe (Neomax) oral magnet and a commercial ESR spectrometer. The front molar is attached to the aperture of the cavity to detect radicals created by radiation in the tooth enamel. Optimum dosimetry conditions were investigated using an extracted human tooth. (author)

  11. Three tooth kinematic coupling

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Layton C. (Livermore, CA)

    2000-01-01

    A three tooth kinematic coupling based on having three theoretical line contacts formed by mating teeth rather than six theoretical point contacts. The geometry requires one coupling half to have curved teeth and the other coupling half to have flat teeth. Each coupling half has a relieved center portion which does not effect the kinematics, but in the limit as the face width approaches zero, three line contacts become six point contacts. As a result of having line contact, a three tooth coupling has greater load capacity and stiffness. The kinematic coupling has application for use in precision fixturing for tools or workpieces, and as a registration device for a work or tool changer or for optics in various products.

  12. The Rachitic Tooth

    OpenAIRE

    Foster, Brian L; Nociti, Francisco H.; Somerman, Martha J.

    2013-01-01

    Teeth are mineralized organs composed of three unique hard tissues, enamel, dentin, and cementum, and supported by the surrounding alveolar bone. Although odontogenesis differs from osteogenesis in several respects, tooth mineralization is susceptible to similar developmental failures as bone. Here we discuss conditions fitting under the umbrella of rickets, which traditionally referred to skeletal disease associated with vitamin D deficiency but has been more recently expanded to include new...

  13. Clinical measurement of tooth wear: Tooth wear indices

    OpenAIRE

    López-Frías, Francisco J.; Castellanos-Cosano, Lizett; Martín-González, Jenifer; Llamas-Carreras, José M.; Segura-Egea, Juan J.

    2012-01-01

    Attrition, erosion, and abrasion result in alterations to the tooth and manifest as tooth wear. Each classification corresponds to a different process with specific clinical features. Classifications made so far have no accurate prevalence data because the indexes do not necessarily measure a specific etiology, or because the study populations can be diverse in age and characteristics. Tooth wears (attrition, erosion and abrasion) is perceived internationally as a growing problem. However...

  14. Studies on the enhanced effect of acupuncture analgesia and acupuncture anesthesia by D-phenylalanine (2nd report)--schedule of administration and clinical effects in low back pain and tooth extraction.

    Science.gov (United States)

    Kitade, T; Odahara, Y; Shinohara, S; Ikeuchi, T; Sakai, T; Morikawa, K; Minamikawa, M; Toyota, S; Kawachi, A; Hyodo, M

    1990-01-01

    D-phenylalanine (DPA) is known to block the activity of carboxypeptidase, an enzyme which degrades enkephalins, endogenous morphine-like substances. Therefore, it is considered that DPA administered as an inhibiting drug of this degrading enzyme might prolong analgesia induced by acupuncture. 1) Thirty patients suffering from chronic low back pain were treated with acupuncture 30 minutes after the oral administration of 4.0 grams of DPA. The results were: excellent in 7 cases, good in 11, fair in 6 and poor in 6. Cases graded excellent and good were then compared with a placebo group. The effect was increased 26% in the DPA-acupuncture group, which shows no statistically significant difference (P less than 0.1). 2) In 56 patients, tooth extraction was performed under acupuncture anesthesia: 18 had received 4.0 gram of DPA (P.O.) 30 minutes earlier. The results were excellent in 8, good in 6, fair in 3, and poor in 1. The excellent and good cases were compared with 38 placebo group cases. The effect in the DPA-acupuncture anesthesia group was significantly increased by 35% (P less than 0.01). 3) In order to determine the optimum time for the administration of DPA, two schedules of administration were compared. [1] DPA was given on the previous day in three 0.5 gram doses (26 cases). [2] A single 4 gram dose was administered 30 minutes before treatment (30 cases). The results from the "excellent", "good" and "fair" cases showed a 16% increase in effectiveness when DPA was administered the day before, not a statistically significant difference (P less than 0.1), but a clear tendency to increase was observed. The above findings show that DPA has an enhancing effect on acupuncture analgesia and anesthesia in clinical practice. PMID:1978503

  15. Autogenous transplantation of mandibular third molar to replace tooth with vertical root fracture

    OpenAIRE

    Asgary, Saeed

    2009-01-01

    Autogenous tooth transplantation (ATT) can be considered when there is a hopeless molar tooth and suitable donor present. This report presents an unconventional case of successful ATT of a third molar replacing the adjacent fractured second molar in a 33 year old woman. This wisdom tooth had completely developed roots. Root-end filling with Calcium Enriched Mixture (CEM) cement was performed in the third molar. The second molar was extracted non-traumatically without any bone removal; the wis...

  16. The Human Sweet Tooth

    OpenAIRE

    McDaniel Amanda H; Reed Danielle R

    2006-01-01

    Abstract Humans love the taste of sugar and the word "sweet" is used to describe not only this basic taste quality but also something that is desirable or pleasurable, e.g., la dolce vita. Although sugar or sweetened foods are generally among the most preferred choices, not everyone likes sugar, especially at high concentrations. The focus of my group's research is to understand why some people have a sweet tooth and others do not. We have used genetic and molecular techniques in humans, rats...

  17. Mechanics analysis of molar tooth splitting.

    Science.gov (United States)

    Barani, Amir; Chai, Herzl; Lawn, Brian R; Bush, Mark B

    2015-03-01

    A model for the splitting of teeth from wedge loading of molar cusps from a round indenting object is presented. The model is developed in two parts: first, a simple 2D fracture mechanics configuration with the wedged tooth simulated by a compact tension specimen; second, a full 3D numerical analysis using extended finite element modeling (XFEM) with an embedded crack. The result is an explicit equation for splitting load in terms of indenter radius and key tooth dimensions. Fracture experiments on extracted human molars loaded axially with metal spheres are used to quantify the splitting forces and thence to validate the model. The XFEM calculations enable the complex crack propagation, initially in the enamel coat and subsequently in the interior dentin, to be followed incrementally with increasing load. The fracture evolution is shown to be stable prior to failure, so that dentin toughness, not strength, is the controlling material parameter. Critical conditions under which tooth splitting in biological and dental settings are likely to be met, however rare, are considered. PMID:25584989

  18. Processo de reparo em feridas de extração dentária em camundongos tratados com o complexo Symphytum officinale e Calendula officinallis Process of repair in tooth extraction sores in treated mice with Symphytum officinale and Calendula officinallis compound

    Directory of Open Access Journals (Sweden)

    Eleny BALDUCCI-ROSLINDO

    1999-04-01

    Full Text Available Medicamentos homeopáticos como o Symphytum officinalle e a Calendula officinallis são dotados de propriedades anti-sépticas, antiinflamatória, cicatrizantes e também agem como promotores da consolidação de fraturas ósseas. Neste trabalho, uniram-se esses dois medicamentos similares em um complexo para verificar o seu efeito no reparo em feridas de extração dentária em camundongos. O complexo Symphytum officinalle e Calendula officinallis nas potências de 6CH e 3CH, respectivamente, foi ministrado por via oral ao grupo tratado durante 5 dias antes e após a extração do incisivo superior direito. No grupo controle, administraram-se 5ml de álcool etílico a 70% diluídos em 30 ml de soro fisiológico. Após a proservação, os animais foram sacrificados, a maxila direita separada da esquerda, fixada e processada para inclusão em parafina. Após a microtomia, os cortes obtidos foram corados pela H/E. A análise histológica mostrou que, tanto no grupo controle como no tratado, o alvéolo dentário estava preenchido por tecido de granulação e tecido ósseo neoformado, com graus variáveis de maturação, rico em osteócitos. No entanto, nos animais tratados, o processo de reparo em feridas após extração dentária do incisivo superior direito mostrou um avanço progressivo de neoformação óssea mais acentuado quando comparado ao grupo controle, em tempos equivalentes. Estes resultados enfatizam as propriedades biológicas do complexo Symphytum officinalle e Calendula officinallis e sua possível utilização como recurso terapêutico na Odontologia.Homeopathic medicines as Symphytum officinale and Calendula officinallis are endowed with antiseptic, antiphlogistic and cicatrizant properties and promoter of the consolidation of bone fracture. This research combined these two similar medicines in a compound to examine its action in the repair of tooth extraction sores in mice. The compound Symphytum offic. and Calendula offic. at the respective potencys of 6CH and 3CH was orally administered to the treated group during 5 days before and after the extraction of the rigth upper incisor. To the control group were administered 5 ml of ethylic alchol 70% diluted in 30 ml of physiologic serum. After a period of expectation, the animals were sacrificed, the right maxila was separated of the left maxila, this was fixed and the laboratories techniques were realized for inclusion in paraffin. After that, the piece was cut in the microtome, and the laminas were dyed by H/E. The analysis showed that the control and treated group exhibited the dental alveolus fulfilled with granulation tissue and neoformed bone tissue with variable degrees of maturation, abundant in osteocites. However, at the treated animal the healing process of the sore after the extraction of the rigth upper incisor showed a bone neoformation very pronounced when compared with the control group at equivalent times. Those results showed the biological properties of the compound Symphytum offic. and Calendula offic. and its utilization as a therapeutical help in Odontology.

  19. Partial tooth gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  20. Efecto In Vitro de las Bebidas Refrescantes sobre la Mineralización de la Superficie del Esmalte Dentario de Piezas Permanentes Extraídas / In Vitro Effect of Refreshing Drinks on the Mineralization of Tooth Enamel Surface in Extracted Permanent Dental Pieces

    Scientific Electronic Library Online (English)

    Ximena, Moreno Ruiz; Carmen Gloria, Narváez Carrasco; Verónica, Bittner Schmidt.

    2011-08-01

    Full Text Available El objetivo de este estudio fue determinar el efecto de las bebidas refrescantes sobre la mineralización de la superficie del esmalte de piezas dentarias permanentes extraídas. Para esto se realizó un estudio experimental donde la muestra correspondió a 50 cortes de premolares permanentes extraídos [...] en estado íntegro, estos fueron distribuidos en tres grupos de estudio mediante asignación aleatoria: bebidas gaseosas, jugos y néctares, y aguas minerales purificadas y saborizadas más un grupo control. Los dientes fueron lavados y almacenados en saliva artificial a 4°C. A todos los cortes dentarios se les midió la mineralización con el equipo Diagnodent 2095 (Kavo®) antes de iniciar la exposición, la cual correspondió a un minuto en el tipo de bebida según grupo, seguido por tres minutos en saliva artificial, ciclo que se repitió cinco veces en un tiempo de 20 minutos. Este procedimiento se realizó una vez al día, por un mes y para cada día se utilizaron nuevas bebidas refrescantes. Una vez finalizado se volvió a medir la mineralización para luego realizar las comparaciones entre grupos. El grupo de bebidas gaseosas provocó una mayor desmineralización en la superficie del esmalte dentario (p=0,000), seguido del grupo de jugos y néctares (p=0,000). El grupo de aguas minerales saborizadas y purificadas no provocaron efectos sobre la mineralización de la superficie del esmalte. Por lo tanto, sólo el grupo de gaseosas y jugos provocaron un efecto desmineralizador en la superficie del esmalte de las piezas dentarias, siendo la Coca-cola® la que produjo mayor efecto seguido de la Coca-cola light® y luego el Kapo®. Abstract in english The aim of this study was to determine the effect of refreshing drinks on the mineralization of tooth enamel surface in extracted permanent dental pieces. For this an experimental study was conducted where the sample was composed by 50 permanent premolars extracted as an entire piece. These pieces w [...] ere randomly distributed in three study groups: soft drinks, juices and nectars, and purified and flavored mineral waters, in addition to a control group. The teeth were carefully washed and stored in artificial saliva at 4 C. Before starting the exposure to refreshing drinks, all dental slices were tested in order to measure their baseline mineralization using the Diagnodent 2095 equipment (Kavo®). The exposition consisted in one minute of contact with the drink corresponding to each group, followed of three minutes in artificial saliva. This cycle was repeated 5 times in 20 minutes time. This procedure was carried out once daily, for one month, and every day new refreshing drinks were used. Once the assay finished, the premolar mineralization was measured again, in order to make comparisons between groups. The soft drinks group caused the highest demineralization on the teeth enamel surface (p=0.000), followed by the juices and nectars group (p=0.000). In the purified and flavored mineral waters group, no effects were found on the mineralization of the enamel surface. A demineralizing effect on the enamel surface of dental pieces was observed only in the groups of soft drinks and juices, where Coca-Cola® caused the highest effect, followed by Coca-Cola light® and then Kapo®.

  1. Immediate natural tooth pontic: A viable yet temporary prosthetic solution: A patient reported outcome

    Directory of Open Access Journals (Sweden)

    Sudhir Bhandari

    2012-01-01

    Conclusion: The concept of immediate pontic placement is surely a viable treatment option and promises an excellent transient esthetic solution for a lost tooth as well as enables good preparation of the extraction site for future prosthetic replacement.

  2. Resection of the Tooth Apex with Diode Laser

    Directory of Open Access Journals (Sweden)

    Uzunov Tz.

    2014-06-01

    Full Text Available An “in vitro” experimental study has been carried out on 70 extracted teeth. A laser resection of the root apex has been carried out with diode laser beam with a wavelength of - 810 ± 10 nm. Sequentially a radiation with increasing power has been applied, as follows: 1,3 W, 2W, 3W, 4W, 5W, 6W, 7W, in electro surgery mode. Successful resection of the tooth apex has been performed at: 3W; 4W; 5W; 6W and 7W power. It was established that when laser resected the tooth apex carbonizes.

  3. NSAIDs in orthodontic tooth movement

    OpenAIRE

    Karthi, Muthukumar; Anbuslevan, Gobichettipalyam Jagtheeswaran; Senthilkumar, Kullampalyam Palanisamy; Tamizharsi, Senthilkumar; Raja, Subramani; Prabhakar, Krishnan

    2012-01-01

    Orthodontic tooth movement is basically a biological response toward a mechanical force. The movement is induced by prolonged application of controlled mechanical forces, which create pressure and tension zones in the periodontal ligament and alveolar bone, causing remodeling of tooth sockets. Orthodontists often prescribe drugs to manage pain from force application to biologic tissues. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the drugs usually prescribed. NSAIDs block prostaglandin ...

  4. Restauración inmediata de un implante único post-extracción con presencia de una lesión radicular lateral / Immediate restoration of a single implant placed after tooth extraction with lateral root lesion

    Scientific Electronic Library Online (English)

    José Raúl, Blanco; Felix Alejandro, Mejía; Luis Felipe, Restrepo.

    2013-01-01

    Full Text Available La perdida de un diente en la zona estética anterior y su reemplazo con una restauración implanto soportada representa uno de los mayores desafíos estéticos y funciónales en el campo de la Implantología moderna.La evidencia actual respalda la provisionalización inmediata de un implante después de su [...] inserción con tasas de éxito comparables con las de los protocolos tradicionales utilizados recientemente. Siegenthaler y col, concluyeron que para aquellos implantes donde se alcanzó estabilidad primaria, la colocación de implantes inmediatos en alvéolos postextracción que presentaban lesiones periapicales no conllevó a un aumento en la tasa de complicaciones y resultó en una integración igualmente favorable en comparación con el grupo control. La adecuada selección del caso para este tipo de protocolos es fundamental y debe estar regido por una filosofía clara de Preservación. La preservación de las estructuras orales existentes en el área a intervenir exige un enfoque terapéutico netamente conservador que favorezca un resultado final favorable y exitoso. La paciente tratada es una de 40 años de edad que acude al postgrado de rehabilitación oral de la Universidad CES de Medellín, Colombia cuyo motivo de consulta fue "Para revisión recomendada por periodoncia" según sus propias palabras. Al momento del examen clínico intraoral se observó encía edematizada a nivel de #11 con profundad al sondaje de 10 mm en DP sospechando una fractura vertical que se corroboró con el análisis de la radiografía periapical. Se le planteó claramente a la paciente las distintas opciones de tratamiento por la pérdida del incisivo central superior con las posibles complicaciones y riesgos que se podrían presentar. La paciente aceptó la opción del implante inmediato postextracción con provisionalización y procedió a firmar el consentimiento informado de la historia clínica. Conclusiones: La provisionalización inmediata del implante brinda beneficios adicionales para la integración de los tejidos blandos, ofreciendo unos resultados estéticos de alta calidad. La colocación de implantes inmediatos en alvéolos con procesos infecciosos periapicales tiene un porcentaje de éxito prometedor a corto plazo. Abstract in english The lost of an anterior tooth and it replacement with a retained implant restoration is one of the mayor functional and aesthetic challenges in modern implantogy. Actual Evidence support that immediate implant provisionalization compare with the traditional protocols have similar results in success [...] rates. Siegenthaler y col conclude that in situations when the primary stabilization is obtained, the implant placement in fresh sockets with cronical periapical lesions have similar results versus control group. Carefull must be taken in the case selection for this modern protocol and should be done under the preservation philosophy. The integrity of remaining bone structures and soft tissue is the main goal for the success of this technique. Female patient, 40 years old, who attended the program of oral rehabilitation at the University of CES Medellin, Colombia, whose reason for consultation was "To review recommended by periodontics" in his own words. At the time of clinical examination intraoral gum edema was observed at # 11 with probing 10 mm in DP suspecting a vertical fracture who was corroborated with the analysis of the periapical X-ray. The different treatment options were stated clearly to the patient for the loss of the maxillary central incisor with the possible complications and risks that could arise. The patient agreed to the immediate post-extraction implant option with temporization and proceeded to sign the informed consent of the medical record. Conclusions: The placement of implants immediate with infectious processes periapicals has a success rate in the short term very promising. The immediate provisionalization implant provides additional benefits for the integration of soft tissues, offering some high-quality aesthetic results.

  5. Functional tooth restoration utilising split germs through re-regionalisation of the tooth-forming field.

    Science.gov (United States)

    Yamamoto, Naomi; Oshima, Masamitsu; Tanaka, Chie; Ogawa, Miho; Nakajima, Kei; Ishida, Kentaro; Moriyama, Keiji; Tsuji, Takashi

    2015-01-01

    The tooth is an ectodermal organ that arises from a tooth germ under the regulation of reciprocal epithelial-mesenchymal interactions. Tooth morphogenesis occurs in the tooth-forming field as a result of reaction-diffusion waves of specific gene expression patterns. Here, we developed a novel mechanical ligation method for splitting tooth germs to artificially regulate the molecules that control tooth morphology. The split tooth germs successfully developed into multiple correct teeth through the re-regionalisation of the tooth-forming field, which is regulated by reaction-diffusion waves in response to mechanical force. Furthermore, split teeth erupted into the oral cavity and restored physiological tooth function, including mastication, periodontal ligament function and responsiveness to noxious stimuli. Thus, this study presents a novel tooth regenerative technology based on split tooth germs and the re-regionalisation of the tooth-forming field by artificial mechanical force. PMID:26673152

  6. From hopeless to good prognosis: journey of a failing tooth.

    Science.gov (United States)

    Gupta, Saurabh; Deshmukh, Jeevanand; Khatri, Richa; Kulkarni, Vinaya Kumar; Karthik, B

    2015-02-01

    Chronic periodontitis, along with associated clinical findings such as pathologic tooth migration, diastema, functional and aesthetic aberrations, poses an immense challenge to a dental professional. These findings convert clinical decision making into a daunting task and adversely affect the prognosis and the treatment plan for the presenting clinical problem. An interdisciplinary approach aimed at restoring functional and aesthetic needs of the affected individual within the limitations of such a compromised clinical scenario may be a viable alternative to any radical treatment causing loss of natural tooth structure such as extraction. This article reports the usefulness of the interdisciplinary route for managing an otherwise hopeless clinical situation of chronic periodontitis complicated with extreme mobility and pathologic tooth migration, which resulted in compromised function and aesthetics. PMID:25859109

  7. Patient satisfaction and esthetic outcome after immediate placement and provisionalization of single-tooth implants involving a definitive individual abutment

    DEFF Research Database (Denmark)

    Hartlev, Jens; Kohberg, Peter; Ahlmann, Søren; Andersen, Niels T; Schou, Søren; Isidor, Flemming

    2014-01-01

    OBJECTIVES: To assess patient satisfaction and esthetic outcome after immediate placement and provisionalization of single-tooth implants involving a definitive individual abutment and a provisional crown followed by later placement of a definitive crown. MATERIALS AND METHODS: In private practice, a single-tooth implant was placed immediately after tooth extraction in the esthetic zone of 54 patients. A definitive individual abutment and a provisional crown were mounted in the same visit. The d...

  8. Parameters of tooth enamel spin model and its application in EPR-dosimetry

    International Nuclear Information System (INIS)

    The authors present a model of spin system of tooth enamel EPR spectra which include two types of parametric centres with axial anisotropy. Spectra of 126 samples of tooth enamel with absorbed dose of 4000 mGy of Co-60 gamma-radiation were investigated basing on the parameters of the model with the use of EPR PS-100X radio spectrometer. The suggested model and the results of measurement of the EPR signal noise component with PS-100X radio spectrometer were used to calculate the error of the absorbed doses in tooth enamel with least-aqua res technique. Optimal conditions for investigation of tooth enamel with EPR PS-100X radio spectrometer were determined. Sensitivity of absorbed dose measurement in tooth enamel at the level of 10-15 mGy was evaluated. The error of absorbed dose calculation was shown not to depend considerably on the degree of dentine extraction from the samples

  9. Tooth polishing: The current status

    Directory of Open Access Journals (Sweden)

    Madhuri Alankar Sawai

    2015-01-01

    Full Text Available Healthy teeth and gums make a person feel confident and fit. As people go about their daily routines and with different eating and drinking habits, the tooth enamel turns yellowish or gets stained. Polishing traditionally has been associated with the prophylaxis procedure in most dental practices, which patients know and expect. However, with overzealous use of polishing procedure, there is wearing of the superficial tooth structure. This would lead to more accumulation of local deposits. Also, it takes a long time for the formation of the fluoride-rich layer of the tooth again. Hence, now-a-days, polishing is not advised as a part of routine oral prophylaxis procedure but is done selectively based on the patients? need. The article here, gives an insight on the different aspects of the polishing process along with the different methods and agents used for the same.

  10. Tooth polishing: The current status.

    Science.gov (United States)

    Sawai, Madhuri Alankar; Bhardwaj, Ashu; Jafri, Zeba; Sultan, Nishat; Daing, Anika

    2015-01-01

    Healthy teeth and gums make a person feel confident and fit. As people go about their daily routines and with different eating and drinking habits, the tooth enamel turns yellowish or gets stained. Polishing traditionally has been associated with the prophylaxis procedure in most dental practices, which patients know and expect. However, with overzealous use of polishing procedure, there is wearing of the superficial tooth structure. This would lead to more accumulation of local deposits. Also, it takes a long time for the formation of the fluoride-rich layer of the tooth again. Hence, now-a-days, polishing is not advised as a part of routine oral prophylaxis procedure but is done selectively based on the patients' need. The article here, gives an insight on the different aspects of the polishing process along with the different methods and agents used for the same. PMID:26392683

  11. On gear tooth stiffness evaluation

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; JØrgensen, Martin Felix

    2014-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffnesses of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact width is constant. © 2014 Elsevier Ltd. All rights reserved.

  12. On gear tooth stiffness evaluation

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Jørgensen, Martin Felix

    2014-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation and...... secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffnesses of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact width is constant. © 2014...

  13. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Wednesday, November 18, ... is Baby Bottle Tooth Decay? Learn what those dental words mean. The Life of a Tooth games ...

  14. Fusion of Mandibular Third Molar with Distomolar Impacted Tooth: A Case Report

    Directory of Open Access Journals (Sweden)

    Jamileh Beygom Taheri

    Full Text Available Introduction: Fusion is a developmental anomaly in which two tooth buds are interconnected. In fusion, teeth are joined by dentine in their developmental stage. Fusion could be between normal teeth or between a normal and a supernumerary tooth. Fusion of the posterior teeth and supernumerary ones are rare.Case Report: A 26 year old woman was referred for extraction of semi impacted third molar. Panoramic radiographs were requested for the patient. In dental radiographs, a supernumerary tooth in distal region of the third molar was observed. Teeth looked like fused teeth. After obtaining consent from the patient, teeth were removed by surgical excision.

  15. Stem cells for tooth engineering

    Directory of Open Access Journals (Sweden)

    G Bluteau

    2008-07-01

    Full Text Available Tooth development results from sequential and reciprocal interactions between the oral epithelium and the underlying neural crest-derived mesenchyme. The generation of dental structures and/or entire teeth in the laboratory depends upon the manipulation of stem cells and requires a synergy of all cellular and molecular events that finally lead to the formation of tooth-specific hard tissues, dentin and enamel. Although mesenchymal stem cells from different origins have been extensively studied in their capacity to form dentin in vitro, information is not yet available concerning the use of epithelial stem cells. The odontogenic potential resides in the oral epithelium and thus epithelial stem cells are necessary for both the initiation of tooth formation and enamel matrix production. This review focuses on the different sources of stem cells that have been used for making teeth in vitro and their relative efficiency. Embryonic, post-natal or even adult stem cells were assessed and proved to possess an enormous regenerative potential, but their application in dental practice is still problematic and limited due to various parameters that are not yet under control such as the high risk of rejection, cell behaviour, long tooth eruption period, appropriate crown morphology and suitable colour. Nevertheless, the development of biological approaches for dental reconstruction using stem cells is promising and remains one of the greatest challenges in the dental field for the years to come.

  16. Immediate Implant in Management of Anterior Missing Tooth

    Directory of Open Access Journals (Sweden)

    Harinath Reddy S

    2010-04-01

    Full Text Available Immediate implant placement after extraction has become a favored treatment protocol with many clinicians worldwide. There are many advantages to this protocol, amongst them; shortened treatment time, placement of the implant in sound bone that constitutes the socket wall, placement trajectory guidance by the socket and preservation of bone volume. This case report describes the management of an anterior missing tooth using immediate implant. The result was good, which further validate the use of this technique for suitable patient management.

  17. SAVE THE IRREMEDIABLE TOOTH WITH AID OF HYDROXYAPAT ITE

    Directory of Open Access Journals (Sweden)

    Golmoradizadeh

    2013-02-01

    Full Text Available ABSTRACT: Nowadays saving the irremediable tooth under the old method has low risk success, or in some cases it is impossible. This stu dy suggests a method that could predict a good prognosis after the operation. This case was, a crownless upper righ t 2 nd premolar with a big periapical lesion that extended the periradicular area also, with initial pa latal root resorption . Upon examination Chronic Preapical Periodontitis diagnosed. After RC T, the tooth was extracted, curetting and irrigation of the socket was done, fill ¼ of the so cket with hydroxyapatite and reimplant the tooth, during the reimplantation adjustment of the crown to root ratio considered as well ,then was splinted to the adjacent teeth for two weeks, A ntibiotic was prescribed to the patient for 7 days. Radiographic examination after two y ears shows that no more lesions are seen in the periapical and periradicular area, there was no mobil ity, and root resorption was aborted, and the tooth was in healthy condition.

  18. Fluoridation and tooth wear in Irish adults.

    LENUS (Irish Health Repository)

    Burke, F M

    2010-10-01

    The aim of this study was to determine the prevalence of tooth wear in adults in Ireland and its relationship with water fluoridation. The National Survey of Adult Oral Health was conducted in 2000\\/2001. Tooth wear was determined using a partial mouth examination assessing the upper and lower anterior teeth. A total of 2456 subjects were examined. In this survey, increasing levels and severity of tooth wear were associated with ageing. Men were more affected by tooth wear and were more likely to be affected by severe tooth wear than women. It was found that age, and gender were significant predictors of tooth wear (P < 0.01). Overall, there was no significant relationship between fluoridation and tooth wear in this study.

  19. Proteomic Analysis of Human Tooth Pulp: Proteomics of Human Tooth.

    Czech Academy of Sciences Publication Activity Database

    Eckhardt, Adam; Jágr, Michal; Pataridis, Statis; Mikšík, Ivan

    2014-01-01

    Ro?. 40, ?. 12 (2014), s. 1961-1966. ISSN 0099-2399 R&D Projects: GA ?R(CZ) GA13-17224S; GA ?R(CZ) GAP206/12/0453; GA MZd(CZ) NT14324 Institutional support: RVO:67985823 Keywords : dentin * human pulp * tandem mass spectrometry * tooth proteome * 2-dimensional gel electrophoresis Subject RIV: FF - HEENT, Dentistry Impact factor: 3.375, year: 2014

  20. Charcot-Marie-Tooth disease.

    LENUS (Irish Health Repository)

    Reilly, Mary M

    2011-03-01

    Charcot-Marie-Tooth (CMT) disease is the commonest inherited neuromuscular disorder affecting at least 1 in 2,500. Over the last two decades, there have been rapid advances in understanding the molecular basis for many forms of CMT with more than 30 causative genes now described. This has made obtaining an accurate genetic diagnosis possible but at times challenging for clinicians. This review aims to provide a simple, pragmatic approach to diagnosing CMT from a clinician\\'s perspective.

  1. Mechanism of human tooth eruption

    DEFF Research Database (Denmark)

    Kjær, Inger

    2014-01-01

    Human eruption is a unique developmental process in the organism. The aetiology or the mechanism behind eruption has never been fully understood and the scientific literature in the field is extremely sparse. Human and animal tissues provide different possibilities for eruption analyses, briefly discussed in the introduction. Human studies, mainly clinical and radiological, have focused on normal eruption and gender differences. Why a tooth begins eruption and what enables it to move eruptively ...

  2. Prosthetic clone and natural human tooth comparison by speckle interferometry

    Science.gov (United States)

    Slangen, Pierre; Corn, Stephane; Fages, Michel; Raynal, Jacques; Cuisinier, Frederic J. G.

    2010-09-01

    New trends in dental prosthodontic interventions tend to preserve the maximum of "body" structure. With the evolution of CAD-CAM techniques, it is now possible to measure "in mouth" the remaining dental tissues. The prosthetic crown is then designed using this shape on which it will be glued on, and also by taking into account the contact surface of the opposite jaw tooth. Several theories discuss on the glue thickness and formulation, but also on the way to evolve to a more biocompatible crown and also new biomechanical concepts. In order to validate these new concepts and materials, and to study the mechanical properties and mechanical integrity of the prosthesis, high resolution optical measurements of the deformations of the glue and the crown are needed. Samples are two intact premolars extracted for orthodontics reasons. The reference sample has no modifications on the tooth while the second sample tooth is shaped to receive a feldspathic ceramic monoblock crown which will be glued. This crown was manufactured with a chairside CAD-CAM system from an intra-oral optical print. The software allows to realize a nearly perfect clone of the reference sample. The necessary space for the glue is also entered with ideal values. This duplication process yields to obtain two samples with identical anatomy for further processing. The glue joint thickness can also be modified if required. The purpose is to compare the behaviour of a natural tooth and its prosthetic clone manufactured with "biomechanical" concepts. Vertical cut samples have been used to deal with planar object observation, and also to look "inside" the tooth. We have developed a complete apparatus enabling the study of the compressive mechanical behaviour of the concerned tooth by speckle interferometry. Because in plane displacements are of great interest for orthodontic measurements1, an optical fiber in-plane sensitive interferometer has been designed. The fibers are wrapped around piezoelectric transducers to perform "4-buckets" phase shifting leading to phase variations during the compression test. In-plane displacement fields from speckle interferometry already showed very interesting data concerning the mechanical behaviour of teeth: the dentine-enamel junction (DEJ) and the glue junction have been shown including their interfacing function. Mechanical action of the tooth surrounding medium will also be discussed.

  3. Regional odontodysplasia: A case of progressive tooth development

    Directory of Open Access Journals (Sweden)

    R Ganguly

    2012-01-01

    Full Text Available Regional odontodysplasia (RO is considered a relatively rare dental anomaly despite increasing numbers of case reports in recent years. It usually presents as a localized anomaly in tooth development affecting a few adjacent teeth in a single maxillary or mandibular quadrant. The purpose of this paper is to describe an uncommon case of regional odotodysplasia involving noncontiguous mandibular teeth, crossing the midline in a male patient, and showing progressive normalization of tooth anatomy over a period of 6 years. Typically, teeth affected with RO become pulpally involved early on and are either extracted or endodontically treated. Such reports of automatic normalization over time in RO is supportive of a more conservative treatment approach.

  4. Saw tooth patello - Femoral arthritis

    International Nuclear Information System (INIS)

    Four patients with an unusual form of patello-femoral arthritis are described. The characteristic feature of the condition is an erosive 'saw tooth' pattern characteristically seen on both sides of the joint. Radiologically, this pattern is best seen on the skyline view. The other principal features are a lamellar-like pattern on slightly oblique lateral views, a smooth supra patellar erosion of the femur seen on the lateral view and cortical ridging of the lateral femoral condyle seen 'en face' on the AP projection. A possible mechanism to account for the radiological features is proposed. Anbarasu, A., Loughran, C.F. (2000). Clinical Radiology 55, 767-769

  5. On gear tooth stiffness evaluation

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Jørgensen, Martin Felix

    2014-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffnesses of gears are highly non-linear, it is however found that the stiffness of an ...

  6. Restoration of the maxillary anterior tooth using immediate implantation with simultaneous ridge augmentation

    OpenAIRE

    Park Jun-Beom

    2010-01-01

    Atrophy is most severe during the first month of post-extraction in the anterior maxilla with the degree of horizontal bone resorption being nearly twice as high as that of vertical bone resorption. The loss of the buccal alveolar plate following tooth extraction may lead to palatal implant positioning of the implants. Thus, immediate or early implant placement in the extraction socket has been suggested, because it would reduce the time period and the number of surgical intervention and yiel...

  7. Investigation of EPR signals on tooth enamel

    Energy Technology Data Exchange (ETDEWEB)

    Pavlenko, A; Mironova-Ulmane, N; Polakov, M; Riekstina, D [Institute of Solid State Physics, University of Latvia, Riga (Latvia)

    2007-12-15

    Calcified tissues are involved in continues metabolic process in human organism exchanging a number of chemical elements with environment. The rate of biochemical reactions is tissue dependent and the slowest one at the tooth enamel, the most mineralized tissue of human organism. The long time stability and unique chemical composition make tooth enamel suitable for number of application. The assessment of individual radiation dose by Electron Paramagnetic Resonance (EPR) and evaluations of elemental composition by Instrumentation Neutron Activation Analysis (INAA) are the well known procedures where properties of tooth enamel intensively used. The current work is focused on investigation of EPR signals and determination of chemical composition on several teeth samples having different origin. The EPR spectra and INAA element content of milk tooth, caries tooth, and paradantose tooth have been compared to each other. The results showed that the intensity of EPR signal is much higher for the caries tooth than the for paradantose tooth that is in agreement with depleted Ca content.

  8. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... is Oral Health Important for Men? Pacifiers Have Negative and Positive Effects Is My Child at Risk for Early Childhood Tooth Decay? Headaches and Jaw Pain? Check Your Posture! Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral ...

  9. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Saturday, November 14, 2015 About | Contact InfoBites Quick Reference ... Learn more Halitosis (Bad Breath) How Do I Care for My Child's Baby Teeth? Is My Child at Risk for Early Childhood Tooth Decay? What is Baby Bottle Tooth ...

  10. Investigation of EPR signals on tooth enamel

    International Nuclear Information System (INIS)

    Calcified tissues are involved in continues metabolic process in human organism exchanging a number of chemical elements with environment. The rate of biochemical reactions is tissue dependent and the slowest one at the tooth enamel, the most mineralized tissue of human organism. The long time stability and unique chemical composition make tooth enamel suitable for number of application. The assessment of individual radiation dose by Electron Paramagnetic Resonance (EPR) and evaluations of elemental composition by Instrumentation Neutron Activation Analysis (INAA) are the well known procedures where properties of tooth enamel intensively used. The current work is focused on investigation of EPR signals and determination of chemical composition on several teeth samples having different origin. The EPR spectra and INAA element content of milk tooth, caries tooth, and paradantose tooth have been compared to each other. The results showed that the intensity of EPR signal is much higher for the caries tooth than the for paradantose tooth that is in agreement with depleted Ca content

  11. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... InfoBites Quick Reference Learn more Pregnancy and Oral Health How Do I Care for My Child's Baby Teeth? Men: Looking for a Better Job? Start by Visiting the Dentist What is Baby Bottle Tooth Decay? Check Menstrual Calendar for Tooth ... a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  12. A Radiographic method for determining the actual tooth length

    Energy Technology Data Exchange (ETDEWEB)

    Nah, Kyung Soo; Cho, Bong Hae [Dept. of Oral Radiology, College of Dentistry, Pusan National University, Pusan (Korea, Republic of)

    1995-08-15

    Tooth length determination is a crucial step in endodontic treatment. Traditionally, radiographs are used to confirm working length of the root length. This study was performed to evaluate the radiographic distortion (magnification) and calculate correction coefficients for the object-film distance. Ninety-six radiographs were made of eight extracted teeth (two upper first premolars, two lower first premolars, two upper first molars, and two lower first molars) by using the 16 inch long cone paralleling techniques with 1 mm interval from 5 to 16 mm tooth-film distance. The following results obtained; 1. The least mean radiographic distortion from 5 to 16 mm tooth-film distance was 2.42 {+-}0.68% (the length of mesiobuccal cusp-mesial root of lower first molars), the greatest distortion was 4.74 {+-}1.36% (the length of mesiobuccal cusp-mesiobuccal root of upper first molars). 2. The greatest correction coefficient was 0.986 (the mesiobuccal cusp-mesial root of lower molars, the lowest one was 0.937 (the mesiobuccal cusp-mesiobuccal root of upper first molars).

  13. USE THE REIMPLANTED TOOTH AS ABUTMENT FOR FIXED PAR TIAL DENTURE

    Directory of Open Access Journals (Sweden)

    Golmoradizadeh

    2013-04-01

    Full Text Available ABSTRACT: OBJECTIVE: Use of the fixed partial denture is more favorable t han the removable partial denture for my patient, she complained about e dentulism in upper right side and a little discomfort with second upper premolar. Clinical examin ation shows the tooth was crown less and radio graphically tooth had a big periapical lesi on with poor prognosis. METHOD: After root canal treatment and extraction the tooth, clea n and irrigate the socket, we are implanted it with hydroxyapatite again and follow the patient for six months. After six months, radio graph shows that the tooth was in ideal condition without mobility, then the tooth has used as an abutment for fixed partial denture with canine and 2 nd molar in order to have a better prognosis we used semi precision attachment, and foll ow her for three years. RESULT: Three years follow the patient shows the tooth is in an ac ceptable condition radio-graphically without mobility and patient was comfortable esthetically a nd functionally. CONCLUSION: In my opinion in this case use of the hydroxyapatite, crown lengthening during the re- implantation and use the semi precision attachment was the reaso n of increase the prognosis after treatment

  14. Possibilities of ESR-spectroscopy of the tooth enamel for in vivo determination of the radiation dose

    International Nuclear Information System (INIS)

    A review of recent publications on the topic is presented. The characteristics of the tooth as an in vivo dosemeter for the assessment of the individual cumulated dose are analysed. The correlation between the intensity of ESR-signal and the dose as well as the distinguishing of the signal caused by the native crystal structure of the tooth enamel and the one induced during the previous X-ray diagnostic procedures is discussed. The possibilities for in vivo measurement (without preliminary extraction of the tooth) is also reported. 4 figs., 44 refs

  15. Saw-toothed fish bone ingestion: A method for propulsion

    Scientific Electronic Library Online (English)

    Emily, Broadis; Wakisa, Mulwafu.

    2010-05-01

    Full Text Available We describe the case of an 11-year-old girl who presented with a lump in her neck. On exploration a 4 cm saw-toothed fish bone was extracted from the soft tissue of the anterior triangle of the neck. Ingested fish bones are a common presentation in accident and emergency departments, but there are o [...] nly a small number of reports of migration through the pharynx into soft tissues. Rare complications can include oesophageal perforation, haematoma formation, retropharyngeal abscesses and recurrent infections. To the best of our knowledge this is the first reported case of migration of an ingested fish bone in Malawi.

  16. Mechanism of human tooth eruption

    DEFF Research Database (Denmark)

    Kjær, Inger

    2014-01-01

    , and the ability of the periodontal ligament to adapt to eruptive movements. Animal studies and studies on normal and pathological eruption in humans can support and explain different aspects in the new theory. The eruption mechanism still needs elucidation and the paper recommends that future research...... discussed in the introduction. Human studies, mainly clinical and radiological, have focused on normal eruption and gender differences. Why a tooth begins eruption and what enables it to move eruptively and later to end these eruptive movements is not known. Pathological eruption courses contribute to...... insight into the aetiology behind eruption. A new theory on the eruption mechanism is presented. Accordingly, the mechanism of eruption depends on the correlation between space in the eruption course, created by the crown follicle, eruption pressure triggered by innervation in the apical root membrane...

  17. Assessment of Corticotomy Facilitated Tooth Movement and Changes in Alveolar Bone Thickness - A CT Scan Study

    OpenAIRE

    Bhattacharya, Preeti; Bhattacharya, Hirak; Anjum, Arbab; Bhandari, Ravi; Agarwal, D. K.; Gupta, Ankur; Ansar, Juhi

    2014-01-01

    Introduction: Corticotomy is an effective method of accelerating the orthodontic treatment. The aim of this study was to compare the treatment time for the extraction space closure, between corticotomy assisted and conventional orthodontic tooth movement and to check the alveolar bone thickness before and after corticotomy procedure in the corticotomy group.

  18. Tooth fractures in canine clinical practice

    International Nuclear Information System (INIS)

    Tooth fractures constitute a considerable fraction of all tooth diseases. Out of the 5,370 dogs treated during four years, 492 were presented with dental problems and 28.3 % of the latter were treated for tooth fractures. Canines were the most frequently affected teeth (38.8 %), followed by premolars (33.1 %), incisors (25.9 %), and molars (2.2 %), 55.4 % of the patients with canine and incisor fractures being large breed dogs. Fractures of premolars (mostly of 108, 208) were divided evenly irrespective of breed or body size. Nonsurgical endodontic treatment yielded good therapeutic results in most cases, but repeated treatment was necessary in some patients

  19. Regenerative Applications Using Tooth Derived Stem Cells in Other Than Tooth Regeneration: A Literature Review

    Science.gov (United States)

    Park, Yun-Jong; Cha, Seunghee; Park, Young-Seok

    2016-01-01

    Tooth derived stem cells or dental stem cells are categorized according to the location from which they are isolated and represent a promising source of cells for regenerative medicine. Originally, as one kind of mesenchymal stem cells, they are considered an alternative of bone marrow stromal cells. They share many commonalties but maintain differences. Considering their original function in development and the homeostasis of tooth structures, many applications of these cells in dentistry have aimed at tooth structure regeneration; however, the application in other than tooth structures has been attempted extensively. The availability from discarded or removed teeth can be an innate benefit as a source of autologous cells. Their origin from the neural crest results in exploitation of neurological and numerous other applications. This review briefly highlights current and future perspectives of the regenerative applications of tooth derived stem cells in areas beyond tooth regeneration. PMID:26798366

  20. Regenerative Applications Using Tooth Derived Stem Cells in Other Than Tooth Regeneration: A Literature Review.

    Science.gov (United States)

    Park, Yun-Jong; Cha, Seunghee; Park, Young-Seok

    2016-01-01

    Tooth derived stem cells or dental stem cells are categorized according to the location from which they are isolated and represent a promising source of cells for regenerative medicine. Originally, as one kind of mesenchymal stem cells, they are considered an alternative of bone marrow stromal cells. They share many commonalties but maintain differences. Considering their original function in development and the homeostasis of tooth structures, many applications of these cells in dentistry have aimed at tooth structure regeneration; however, the application in other than tooth structures has been attempted extensively. The availability from discarded or removed teeth can be an innate benefit as a source of autologous cells. Their origin from the neural crest results in exploitation of neurological and numerous other applications. This review briefly highlights current and future perspectives of the regenerative applications of tooth derived stem cells in areas beyond tooth regeneration. PMID:26798366

  1. Assessment of proprioceptive allodynia after tooth-clenching exercises

    DEFF Research Database (Denmark)

    Dawson, Andreas; List, Thomas; Ernberg, Malin; Svensson, Peter

    2012-01-01

    To (A) evaluate test-retest reliability of vibrotactile sensitivity in the masseter muscle and (B) test if (1) the vibration threshold is decreased after experimental tooth clenching, (2) intense vibrations exacerbate pain after tooth clenching, (3) pain and fatigue are increased after tooth clenching, and (4) pressure pain thresholds are decreased after tooth clenching.

  2. Restoration of the maxillary anterior tooth using immediate implantation with simultaneous ridge augmentation

    Directory of Open Access Journals (Sweden)

    Park Jun-Beom

    2010-01-01

    Full Text Available Atrophy is most severe during the first month of post-extraction in the anterior maxilla with the degree of horizontal bone resorption being nearly twice as high as that of vertical bone resorption. The loss of the buccal alveolar plate following tooth extraction may lead to palatal implant positioning of the implants. Thus, immediate or early implant placement in the extraction socket has been suggested, because it would reduce the time period and the number of surgical intervention and yield higher patient satisfaction compared with delayed placed implants. However, placement of an implant immediately after tooth extraction may result in a gap between the occlusal portion of the implant and the surrounding alveolar bone crest. In this case report, an implant-supported restoration which is in harmony with the surrounding hard and soft tissue was created by the immediate implant placement with ridge augmentation in anterior region with high satisfaction from the patient.

  3. Three Ways To Be a Saber-Toothed Cat

    Science.gov (United States)

    Martin, L. D.; Babiarz, J. P.; Naples, V. L.; Hearst, J.

    Saber-toothed carnivores, until now, have been divided into two groups: scimitar-toothed cats with shorter, coarsely serrated canines coupled with long legs for fast running, and dirk-toothed cats with more elongate, finely serrated canines coupled to short legs built for power rather than speed. In the Pleistocene of North America, as in Europe, the scimitar-cat was Homotherium; the North American dirk-tooth was Smilodon. We now describe a new sabercat from the Early Pleistocene of Florida, combining the scimitar-tooth canine with the short, massive limbs of a dirk-tooth predator. This presents a third way to construct a saber-toothed carnivore.

  4. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... is Oral Health Important for Men? Pacifiers Have Negative and Positive Effects Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral ...

  5. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Tuesday, January 19, ... More Than You Can Chew? Learn what those dental words mean. The Life of a Tooth games ...

  6. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Contact InfoBites Quick Reference Learn more Children's Oral Health How Do I Care for My Child's Baby ... Dentist? What is Orofacial Pain? Why is Oral Health Important for Men? What is Baby Bottle Tooth ...

  7. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... 2016 About | Contact InfoBites Quick Reference Learn more Children's Oral Health Pacifiers Have Negative and Positive Effects ... Job? Start by Visiting the Dentist Is My Child at Risk for Early Childhood Tooth Decay? What ...

  8. External resorption presenting as an intracoronal radiolucent lesion in a pre-eruptive tooth.

    LENUS (Irish Health Repository)

    McNamara, C M

    1997-09-01

    A large intracoronal radiolucent lesion in an unerupted permanent molar was found during the routine assessment of a young male Caucasian prior to orthodontic treatment. The tooth was extracted. Histological examination indicated the lesion was caused by external resorption. The defect extended widely into the enamel and dentine, and was repaired in part by bone. The pulp chamber was not involved. The aetiology of these lesions is often obscure but in this case it appeared to have originated in the floor of two developmental pits on the occlusal surface of the tooth.

  9. Tooth in Ethmoid Sinus: A Case Report

    OpenAIRE

    Tayebe Kazemei; Akbar Bayat; Mahmood Shishegar

    2009-01-01

    Ectopic eruption of teeth occurs in a variety of locations.Commonly seen in palate and maxillary sinus, they have alsobeen reported in nasal cavity, orbit, mandibular condyle,coronoid process, and facial skin.Here, we report a rare case of recurrent sinusitis caused byectopic tooth in right ethmoid sinus and successful endoscopicremoval of it. The symptoms of the patient disappeared aftersurgery. Such case has not been yet reported in the Englishliterature.Ectopic tooth is an uncommon cause o...

  10. Dielectric response of the human tooth dentine

    International Nuclear Information System (INIS)

    Dielectric properties of tooth dentine can be well described by the model which was developed for the dielectric response to hydrating porous cement paste. It is shown that the normalized dielectric constant and the normalized specific conductivity are proportional to the model parameters -bar v0 and ?v, indicating the deposition of AgCl in the dentine tubules during the duration of the precipitation. The fractal dimension of the tooth dentine was determined by dielectric spectroscopy

  11. In Vitro Spectrophotometry of Tooth Discoloration Induced by Tooth-Colored Mineral Trioxide Aggregate and Calcium-Enriched Mixture Cement

    Science.gov (United States)

    Arman, Marjan; Khalilak, Zohreh; Rajabi, Moones; Esnaashari, Ehsan; Saati, Keyvan

    2015-01-01

    Introduction: There are numerous factors that can lead to tooth discoloration after endodontic treatment, such as penetration of endodontic materials into the dentinal tubules during root canal treatment. The aim of this in vitro study was to compare discoloration induced by tooth colored mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement in extracted human teeth. Methods and Materials: Thirty two dentin-enamel cuboid blocks (7×7×2 mm) were prepared from extracted maxillary central incisors. Standardized cavities were prepared in the middle of each cube, leaving 1 mm of enamel and dentin on the labial surface. The specimens were randomly divided into two study groups (n=12) and two positive and negative control groups (n=4). In either study groups the cavities were filled with MTA or CEM cement. The positive and negative control groups were filled with blood or left empty, respectively. The cavities were sealed with composite resin and stored in normal saline. Color measurement was carried out by spectrophotometry at different time intervals including before (T0), and 1 week (T1), 1 month (T2) and 6 months (T3) after placement of materials. Repeated-measures ANOVA was used to compare the discoloration between the groups; the material type was considered as the inter-subject factor. The level of significance was set at 0.05. Results: No significant differences were detected between the groups in all time intervals (P>0.05). Conclusion: Tooth discoloration was similarly detectable with both of the two experimental materials.

  12. Dose estimation by ESR on tooth enamel from two workers exposed to radiation due to the JCO accident

    International Nuclear Information System (INIS)

    Electron spin resonance (ESR) dosimetry is useful to estimate the external dose for the general population as well as for occupational workers in a nuclear emergency. Three teeth were extracted from two exposed workers (A and B) related to the JCO criticality accident. Tooth enamel was carefully separated from other tooth parts and subjected to ESR dosimetry. Doses equivalent to the ?-ray dose of 60Co were estimated as follows: for worker A, the buccal and lingual sides of the eighth tooth in the upper right side, 11.8±3.6 and 12.0±3.6 Gy, respectively; for worker B, the buccal and lingual sides of the fourth tooth in the upper right side and the fifth tooth in the upper left side, 11.3±3.4 and 10.8±3.3 Gy, 11.7±3.5 and 11.4±3.4 Gy, respectively. The estimated doses were found to be similar and not dependent on the tooth positions, whether the buccal or lingual sides in each tooth. (author)

  13. Effect of Tooth-structure Thickness on Light Attenuation and Depth of Cure.

    Science.gov (United States)

    Hamlin, N J; Bailey, C; Motyka, N C; Vandewalle, K S

    2016-01-01

    Newer bulk-fill composites claim a greater depth of cure than conventional resin-based composites. To facilitate complete curing, the manufacturer of SonicFill (Kerr) recommends curing from the occlusal, as well as the buccal and lingual, surfaces of the tooth. The purpose of this study was to quantify the degree of curing light attenuation as it passes through natural tooth structure, and how this attenuation affects the depth of cure of different posterior resin composites. Ten noncarious extracted mandibular third molars were sectioned to produce 5-mm-thick pieces of buccal tooth structure. Sanding 0.5-mm increments from the flattened surface produced 4.5-, 4.0-, 3.5-, 3.0-, 2.5-, 2.0-, and finally 1.5-mm-thick sections. A Bluephase G2 (Ivoclar) curing light with an 8-mm-diameter light guide set on high for 20 seconds was used for measurement of irradiance as it passed through different thicknesses of tooth structure and air. The average irradiance (mW/cm(2)) was measured with a MARC-RC Resin Calibrator with a 4-mm-diameter sensor (BlueLight Analytics). To measure depth of cure of a conventional hybrid composite (Herculite Ultra; Kerr) vs a bulk-fill hybrid composite (SonicFill) through varying thicknesses of tooth structure, composites were cured in a 4-mm-diameter × 10.25-mm-long split mold according to International Organization for Standardization 4049. A mean and standard deviation was determined per group. Data were analyzed with a one-way analysis of variance (ANOVA)/Tukey test and two-way ANOVA/Tukey test (?=0.05). One-way ANOVA/Tukey found a significant decrease in irradiance based on thickness of tooth structure or distance through air (pcure based on thickness of tooth structure (pcomposite type (pcure than Herculite Ultra. PMID:26509234

  14. Efeito comparativo entre a dipirona sódica e a dipirona sódica associada à cafeína no controle da dor pós-exodontia / Comparative effect of sodium dipyrone and sodium dipyrone associated to caffeine to control post-tooth extraction pain

    Scientific Electronic Library Online (English)

    Carllini Barroso, Vicentini; Juliana Cama, Ramacciato; Rubens Gonçalves, Teixeira; Francisco Carlos, Groppo; Rogério Heládio Lopes, Motta.

    2013-09-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O adequado controle da dor pós-operatória constitui um desafio entre as especialidades cirúrgicas, a despeito dos recentes avanços das técnicas de analgesia e dos analgésicos. A cafeína tem sido utilizada como adjuvante terapêutico para potencializar a eficácia analgésica [...] de alguns fármacos, porém ainda não existe relatos de investigação científica da associação com a dipirona sódica em dor pós-operatória em procedimentos odontológicos. Dessa forma, o objetivo deste estudo foi observar e comparar a eficácia da dipirona sódica isolada e da dipirona sódica associada à cafeína no controle da dor pós-operatória em cirurgia dental, considerando os parâmetros hemodinâmicos dos pacientes como indicador de ansiedade e de dor durante a cirurgia. MÉTODOS: Estudo cruzado e duplo encoberto incluiu 50 pacientes jovens e saudáveis (25 homens e 25 mulheres) com indicação de exodontia bilateral de terceiros molares mandibulares impactados. O lado operado, o gênero do paciente e o fármaco analgésico usado foram randomizados. Os escores obtidos pela escala analógica visual foram submetidos ao teste de Friedman (? = 0,05) para comparação das intensidades dolorosas em intervalos definidos (pré-operatório, pós-operatório imediato, 1, 2, 4 12 horas, 1, 2, 3 e 7 dias após as cirurgias) e as alterações nos parâmetros de pressão arterial e frequên­cia cardíaca foram mensurados no pré-operatório, após a injeção anestésica e no pós-operatório (teste de Friedman, ? = 0,05). RESULTADOS: Os pacientes experimentaram dor leve nos dois primeiros dias de pós-operatório e não houve diferença estatisticamente significante entre a eficácia analgésica da dipirona sódica isolada e da dipirona sódica associada à cafeína nos diferentes intervalos medidos. A maioria das alterações cardiovasculares observadas estava dentro da normalidade, considerando a ansiedade e estresse induzido pela cirurgia. CONCLUSÃO: O protocolo terapêutico proposto neste estudo não demonstrou diferença estatística significante na eficiência analgésica da dipirona sódica associada ou não a cafeína no controle da dor pós-exodontia. Abstract in english BACKGROUND AND OBJECTIVES: Adequate postoperative pain control is a challenge among surgical specialties, in spite of recent advances in analgesic techniques and analgesics. Caffeine has been used as therapeutic adjuvant to potentiate analgesic efficacy of some drugs, however there are still no scie [...] ntific investigation reports on the association with sodium dipyrone in the postoperative period of dental procedures. So, this study aimed at observing and comparing the efficacy of sodium dipyrone alone or in association with caffeine to control postoperative pain of dental procedures, considering hemodynamic parameters of patients as indicators of anxiety and pain during surgery. METHODS: This is a crossover and double-blind study involving 50 young and healthy patients (25 males and 25 females) referred for bilateral extraction of impacted mandibular third molars. Operated side, patient's gender and analgesic drug used were randomized. Visual analog scale scores were submitted to Friedman test (? = 0.05) to compare pain intensity at defined intervals (preoperative, immediate postoperative, 1, 2, 4 and 12 hours, 1, 2, 3 and 7 days after surgery). Blood pressure and heart rate were measured in the preoperative period, after anesthetic injection and in the postoperative period (Friedman test, (? = 0.05). RESULTS: Patients have referred mild pain in the first two postoperative days and there has been no statistically significant difference between the analgesic efficacy of sodium dipyrone alone or in association with caffeine in different evaluated intervals. Most cardiovascular changes were within normality, considering anxiety and stress induced by surgery. CONCLUSION: The therapeutic protocol proposed in this study has not shown statistically significant difference between sodium dipyrone associated

  15. Evaluation of the Effect of Corticotomy on Rate of Tooth Movement and Comparison with Conventional Method

    Directory of Open Access Journals (Sweden)

    B. Rahsepar

    2005-02-01

    Full Text Available Statement of Problem: Reduction of orthodontic therapy treatment time is considered an important goal inthe management of malocclusion in adult patients. Corticotomy- facilitated orthodontic treatment may beconsidered an intermediate therapy between orthognatic surgry and conventional orthodontics for reducing treatment time.Purpose: This study was undertaken to evaluate and compare the rate of tooth movement of upper canine following corticotomy with conventional method.Materials and Methods: Ten young adult patients, 17-25 years old was selected through sequential sampling procedure in orthodontics department of Shiraz Dental School. The patients exhibited different orthodontic problems and needed extraction of premolars. Following extraction of premolars and initial phase oforthodontic treatment, corticotomy were performed unilaterally on buccual and palatal sides of extraction areaas described by Takami. The other imoperated sides were used as control. After subsiding the resultant inflammation, the activated NiTi spring was used and measurement of the amount of tooth movement wereassessed by using Rugae as reference point. The panoramic radiographs were super imposed for evaluation of canines tipping. For analyzing the results, Kolmogorou- simirnov and t.tcst were used. Results: The rate of canine tooth movement was much greater in the corticotomy sides than the unoperated (control side (P=0.015. This was especially significant at the end of first week of tooth movement(P=0.000. Comparing the two sides, the amount of canine tipping was much lesser in corticotomy group than the control group (P=0.046. There was no significant difference concerning the anchorage loss between thetwo groups (P=0.410.Conclusion: Corticotomy procedure had a positive effect on the rate of tooth movement with less tipping of the canines comparing to conventional orthodontic treatment. To get more benefit from this procedure, it is recommended to select those patients who do not need canine alignment after premolars extraction, such asbimaxillary dento alveolar protrusions.

  16. Efficacy of various materials in recording enamel rod endings on tooth surface for personal identification

    Directory of Open Access Journals (Sweden)

    K Manjunath

    2011-01-01

    Full Text Available Aim: To analyze efficacy of cellulose acetate film, cellophane tape, and light body impression material in recording enamel rod endings on tooth surface for personal identification. Materials and Methods: Surface enamel rod endings of 30 extracted teeth were recorded from the same area of the same tooth for two times using cellulose acetate film, cellophane tape, and light body impression material. Photomicrographs of enamel rod endings were taken and subjected to Verifinger standard SDK version 5.0 software for analysis. Minutiae scores of all enamel rod end patterns obtained using these three imprint materials were statistically analyzed. Results: Cellulose acetate film imprint showed complete enamel rod end patterns and the software was able to identify the particular tooth with the same previous identification number in subsequent recordings as well. Cellophane tape and light body rubber-base impression material imprint showed incomplete enamel rod end patterns and the software failed to identify the particular tooth with the same previous identification number in subsequent recordings. Statistical analysis revealed that cellulose acetate film recorded more number of minutiae points compared with the other imprint materials. Conclusion: Cellulose acetate film is a reliable material for recording enamel rod endings on tooth surface for personal identification compared with cellophane tape and light body rubber-base impression material.

  17. Gamma-ray dose response of ESR signals in tooth enamel of cows and mice in comparison with human teeth

    International Nuclear Information System (INIS)

    The ESR dose responses of the tooth enamel samples prepared from teeth of cow and mice were examined in comparison with that of human. The samples were prepared with combined procedures of mechanical and chemical treatments of teeth. The ESR dose response was extracted from the total ESR spectra of tooth enamel samples by a specially developed matrix method. The dosimetric signal was found to be increased linearly with gamma dose for all studied tooth enamel samples. The radiation sensitivity of cow tooth enamel was found to be close to that of human teeth while that of mouse teeth was about 25% lower. The present results indicate that, having high radiation sensitivity, cow and mouse teeth can be used for retrospective radiation dosimetry in low-dose level

  18. Adhesion of Dental Materials to Tooth Structure

    Science.gov (United States)

    Mitra, Sumita B.

    2000-03-01

    The understanding and proper application of the principles of adhesion has brought forth a new paradigm in the realm of esthetic dentistry. Modern restorative tooth procedures can now conserve the remaining tooth-structure and also provide for the strengthening of the tooth. Adhesive restorative techniques call for the application and curing of the dental adhesive at the interface between the tooth tissue and the filling material. Hence the success of the restoration depends largely on the integrity of this interface. The mechanism of adhesion of the bonding materials to the dental hard tissue will be discussed in this paper. There are four main steps that occur during the application of the dental adhesive to the oral hard tissues: 1) The first step is the creation of a microstructure in the tooth enamel or dentin by means of an acidic material. This can be through the application of a separate etchant or can be accomplished in situ by the adhesive/primer. This agent has to be effective in removing or modifying the proteinaceous “smear” layer, which would otherwise act as a weak boundary layer on the surface to be bonded. 2) The primer/adhesive must then be able to wet and penetrate the microstructure created in the tooth. Since the surface energies of etched enamel and that of etched dentin are different finding one material to prime both types of dental tissues can be quite challenging. 3) The ionomer types of materials, particularly those that are carboxylate ion-containing, can chemically bond with the calcium ions of the hydroxyapatite mineral. 4) Polymerization in situ allows for micromechanical interlocking of the adhesive. The importance of having the right mechanical properties of the cured adhesive layer and its role in absorbing and dissipating stresses encountered by a restored tooth will also be discussed.

  19. Preimplantation filling of tooth socket with ?-tricalcium phosphate/polylactic-polyglycolic acid (?-TCP/PLGA root analogue: clinical and histological analysis in a patient

    Directory of Open Access Journals (Sweden)

    Kokovi? Vladimir

    2011-01-01

    Full Text Available Introduction. Bone resorption is a physiological process after tooth extraction. The use of bone substitutes to fill the tooth socket is suggested to prevent bone resorption and establish good bone architecture for implant placement. A pure ß-tricalcium phosphate coated with copolymer (polylactic-polyglycolic acid as a root analogue, is suitable for filling tooth sockets. Case report. We presented a patient successfully treated with root analogue after extraction of the right second lower premolar. Three months later, the patient was planned for the placement of six TE® ITI dental implants into the mandible. During the surgery, the biopsy of bone-like tissue from the previously treated socket was taken. All the implants were immediately loaded due to good primary stability. Histological analysis of the specimen revealed fibrous healing in the area treated with root analogue. Conclusion. The use of ß-tricalcium phosphate coated with copolymers after tooth extraction enables satisfactory bone architecture for consequent implant treatment.

  20. Hydroxyapatite coating on damaged tooth surfaces by immersion

    International Nuclear Information System (INIS)

    Hydroxyapatite (HAp) was coated on scratched areas of a human tooth and HAp disks by the immersion method in a HAp colloidal solution (?20 ?m of average diameter dispersed in DI water). The surface morphologies of the scratched area after immersion for 1-3 months were investigated showing that the damaged surfaces were remarkably recovered. Then, the mechanical property and chemical stability of the HAp coating layers on both specimens were determined via the Vickers hardness test and concentration measurement of extracted Ca2+ ions, respectively, after strong acidic treatment. The cellular behavior of mouse calvaria-derived pre-osteoblastic cells (MC3T3-E1) was also examined on the HAp layers regenerated on micro-scratched HAp disks for the purpose of their potential applications on maxillofacial bone conservation and reconstruction for prosthetic dentistry, and artificial disk preparation of a vertebral column. The notable loss of Ca2+ ions under a highly acidic condition was not observed in the layers coated by HAp adsorption, indicating that the coating surface was well adhered with the original surfaces of the respective specimen. Moreover, the HAp adsorption did not adversely affect the adhesion, growth and proliferation of MC3T3-E1 cells on the coated HAp layers for up to 21 days. These results suggest that the HAp coating on the scratched areas of the tooth would be effectively applicable for the development of long-term prevention of micro-cleavage and tooth health supporters to reduce discoloration and further maxillofacial and orthopedic applications.

  1. Evaluation of effect of low level laser therapy on pain during orthodontic tooth movement in human

    Directory of Open Access Journals (Sweden)

    Hosseini MH

    2010-06-01

    Full Text Available "nBackground and Aims: Lasers with different characteristics have been used to stimulate orthodontic tooth movements and to inhibit the pain during tooth movements. Considering the contradictory finding in this respect, the effect of low level laser therapy (LLLT was evaluated on the pain during orthodontic tooth movement. "nMaterials and Methods: In this randomized clinical trial study, 12 patients were included with extracted upper first premolars and required canine retraction into extraction site. While in both sides canines were retracted by Niti coil spring, one side was exposed to GaAlAs laser (890nm. LLLT was done on the buccal and palatal mucosa by slow movement of probe. The patients were asked about their pain on both sides 2 days after beginning of retraction. Pain measurement was evaluated with VAS. "nResults: Pain perception in LLLT side significantly decreased (P=0.007. "nConclusion: Based on the results, single irradiation of GaAlAs laser (12J energy per tooth can decrease pain perception.

  2. ESR dosimetry using human tooth enamel

    International Nuclear Information System (INIS)

    To estimate the individual cumulative dose of atomic bomb (A-bomb) survivors or radiologic technologists by measuring electron spin resonance (ESR) of teeth, some characteristics of tooth enamel as ESR dosimeter were studied. The ESR signal of CO33- was stable and increased linearly with exposed dose. The response of ESR signal, however, was changed with photon energy. This indicates that the exposed radiation quality must be considered in evaluating the absorbed dose. The merit of this method is that it permits direct estimation of the absorbed dose by measuring the intensity of ESR of tooth taken from exposed persons. (author)

  3. Tooth mobility changes subsequent to root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    pulp necrosis in the coronal fragment. Furthermore, the effect of age, location of the fracture on the root, and observation period on mobility values was analyzed. Mobility values were measured for 44 of 95 previous reported root-fractured permanent incisors. Mobility changes were measured with a...... reflect the radiographic healing stages and known age effects upon tooth mobility.......The purpose of this study was to analyze tooth mobility changes in root-fractured permanent teeth and relate this to type of interfragment healing (hard tissue healing (HT), interfragment healing with periodontal ligament (PDL) and nonhealing with interposition of granulation tissue (GT) because of...

  4. Causes of Charcot-Marie-Tooth Disease (CMT)

    Science.gov (United States)

    ... MDA clinic. Also, see Facts About Genetics and Neuromuscular Diseases . Disease: Charcot-Marie-Tooth Disease (CMT) Hereditary Motor ... Marie-Tooth & Related Diseases Facts About Genetics and Neuromuscular Diseases A Teacher's Guide to Neuromuscular Disease Learning to ...

  5. Genetics Home Reference: Charcot-Marie-Tooth disease

    Science.gov (United States)

    ... step (or gait) and increase the risk of ankle injuries and tripping. As the disease progresses, muscles in ... of Charcot-Marie-Tooth disease and may include treatment providers. Gene Review: Charcot-Marie-Tooth Hereditary Neuropathy ...

  6. A Review of the Use of Dental Implants in Children with Tooth Agenesis

    Directory of Open Access Journals (Sweden)

    A Moghareh Abed

    2010-01-01

    Full Text Available Introduction: Several treatment modalities have so far been introduced for tooth agenesis, among which dental implants seem to be of greater importance. The prognosis of this treatment in children is not however as predictable as in adults because of issues such as higher risk of surgery in younger individuals and continuing growth of jaws after implant placement. The aim of this study was to systematically review the literature and find out when it is the best time to extract deciduous teeth and place implants in young individuals with tooth agenesis.Materials and Methods: A search was made in MEDLINE on combinations of the terms ‘tooth agenesis’, ‘deciduous teeth’ and ‘dental implants’ from 1972 to 2009. Publications on the prevalence of tooth agenesis and oligodontia, persisting deciduous teeth and the long-term function of dental implants in children also were added. A total of 123 references were finally included.Results: The information currently available on the placement of dental implants in young individuals with tooth agenesis is mostly based on reports from multi-disciplinary teams and case reports.Conclusion: Implantations for young individuals should be postponed after the completion of the 15th year of age in girls and the 17th year of age in boys. Skeletal growth ought to be completed. Implantation during childhood should be restricted to those patients who may not be conventionally provided with an aesthetically and functionally satisfying prosthodontic restoration due to the large extent of their missing teeth. Key words: Dental implants, Tooth agenesis, Deciduous teeth.

  7. Patient Discomfort Following Single-Tooth Implant Placement

    DEFF Research Database (Denmark)

    Spin-Neto, Rubens; Pontes, Ana Emília Farias; Wenzel, Ann; Sakakura, Celso Eduardo

    2014-01-01

    Aims: Evaluate postoperative discomfort (pain, bleeding and swelling) in single-tooth implant patients submitted to immediate or conventional tooth restoration together with assessment of treatment time. Methods: Twenty-four patients who received single-tooth maxillary dental implants were randomly assigned to an IR (Immediate Restoration) or CR (Conventional Restoration) group. In IR, an implant was inserted and a provisional tooth crown was delivered within the same session, while in CR it was...

  8. Tooth-marked small theropod bone: an extremely rare trace

    DEFF Research Database (Denmark)

    Jacobsen, Aase Roland

    2001-01-01

    Tooth-marked dinosaur bones provide insight into feeding behaviours and biting strategies of theropod dinosaurs. The majority of theropod tooth marks reported to date have been found on herbivorous dinosaur bones, although some tyrannosaurid bones with tooth marks have also been reported. In 1988 a partial skeleton of the dromaeosaurid Saurornitholestes was collected from southern Alberta, Canada, that bore marks on one dentary. The location and morphology of the tooth marks suggests that a ther...

  9. Decision-making deficits associated with disrupted synchronization between basolateral amygdala and anterior cingulate cortex in rats after tooth loss.

    Science.gov (United States)

    Xu, Xiaoxiang; Cao, Bing; Wang, Jun; Yu, Tianran; Li, Ying

    2015-07-01

    Human studies have shown that multiple teeth loss was significantly associated with cognitive impairment, dementia and Alzheimer's disease. However, the causal relationship between tooth loss and cognitive deficits has not been clarified. Rodents demonstrate human-like cognitive faculties. In this study by performing rat gambling task (RGT), we reported that prolonged tooth loss condition by extracting all left molars in the rats led to an increase in the proportion of poor decision-makers, and decrease in the proportion of good decision-makers compared with controls. No influence was detected on the general activity and motivation after tooth loss. Recent experiments have shown that decision-making performances in the RGT rely on the functional integrity of the amygdala and anterior cingulate cortex (ACC). The theta band brain oscillation has been acknowledged for extensive cognitive functions. Here, we performed multiple-electrode array recordings of local field potential (LFP) in anesthetized rats. The results exhibited an increase in accumulative power of the theta frequency of LFP in the basolateral amygdala (BLA) and decrease of theta power in the ACC in tooth loss rats. Furthermore, cross-correlation analysis displayed that tooth loss suppressed the synchronization of theta frequency of LFP between the BLA and ACC, indicating reduced neuronal communications between these two regions. In conclusion, we demonstrate for the first time that tooth loss leads to higher-order cognitive deficits accompanied by the alteration of theta frequency of LFP in brain circuitries and disruption of neural network integrity. PMID:25684327

  10. A study on ESR dating characteristics of tooth enamel fossils

    International Nuclear Information System (INIS)

    The characteristics of ESR signals used in the dating of animal tooth enamel fossils have been investigated. According to the comparison of the results obtained from tooth enamel with those from pure substance and the study by positron annihilation technique, it can be concluded that the paramagnetic centers of tooth enamel is produced by PO43- ion formed F centers

  11. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Contact InfoBites Quick Reference Learn more Children's Oral Health Temporomandibular Joint Disorder What is Baby Bottle Tooth ... Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  12. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Saturday, March 12, 2016 About | Contact InfoBites Quick Reference ... of Dental Advances What is Baby Bottle Tooth Decay? When Should My Child First See a Dentist? How Do I Care for My Child's Baby Teeth? Learn what those ...

  13. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Saturday, January 02, 2016 About | Contact InfoBites Quick Reference ... Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find ...

  14. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Saturday, March 05, 2016 About | Contact InfoBites Quick Reference ... Learn more Pregnancy and Oral Health Is My Child at Risk for Early Childhood Tooth Decay? How Do I Care for My Child's Baby Teeth? Temporomandibular Joint Disorder ...

  15. Life of a Tooth: A Visual Timeline

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    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Tuesday, November 10, 2015 About | Contact InfoBites Quick Reference ... (Bad Breath) The History of Dental Advances How Do I Care for My Child's Baby Teeth? What is Baby Bottle Tooth Decay? What is a Composite Resin (White Filling)? Headaches and ...

  16. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Contact InfoBites Quick Reference Learn more Children's Oral Health How Do I Care for My Child's Baby Teeth? The History of Dental Advances Headaches and Jaw Pain? Check Your Posture! Is My Child at Risk for Early Childhood Tooth ... Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  17. Recent Approaches in Tooth Engineering Research.

    Czech Academy of Sciences Publication Activity Database

    Švandová, Eva; Veselá, Barbora; K?ivánek, J.; Hampl, A.; Matalová, Eva

    2014-01-01

    Ro?. 60, Suppl 1 (2014), s. 21-29. ISSN 0015-5500 R&D Projects: GA ?R GAP304/11/1418; GA MZd(CZ) NT11420 Institutional support: RVO:67985904 Keywords : engineering * tooth * stem cells * culture techniques Subject RIV: EA - Cell Biology Impact factor: 1.000, year: 2014

  18. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Friday, January 08, 2016 About | Contact InfoBites Quick Reference ... Oral Health What is Baby Bottle Tooth Decay? What is Dental Amalgam (Silver Filling)? Temporomandibular Joint Disorder How Do I Care for My Child's Baby Teeth? What is a ...

  19. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Contact InfoBites Quick Reference Learn more Children's Oral Health What is Baby Bottle Tooth Decay? What is ... Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  20. Death in the life of a tooth.

    Czech Academy of Sciences Publication Activity Database

    Matalová, Eva; Tucker, A. S.; Sharpe, P. T.

    2004-01-01

    Ro?. 83, ?. 1 (2004), s. 11-16. ISSN 0022-0345 R&D Projects: GA ?R GP204/02/P112 Institutional research plan: CEZ:AV0Z5045916 Keywords : apoptosis * tooth development Subject RIV: EA - Cell Biology Impact factor: 3.131, year: 2004

  1. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Contact InfoBites Quick Reference Learn more Children's Oral Health How Do I Care for My Child's Baby Teeth? When Should My Child First See a Dentist? What is Orofacial Pain? Why is Oral Health Important for Men? What is Baby Bottle Tooth ...

  2. Apoptotic cell elimination during early tooth development.

    Czech Academy of Sciences Publication Activity Database

    Matalová, Eva; Míšek, Ivan; Chovancová, Eva

    2003-01-01

    Ro?. 72, ?. 7 (2003), s. 34. ISSN 0001-7213. [Congress of the European Association of Veterinary Anatomists/24./. 21.07.2002-25.07.2002, Brno] R&D Projects: GA ?R GP204/02/P112 Institutional research plan: CEZ:AV0Z5045916 Keywords : tooth development Subject RIV: FF - HEENT, Dentistry

  3. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Learn more Halitosis (Bad Breath) When Should My Child First See a Dentist? Men: Looking for a Better Job? Start by Visiting the Dentist What is Baby Bottle Tooth Decay? Why is Oral Health Important for Men? Pacifiers Have Negative and Positive Effects Learn what those dental words mean. The Life ...

  4. Neurologic Regulation and Orthodontic Tooth Movement.

    Science.gov (United States)

    Kyrkanides, Stephanos; Huang, Hechang; Faber, Richard D

    2016-01-01

    Pain and discomfort are prevalent symptoms among the vast majority of patients with fixed orthodontic appliances and is the most disliked aspect of treatment. The periodontium is a highly innervated structure that also provides the necessary trophic factors, such as nerve growth factor, which promote neuronal survival, maintenance and axonal growth, via interaction with specific nerve surface receptors, such as TrkA. Various types of nerves are found in the periodontium, including thinly myelinated and unmyelinated sensory fibers that express the neuropeptides substance P and calcitonin gene-related peptide among others. Tooth movement activates peripheral sensory nerve endings, which transmit painful signals to the brain after being processed at the trigeminal spinal nucleus, resulting in local expression of pain related genes, such as c-Fos. Concurrently, an attendant inflammatory process is detected in the trigeminal spinal nucleus, including activation of astrocytes, microglia and neurons. This complex neurologic reaction to tooth movement mediates orthodontic pain and also serves a source of neurogenic inflammation exhibited in the trigeminal spinal nucleus and the periodontium. Activated periodontal sensory fibers release neuropeptides in the periodontal environment, which in turn induce a local inflammatory cascade aiding in alveolar bone turnover and tooth movement per se. Control of pain with nonsteroidal anti-inflammatory drugs and other prescription or over-the-counter pain killers effectively reduce this neurologic reaction and alleviate the attendant pain, but also reduce the neurogenic inflammatory component of orthodontic tooth movement causing a slowdown in bone turnover and consequently delaying orthodontic treatment. PMID:26599119

  5. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Monday, January 18, 2016 About | Contact InfoBites Quick Reference Learn more Children's Oral Health Is My Child at Risk for Early Childhood Tooth Decay? How Do I Care for My Child's Baby Teeth? Are You Biting ...

  6. Tooth’s Tensions Analysis of Face Worm Gears with Cylindrical Pinion Development of FEA

    Directory of Open Access Journals (Sweden)

    Gavrila Ion

    2009-12-01

    Full Text Available Tooth’s tension in lapping process for worm face gear is proposed. The stress analysis of the gear drive is performed using a three-dimensional finite element analysis. The developed simulation is illustrated with numerical examples. This complex and intuitive simulation was created with CAD-CAM, MATH-CAD and FEM support. This simulation contain data collected from EU standards

  7. Is tooth wear in the primary dentition predictive of tooth wear in the permanent dentition? Report from a longitudinal study.

    LENUS (Irish Health Repository)

    Harding, M A

    2010-03-01

    To determine the prevalence of tooth wear in the permanent dentition of a sample of 12-year-old school children and establish whether an association exists between tooth wear recorded now and tooth wear recorded in their primary dentition at age five.

  8. Tooth Movement Alterations by Different Low Level Laser Protocols: A Literature Review

    OpenAIRE

    Seifi, Massoud; Vahid-Dastjerdi, Elahe

    2015-01-01

    Low-Level Laser Therapy (LLLT) provides several benefits for patients receiving orthodontic treatment. According to some literatures, Orthodontic Tooth Movement (OTM) can be enhanced but some investigators have reported contradictory results. This article reviews the literature regarding the different aspects of the use of LLLT on OTM and its alterations. The general data regarding the study design, sample size, wavelength (nm), power (mW), and duration were extracted and recorded independent...

  9. The teamwork approach to esthetic tooth replacement with immediate implant placement and immediate temporization.

    Science.gov (United States)

    Levin, Barry P; Wilk, Brian L

    2015-10-01

    Enduring a period of edentulism between extraction and final restoration is difficult for patients- especially when it concerns the esthetic zone. The approach described demonstrates key points of consideration when replacing a maxillary anterior tooth with a dental implant using immediate implant placement, hard- and soft-tissue augmentation, and provisionalization. The authors stress adherence to patient selection and prosthetic design guidelines, and recommend the use of a digital impression technique, rather than traditional, rubber-based impressions. PMID:26448151

  10. Biodosimetry: chromosome aberration in lymphocytes and electron paramagnetic resonance in tooth enamel from atomic bomb survivors

    International Nuclear Information System (INIS)

    One hundred enamel samples isolated from extracted teeth donated by atomic bomb survivors were subjected to free radical measurement by means of electron paramagnetic resonance (ESR). Results comparing ESR with the chromosome aberration frequency in lymphocytes of the tooth donors, and with the physically estimated DS86 dose suggested that ESR data correlated more closely with chromosome data than with the estimated DS86 doses, probably because DS86 may depend on erroneous memory in some cases. 9 refs, 4 figs

  11. Effect of Multiple Adhesive Coating on Microshear Bond Strength to Primary Tooth Dentin

    OpenAIRE

    Beheshteh Malekafzali Malekafzali; Amir Ghasemi; Hassan Torabzadeh; Reza Hamedani; Nekoo Tadayon

    2013-01-01

    Objective: Multiple adhesive coating is a controversial topic, especially in primary dentition that should be clarified. We evaluated the effect of multiple consecutive adhesive resin coatings on the microshear bond strength (µSBS) of composite resin to primary tooth dentin utilizing a filled (Adper Single Bond Plus) and an unfilled (Adper Single Bond) adhesive resin.Materials and Methods: Thirty extracted primary canines were randomly allocated into two groups based on the adhesive used. Den...

  12. [Biomechanical study on orthodontic tooth movement: changes in biomechanical property of the periodontal tissue in terms of tooth mobility].

    Science.gov (United States)

    Inoue, Y

    1989-12-01

    The magnitude of tooth mobility has been frequently used for evaluating biomechanical response of the periodontal tissue to applied forces. However, tooth mobility during orthodontic tooth movement has not been measured. The purpose of this study was to investigate changes in biomechanical property of the periodontal tissue during canine retraction, in terms of tooth mobility. The upper canines on both sides of ten orthodontic patients were moved in the distal direction for about four weeks with an initial force of 200 gf. An amount of tooth movement and a magnitude of tooth mobility were measured every 3 or 4 days during retraction. A distally directed force up to 500 gf was continuously applied to each canine and tooth mobility was measured with a noncontact type of eddy current displacement sensor. A two-dimensional finite element model was constructed and displacements of the finite element model were calculated with various Young's moduli in loading with a 100 gf force in the distal direction. In comparison with the magnitudes of the tooth mobility, Young's modulus of the periodontal membrane before retraction and the influence of the biomechanical factors on changes in tooth mobility were investigated. The tooth movement curve was divided into three phases; an initial phase, a lag phase and a post-lag phase. The magnitudes of tooth mobility at the initial phase were significantly larger than those before retraction within the range of 250 gf to 500 gf and these magnitudes decreased during the lag phase. The magnitudes of tooth mobility at the post-lag phase significantly increased, within the range of 50 gf to 500 gf, than those before retraction. As a result of curveliniar regression analysis, the tooth mobility curves approximated to delta = AFB, where delta and F denote tooth mobility and force respectively. The coefficients A and B changed according to the phases of tooth movement. An inclination of the tooth mobility curve expressed by a tangent at the 400 gf force was the largest at the initial phase, and this inclination at the 100 gf force was the largest at the post-lag phase. Young's modulus of the periodontal membrane before retraction was determined to be approximately 35 gf/mm2 and Young's modulus of the periodontal membrane was the most important factor on the increase of tooth mobility. Tooth mobility significantly varied associated with tooth movement. It was indicated that biomechanical property of the periodontal tissue changes in response to each phase of tooth movement. In particular, Young's modulus of the periodontal membrane decreased at the post-lag phase of the orthodontic tooth movement. PMID:2488921

  13. A TOOTH TATTOO WITH A PURPOSE: AN INNOVATIVE APPROACH

    Directory of Open Access Journals (Sweden)

    Neetu

    2014-01-01

    Full Text Available Skin is not the only place that can be decorated with a tattoo. You can decorate your tooth with amazing tattoos. Tooth tattoos and tooth jewels have become one of the hottest fashion trends , and a very popular arrival in cosmetic dentistry. But won’t it be a boon if it had some preventive or medicinal v alue. Yes tooth tattoos can act as indicators of once illness. These tiny electronic sensors can diagnose illnesses by 'tasting' your breath. This paper is an insight into how a tooth tattoos can pick up early warning signs of sickness or infection by bact eria in people's breath.

  14. Computer aided design and analysis of gear tooth geometry

    Science.gov (United States)

    Chang, S. H.; Huston, R. L.

    1987-01-01

    A simulation method for gear hobbing and shaping of straight and spiral bevel gears is presented. The method is based upon an enveloping theory for gear tooth profile generation. The procedure is applicable in the computer aided design of standard and nonstandard tooth forms. An inverse procedure for finding a conjugate gear tooth profile is presented for arbitrary cutter geometry. The kinematic relations for the tooth surfaces of straight and spiral bevel gears are proposed. The tooth surface equations for these gears are formulated in a manner suitable for their automated numerical development and solution.

  15. Delayed tooth replantation in rats: effect of systemic antibiotic therapy with amoxicillin and tetracycline.

    Science.gov (United States)

    de Souza Gomes, Weglis Dyanne; Silva, Cristina Antoniali; Melo, Moriel Evangelista; da Silva, Vanessa Ferreira; de Almeida, Melyna Marques; Pedrini, Denise; Poi, Wilson Roberto; Sonoda, Celso Koogi; Panzarini, Sônia Regina

    2015-12-01

    Systemic antibiotic therapy (SAT) has usually been recommended after tooth replantation, but its actual value has been questioned. As there are no reports in the literature about its influence on tooth replantation, the aim of this study was to evaluate the influence of systemic administration of antibiotics (amoxicillin and tetracycline) at the different phases of the repair process (7, 15, 30 days) in delayed rat tooth replantation. Ninety Wistar rats (Rattus norvegicus albinus) had their maxillary right incisors extracted and bench-dried for 60 min. The dental papilla, enamel organ, pulp tissue, and root surface-adhered periodontal ligament were removed, and the teeth were replanted. The animals received no antibiotics (n = 30) or were medicated systemically with amoxicillin (n = 30) and tetracycline (n = 30), and were euthanized after 7, 15, and 30 days. Regardless of the evaluation period, the acute inflammatory infiltrate was less intense and root resorption presented smaller extent and depth in the group treated with amoxicillin. The results suggest that SAT has a positive influence on the repair process in delayed tooth replantation and that amoxicillin is an excellent treatment option. PMID:26332890

  16. Study on electron spin resonance dosimetry of dog tooth enamel

    International Nuclear Information System (INIS)

    Four groups dog tooth enamel samples were irradiated with different dose by 137Cs ?-rays. Their electron spin resonance (ESR) spectra pre- and post-irradiated were measured and the changes of ESR signal intensities were analyzed. The results showed that the average intensity of native signals of dog tooth samples was 20.8±2.9, much weaker than that of human 39.5; the dosimetric signal intensities of dog tooth enamel increased with the absorbed doses; the mass of each sample is 100 mg. The average irradiation response of dog tooth enamel samples was (37.1±2.1) Gy-1, very close to that of human tooth samples (36.3 Gy-1). The dog tooth can be used for retrospective dosimetry when human tooth are difficult to collect. (authors)

  17. Large scale study of tooth enamel

    International Nuclear Information System (INIS)

    Human tooth enamel contains traces of foreign elements. The presence of these elements is related to the history and the environment of the human body and can be considered as the signature of perturbations which occur during the growth of a tooth. A map of the distribution of these traces on a large scale sample of the population will constitute a reference for further investigations of environmental effects. On hundred eighty samples of teeth were first analyzed using PIXE, backscattering and nuclear reaction techniques. The results were analyzed using statistical methods. Correlations between O, F, Na, P, Ca, Mn, Fe, Cu, Zn, Pb and Sr were observed and cluster analysis was in progress. The techniques described in the present work have been developed in order to establish a method for the exploration of very large samples of the Belgian population. (author)

  18. Large scale study of tooth enamel

    International Nuclear Information System (INIS)

    Human tooth enamel contains traces of foreign elements. The presence of these elements is related to the history and the environment of the human body and can be considered as the signature of perturbations which occur during the growth of a tooth. A map of the distribution of these traces on a large scale sample of the population will constitute a reference for further investigations of environmental effects. One hundred eighty samples of teeth were first analysed using PIXE, backscattering and nuclear reaction techniques. The results were analysed using statistical methods. Correlations between O, F, Na, P, Ca, Mn, Fe, Cu, Zn, Pb and Sr were observed and cluster analysis was in progress. The techniques described in the present work have been developed in order to establish a method for the exploration of very large samples of the Belgian population

  19. Retrospective biodosimetry with small tooth enamel samples using K-Band and X-Band

    International Nuclear Information System (INIS)

    In an attempt to make the in vitro electron spin resonance (ESR) retrospective dosimetry of the tooth enamel a lesser invasive method, experiments using X-Band and K-Band were performed, aiming to determine conditions that could be used in cases of accidental exposures. First, a small prism from the enamel was removed and ground with an agate mortar and pestle until particles reach a diameter of approximately less than 0.5 mm. This enamel extraction process resulted in lower signal artifact compared with the direct enamel extraction performed with a diamond burr abrasion. The manual grinding of the enamel does not lead to any induced ESR signal artifact, whereas the use of a diamond burr at low speed produces a signal artifact equivalent to the dosimetric signal induced by a dose of 500 mGy of gamma irradiation. A mass of 25 mg of enamel was removed from a sound molar tooth previously irradiated in vitro with a dose of 100 mGy. This amount of enamel was enough to detect the dosimetric signal in a standard X-Band spectrometer. However using a K-Band spectrometer, samples mass between 5 and 10 mg were sufficient to obtain the same sensitivity. An overall evaluation of the uncertainties involved in the process in this and other dosimetric assessments performed at our laboratory indicates that it is possible at K-Band to estimate a 100 mGy dose with 25% accuracy. In addition, the use of K-Band also presented higher sensitivity and allowed the use of smaller sample mass in comparison with X-Band. Finally, the restoration process performed on a tooth after extraction of the 25 mg of enamel is described. This was conducted by dental treatment using photopolymerizable resin which enabled complete recovery of the tooth from the functional and aesthetic viewpoint showing that this procedure can be minimally invasive.

  20. Retrospective biodosimetry with small tooth enamel samples using K-Band and X-Band

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Jorge A. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Kinoshita, Angela [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Leonor, Sergio J. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Belmonte, Gustavo C. [Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Baffa, Oswaldo, E-mail: baffa@usp.br [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

    2011-09-15

    In an attempt to make the in vitro electron spin resonance (ESR) retrospective dosimetry of the tooth enamel a lesser invasive method, experiments using X-Band and K-Band were performed, aiming to determine conditions that could be used in cases of accidental exposures. First, a small prism from the enamel was removed and ground with an agate mortar and pestle until particles reach a diameter of approximately less than 0.5 mm. This enamel extraction process resulted in lower signal artifact compared with the direct enamel extraction performed with a diamond burr abrasion. The manual grinding of the enamel does not lead to any induced ESR signal artifact, whereas the use of a diamond burr at low speed produces a signal artifact equivalent to the dosimetric signal induced by a dose of 500 mGy of gamma irradiation. A mass of 25 mg of enamel was removed from a sound molar tooth previously irradiated in vitro with a dose of 100 mGy. This amount of enamel was enough to detect the dosimetric signal in a standard X-Band spectrometer. However using a K-Band spectrometer, samples mass between 5 and 10 mg were sufficient to obtain the same sensitivity. An overall evaluation of the uncertainties involved in the process in this and other dosimetric assessments performed at our laboratory indicates that it is possible at K-Band to estimate a 100 mGy dose with 25% accuracy. In addition, the use of K-Band also presented higher sensitivity and allowed the use of smaller sample mass in comparison with X-Band. Finally, the restoration process performed on a tooth after extraction of the 25 mg of enamel is described. This was conducted by dental treatment using photopolymerizable resin which enabled complete recovery of the tooth from the functional and aesthetic viewpoint showing that this procedure can be minimally invasive.

  1. Tooth Regeneration with Stem Cell Sources

    OpenAIRE

    Neda Naghavi

    2014-01-01

    Introduction: During the last decade, advances in tissue engineering and stem cell-based tooth regeneration have provided realistic and attractive means of replacing lost or damaged teeth. The first adult stem cells isolated from dental tissues were dental pulp stem cells (DPSCs). When transplanted with hydroxyl apatite/tri calcium phosphate (HA/TCP) powder, they formed a dentin-like structure lined with odontoblast-like cells that surrounded a pulp-like interstitial tissue. DPSCs could di...

  2. Gastroesophageal Reflux Disease and Tooth Erosion

    OpenAIRE

    Smales, Roger J.; John A. Kaidonis; Sarbin Ranjitkar

    2012-01-01

    The increasing prevalence of gastroesophageal reflux disease (GERD) in children and adults, and of “silent refluxers” in particular, increases the responsibility of dentists to be alert to this potentially severe condition when observing unexplained instances of tooth erosion. Although gastroesophageal reflux is a normal physiologic occurrence, excessive gastric and duodenal regurgitation combined with a decrease in normal protective mechanisms, including an adequate production of saliva, may...

  3. The evolution of tooth wear indices

    OpenAIRE

    Bardsley, Penny Fleur

    2008-01-01

    Tooth wear—attrition, erosion and abrasion—is perceived internationally as an ever-increasing problem. Clinical and epidemiological studies, however, are difficult to interpret and compare due to differences in terminology and the large number of indices that have been developed for diagnosing, grading and monitoring dental hard tissue loss. These indices have been designed to identify increasing severity and are usually numerical. Some record lesions on an aetiological basis (e.g. erosion in...

  4. Frictional Effects on Gear Tooth Contact Analysis

    OpenAIRE

    Ken Mao; Zheng Li

    2013-01-01

    The present paper concentrates on the investigations regarding the situations of frictional shear stress of gear teeth and the relevant frictional effects on bending stresses and transmission error in gear meshing. Sliding friction is one of the major reasons causing gear failure and vibration; the adequate consideration of frictional effects is essential for understanding gear contact behavior accurately. An analysis of tooth frictional effect on gear performance in spur gear is presented us...

  5. ISS protocol for EPR tooth dosimetry

    International Nuclear Information System (INIS)

    The accuracy in Electron Paramagnetic Resonance (EPR) dose reconstruction with tooth enamel is affected by sample preparation, dosimetric signal amplitude evaluation and unknown dose estimate. Worldwide efforts in the field of EPR dose reconstruction with tooth enamel are focused on the optimization of the three mentioned steps in dose assessment. In the present work, the protocol implemented at ISS in the framework of the European Community Nuclear Fission Safety project 'Dose Reconstruction' is presented. A combined mechanical-chemical procedure for ground enamel sample preparation is used. The signal intensity evaluation is carried out with powder spectra simulation program. Finally, the unknown dose is evaluated individually for each sample with the additive dose method. The unknown dose is obtained by subtracting a mean native dose from the back-extrapolated dose. As an example of the capability of the ISS protocol in unknown dose evaluation, the results obtained in the framework of the 2nd International Intercomparison on EPR tooth enamel dosimetry are reported

  6. Evaluating tooth restorations: micro-computed tomography in practical training for students in dentistry

    Science.gov (United States)

    Deyhle, Hans; Schmidli, Fredy; Krastl, Gabriel; Müller, Bert

    2010-09-01

    Direct composite fillings belong to widespread tooth restoration techniques in dental medicine. The procedure consists of successive steps, which include etching of the prepared tooth surface, bonding and placement of composite in incrementally built up layers. Durability and lifespan of the composite inlays strongly depend on the accurate completion of the individual steps to be also realized by students in dental medicine. Improper handling or nonconformity in the bonding procedure often lead to air enclosures (bubbles) as well as to significant gaps between the composite layers or at the margins of the restoration. Traditionally one analyzes the quality of the restoration cutting the tooth in an arbitrarily selected plane and inspecting this plane by conventional optical microscopy. Although the precision of this established method is satisfactory, it is restricted to the selected two-dimensional plane. Rather simple micro computed tomography (μCT) systems, such as SkyScan 1174™, allows for the non-destructive three-dimensional imaging of restored teeth ex vivo and virtually cutting the tomographic data in any desired direction, offering a powerful tool for inspection of the restored tooth with micrometer resolution before cutting and thus also to select a two-dimensional plane with potential defects. In order to study the influence of the individual steps on the resulted tooth restoration, direct composite fillings were placed in mod cavities of extracted teeth. After etching, an adhesive was applied in half of the specimens. From the tomographic datasets, it becomes clear that gaps occur more frequently when bonding is omitted. The visualization of air enclosures offers to determine the probability to find a micrometer-sized defect using an arbitrarily selected cutting plane for inspection.

  7. Radiographic interpretation of experimental lesions in radicular tooth structure of human maxillary anterior teeth.

    Science.gov (United States)

    Bernier-Rodriguez, Joseph A; Sidow, Stephanie J; Joyce, Anthony P; McNally, Kathleen; McPherson, James C

    2008-12-01

    External resorption is often first detected radiographically. Early detection can lead to timely intervention and improvement of treatment outcome. The purpose of this study was to determine the minimal radicular defect size in maxillary anterior teeth that is radiographically detectable. Six teeth were selected in a cadaver maxilla (#6-11) and extracted. The teeth were then replanted in the maxilla, and three horizontally angled radiographs (0 degrees , 30 degrees from the mesial, and 30 degrees from the distal) were exposed as a baseline. Then, a sequence of tooth removal, placement of a 0.1-mm deep defect in the interproximal and midroot surface, tooth replantation, and radiograph exposure was begun and repeated eight times. Each time the defect depth was increased by 0.1 mm. Ten clinicians interpreted the subsequent radiographs to determine if they visualized a defect on each tooth and the location of the defect. The evaluators' ability to detect experimental lesions according to the depth of the defect was shown to be statistically significant for both tooth type and location of the radicular defect (analysis of variance, p < 0.05). The average size of defect needed for radiographic visualization was as follows: central incisor (0.28 mm on the interproximal [IP] and 0.74 mm on the midroot [MR] [palatal], lateral incisor (0.39 mm on the IP and 0.55 mm on the MR); and canine [0.45 mm on the IP and 0.71 mm on the MR). Based on the results of this study, the minimal defect size detected was 0.28 mm to 0.74 mm depending on defect location and tooth selected. PMID:19026875

  8. Clinical management of the avulsed tooth.

    Science.gov (United States)

    Trope, M

    1995-01-01

    Treatment outside the dental office: Replant immediately after gentle washing if practical. If replantation is not practical, store the tooth in the best medium available. Storage media in order of preference are Hank's Balanced Salt Solution (HBSS), milk, saline, and saliva (buccal vestibule). Water is the least desirable storage medium. Treatment in the office: Emergency visit; Place tooth in HBSS while exam is conducted and history is taken. Prepare socket for gentle repositioning of the tooth. Prepare the root. Extraoral dry time Extraoral dry time 20 to 60 minutes: Soak in HBSS for 30 minutes and replant. Extraoral dry time > 60 minutes: soak in citric acid, 2% stannous fluoride, and doxycycline and replant. Endodontics can be done extraorally. Semirigid splint for 7 to 10 days. (If alveolar fracture is present, rigid splint for 4 to 8 weeks). Suture soft-tissue lacerations, particularly in the cervical area. Administer systemic antibiotics (penicillin V potassium if possible) Chlorhexidine rinses and stringent oral hygiene while the splint is in place (7 to 10 days). Analgesics as required. Second visit after 7 to 10 days: Endodontic treatment: Tooth with open apex and extraoral dry time of extraoral dry time > 60 minutes: If endodontics was not completed in the emergency visit, start endodontics and follow apexification procedure. Tooth with closed apex: Endodontics should be initiated after 7 to 10 days. Careful chemomechanical instrumentation under strict asepsis. Splint removed at end of visit. Obturation visit: If endodontics was initiated 7 to 10 days after the avulsion, obturation can take place after short-term calcium hydroxide treatment. If endodontics was initiated more than 14 days after the avulsion or inflammatory resorption, long-term calcium hydroxide for 6 to 24 months, obturated when an intact lamina dura is traced. Restorations: Temporary restorations: Should be 4 mm deep. Reinforced zinc-oxide-eugenol, acid-etch composite resin, glass-ionomer cement. Permanent restoration: Placed immediately after obturation. Acid-etch resin and dentin bonding agents. Follow-up care: Twice per year for 3 years and yearly for as long as possible. Late complications are common. PMID:7890110

  9. An automated dental caries detection and scoring system for optical images of tooth occlusal surface.

    Science.gov (United States)

    Ghaedi, Leila; Gottlieb, Riki; Sarrett, David C; Ismail, Amid; Belle, Ashwin; Najarian, Kayvan; Hargraves, Rosalyn Hobson

    2014-01-01

    Dental caries are one of the most prevalent chronic diseases. The management of dental caries demands detection of carious lesions at early stages. This study aims to design an automated system to detect and score caries lesions based on optical images of the occlusal tooth surface according to the International Caries Detection and Assessment System (ICDAS) guidelines. The system detects the tooth boundaries and irregular regions, and extracts 77 features from each image. These features include statistical measures of color space, grayscale image, as well as Wavelet Transform and Fourier Transform based features. Used in this study were 88 occlusal surface photographs of extracted teeth examined and scored by ICDAS experts. Seven ICDAS codes which show the different stages in caries development were collapsed into three classes: score 0, scores 1 and 2, and scores 3 to 6. The system shows accuracy of 86.3%, specificity of 91.7%, and sensitivity of 83.0% in ten-fold cross validation in classification of the tooth images. While the system needs further improvement and validation using larger datasets, it presents promising potential for clinical diagnostics with high accuracy and minimal cost. This is a notable advantage over existing systems requiring expensive imaging and external hardware. PMID:25570356

  10. Molecular phylogenetic inference from saber-toothed cat fossils of Rancho La Brea.

    Science.gov (United States)

    Janczewski, D N; Yuhki, N; Gilbert, D A; Jefferson, G T; O'Brien, S J

    1992-10-15

    A method for the successful extraction of sequestered cellular DNA from 14,000-year-old fossil bones was developed and applied to asphalt-preserved specimens of the extinct saber-toothed cat, Smilodon fatalis. Two distinct gene segments, the mitochondrial gene for 12S rRNA and nuclear FLA-I (the feline class I major histocompatibility complex gene), from three different individual fossil specimens were cloned and sequenced after PCR amplification. Comparison of fossil-derived DNA sequences to homologous regions in 15 living carnivorous species, including 9 species of Felidae and 6 nonfelids, affirmed the phylogenetic placement of Smilodon within the modern radiation of Felidae distinct from the Miocene paleofelid (Nimravidae) saber-toothed "cat" species. These results raise the prospect of obtaining genetically informative DNA from preserved bones of extinct fossil species, particularly among the 2 million specimens excavated from the asphaltic sediments at Rancho La Brea in metropolitan Los Angeles. PMID:1409696

  11. ESR dosimetry for atomic bomb survivors using shell buttons and tooth enamel

    International Nuclear Information System (INIS)

    Atomic bomb radiation doses to humans at Nagasaki and Hiroshima are investigated by electron spin resonance (ESR) from shell buttons and tooth enamel voluntarily supplied by survivors. A shell button gives a dose of 2.1+-0.2 Gy with ESR signals at g=2.001 and g=1.997 while the signal at g=1.997 for the tooth enamel of the same person is 1.9+-0.5 Gy. Other teeth show doses from about 0.5 Gy to 3 Gy. An apparent shielding converted to a concrete thickness is given using the T65D calculated in 1965. Teeth extracted during dental treatment should be preserved for cumulative radiation dosimetry. (author)

  12. Hair keratin mutations in tooth enamel increase dental decay risk

    OpenAIRE

    Duverger, Olivier; Ohara, Takahiro; Shaffer, John R; Donahue, Danielle; Zerfas, Patricia; Dullnig, Andrew; Crecelius, Christopher; Beniash, Elia; Marazita, Mary L; Morasso, Maria I.

    2014-01-01

    Tooth enamel is the hardest substance in the human body and has a unique combination of hardness and fracture toughness that protects teeth from dental caries, the most common chronic disease worldwide. In addition to a high mineral content, tooth enamel comprises organic material that is important for mechanical performance and influences the initiation and progression of caries; however, the protein composition of tooth enamel has not been fully characterized. Here, we determined that epith...

  13. The Association Between childhood Obesity and Tooth Eruption

    OpenAIRE

    MUST, AVIVA; Phillips, Sarah M.; TYBOR, DAVID J.; Lividini, Keith; Hayes, Catherine

    2012-01-01

    Obesity is a growth-promoting process as evidenced by its effect on the timing of puberty. Although studies are limited, obesity has been shown to affect the timing of tooth eruption. Both the timing and sequence of tooth eruption are important to overall oral health. The purpose of this study was to examine the association between obesity and tooth eruption. Data were combined from three consecutive cycles (2001–2006) of the National Health and Nutrition Examination Survey (NHANES) and analy...

  14. A theropod tooth from the Late Triassic of southern Africa

    Indian Academy of Sciences (India)

    Sanghamitra Ray; Anusuya Chinsamy

    2002-06-01

    An isolated, large recurved and finely serrated tooth found associated with the prosauropod Euskelosaurus from the Late Triassic part of the Elliot Formation is described here. It is compared to the Triassic thecodonts and carnivorous dinosaurs and its possible affinity is discussed. The tooth possibly belongs to a basal theropod and shows some features similar to the allosauroids. This tooth is of significance, as dinosaur remains except for some footprints and trackways, are poorly known in the Late Triassic horizons of southern Africa.

  15. Protection and Reinforcement of Tooth Structures by Dental Coating Materials

    OpenAIRE

    Toru Nikaido; Rena Takahashi; Meu Ariyoshi; Junji Tagami; Alireza Sadr

    2012-01-01

    It has been proposed that a resin coating can serve as a means to protect dental structure after preparation of the tooth for indirect restorations, sealing the exposed dentin. The resin coating is applied on the cut surfaces immediately after tooth preparation and before making an impression by assembling a dentin bonding system and a flowable composite. Resin coatings minimize pulp irritation and improve the bond strength between a resin cement and tooth when bonding the restoration to toot...

  16. Tooth-marked small theropod bone: an extremely rare trace

    DEFF Research Database (Denmark)

    Jacobsen, Aase Roland

    2001-01-01

    Tooth-marked dinosaur bones provide insight into feeding behaviours and biting strategies of theropod dinosaurs. The majority of theropod tooth marks reported to date have been found on herbivorous dinosaur bones, although some tyrannosaurid bones with tooth marks have also been reported. In 1988 a partial skeleton of the dromaeosaurid Saurornitholestes was collected from southern Alberta, Canada, that bore marks on one dentary. The location and morphology of the tooth marks suggests that a theropod (possible a juvenile tyrannosaurid) included a Saurornitholestes in its diet.

  17. Tooth’s Tensions Analysis of Face Worm Gears with Cylindrical Pinion Development of FEA

    OpenAIRE

    Ion Gavrila

    2009-01-01

    Tooths tension in lapping process for worm face gear is proposed. The stress analysis of the gear drive is performed using a three-dimensional finite element analysis. The developed simulation is illustrated with numerical examples. This complex and intuitive simulation was created with CAD-CAM, MATH-CAD and FEM support. This simulation contains data collected from EU standards.

  18. Thermal induced EPR signals in tooth enamel

    International Nuclear Information System (INIS)

    Electron paramagnetic resonance (EPR) spectroscopy was used to detect the effects of temperature on powdered human tooth enamel, not irradiated in the laboratory. Samples were heated at temperature between 350 and 450, at 600 and at 1000 deg. C, for different heating times, between 6 min and 39 h. Changes in the EPR spectra were detected, with the formation of new signals. Possible correlation between the changes in EPR spectra and modifications in the enamel and in the mineral phase of bone detected with other techniques is discussed. The implications for dosimetric applications of signals induced by overheating due to mechanical friction during sample preparation are underlined

  19. Mechanically induced EPR signals in tooth enamel

    International Nuclear Information System (INIS)

    Sample preparation of tooth enamel for electron paramagnetic resonance (EPR) dosimetry usually involves mechanical operations. The present study shows that mechanical operations performed without water cooling generate a paramagnetic center inducing a stable isotropic EPR signal with g-value of 2.00320 and linewidth of about 0.1 mT. Using EPR spectrum simulation, the similarity between the mechanically induced signal and the signal generated when the enamel is heated in air at a temperature above 600 deg. C was investigated. Results indicate that the mechanically induced signal is related to sample temperature increase during mechanical friction

  20. 21 CFR 872.3910 - Backing and facing for an artificial tooth.

    Science.gov (United States)

    2010-04-01

    ...false Backing and facing for an artificial tooth. 872.3910 Section 872...3910 Backing and facing for an artificial tooth. (a) Identification. A backing and facing for an artificial tooth is a device...

  1. Microhardness and chemical composition of human tooth

    Directory of Open Access Journals (Sweden)

    Maria del Pilar Gutiérrez-Salazar

    2003-06-01

    Full Text Available Hardness of human tooth, both in enamel and dentin, has been measured at different sites using a Vicker's diamond. In this work we show that these values are almost constant all along the enamel and dentin thicknesses. Indentations were done from outer enamel surface to inner dentin layer, going through the enamel-dentin junction, both in transverse and longitudinal samples. Geometrical well-shape indentation uniformity was checked both with light and with scanning electron microscopes, and the chemical composition of the tooth was analyzed with characteristic X-ray energy dispersive spectroscopy. Hardness measurements were in the range from 270 to 360 VHN for enamel and 50 to 60 VHN for dentin. Cervical zone in longitudinal section showed the lowest value while in transverse sections the highest. All the hardness values were statically significative. Tour results indicate that the difference between enamel and dentin hardness has nothing to do with the content of Na, Cl and Mg, but the percentage of organic and inorganic materials in enamel and dentin.

  2. Hierarchical structure and biomineralization in cricket tooth

    CERN Document Server

    Xing, Xueqing; Cai, Quan; Mo, Guang; Du, Rong; Chen, Zhongjun; Wu, Zhonghua

    2012-01-01

    Cricket is a truculent insect with stiff and sharp teeth as a fighting weapon. The structure and possible biomineralization of the cricket teeth are always interested. Synchrotron radiation X-ray fluorescence, X-ray diffraction and small angle X-ray scattering techniques were used to probe the element distribution, possible crystalline structures and size distribution of scatterers in cricket teeth. Scanning electron microscope was used to observe the nanoscaled structure. The results demonstrate that Zn is the main heavy element in cricket teeth. The surface of the cricket teeth has a crystalline compound like ZnFe2(AsO4)2(OH)2(H2O)4. While, the interior of the teeth has a crystalline compound like ZnCl2, which is from the biomineralization. The ZnCl2-like biomineral forms nanoscaled microfibrils and their axial direction points at the top of tooth cusp. The microfibrils aggregate random into intermediate filaments, forming a hierarchical structure. A sketch map of the cricket tooth cusp was proposed and a d...

  3. Tooth structure and fracture strength of cavities

    DEFF Research Database (Denmark)

    Mondelli, José; Sene, Fábio; Ramos, Renata Pereira; Benetti, Ana Raquel

    2007-01-01

    This study evaluated, in vitro, the loss of tooth substance after cavity preparation for direct and indirect restorations and its relationship with fracture strength of the prepared teeth. Sixty sound human maxillary first premolars were assigned to 6 groups (n=10). MOD direct composite cavities......) or 1/2 (Groups III and VI) of the intercuspal distance. Teeth were weighed (digital balance accurate to 0.001 g) before and after preparation to record tooth substance mass lost during cavity preparation. The prepared teeth were submitted to occlusal loading to determine their fracture strength using...... percent mean mass loss (13.91%) than composite resin preparations with the same width (10.02%). 1/2-inlay cavities had 21.34% of mass loss versus 16.19% for the 1/2-composite resin cavities. Fracture strength means (in kgf) were: GI = 187.65; GII = 143.62; GIII = 74.10; GIV = 164.22; GV = 101.92; GVI = 50...

  4. An Analysis of the Symptomatic Domains Most Relevant to Charcot Marie Tooth Neuropathy (CMT) Patients

    Science.gov (United States)

    2015-04-28

    Charcot Marie Tooth Disease (CMT); Hereditary Sensory and Motor Neuropathy; Nerve Compression Syndromes; Tooth Diseases; Congenital Abnormalities; Genetic Diseases, Inborn; Heredodegenerative Disorders, Nervous System

  5. Tooth regeneration: challenges and opportunities for biomedical material research.

    Science.gov (United States)

    Du, Chang; Moradian-Oldak, Janet

    2006-03-01

    Tooth regeneration presents many challenges to researchers in the fields of biology, medicine and material science. This review considers the opportunities for biomedical material research to contribute to this multidisciplinary endeavor. We present short summaries and an overview on the collective knowledge of tooth developmental biology, advances in stem-cell research, and progress in the understanding of the tooth biomineralization principles as they provide the foundation for developing strategies for reparative and regenerative medicine. We emphasize that various biomaterials developed via biomimetic strategies have great potential for tooth tissue engineering and regeneration applications. The current practices in tooth tissue engineering approaches and applications of biomimetic carriers or scaffolds are also discussed. PMID:18458377

  6. Tooth agenesis: from molecular genetics to molecular dentistry.

    Science.gov (United States)

    Matalova, E; Fleischmannova, J; Sharpe, P T; Tucker, A S

    2008-07-01

    Tooth agenesis may originate from either genetic or environmental factors. Genetically determined hypodontic disorders appear as isolated features or as part of a syndrome. Msx1, Pax9, and Axin2 are involved in non-syndromic hypodontia, while genes such as Shh, Pitx2, Irf6, and p63 are considered to participate in syndromic genetic disorders, which include tooth agenesis. In dentistry, artificial tooth implants represent a common solution to tooth loss problems; however, molecular dentistry offers promising solutions for the future. In this paper, the genetic and molecular bases of non-syndromic and syndromic hypodontia are reviewed, and the advantages and disadvantages of tissue engineering in the clinical treatment of tooth agenesis are discussed. PMID:18573979

  7. The 4th international comparison on EPR dosimetry with tooth enamel

    Energy Technology Data Exchange (ETDEWEB)

    Fattibene, P., E-mail: paola.fattibene@iss.it [Istituto Superiore di Sanita, Department of Technology and Health, Viale Regina Elena 299, I-00162 Rome (Italy); Wieser, A. [Helmholtz Zentrum Muenchen, Neuherberg D-85764 (Germany); Adolfsson, E. [Linkoeping University, SE-58185 Linkoeping (Sweden); Benevides, L.A. [Naval Dosimetry Center, Bethesda MD 20889-5600 (United States); Brai, M. [University of Palermo, I-90128 Palermo (Italy); Callens, F. [Ghent University, B-9000 Gent (Belgium); Chumak, V. [Research Center for Radiation Medicine AMS, 04050 Kiev (Ukraine); Ciesielski, B. [Medical University of Gdansk, 80-211 Gdansk (Poland); Della Monaca, S. [Istituto Superiore di Sanita, Department of Technology and Health, Viale Regina Elena 299, I-00162 Rome (Italy); Regina Elena Institute, I-00144 Rome (Italy); Emerich, K. [Medical University of Gdansk, 80-211 Gdansk (Poland); Department of Paediatric Dentistry, 80-208 Gdansk (Poland); Gustafsson, H. [Linkoeping University, SE-58185 Linkoeping (Sweden); Hirai, Y. [Radiation Effects Research Foundation, Minami-ku, Hiroshima 732-0815 (Japan); Hoshi, M. [Hiroshima University, Minami-ku, Hiroshima 734-8553 (Japan); Israelsson, A. [Linkoeping University, SE-58185 Linkoeping (Sweden); Ivannikov, A. [Medical Radiological Research Center, Obninsk, Kaluga region (Russian Federation); Ivanov, D. [Institute of Metal Physics, Yekaterinburg 620041 (Russian Federation); Kaminska, J. [Medical University of Gdansk, 80-211 Gdansk (Poland); Ke, Wu [Beijing Institute of Radiation Medicine, Beijing 100850 (China); Lund, E. [Linkoeping University, SE-58185 Linkoeping (Sweden); Marrale, M. [University of Palermo, I-90128 Palermo (Italy)

    2011-09-15

    This paper presents the results of the 4th International Comparison of in vitro electron paramagnetic resonance dosimetry with tooth enamel, where the performance parameters of tooth enamel dosimetry methods were compared among sixteen laboratories from all over the world. The participating laboratories were asked to determine a calibration curve with a set of tooth enamel powder samples provided by the organizers. Nine molar teeth extracted following medical indication from German donors and collected between 1997 and 2007 were prepared and irradiated at the Helmholtz Zentrum Muenchen. Five out of six samples were irradiated at 0.1, 0.2, 0.5, 1.0 and 1.5 Gy air kerma; and one unirradiated sample was kept as control. The doses delivered to the individual samples were unknown to the participants, who were asked to measure each sample nine times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated by the organizers on the basis of the calibration-curve parameters obtained at every laboratory. For calibration curves obtained by measuring every calibration sample three times, the mean value of the detection limit was 205 mGy, ranging from 56 to 649 mGy. The participants were also invited to provide the signal response and the nominal dose of their current dose calibration curve (wherever available), the critical dose and detection limit of which were also calculated by the organizers.

  8. Minimally Invasive Techniques to Accelerate the Orthodontic Tooth Movement: A Systematic Review of Animal Studies

    Science.gov (United States)

    Qamruddin, Irfan; Alam, Mohammad Khursheed; Khamis, Mohd Fadhli; Husein, Adam

    2015-01-01

    Objective. To evaluate various noninvasive and minimally invasive procedures for the enhancement of orthodontic tooth movement in animals. Materials and Methods. Literature was searched using NCBI (PubMed, PubMed Central, and PubMed Health), MedPilot (Medline, Catalogue ZB MED, Catalogue Medicine Health, and Excerpta Medica Database (EMBASE)), and Google Scholar from January 2009 till 31 December 2014. We included original articles related to noninvasive and minimally invasive procedures to enhance orthodontic tooth movement in animals. Extraction of data and quality assessments were carried out by two observers independently. Results. The total number of hits was 9195 out of which just 11 fulfilled the inclusion criteria. Nine articles were good and 5 articles were moderate in quality. Low level laser therapy (LLLT) was among the most common noninvasive techniques whereas flapless corticision using various instruments was among the commonest minimally invasive procedures to enhance velocity of tooth movement. Conclusions. LLLT, low intensity pulsed ultrasound (LIPUS), mechanical vibration, and flapless corticision are emerging noninvasive and minimally invasive techniques which need further researches to establish protocols to use them clinically with conviction. PMID:26881201

  9. Isolation of epithelial cells from tooth brush and gender identification by amplification of SRY gene

    Directory of Open Access Journals (Sweden)

    A Vikram Simha Reddy

    2011-01-01

    Full Text Available Introduction: This study determines the importance of tooth brush from which DNA can be isolated and used for sex determination in forensic analysis. Materials and Methods: A total of 30 samples were collected and stored at room temperature for different periods of time interval. The epithelial cells adhered to the bristles of tooth brush were collected and genomic DNA was extracted and quantified using Nanodrop 1000 spectrophotometer. Results: Gender identification was done by amplification of sex determining region on Y chromosome (SRY gene using real-time polymerase chain reaction and minimal amount of DNA (in pico grams with 100% sensitivity and 73.3% specificity, i.e., all male samples showed positive results and out of 15 female samples 4 showed false positive results, i.e wrongly identified as males. Conclusion: With this study, we conclude that PCR is a valuable and sensitive procedure where minute contamination may cause alteration in the result, i.e, 4 females showed false positive result. Minute amount of DNA in picograms, which was collected at different intervals is enough for amplification of SRY gene and tooth brush can be used as one of the very valuable sources of gender identification.

  10. Delayed tooth replantation: MTA as root canal filling

    Scientific Electronic Library Online (English)

    Sônia Regina, PANZARINI; Celso Koogi, SONODA; Célia Tomiko Matida Hamata, SAITO; Elizane Ferreira, HAMANAKA; Wilson Roberto, POI.

    Full Text Available MTA has been investigated as a root-end filling material. Its mechanism of action has some similarities to that of Ca(OH)2. The purpose of this study was to evaluate the repair process taking place in the delayed replantation of monkey teeth using calcium hydroxide and MTA as root canal filling mate [...] rials. Five monkeys had their lateral incisors extracted and bench-dried for 60 minutes. After root canal preparation, the teeth were assigned to two groups according to root canal filling material: I, calcium hydroxide; and II, MTA. The same treatment sequence was followed for both groups: coronal seal, periodontal ligament removal, immersion of the tooth in 2% acidulated-phosphate sodium fluoride, irrigation of the socket with saline and replantation. Both groups exhibited replacement resorption, areas of ankylosis and absence of inflammatory root resorption. Statistically similar results (p > 0.05) were observed for both groups regarding replacement root resorption, but the groups differed significantly (p

  11. Collagen analysis in human tooth germ papillae

    Scientific Electronic Library Online (English)

    Ivete Jorge, Abrahão; Manoela Domingues, Martins; Emílio, Katayama; João Humberto, Antoniazzi; Angelo, Segmentilli; Márcia Martins, Marques.

    Full Text Available A matriz extracelular (MEC) tem um papel importante na regulação do crescimento e na diferenciação e organização dos tecidos. Com base nestes aspectos o objetivo do deste estudo foi analisar o colágeno, maior componente orgânico da MEC da polpa dentária, na papila de germes dentários humanos, em dif [...] erentes fases do desenvolvimento. Foram obtidos fragmentos de maxilas e mandíbulas de 9 fetos humanos com 10 a 22 semanas de vida intra-uterina, dos quais foram analisados 16 germes dentários (1 em estágio de capuz, 8 em estágio de campânula precoce e 7 em estágio de campânula tardia). Secções histológicas seriadas foram coradas com hematoxilina e eosina, tricrômico de Masson e técnica de coloração do picrosirius. Ambos os tipos de colágeno na papila dentária foram somente detectados pela técnica de coloração do picrosirius usando microscopia de luz polarizada. Colágeno tipo III foi detectado em todas as amostras. Colágeno tipo I estava presente em áreas focais da papila dental em algumas amostras. Concluiu-se que o colágeno tipo III mostrou-se um componente regular da papila de germes dentários humanos, enquanto o colágeno tipo I esteve presente em quantidade significativamente menor. Abstract in english The extracellular matrix (ECM) performs a very important role in growth regulation and tissue differentiation and organization. In view of this, the purpose of this study was to analyze the collagen, the major organic component of dental pulp ECM, in papillae of human tooth germs in different develo [...] pmental phases. The maxillas and mandibles of 9 human fetuses ranging from 10 to 22 weeks of intrauterine life were removed and 16 tooth germs (1 in the cap stage, 8 in the early bell stage and 7 in the late bell stage) were obtained. The pieces were processed for histological analysis and stained with hematoxylin-eosin, Masson's Trichrome and picrosirius staining technique. Both types of collagen in the dental papilla were only detected by the picrosirius staining technique under polarized light microscopy. Type III collagen was detected in all specimens. Type I collagen was present in focal areas of the dental papilla only in some specimens. In conclusion, the findings of this study showed that type III collagen is a regular component of the papillae of human tooth germs whereas type I collagen is present in a significantly lesser amount.

  12. Estimation of age based on tooth cementum annulations using three different microscopic methods

    Directory of Open Access Journals (Sweden)

    Siddharth Pundir

    2009-01-01

    Full Text Available Background: The hard tissues of human dentition are able to resist decay and degradation long after other tissues are lost. This resistance to decay has made teeth useful for calculation of age at death of an individual. Recent research indicates that tooth cementum annulations (TCA may be used more reliably than other morphological or histological traits of the adult skeleton for estimation of age. Objectives: The purpose of this study was to examine the correlation between age and the number of incremental lines in human dental cementum and to ascertain which, among three different forms of microscopy (light, polarized, phase-contrast was the most reliable method of studying cementum. Materials and Methods: The study sample consisted of 40 teeth that had been extracted from patients ranging in age from 20?70 years. Longitudinal ground sections of each tooth were prepared and examined under light microscopy, polarized microscopy, and phase-contrast microscopy. The images were magnified on a computer and the cemental lines were counted with the help of Image Analysis Pro 6.0 software. Only the dark lines were counted. Results: There was a strong positive correlation between the estimated age and calculated age when phase-contrast microscopy was used; the correlation was less for light and polarized microscopy. Our results suggest that there is no significant influence of sex, age, periodontal disease, or tooth type on age estimation by the TCA method. This suggests that the accuracy and repeatability of the method is not dependent on tooth type or location and that this method can be applied to the general population regardless of systemic or periodontal health. Conclusion: With this study we conclude that among the methods of counting incremental lines by various types of microscopy phase-contrast microscopy improves the accuracy of age estimation and may serve as a valuable aid in forensic identification.

  13. Effects of Ion-Releasing Tooth-Coating Material on Demineralization of Bovine Tooth Enamel

    OpenAIRE

    Koji Kawasaki; Masaki Kambara

    2014-01-01

    We compared the effect of a novel ion-releasing tooth-coating material that contained S-PRG (surface-reaction type prereacted glass-ionomer) filler to that of non-S-PRG filler and nail varnish on the demineralization of bovine enamel subsurface lesions. The demineralization process of bovine enamel was examined using quantitative light-induced fluorescence (QLF) and electron probe microanalyzer (EPMA) measurement. Ion concentrations in demineralizing solution were measured using inductively c...

  14. Molecular phylogenetic inference from saber-toothed cat fossils of Rancho La Brea.

    OpenAIRE

    Janczewski, D N; Yuhki, N; Gilbert, D A; Jefferson, G T; O'Brien, S. J.

    1992-01-01

    A method for the successful extraction of sequestered cellular DNA from 14,000-year-old fossil bones was developed and applied to asphalt-preserved specimens of the extinct saber-toothed cat, Smilodon fatalis. Two distinct gene segments, the mitochondrial gene for 12S rRNA and nuclear FLA-I (the feline class I major histocompatibility complex gene), from three different individual fossil specimens were cloned and sequenced after PCR amplification. Comparison of fossil-derived DNA sequences to...

  15. Unusual intraosseous transmigration of impacted tooth

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Santosh; Urala, Arun Srinivas; Kamath, Abhay Taranath; Jayaswal, Priyanka; Valiathan, Ashima [Manipal College of Dental Sciences, Manipal (India)

    2012-03-15

    Transmigration of an impacted tooth through the symphyseal suture is a rare and special developmental anomaly of unknown etiology that is unique to the mandibular canine. Maxillary canine transmigration is even rarer. Transmigrated canines are particularly significant due to the aesthetic and functional importance. A maxillary lateral incisor crossing the mid-palatal suture has never been reported in the literature. The aim of this report is to present the first case of simultaneous transmigration of a lateral incisor and canine in the maxilla. The paper also reports four unusual cases of unilateral canine transmigration in the maxilla and mandible and successful eruption of one of the transmigrated mandibular canines following orthodontic traction. Etiology of transmigration and its clinical considerations are also discussed.

  16. Abrasive Wear of Digger Tooth Steel

    Directory of Open Access Journals (Sweden)

    Hussein Sarhan sarhan, Nofal Al-Araji, Rateb Issa , Mohammad Alia

    2011-08-01

    Full Text Available The influence of silicon carbide SiC abrasive particles of 20, 30, 40, 50 and60?m size on carburized digger tooth steel was studied. Four types of steel, withdifferent hardness, were tested at two constant linear sliding speeds and undervarious loads of 10, 20, 30, 40 and 50N. Tests were carried out for sliding time of0.5, 1.0, 1.5, 2.0 and 2.5min. Experimental results showed that there wasconsistent reduction in abrasive wear as the hardness of the materials wasincreased. It was found that wear increased with the increase of applied load,linear sliding speed and sliding time. Also, it was noticed that the wear increasedwith increase in abrasive particle size, and the most effective size was 40 ?m.SEM observations of the worm surface showed that the cutting and ploughingwere the dominant abrasive wear mechanisms.

  17. Anomalies of tooth formation in hypohidrotic ectodermal dysplasia.

    DEFF Research Database (Denmark)

    Lexner, Michala O; Bardow, Allan

    2007-01-01

    OBJECTIVE: The X-linked hypohidrotic ectodermal dysplasia (HED) is the most common type of ectodermal dysplasia. The clinical identification of possible heterozygous females can be difficult because of the varying degrees of clinical signs caused by X-chromosome inactivation. This study is the first to elaborate on anomalies of tooth formation found in a group of hemizygous males and heterozygous females with known ED1 mutations. These tooth anomalies may be used as dental biomarkers for heterozygous females, enabling an earlier diagnosis, and therefore, better treatment and genetic counselling. METHODS: Anomalies of tooth formation were examined using panoramic radiographs, dental casts and oral photographs in hemizygous males and heterozygous females who were identified by molecular genetic analysis. The results were compared to existing controls and normative data. RESULTS: All affected males had multiple missing permanent teeth and tooth malformations. The heterozygous females had a significantly higher frequency of agenesis of permanent teeth compared to normative data. The heterozygous females had an increased prevalence of tooth malformations and reduced tooth size, especially in the mesiodistal dimension. CONCLUSIONS: We conclude that observed anomalies of tooth formation may be used as dental biomarkers in the clinical identification of potentially heterozygous females. Udgivelsesdato: 2007-Jan

  18. Tooth resorption in the Swedish Eurasion lynx (Lynx lynx).

    Science.gov (United States)

    Pettersson, Ann

    2010-01-01

    The etiology of tooth resorption in the domestic cat remains unknown. The high prevalence and progressive nature of the disease complicates defining healthy control groups. In order to evaluate the possible influence of various life style changes on the prevalence of tooth resorption, healthy control groups are a prerequisite. This paper presents a prevalence study for tooth resorption in a free-ranging wild felidae population. Skulls from 46 free-ranging Eurasian lynx (Lynx lynx) were examined. The age of the animals had previously been estimated based on cementum annuli in the maxillary right canine tooth. The dental examination included both dental probing and radiographic imaging. Complicated fractures of the canine teeth were found in 9/46 (19.5%) skulls. In one fractured canine, apical root resorption and periapical lucency was detected. The root resorption was attributed to inflammatory resorption as a consequence of the initial dental trauma and necrotic pulp. No signs of tooth resorption were found in the remaining teeth. Supernumerary roots were detected in 18/46 skulls (39.1 %). Supernumerary "peg" teeth caudal to the mandibular first molar tooth were detected in 6/46 (13.0%) skulls. Although further studies on dental ultra-structure are needed, the Swedish Eurasian lynx may, in the future, be useful as a healthy comparative model for studies on the etiopathogenesis of tooth resorption in the domestic cat. PMID:21322429

  19. Mesiodistal tooth angulation to segmental occlusal plane in panoramic radiography

    International Nuclear Information System (INIS)

    To evaluate the stability of the segmental occlusal plane and anatomical line as the reference line for measuring the mesiodistal tooth angulation in panoramic radiography and to determine the mean angle and the range of the mesiodistal tooth angulation in Korean population with normal occlusions. Twenty nine subjects (15 men, 14 women) with normal occlusion were selected. A total of 29 panoramic radiograms were taken at normal head position and then 10 images of 5 subjects selected were repeatedly taken with repositioning 2 times at each of the head down (V-shaped occlusion) and up (horizontal occulsion) for evaluation of stability of adopted reference lines by using PM2002CC (Planmeca, Finland). The images were traced with adoption of two test reference lines and the long axes of the teeth. The mesial angles formed by each reference line and the long axes of the teeth were measured and analyzed. With anatomical reference line, the mesiodistal tooth angulations of the molars showed the significant difference by over 5 degree between the normal and each changed head position. With segmented occlusal reference line, deviations of mesiodistal tooth angulations by the two changed head positions were less than 1 degree. The means, standard deviations, and maximum and minimum values of mesiodistal tooth angulations to segmental occlusal reference line on panoramic radiography were determined. It would appear that mesiodistal tooth angulations to segmental occlusal plane as reference line in panograms are predictable as standards of normal occlusion and useful for evaluation of tooth arrangement between adjacent teeth.

  20. Mesiodistal tooth angulation to segmental occlusal plane in panoramic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Duk; Kim, Jin Soo; You, Choong Hyun [Chosun University College of Medicine, Kwangju (Korea, Republic of)

    2005-03-15

    To evaluate the stability of the segmental occlusal plane and anatomical line as the reference line for measuring the mesiodistal tooth angulation in panoramic radiography and to determine the mean angle and the range of the mesiodistal tooth angulation in Korean population with normal occlusions. Twenty nine subjects (15 men, 14 women) with normal occlusion were selected. A total of 29 panoramic radiograms were taken at normal head position and then 10 images of 5 subjects selected were repeatedly taken with repositioning 2 times at each of the head down (V-shaped occlusion) and up (horizontal occulsion) for evaluation of stability of adopted reference lines by using PM2002CC (Planmeca, Finland). The images were traced with adoption of two test reference lines and the long axes of the teeth. The mesial angles formed by each reference line and the long axes of the teeth were measured and analyzed. With anatomical reference line, the mesiodistal tooth angulations of the molars showed the significant difference by over 5 degree between the normal and each changed head position. With segmented occlusal reference line, deviations of mesiodistal tooth angulations by the two changed head positions were less than 1 degree. The means, standard deviations, and maximum and minimum values of mesiodistal tooth angulations to segmental occlusal reference line on panoramic radiography were determined. It would appear that mesiodistal tooth angulations to segmental occlusal plane as reference line in panograms are predictable as standards of normal occlusion and useful for evaluation of tooth arrangement between adjacent teeth.

  1. ATTITUDE AND KNOWLEDGE TOWARDS TOOTH AVULSION AMONG SPORTS TEACHERS

    Directory of Open Access Journals (Sweden)

    FARHEEN USTAD

    2013-05-01

    Full Text Available Background: Tooth avulsion is one of the commonest types of physical sport injury. Themanagement of these cases is critical in order to prevent complete loss of tooth and its subsequentconsequences. The prognosis of such avulsed tooth depends on prompt treatment. The emergencymanagement of such avulsed tooth is made by the sports teacher who is present at the sports ground. Thefirst–aid knowledge about tooth avulsion is must for the sports teacher. Aim: The objective of the presentstudy was to evaluate the knowledge about management of tooth avulsion among sports teachers inAhmednagar District. Methods: A sample of 60 sports teachers were interviewed from different schools.The data was collected using a self administered questionnaire containing seven items which wasdistributed among the sports teacher from different schools. Results: we found that 90% of the sportsteachers were not having the first-aid knowledge about the emergency management of avulsed tooth andthe benefit of timely care. This demands an effort to properly educate sports teachers about first-aidmanagement and consequently change their attitude towards dental trauma.

  2. Tooth loss prevalence among cardiac males and females

    International Nuclear Information System (INIS)

    Objective of study was to observe differences of tooth loss prevalence in males and females with Cardiac diseases Poor oral health, tooth loss and periodontal diseases have been reported to be associated with coronary heart diseases. Studies report gender differences in prevalence of cardiac diseases and tooth loss. This paper presents gender differences of tooth loss in cardiac patients of a cardiac hospital of Lahore, Pakistan. Methodology: Age matched Cardiac males and females attending OPD of the Punjab Institute of Cardiology (PIC), Lahore were included in the study. Personal and health-related information were questioned and noted. Oral examination was performed for recording of missing teeth. 1200 CHD study subjects with age-range of 30 to 80 years were enrolled for study. 1045 age matched, 766 (73.30%) males and 279 (26.70%) females were examined for tooth loss. 852 (81.53%) genders had at least one tooth missing. 599 (78.19) males and 253 (90.68%) females were observed with mean tooth loss of 7.5 (SD 8.720) and 11.15 (SD 10.375)respectively statistical association among them was also significant (P= 0.000) with OR of 2.339. More subjects (76.29%) showed a loss of 1-15 teeth that I was also significant among males and females. Tooth loss was significant in age groups of 41-50 years (P=0.001) and 51-60 years (P=0.000) Gender differences of tooth loss prevalence among CHD Subjects were significant with more risk for males as compared to females. (author)

  3. Burried broken extraction instrument fragment

    OpenAIRE

    Balaji, S. M.

    2013-01-01

    Despite adequate effort to perform tooth removal carefully, some accidents may happen when defective instruments are unknowingly used. This article reports of a non-symptomatic case of a retained fractured dental elevator tip during an uneventful extraction a decade earlier. Patient was not aware till routine radiographic examination revealed its presence. Use of three dimensional imaging techniques in this case is highlighted. Rarely, instruments breakage may occur during surgical procedures...

  4. Study on differences of radiosensitivity of human tooth enamel

    International Nuclear Information System (INIS)

    To study differences of radiosensitivity of human tooth enamel, 84 tooth enamel samples from 5 subjects were separated, and irradiated with radiation dose of 5 Gy from 60Co ? rays. After irradiation each sample was measured by ESR technique. Experimental results indicate that some difference in radiosensitivity exists for teeth from each subject (coefficients of variation of each subject range from 9.3% to 14.0%). Nevertheless, the mean values for all teeth of each subject among 5 subjects agree within the range of 325.77 to 386.80. It shows that the radiosensitivity of tooth enamel is basically uniform

  5. A local intercomparison study of ESR dosimetry using tooth enamel

    International Nuclear Information System (INIS)

    Using electron spin resonance (ESR), tooth enamel is a possible dosimeter in case of a radiation accident. To check the present status of this technique, we conducted a local intercomparison study. We irradiated several samples of tooth enamel with a 60Co source. Three institutes in Belgium and The Netherlands recorded the ESR signal of the samples. The results of the measurements and the methods used are compared. It is concluded that ESR on tooth enamel can be a useful technique in accident dosimetry, provided further research is done. (author)

  6. The effect of nano-hydroxyappatite solution on the permanent tooth remineralization following exposure to soft beer (in situ

    Directory of Open Access Journals (Sweden)

    Haghgoo Roza

    2015-01-01

    Full Text Available   Background and Aims: The main cause of erosion is acid exposure . Side effects of erosion necessitate therapeutic agents’ uses. The aim of this study was to investigate the effects of nano- hydroxy apatite in tooth remineralization following exposure to soft beer.   Materials and Methods: This in vitro experimental study was conducted on 18 human impacted third molars that had been surgically extracted. The microhardness of specimens was measured. Then teeth were exposed to soft beer and their secondary microhardness was measured. The teeth were divided into 2 groups (water and nano-hydroxy apatite solution and were placed on 9 orthodontics appliances and delivered to 9 volunteers. These volunteers placed the tooth on one side in water for 5 minutes and the tooth in opposite side in nano-hydroxyapatite solution. This application was repeated 6 times a day for 10 days. The microhardness of teeth was measured again. Data were analyzed using Paired T-test.   Results: The tooth enamel microhardness reduced after exposure to soft beer significantly (P=0.04. The microhardness of 9 teeth after being in water showed significant changes (P=0.012. The microhardness of 9 teeth significantly changed after exposure to nano -hydroxyapatite solution (P=0.001 .   Conclusion: Based on the results of this study, 10% solution of nano- hydroxy appatite could restore the erosive lesions .

  7. Impact Damage Evaluation Method of Friction Disc Based on High-Speed Photography and Tooth-Root Stress Coupling

    Science.gov (United States)

    Yin, L.; Shao, Y. M.; Liu, J.; Zheng, H. L.

    2015-07-01

    The stability of friction disc could be seriously affected by the tooth surface damage due to poor working conditions of the wet multi-disc brake in heavy trucks. There are few current works focused on the damage of the friction disc caused by torsion-vibration impacts. Hence, it is necessary to investigate its damage mechanisms and evaluation methods. In this paper, a damage mechanism description and evaluation method of a friction disc based on the high-speed photography and tooth-root stress coupling is proposed. According to the HighSpeed Photography, the collision process between the friction disc and hub is recorded, which can be used to determine the contact position and deformation. Combined with the strain-stress data obtained by the strain gauge at the place of the tooth-root, the impact force and property are studied. In order to obtain the evaluation method, the damage surface morphology data of the friction disc extracted by 3D Super Depth Digital Microscope (VH-Z100R) is compared with the impact force and property. The quantitative relationships between the amount of deformation and collision number are obtained using a fitting analysis method. The experimental results show that the damage of the friction disc can be evaluated by the proposed impact damage evaluation method based on the high-speed photography and tooth-root stress coupling.

  8. Molar tooth sign − looking beyond the obvious

    Directory of Open Access Journals (Sweden)

    Nasreen Mahomed

    2013-08-01

    Full Text Available The molar tooth sign was initially identified in Joubert syndrome, named after Marie Joubert who first described it in 1968 as a rare autosomal recessive disorder characterised by the neuroradiological hallmark of the molar tooth sign caused by cerebellar vermian hypoplasia. Subsequently, it emerged that the molar tooth sign encompasses many syndromes that are now grouped together and termed Joubert syndrome and related disorders (JSRDs. Knowledge of the newer classification system and the subtypes is important and helps to direct and interpret imaging studies based on clinical signs so as to avoid delay in diagnosis of the hepatic oculorenal and renal subtypes of JSRDs in patients in whom the molar tooth sign is identified on brain MRI.

  9. [Nasal cavity supernumerary tooth and maxillary sinusitis: one case reported].

    Science.gov (United States)

    Guo, Guangliang; Hu, Limin; Lu, Yuan

    2015-08-01

    Supernumerary tooth is a rare case. This report described a case of nasal cavity supernumerary tooth association with maxillary sinusitis. A 28-year-old male patient reported with the chief complaint of nasal obstruction, headache and purulent secretion for the past three months. Clinic examination and CT examination showed that there was a supernumerary tooth in the right nasal bottom, and maxillary sinus was infected in the same side. This patient was performed supernumerary tooth removing and given antibiotics for 3 days. Ten days after the operation, there was no clinical symptoms, and nasal bottom mucosa was normal. After 3 months of follow-up, reexamination of coronal CT scan appeared normal. PMID:26665468

  10. Two mathematical models for generation of crowned tooth surface.

    Science.gov (United States)

    Kelemen, Laszlo; Szente, Jozsef

    2014-01-01

    Gear couplings are mechanical components to connect shaft ends and eliminate the misalignments. The most important element of the gear coupling is the hub which is an external gear having crowned teeth. The crowned teeth on the hub are typically produced by hobbing. The resulting tooth surface depends on several parameters. It is influenced by the size of the hob and the feed. In this paper two mathematical models of the crowned tooth surface are introduced for the generation of the idealized tooth surfaces. These are the profile-shifting and the two-parameter enveloping methods. Our aim is to compare the obtained crowned tooth profiles for the two examined models and to investigate the results. From our numerical results, it was found that the two profiles show indistinguishable differences. PMID:24578653

  11. Diaphragm weakness in Charcot-Marie-Tooth disease.

    OpenAIRE

    Laroche, C M; Carroll, N; Moxham, J.; Stanley, N N; Evans, R. J.; Green, M.

    1988-01-01

    Two patients are described with Charcot-Marie-Tooth disease and chronic peripheral neuropathy. Both had dyspnoea, orthopnoea, and evidence of severe diaphragm weakness. Expiratory muscle function was well preserved and abnormalities of gas exchange during sleep were only minor.

  12. Enhanced Prediction of Gear Tooth Surface Fatigue Life Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Sentient will develop an enhanced prediction of gear tooth surface fatigue life with rigorous analysis of the tribological phenomena that contribute to pitting...

  13. Geographic Variations in the EPR Spectrum of Tooth Enamel

    International Nuclear Information System (INIS)

    The presence of stable radiation-induced radicals in the mineral component of tooth enamel allows use of this material as a biological dosemeter. Estimation of the dose absorbed in tooth enamel can be done by EPR. Generally, for the purpose of dose reconstruction, the EPR spectrum of tooth enamel is interpreted in terms of two main components. The first is a broad background signal often called the native signal centered at a g value of 2.0045. The origin of this signal is not precisely known. The second main component in the tooth enamel spectrum is purely radiation induced and can be used for retrospective dosimetry. Internal structure of the native signal and variations of its amplitude and linewidth were investigated for the samples prepared from modern teeth obtained from different geographic locations (USA and Russia). Possible reasons for the variations observed are discussed as are the potential effects of the variations on the reliability of dose estimation. (author)

  14. Analysis of absorbed dose to tooth enamel for ESR dosimetry

    International Nuclear Information System (INIS)

    Absorbed dose to tooth enamel was quantitatively correlated to organ doses by Monte Carlo calculations using the Electron Gamma Shower Code Version 4 for the Electron Spin Resonance (ESR) dosimetry using teeth. A region for teeth was newly added to a mathematical human model. Kerma coefficients for whole tooth and enamel part were prepared to estimate the dose to tooth enamel. Experiments were also carried out with a physical head phantom, which is made of tissue equivalent materials. Tooth samples and thermo-luminescence dosimeters (TLDs) of CaSO4 crystal were set at the teeth position in the head phantom. Addition Monte Carlo calculations were performed to verify the results of the experiments by using a Voxel-type phantom reconstructed from computed tomographic (CT) images of the physical phantom. The obtained data are to be useful for retrospective dose assessments in past radiation events by the ESR dosimetry with teeth. (author)

  15. Seal Out Tooth Decay: A Fact Sheet for Parents

    Science.gov (United States)

    ... Institute of Dental and Craniofacial Research Seal Out Tooth Decay A Fact Sheet for Parents What are dental sealants? Sealants are thin, plastic coatings painted on the chewing surfaces of the back ...

  16. The Influence of Age on Tooth Root Colour Changes

    OpenAIRE

    Laškarin, Mirko; Brki?, Hrvoje; Pichler, Goran; Bukovi?, Dino

    2006-01-01

    The purpose of this study was to examine the relationship between tooth root colour and age, and its possible application in age assessment. In this research altogether 100 tooth roots have been analysed. All teeth, that is their roots, were digitally recorded and the colorimetric treatment was made using Adobe Photoshop 7.0 computer program. Studies have shown no significant difference between RGB values analysed on the whole root surface or only on its central part, with certain...

  17. Anomalies of tooth formation in hypohidrotic ectodermal dysplasia

    DEFF Research Database (Denmark)

    Lexner, Michala Oron; Bardow, Allan; Hertz, Jens Michael; Nielsen, Lis; Kreiborg, Sven

    2007-01-01

    The X-linked hypohidrotic ectodermal dysplasia (HED) is the most common type of ectodermal dysplasia. The clinical identification of possible heterozygous females can be difficult because of the varying degrees of clinical signs caused by X-chromosome inactivation. This study is the first to elaborate on anomalies of tooth formation found in a group of hemizygous males and heterozygous females with known ED1 mutations. These tooth anomalies may be used as dental biomarkers for heterozygous femal...

  18. Regional odontodysplasia: A case of progressive tooth development

    OpenAIRE

    Ganguly, R.; Ramesh, A

    2012-01-01

    Regional odontodysplasia (RO) is considered a relatively rare dental anomaly despite increasing numbers of case reports in recent years. It usually presents as a localized anomaly in tooth development affecting a few adjacent teeth in a single maxillary or mandibular quadrant. The purpose of this paper is to describe an uncommon case of regional odotodysplasia involving noncontiguous mandibular teeth, crossing the midline in a male patient, and showing progressive normalization of tooth anato...

  19. Three-dimensional analysis of mandibular growth and tooth eruption

    DEFF Research Database (Denmark)

    Krarup, S.; Darvann, Tron Andre; Larsen, Per; Marsh, J.L.; Kreiborg, S.

    2005-01-01

    Normal and abnormal jaw growth and tooth eruption are topics of great importance for several dental and medical disciplines. Thus far, clinical studies on these topics have used two-dimensional (2D) radiographic techniques. The purpose of the present study was to analyse normal mandibular growth and tooth eruption in three dimensions based on computer tomography (CT) scans, extending the principles of mandibular growth analysis proposed by Bjork in 1969 from two to three dimensions. As longitudi...

  20. Stem cell-based biological tooth repair and regeneration

    OpenAIRE

    Volponi, Ana Angelova; Pang, Yvonne; Sharpe, Paul T.

    2010-01-01

    Teeth exhibit limited repair in response to damage, and dental pulp stem cells probably provide a source of cells to replace those damaged and to facilitate repair. Stem cells in other parts of the tooth, such as the periodontal ligament and growing roots, play more dynamic roles in tooth function and development. Dental stem cells can be obtained with ease, making them an attractive source of autologous stem cells for use in restoring vital pulp tissue removed because of infection, in regene...

  1. Anomalies of tooth formation in hypohidrotic ectodermal dysplasia

    DEFF Research Database (Denmark)

    Lexner, Michala O; Bardow, Allan; Hertz, Jens Michael; Nielsen, Lis A; Kreiborg, Sven

    2007-01-01

    OBJECTIVE: The X-linked hypohidrotic ectodermal dysplasia (HED) is the most common type of ectodermal dysplasia. The clinical identification of possible heterozygous females can be difficult because of the varying degrees of clinical signs caused by X-chromosome inactivation. This study is the first to elaborate on anomalies of tooth formation found in a group of hemizygous males and heterozygous females with known ED1 mutations. These tooth anomalies may be used as dental biomarkers for heteroz...

  2. Ridge Alterations Post-extraction in the Esthetic Zone: A 3D Analysis with CBCT

    OpenAIRE

    Chappuis, V.; Engel, O.; M. Reyes; K. Shahim; Nolte, L. -P.; Buser, D

    2013-01-01

    Dimensional alterations of the facial bone wall following tooth extractions in the esthetic zone have a profound effect on treatment outcomes. This prospective study in 39 patients is the first to investigate three-dimensional (3D) alterations of facial bone in the esthetic zone during the initial 8 wks following flapless tooth extraction. A novel 3D analysis was carried out, based on 2 consecutive cone beam computed tomographies (CBCTs). A risk zone for significant bone resorption was identi...

  3. Corticotomy-/osteotomy-assisted tooth movement microCTs differ.

    Science.gov (United States)

    Lee, W; Karapetyan, G; Moats, R; Yamashita, D-D; Moon, H-B; Ferguson, D J; Yen, S

    2008-09-01

    Corticotomy-assisted and osteotomy-assisted tooth movement involves surgical incisions through the alveolar bone. To ascertain whether teeth move by distraction osteogenesis or by regional accelerated phenomenon (RAP), we randomly assigned 30 Sprague-Dawley rats to one of 5 experimental groups: corticotomy alone, corticotomy-assisted tooth movement, osteotomy alone, osteotomy-assisted tooth movement, or tooth movement alone. Each animal was imaged by microtomography immediately after surgery, after 21 days, and after 2 months. After 21 days, regional accelerated phenomenon was observed in the alveolar bone of the corticotomy-treated animals and distraction osteogenesis in the osteotomy-assisted tooth movement animals. Pixel count data were analyzed by nested ANOVA for 5 experimental groups, split-mouth controls, 3 levels along the root, and 5 sites per level. The most demineralized sites after 21 days differed for each of the experimental groups. Our study indicates that osteotomies and corticotomies induce different alveolar bone reactions, which can be exploited for tooth movement. PMID:18719214

  4. Personalized Orthodontic Accurate Tooth Arrangement System with Complete Teeth Model.

    Science.gov (United States)

    Cheng, Cheng; Cheng, Xiaosheng; Dai, Ning; Liu, Yi; Fan, Qilei; Hou, Yulin; Jiang, Xiaotong

    2015-09-01

    The accuracy, validity and lack of relation information between dental root and jaw in tooth arrangement are key problems in tooth arrangement technology. This paper aims to describe a newly developed virtual, personalized and accurate tooth arrangement system based on complete information about dental root and skull. Firstly, a feature constraint database of a 3D teeth model is established. Secondly, for computed simulation of tooth movement, the reference planes and lines are defined by the anatomical reference points. The matching mathematical model of teeth pattern and the principle of the specific pose transformation of rigid body are fully utilized. The relation of position between dental root and alveolar bone is considered during the design process. Finally, the relative pose relationships among various teeth are optimized using the object mover, and a personalized therapeutic schedule is formulated. Experimental results show that the virtual tooth arrangement system can arrange abnormal teeth very well and is sufficiently flexible. The relation of position between root and jaw is favorable. This newly developed system is characterized by high-speed processing and quantitative evaluation of the amount of 3D movement of an individual tooth. PMID:26208593

  5. Mechanics of microwear traces in tooth enamel.

    Science.gov (United States)

    Borrero-Lopez, Oscar; Pajares, Antonia; Constantino, Paul J; Lawn, Brian R

    2015-03-01

    It is hypothesized that microwear traces in natural tooth enamel can be simulated and quantified using microindentation mechanics. Microcontacts associated with particulates in the oral wear medium are modeled as sharp indenters with fixed semi-apical angle. Distinction is made between markings from static contacts (pits) and translational contacts (scratches). Relations for the forces required to produce contacts of given dimensions are derived, with particle angularity and compliance specifically taken into account so as to distinguish between different abrasives in food sources. Images of patterns made on human enamel with sharp indenters in axial and sliding loading are correlated with theoretical predictions. Special attention is given to threshold conditions for transition from a microplasticity to a microcracking mode, corresponding to mild and severe wear domains. It is demonstrated that the typical microwear trace is generated at loads on the order of 1N - i.e. much less than the forces exerted in normal biting - attesting to the susceptibility of teeth to wear in everyday mastication, especially in diets with sharp, hard and large inclusive intrinsic or extraneous particulates. PMID:25484336

  6. [Pathology of Charcot-Marie-Tooth Disease].

    Science.gov (United States)

    Oka, Nobuyuki

    2016-01-01

    Although genetic testing is available, nerve biopsy is useful in selected patients for the diagnosis of Charcot-Marie-Tooth disease (CMT). These are sporadic cases of hereditary neuropathy, or familial cases in which genetic testing is negative. CMT is caused by mutations of various genes. The pathological features of CMT have mostly been investigated using nerve biopsy, which may shed light on the presumed functions of mutated gene products. PMP22 duplication in CMT1A induces numerous large onion bulb lesions (OB). Compared to chronic inflammatory demyelinating polyradiculoneuropathy, the differential features of CMT1A are patchy distribution of OB and non-inflammatory lesions. CMT1B also manifests as OB, but presents abnormal compaction of myelin sheaths caused by uncompacted myelin or excessive myelin folding. CMT2 includes axonal neuropathies and many causative genes have been found. CMT2A (MFN2 mutation) shows abnormal mitochondria with a spherical morphology instead of tubular in the longitudinal direction. CMT4 consists of autosomal recessive forms with demyelinating pathology. Most subtypes have mutations of genes relating to myelin maintenance, and pathologically, they show abnormal folding of the myelin structure. PMID:26764296

  7. Trace Elements in Human Tooth Enamel

    International Nuclear Information System (INIS)

    The trace elements are considered to play a role in the resistance of teeth to dental caries. The exact mechanism by which they act has not yet been fully established. Estimations of trace elements have been undertaken in sound human teeth. By means of activation analysis it has been possible to determine trace element concentrations in different layers of enamel in the same tooth. The concentrations of the following elements have been determined: arsenic, antimony, copper, zinc, manganese, mercury, molybdenum and vanadium. The distribution of trace elements in enamel varies from those with a narrow range, such as manganese, to those with a broad range, such as antimony. The elements present in the broad range are considered to be non-essential and their presence is thought to result from a chance incorporation into the enamel. Those in the narrow range appear to be essential trace elements and are present in amounts which do not vary unduly from other body tissues. Only manganese and zinc were found in higher concentrations in the surface layer of enamel compared with the inner layers. The importance of the concentration of trace elements on this surface layer of enamel is emphasized as this layer is the site of the first attack by the carious process. (author)

  8. [Rehabilitation of Charcot-Marie-Tooth Disease].

    Science.gov (United States)

    Tajima, Fumihiro; Nakamura, Takeshi; Nishimura, Yukihide; Arakawa, Hideki; Kawasaki, Takashi; Ogawa, Takahiro; Nishiyama, Kazunari

    2016-01-01

    Charcot-Marie-Tooth disease (CMT) is one of the most commonly inherited neuromuscular diseases causing progressive muscle weakness; contracture; deformity in the feet, legs, and hands; and impairments of ambulation and handgrip. Reduced physical ability can be attributed not only to the disease but also to physical deconditioning. Previously, most physicians in the field of rehabilitation were anxious about the hypothesis of overwork weakness in CMT, and did not conduct intensive exercise programs for patients with CMT. However, recent studies have reported that progressive resistance strengthening programs for lower extremities are feasible, safe, beneficial, and improve exercise intolerance and undue fatigue in patients with CMT. Although the improvement in exercise tolerance may be partly due to the reversal of deconditioning effect of related sedentary lifestyle, progressive resistance training and physical fitness can improve walking function, activities of daily living, and subjective perception of pain and fatigue in patients with CMT. To increase the daily physical function, some studies described the potential benefits of ankle-foot orthoses (AFOs); however, no control study supported it. So far, the training programs on CMT have been dependent on the exercise programs for able-bodied individuals. To increase the effects of rehabilitation, optimal programs that combine the training protocol and AFO strategies will have to be designed for patients with CMT. PMID:26764300

  9. Anterior tooth morphology and its effect on torque.

    Science.gov (United States)

    van Loenen, M; Degrieck, J; De Pauw, G; Dermaut, L

    2005-06-01

    This study was undertaken to determine the variation in crown-root angle (CRA) of the upper incisors and canines as well as the variation in their labial contour. In addition, the influence of the variability of the labial contour and of different bracket heights on torque was evaluated. Proximal radiographs were taken of 160 extracted maxillary teeth (81 incisors and 79 canines). They were digitized and analysed with Jasc Paint Shop Pro 7TM and Mathcad 2001 Professional. The incisal edge, the centre of the cemento-enamel junction (CEJ), and the root apex were digitized to define the crown and root long axis. For all teeth the CRA was measured. At several heights of the labial surface a tangent was determined, enabling measurement of the inclination of the labial surface. The CRA had great variability, ranging from 167 to 195 degrees for the canines (mean value 183 degrees) and from 171 to 195 degrees for the incisors (average 184 degrees). The mean inclinations of the labial surfaces for the incisors varied greatly. Between 4 and 4.5 mm from the incisal edge the standard deviations (SD) were the smallest and between 2 and 4.5 mm from the incisal edge the labial surface angle differed by approximately 10 degrees. For the canines the mean inclinations of the buccal surface also varied. This angle differed by around 10 degrees between 2 and 4.5 mm from the incisal edge, but the SD were much larger than for the incisors. It can be concluded that placement of a bracket on a tooth at varying heights, still within a clinically acceptable range, results in important differences in the amount of root torque. PMID:15947225

  10. Intentional reim plantation of a tooth with severe periodontal involvement using enamel matrix derivative in combination with guided tissue regeneration and bone grafting: a case report.

    Science.gov (United States)

    Sugai, Kenji; Sato, Shuichi; Suzuki, Kuniharu; Ito, Koichi

    2008-02-01

    This case involved the intentional reimplantation of a tooth with severe periodontal involvement using regenerative therapies. The maxillary left central incisor was intentionally extracted, enamel matrix derivative (EMD) was applied, and the tooth was repositioned accurately. The bone defect was filled with a xenograft and a demineralized freeze-dried bone allograft, and a guided tissue regeneration membrane was adapted over the site. After 5 years, a reduction in probing depth and a gain in clinical attachment were observed. Conventional radiographs and cone-beam computerized tomographs showed hard tissue improvement. Favorable clinical results were obtained with reimplantation with applied EMD, combined with regenerative therapies, for treating a tooth with severe periodontal involvement. PMID:18351207

  11. Laser assisted tooth replantation case report

    OpenAIRE

    Lu, Cheng Hsiang; Lu, Hung Chieh; KE, Jyuhn H.; Lan, Wan Hong

    2011-01-01

    Background and aim: Although intentional replantation for extraoral treatment is a solution for complicated endodontic cases, it is accompanied with risk of root resorption which is most likely due to extraction trauma and infected remnants. Laser therapies have long been proved for bactericidal and biostimulation effects. In the present case, a pulpitis combined severe periodontal destruction molar was extracted with an Er:YAG laser for thorough degranulation and disinfection. Before the ext...

  12. Evaluation of Reasons of Permanent Teeth Extraction in Iranian People (2009

    Directory of Open Access Journals (Sweden)

    Kakoei S.

    2012-02-01

    Full Text Available Statement of Problem: Everyday, many people lose their teeth because of various reasons. Knowing the reasons of tooth extraction would help officials to make decisions for helping patients saving their teeth.Purpose: The aim of this study was to investigate the reasons of teeth extraction in dental clinics and some private offices in the city of Kerman in November 2009- February 2010.Materials and Method: In this cross-sectional study, the reasons of teeth extraction in 2076 teeth from 1500 patients selected by simple sampling from Kerman dental clinics were evaluated. Personal data such as gender, age, educational level, occupation, and family size as well as the main reason of tooth extraction (decay, periodontal diseases, prosthesis, tooth impaction, orthodontic reasons, and patient’s request and the type of tooth were collected by a checklist. Data were analyzed in SPSS, version 11.5 using ?² test.Results: The two main reasons of tooth extraction were dental caries (43.6% and patient request (30.6%, respectively. Overall, the first and third molars of the lower jaw were the most commonly extracted teeth. There was a significant relationship between gender and tooth extraction because of caries and orthodontic reasons ( p <0.0001. Meanwhile, the patients’ age had a significant relationship with most teeth extraction reasons ( p <0.0001. Except for patient’s request, educational level had a significant impact on other teeth extraction reasons ( p <0.0001. Conclusion: According to the results of this study, the most common reasons of tooth extraction were dental caries and patient request despite their restorability. Preventive programs and routine dental examination are recommended.

  13. Effects of ion-releasing tooth-coating material on demineralization of bovine tooth enamel.

    Science.gov (United States)

    Kawasaki, Koji; Kambara, Masaki

    2014-01-01

    We compared the effect of a novel ion-releasing tooth-coating material that contained S-PRG (surface-reaction type prereacted glass-ionomer) filler to that of non-S-PRG filler and nail varnish on the demineralization of bovine enamel subsurface lesions. The demineralization process of bovine enamel was examined using quantitative light-induced fluorescence (QLF) and electron probe microanalyzer (EPMA) measurement. Ion concentrations in demineralizing solution were measured using inductively coupled plasma atomic (ICP) emission spectrometry and an ion electrode. The nail varnish group and the non-S-PRG filler group showed linear demineralization. Although the nail varnish group and the non-S-PRG filler group showed linear demineralization, the S-PRG filler group did not. Further, plane-scanning by EPMA analysis in the S-PRG filler group showed no changes in Ca ion distribution, and F ions showed peak levels on the surface of enamel specimens. Most ions in the demineralizing solution were present at higher concentrations in the S-PRG filler group than in the other two groups. In conclusion, only the S-PRG filler-containing tooth-coating material released ions and inhibited demineralization around the coating. PMID:24578706

  14. Asymmetric extractions in orthodontics

    Scientific Electronic Library Online (English)

    Camilo Aquino, Melgaço; Mônica Tirre de Souza, Araújo.

    2012-04-01

    Full Text Available INTRODUCTION: Extraction decisions are extremely important in during treatment planning. In addition to the extraction decision orthodontists have to choose what tooth should be extracted for the best solution of the problem and the esthetic/functional benefit of the patient. OBJECTIVE: This article [...] aims at reviewing the literature relating the advantages, disadvantages and clinical implications of asymmetric extractions to orthodontics. METHODS: Keywords were selected in English and Portuguese and the EndNote 9 program was used for data base search in PubMed, Web of Science (WSc) and LILACS. The selected articles were case reports, original articles and prospective or retrospective case-control studies concerning asymmetrical extractions of permanent teeth for the treatment of malocclusions. CONCLUSION: According to the literature reviewed asymmetric extractions can make some specific treatment mechanics easier. Cases finished with first permanent molars in Class II or III relationship in one or both sides seem not to cause esthetic or functional problems. However, diagnosis knowledge and mechanics control are essential for treatment success.

  15. Amery Ice Shelf's 'Loose Tooth' Gets Looser

    Science.gov (United States)

    2002-01-01

    The Amery Ice Shelf is an important dynamic system responsible for draining about 16% of the grounded East Antarctic ice sheet through only 2% of its coastline. Most of the mass input to the system occurs from the Lambert and several other glaciers. Mass loss from the system occurs through basal melting and iceberg calving. These images from the Multi-angle Imaging SpectroRadiometer (MISR) portray the ice shelf front on October 6, 2001 (top) and September 29, 2002 (bottom), and illustrate changes that took place over the year elapsed between the two views.Two longitudinal rifts, oriented roughly parallel to the direction of ice flow and measuring about 25 and 15 kilometers in length, are apparent near the seaward edge of the ice shelf. Between them, a transverse fracture extends eastward from the base of the western rift. This rift system is colloquially named the Amery 'loose tooth.' Over the course of the one-year interval between these two MISR images, the ice front has advanced approximately 1.6 - 1.7 kilometers, and the transverse fracture and a three-way fissure at the juncture of the rifts have widened. When the transverse fracture eventually reaches the eastern rift, a large iceberg (25 kilometers x 25 kilometers) will be released.These false-color multi-angle composites combine red-band data from MISR's 60o forward, nadir, and 60o aftward viewing cameras, displayed as red, green and blue, respectively. Different colors represent angular reflectance variations. Since generally smooth surfaces predominantly forward-scatter sunlight, these appear in shades of blue. Rough surfaces tend to backward-scatter sunlight, and these appear in shades of red or orange. Low clouds appear bright purple, since they exhibit both forward and backward-scattering. Using this technique, textural variations among ice types are revealed, and clouds can be easily distinguished from ice. Illumination conditions on the two dates are nearly identical.Understanding the 'normal' frequency of calving events from a particular ice shelf is necessary before it can be determined whether calving rates are changing. As part of an effort to determine the normal rate of ice flow and iceberg calving events, the Amery Ice Shelf front has been monitored by various remote sensing instruments for many years. The Amery Ice Shelf is currently considered to be about two-thirds of the way through a calving cycle. The last major calving event occurred in the early 1960's, when a massive iceberg (measuring about 140 kilometers x 70 kilometers) was released.The Amery 'loose tooth' is the subject of a joint field experiment during the 2002 austral summer, partially funded by NASA and undertaken by the Scripps Institution of Oceanography and the Australian Antarctic Division. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 9579 and 14807. The panels cover an area of about 204 kilometers x 110 kilometers, and utilize data from blocks 146 to 147 within World Reference System-2 paths 127 and 128, respectively. Data from the two orbital paths have been remapped to identical polar projections, and were cropped to include the same geographic area.MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center,Greenbelt, MD. JPL is a division of the California Institute of Technology.

  16. Tooth structure and fracture strength of cavities

    Scientific Electronic Library Online (English)

    José, Mondelli; Fábio, Sene; Renata Pereira, Ramos; Ana Raquel, Benetti.

    Full Text Available O objetivo deste estudo foi avaliar, in vitro, a perda de estrutura dentária após o preparo cavitário para restaurações diretas e indiretas e sua relação com a resistência à fratura do dente. 60 pré-molares superiores humanos foram divididos em 6 grupos (n=10). Cavidades MOD para resina composta dir [...] eta (Grupos I, II e III) e cavidades "inlay" (Grupos IV, V e VI) foram preparadas mantendo dimensões padronizadas. A extensão vestíbulo-lingual da caixa oclusal foi estabelecida em 1/4 (Grupos I e IV), 1/3 (Grupos II e V) ou 1/2 (Grupos III e VI) da distância intercuspídea. Os dentes foram pesados, em uma balança de precisão, antes e após o preparo cavitário para aferir a perda de massa dentária. Os dentes preparados foram submetidos à força de compressão para determinar a resistência à fratura em uma máquina universal de ensaios sob uma velocidade de 0.5 mm/min. Os dados foram submetidos à análise de variância a dois critérios e ao teste de Tukey (alfa = 0.05). As cavidades do tipo "1/4-inlay" apresentaram maior percentual de perda de massa (9.71%) em relação às cavidades para resina composta com mesma extensão (7.07%). As cavidades do tipo "1/3-inlay" também apresentaram maior percentual de perda de massa (13.91%) quando comparada às cavidades para resina composta com a mesma extensão (10.02%). As cavidades do tipo "1/2-inlay" apresentaram 21.34% de perda de massa, enquanto as cavidades com extensão de 1/2 para resina composta apresentaram uma perda de 16.19%. As médias de resistência à fratura (em kgf) foram: GI = 187.65; GII = 143.62; GIII = 74.10; GIV = 164.22; GV = 101.92; GVI = 50.35. Diferenças estatisticamente significantes (p Abstract in english This study evaluated, in vitro, the loss of tooth substance after cavity preparation for direct and indirect restorations and its relationship with fracture strength of the prepared teeth. Sixty sound human maxillary first premolars were assigned to 6 groups (n=10). MOD direct composite cavities (Gr [...] oups I, II and III) and indirect inlay cavities (Groups IV, V and VI) were prepared maintaining standardized dimensions: 2-mm deep pulpal floors, 1.5-mm wide gingival walls and 2-mm high axial walls. Buccolingual width of the occlusal box was established at 1/4 (Groups I and IV), 1/3 (Groups II and V) or 1/2 (Groups III and VI) of the intercuspal distance. Teeth were weighed (digital balance accurate to 0.001 g) before and after preparation to record tooth substance mass lost during cavity preparation. The prepared teeth were submitted to occlusal loading to determine their fracture strength using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed by two-way ANOVA and Tukey test (alpha= 0.05). 1/4-inlay cavities had higher percent mean mass loss (9.71%) than composite resin cavities with the same width (7.07%). 1/3-inlay preparations also produced higher percent mean mass loss (13.91%) than composite resin preparations with the same width (10.02%). 1/2-inlay cavities had 21.34% of mass loss versus 16.19% for the 1/2-composite resin cavities. Fracture strength means (in kgf) were: GI = 187.65; GII = 143.62; GIII = 74.10; GIV = 164.22; GV = 101.92; GVI = 50.35. Statistically significant difference (p

  17. The challenges of treating a fused tooth

    Scientific Electronic Library Online (English)

    Flares, Baratto-Filho; Denise Piotto, Leonardi; Bruno Monguilhott, Crozeta; Samantha Pugsley, Baratto; Edson Alves, Campos; Flavia Sens Fagundes, Tomazinho; Tatiana Miranda, Deliberador.

    Full Text Available Este caso descreve o tratamento multidisciplinar de um incisivo lateral superior permanente fusionado a um dente supranumerário, ambos apresentando necrose pulpar e lesão periapical. Paciente compareceu ao consultório se queixando de dor, edema e mobilidade do incisivo lateral superior. O preparo en [...] dodôntico foi realizado no sentido coroa-ápice e foi colocada pasta de hidróxido de cálcio como medicação intra-canal por 15 dias. A seguir, a obturação foi realizada pela termoplastificação da guta-percha. Após 18 meses, foram realizados exames clínicos e radiográficos indicando ausência de dor e edema. Dois anos após o tratamento endodôntico, o paciente retornou para o tratamento periodontal e estético. Nove meses depois, foi realizada tomografia computadorizada e observou-se presença de defeito periodontal e lesão periapical. Foi então indicada e planejada a cirurgia paraendodôntica. O dente supranumerário foi removido e a área de comunicação com o canal radicular do incisivo lateral foi preenchida; a loja cirúrgica foi preenchida com vidro bioativo e osso orgânico bovino desmineralizado. O tecido patológico da lesão periapical foi submetido à análise histopatológica sendo diagnosticado como cisto periapical. Um ano após a cirurgia parendodôntica, uma nova tomografia computadorizada mostrou neoformação óssea na região periapical do dente em questão. Doi anos após a cirurgia, a restauração foi trocada devido à motivos estéticos e uma radiografia periapical mostrou sucesso do tratamento (5 anos após o tratamento inicial). Um correto diagnóstico e plano de tratamento multidisciplinar é essencial para o sucesso do tratamento de dentes fusionados à dentes supranumerários. Abstract in english This paper describes and discusses the multidisciplinary treatment involving a permanent maxillary lateral incisor fused to a supernumerary tooth, both presenting pulp necrosis and periapical lesion. A 15-year-old male patient sought treatment complaining of pain, swelling and mobility on the maxill [...] ary right lateral incisor. After clinical and radiographic examination, root canal preparation was performed according to the crown-down technique and a calcium hydroxide dressing was placed for 15 days. The patient returned and the definitive endodontic filling was done with thermomechanical compaction of gutta-percha and sealer. After 18 months, clinical and radiographic examinations were carried out and no pain or swelling was reported. Two years after endodontic treatment, the patient returned for periodontal and cosmetic treatments. Nine months later, a cone-beam computed tomography (CBCT) revealed that the previously detected periodontal defect and periapical lesion were persistent. Apical endodontic surgery was indicated. The supernumerary tooth was removed, the communicating distal surface was filled and the surgical site received bioactive glass and demineralized bovine organic bone. The pathological tissue was submitted to histopathological examination and the diagnosis was periapical cyst. One year after the apical endodontic surgery, CBCT showed bone formation at maxillary lateral incisor apical area. Two years after the surgery, the restoration was replaced due to aesthetic reasons and periapical radiograph showed success after 5 years of treatment. A correct diagnosis and establishment of an adequate treatment plan resulted in a successful management of the case.

  18. Intrusion of supraerupted maxillary molar using a high interim restoration on the defective opposing tooth: a clinical report.

    Science.gov (United States)

    Tao, Ye; Luo, Xiao Ping; Bartlett, David W

    2015-04-01

    Wear, extraction, or fracture of all or part of a mandibular first molar can lead to the supraeruption of the opposing maxillary molar, resulting in occlusal interference and lack of restoration space. This report describes a method to gain sufficient vertical space for permanent restoration. A direct composite resin restoration was placed on the occlusal surface of a lower molar, intentionally making the interim restoration high and intruding the maxillary molar. After 6 weeks, the extruded tooth returned to the desired position, and functional occlusion was restored, enabling a ceramic restoration on the mandibular molar. No marked adverse sensory reaction was reported in this therapeutic process, and no deleterious signs were detected in the teeth, periodontium, or temporomandibular joints. The simple treatment type was effective, noninvasive, and time saving, while also preserving maximum tooth structures. PMID:24975824

  19. Malformations of the tooth root in humans.

    Science.gov (United States)

    Luder, Hans U

    2015-01-01

    The most common root malformations in humans arise from either developmental disorders of the root alone or disorders of radicular development as part of a general tooth dysplasia. The aim of this review is to relate the characteristics of these root malformations to potentially disrupted processes involved in radicular morphogenesis. Radicular morphogenesis proceeds under the control of Hertwig's epithelial root sheath (HERS) which determines the number, length, and shape of the root, induces the formation of radicular dentin, and participates in the development of root cementum. Formation of HERS at the transition from crown to root development appears to be very insensitive to adverse effects, with the result that rootless teeth are extremely rare. In contrast, shortened roots as a consequence of impaired or prematurely halted apical growth of HERS constitute the most prevalent radicular dysplasia which occurs due to trauma and unknown reasons as well as in association with dentin disorders. While odontoblast differentiation inevitably stops when growth of HERS is arrested, it seems to be unaffected even in cases of severe dentin dysplasias such as regional odontodysplasia and dentin dysplasia type I. As a result radicular dentin formation is at least initiated and progresses for a limited time. The only condition affecting cementogenesis is hypophosphatasia which disrupts the formation of acellular cementum through an inhibition of mineralization. A process particularly susceptible to adverse effects appears to be the formation of the furcation in multirooted teeth. Impairment or disruption of this process entails taurodontism, single-rooted posterior teeth, and misshapen furcations. Thus, even though many characteristics of human root malformations can be related to disorders of specific processes involved in radicular morphogenesis, precise inferences as to the pathogenesis of these dysplasias are hampered by the still limited knowledge on root formation. PMID:26578979

  20. Effect of several tooth-colored restorative materials on reinforcement of unsupported enamel

    Directory of Open Access Journals (Sweden)

    Mohammadreza Malekipour

    2012-01-01

    Full Text Available Introduction: Adhesive restorations properly transmit and distribute functional stresses at the bonding interface to tooth structures and have the potential to reinforce remaining weakened tooth structures after removal of extensive carious lesions. This study evaluated the effect of a number of adhesive restorative materials on reinforcing unsupported enamel. Materials and Methods: Seventy-five extracted sound maxillary premolars collected over 3 months and stored in 0.2% thymol solution received MOD cavities; the lingual cusps were reduced up to the pulp level. The specimens were divided into five groups (n=15. In group 1 (the positive control, dentinal tissue of the buccal wall was preserved. In other groups the buccal dentin was completely removed. In group 2 (the negative control, no restorative material was used to replace the lost dentin. The removed buccal dentin was replaced with composite resin, flowable composite resin and glass-ionomer in groups 3, 4 and 5, respectively. After thermocycling, the specimens were tested in an Instron universal testing machine. Data were analyzed with ANOVA and LSD test (a < 0.05. Results: The mean and standard deviations of fracture loads of the five groups were 122.97 ± 15.11, 44.71 ± 14.23, 78.32±17.58, 81.17 ± 19.53, and 85.33 ± 22.07 Newtons, respectively. One-way ANOVA revealed significant differences between the groups (p value = 0.00. There were significant differences in fracture loads between groups 1 and 2 and others (p value = 0.00. The difference in fracture loads between group 3 and 4 (p value = 0.678, groups 3 and 5 (p value = 0.344, and groups 4 and 5 (p value = 0.589 were not significant. Conclusion: It can be concluded that the three types of adhesive restorative materials in this study can reinforce unsupported enamel to a certain degree. Key words: Composite resin, Dental adhesives, Reinforcement, Tooth enamel.

  1. Effect of Multiple Adhesive Coating on Microshear Bond Strength to Primary Tooth Dentin

    Directory of Open Access Journals (Sweden)

    Beheshteh Malekafzali Malekafzali

    2013-01-01

    Full Text Available Objective: Multiple adhesive coating is a controversial topic, especially in primary dentition that should be clarified. We evaluated the effect of multiple consecutive adhesive resin coatings on the microshear bond strength (µSBS of composite resin to primary tooth dentin utilizing a filled (Adper Single Bond Plus and an unfilled (Adper Single Bond adhesive resin.Materials and Methods: Thirty extracted primary canines were randomly allocated into two groups based on the adhesive used. Dentin occlusal surfaces were exposed and further polished on 400, 600 and 800-grit silicon-carbide paper. The surfaces were divided into two halves in the labial-lingual orientation. After etching, the adhesives were used either in double coats, or four coats on the halves of the same tooth followed by air evaporation for each layer and finally light curing. Cylinders of composite were bonded to the dentin surfaces. After 24 h shear bond testing was evaluated by Bisco tensile tester. ANOVA, Student t test and paired t test were used for statistical analysis.Results: The mean (standard deviation for double coats or four coats in single bond were 31.99 (2.94 and 30.25 (2.69, while they were 29.18 (3.35 and 31.26 (2.07 in single bond plus, respectively. No significant differences were found between the double coated specimens and those receiving four coatings with both adhesives (p>0.05. Micro SBS values of Single Bond double coated specimens were significantly higher than Single Bond Plus (p=0.02. In four-coated specimens, there were no significant differences between Single Bond and Single Bond Plus (p=0.26.Conclusion: Applying four coats of adhesive did not improve the µSBS to primary tooth dentin.

  2. Success Rate of Formocresol Pulpotomy versus Mineral Trioxide Aggregate in Human Primary Molar Tooth

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    S E Jabbarifar

    2004-12-01

    Full Text Available Background: In spite of long time and broad use of formaldehyde derivates (Fixation agent in primary tooth pulp treatment, There is some concerns about these derivates such as variability, inconsistency success rate, mutagenicity, cytotoxicity, alergenicity, and some other potential health hazards of them. Therefore other alternative pulpotomy procedures like Bioactive glass (BAG, Glutaraldehyde (2%, Hydroxyappetite (HA, Bone dried freezed (BDF, ferric sulfate (15%, laser, Electrosurgery (ES, Bone Morphogenic proteins (BMP, recombinant protein-1 (RP1, and Mineral Trioxide Aggregate (MTA have been compared. The purpose of this clinical trial is to assess radiographic and clinical success rate of Formocresol (FC pulpotomy in compare with MTA in human primary molar teeth. Methods: 64 molars were pulpotomized equally and randomly with mineral trioxide Aggregate and Formocresol. Prior to trial, we defined a case as failure, when one or more of the events such as external root resorption, internal root resorption, periapical and furca lucency, pain, swelling, mobility, dental abscess, or early extraction appeared. Every treated tooth was defined as successful, if any noted evident was not shown. Results: Totally, 60 teeth treatment (92.2 percent were successful and 7.8 percent were failed. Failure and success rates for MTA group were 6.3 and 93.7 percent, respectively. Failure and success rates in FC group were 8.4 and 90.2 percent respectively. The difference between MTA and FC treatment methods was not significant (Fisher Exact test. Conclusion: Findings of this study show that mineral trioxide aggregate can be an alternative procedure for FC pulpotomy of primary tooth. Keywords: Mineral trioxide aggregate, formocresol, pulpotomy, success and failure rate.

  3. Conduct of an algorithm in quantifying simulated palatal surface tooth erosion.

    Science.gov (United States)

    Chadwick, R G; Mitchell, H L

    2001-05-01

    In order to test the ability of an algorithm to quantify simulated palatal erosion, a total of 10 extracted permanent upper central incisors were mounted in brass blocks. Baseline impressions were recorded using an addition cured silicone impression material in a metal impression tray. Once set and removed from the teeth, the impressions were coated twice with a high silver content electroconductive paint, applied using a brush, before being backed up with die stone to form an electroconductive replica. Each tooth was then subject to three treatments: application of phosphoric acid etchant gel for 60 s, application of etchant gel for 120 s and immersion for 3 h in Diet Coca-Cola*. After each one the replication process was repeated. Thereafter all replicas were mapped using a computer controlled electrical probe and the resultant digital terrain models (DTMS) compared using a surface matching and difference detection algorithm (SMADDA). Surface matching was unsuccessful only in one instance. As the duration of the insult increased, so did the proportion of the surface that underwent change to a maximum of 33.3%. Anatomical site was significantly (P < 0.05) associated with the susceptibility to erosion. The cingulum periphery appeared most resistant to this. The algorithmic approach offers much scope for monitoring dental erosion as acid dissolution of the tooth's surface appears to occur gradually. The cingulum region appears relatively more resistant to this process than other tooth sites and thus facilitates the process of surface matching. Further testing is however, required to determine precisely the algorithm's upper tolerance level. PMID:11380785

  4. Detecting Gear Tooth Fatigue Cracks in Advance of Complete Fracture

    Science.gov (United States)

    Zakrajsek, James J.; Lewicki, David G.

    1996-01-01

    Results of using vibration-based methods to detect gear tooth fatigue cracks are presented. An experimental test rig was used to fail a number of spur gear specimens through bending fatigue. The gear tooth fatigue crack in each test was initiated through a small notch in the fillet area of a tooth on the gear. The primary purpose of these tests was to verify analytical predictions of fatigue crack propagation direction and rate as a function of gear rim thickness. The vibration signal from a total of three tests was monitored and recorded for gear fault detection research. The damage consisted of complete rim fracture on the two thin rim gears and single tooth fracture on the standard full rim test gear. Vibration-based fault detection methods were applied to the vibration signal both on-line and after the tests were completed. The objectives of this effort were to identify methods capable of detecting the fatigue crack and to determine how far in advance of total failure positive detection was given. Results show that the fault detection methods failed to respond to the fatigue crack prior to complete rim fracture in the thin rim gear tests. In the standard full rim gear test all of the methods responded to the fatigue crack in advance of tooth fracture; however, only three of the methods responded to the fatigue crack in the early stages of crack propagation.

  5. Efficient transport of droplet sandwiched between saw-tooth plates.

    Science.gov (United States)

    Wang, Liya; Wu, Hengan; Wang, Fengchao

    2016-01-15

    The transport of droplet sandwiched between smooth and saw-tooth plates was investigated using molecular dynamics method. The repeated opening and closing of the plates result in sequential stretching and squeezing of the droplet, which provide the driving force. The asymmetrical saw tooth obstructs the backward motion of the droplet, and gives rise to a net forward displacement of the droplet in every opening and closing cycle. This unidirectional motion facilitates the efficient droplet transport, which is referred to as the ratchet-like effect in this work. Our simulations also reveal that the influence of the surface wettability on the droplet transport is different for saw-tooth and smooth plates. Droplet transport efficiency exhibits monotonic decrease with the increase of the solid-liquid interactions for saw-tooth plates. While for smooth plates, unidirectional droplet movement was only observed for certain solid-liquid interactions. Taken together these simulation results and theoretical analysis, we demonstrate that hydrophobic saw-tooth plates can improve the transport efficiency significantly. These findings not only enhance our understanding of the droplet transport from atomistic scale, but also are beneficial to practical applications in designing of micro- and nano-fluidic systems. PMID:26473277

  6. The development of complex tooth shape in reptiles

    Directory of Open Access Journals (Sweden)

    AbigailSaffronTucker

    2014-02-01

    Full Text Available Reptiles have a diverse array of tooth shapes, from simple unicuspid to complex multicuspid teeth, reflecting functional adaptation to a variety of diets and eating styles. In addition to cusps, often complex longitudinal labial and lingual enamel crests are widespread and contribute to the final shape of reptile teeth. The simplest shaped unicuspid teeth have been found in piscivorous or carnivorous ancestors of recent diapsid reptiles and they are also present in some extant carnivores such as crocodiles and snakes. However, the ancestral tooth shape for squamate reptiles is thought to be bicuspid, indicating an insectivorous diet. The development of bicuspid teeth in lizards has recently been published, indicating that the mechanisms used to create cusps and crests are very distinct from those that shape cusps in mammals. Here, we introduce the large variety of tooth shapes found in lizards and compare the morphology and development of bicuspid, tricuspid and pentacuspid teeth, with the aim of understanding how such tooth shapes are generated. Next, we discuss whether the processes used to form such morphologies are conserved between divergent lizards and whether the underlying mechanisms share similarities with those of mammals. In particular, we will focus on the complex teeth of the chameleon, gecko, varanus and anole lizards using SEM and histology to compare the tooth crown morphology and embryonic development.

  7. Properties of goat tooth enamel electron spin resonance dosimetry

    International Nuclear Information System (INIS)

    Objective: To study the properties of goat tooth enamel electron spin resonance (ESR) dosimetry. Methods: Tooth enamel samples of goats were achieved by combined mechanical and chemical treatment at the ages of l, 2, 3, 5, and 6 years, respectively and 9 enamel samples of adult molar were obtained. These enamel samples were exposed to 137Cs ?-rays at the cumulative doses of 0, 0.5, 1.0, 2.0, and 5.0 Gy, respectively. ESR spectra Was measured before and after exposure. Results: The background signal of goat tooth samples was 21.5, significantly lower than that of the adult molar samples (39.5). The dosimetric signal intensity of the goat enamel increased with the radiation dose in a linear manner just as that of the human molars. The average radiation sensitivity of the goat tooth samples was (34.3±1.9)/Gy, close to that of the human tooth samples. Conclusions: Goat teeth can be used for retrospective radiation dose reconstruction when human teeth are unavailable, in order to provide scientific data for dose reconstruction accurately. (authors)

  8. 41Ca - a possible neutron specific biomarker in tooth enamel

    Science.gov (United States)

    Wallner, A.; Arazi, A.; Faestermann, T.; Knie, K.; Korschinek, G.; Maier, H. J.; Nakamura, N.; Rühm, W.; Rugel, G.

    2004-08-01

    The measurement of long-lived radionuclides, produced by neutrons originating from the atomic-bomb explosions, offers the possibility to reconstruct neutron fluences to which survivors in Hiroshima and Nagasaki were exposed. The long-lived radionuclide, 41Ca (T1/2=103 000 years), is suggested here as a means for a retrospective determination of thermal neutron fluences, directly within the human body of a survivor. As proper material tooth enamel is proposed. The 41Ca signal in tooth enamel may be correlated with the exposure to A-bomb induced thermal neutron fluences, provided the natural background level of 41Ca/Ca is significantly lower. Therefore, tooth samples of unexposed survivors of the A-bomb explosions have been examined by means of accelerator mass spectrometry, in order to quantify the natural background level of 41Ca/Ca. Measured 41Ca/Ca ratios were confirmed to be as low as about 2 × 10-15. Thus, the A-bomb induced additional signal should be detectable for survivors at epidemiological relevant distances. Since tooth enamel had already been used as a dosemeter for gamma radiation from the A-bomb explosion, the detection of 41Ca in tooth enamel would allow, for the first time, an assessment of both, ?-ray and neutron exposures in the same biological material.

  9. 41Ca - a possible neutron specific biomarker in tooth enamel

    International Nuclear Information System (INIS)

    The measurement of long-lived radionuclides, produced by neutrons originating from the atomic-bomb explosions, offers the possibility to reconstruct neutron fluences to which survivors in Hiroshima and Nagasaki were exposed. The long-lived radionuclide, 41Ca (T1/2=103 000 years), is suggested here as a means for a retrospective determination of thermal neutron fluences, directly within the human body of a survivor. As proper material tooth enamel is proposed. The 41Ca signal in tooth enamel may be correlated with the exposure to A-bomb induced thermal neutron fluences, provided the natural background level of 41Ca/Ca is significantly lower. Therefore, tooth samples of unexposed survivors of the A-bomb explosions have been examined by means of accelerator mass spectrometry, in order to quantify the natural background level of 41Ca/Ca. Measured 41Ca/Ca ratios were confirmed to be as low as about 2 x 10-15. Thus, the A-bomb induced additional signal should be detectable for survivors at epidemiological relevant distances. Since tooth enamel had already been used as a dosemeter for gamma radiation from the A-bomb explosion, the detection of 41Ca in tooth enamel would allow, for the first time, an assessment of both, ?-ray and neutron exposures in the same biological material

  10. Monte Carlo modeling of human tooth optical coherence tomography imaging

    International Nuclear Information System (INIS)

    We present a Monte Carlo model for optical coherence tomography (OCT) imaging of human tooth. The model is implemented by combining the simulation of a Gaussian beam with simulation for photon propagation in a two-layer human tooth model with non-parallel surfaces through a Monte Carlo method. The geometry and the optical parameters of the human tooth model are chosen on the basis of the experimental OCT images. The results show that the simulated OCT images are qualitatively consistent with the experimental ones. Using the model, we demonstrate the following: firstly, two types of photons contribute to the information of morphological features and noise in the OCT image of a human tooth, respectively. Secondly, the critical imaging depth of the tooth model is obtained, and it is found to decrease significantly with increasing mineral loss, simulated as different enamel scattering coefficients. Finally, the best focus position is located below and close to the dental surface by analysis of the effect of focus positions on the OCT signal and critical imaging depth. We anticipate that this modeling will become a powerful and accurate tool for a preliminary numerical study of the OCT technique on diseases of dental hard tissue in human teeth. (paper)

  11. Susceptibility of enamel to initial erosion in relation to tooth type, tooth surface and enamel depth.

    Science.gov (United States)

    Carvalho, Thiago S; Lussi, A

    2015-01-01

    This study aimed at assessing the susceptibility of different tooth types (molar/premolar), surfaces (buccal/lingual) and enamel depths (100, 200, 400 and 600 ?m) to initial erosion measured by surface microhardness loss (?SMH) and calcium (Ca) release. Twenty molars and 20 premolars were divided into experimental and control groups, cut into lingual/ buccal halves, and ground/polished, removing 100 ?m of enamel. The initial surface microhardness (SMH 0 ) was measured on all halves. The experimental group was subjected to 3 consecutive erosive challenges (30 ml/tooth of 1% citric acid, pH 3.6, 25 ° C, 1 min). After each challenge, ?SMH and Ca release were measured. The same teeth were consecutively ground to 200, 400 and 600 ?m depths, and the experimental group underwent 3 erosive challenges at each depth. No difference was found in SMH 0 between experimental and control groups. Multivariate nonparametric ANOVA showed no significant differences between lingual and buccal surfaces in ?SMH (p = 0.801) or Ca release (p = 0.370). ?SMH was significantly greater in premolars than in molars (p enamel depth. Ca release decreased significantly with increasing depth. Regression between Ca release and ?SMH at 100 ?m depth showed lower slope and r 2 value, associated with greater Ca release values. At 200-600 ?m depths, moderately large r 2 values were observed (0.651-0.830). In conclusion, different teeth and enamel depths have different susceptibility to erosion, so when Ca release is used to measure erosion, the depth of the test facet in enamel should be standardized, whereas this is less important if ?SMH is used. PMID:25592786

  12. A Comparison between Osteotomy and Corticotomy-Assisted Tooth Movement.

    Science.gov (United States)

    Yen, Stephen L-K

    2016-01-01

    Osteotomies and corticotomies used in combination with orthodontic tooth movement can activate different bone responses that may be exploited to accelerate tooth movement. Segmental osteotomies around dental roots can create a tooth-bearing transport disk that may be distracted and positioned with orthodontic appliances and archwires. In difficult craniofacial repairs, alveolar segments can be guided into position with archwires and orthodontic mechanics. The corticotomy extending into the marrow space can activate bone injury repair mechanisms that accelerate bone turnover as the alveolar bone surrounding the dental roots transitions from a demineralization phase to a fibrous replacement phase and, finally, a mineralization phase. The controlled demineralization and replacement of alveolar bone provides a window of opportunity for roots to move though less dense bone prior to remineralization. Although the corticotomies and osteotomies are minor surgeries compared to orthognathic surgery, the goal of future research is to produce similar bone responses by using smaller surgeries or by eliminating the surgeries altogether. PMID:26599126

  13. OCT monitoring of diffusion of clearing agents within tooth dentin

    Science.gov (United States)

    Trunina, N. A.; Lychagov, V. V.; Tuchin, V. V.

    2009-08-01

    Monitoring of agent diffusion within tooth tissues is important in a wide context of tooth therapy (diffusion of medicinal preparations) and cosmetics (chemical whitening agents). We report here the results of optical coherence tomography (OCT) monitoring of diffusion of water and glycerol as clearing agents in samples of human tooth tissue. The diffusion process is analyzed by monitoring the changes in the OCT signal slope and the depth-resolved amplitude of OCT signal from a sample. Slow temporal kinetics of the mean attenuation coefficient was measured to monitor a saturable optical clearing due to the diffusion of the agent. The average permeability coefficient was estimated by dividing the measured thickness of the selected region by the time it took for the agent to diffuse through. The experimental results demonstrate that OCT can be an efficient tool in the study of agent diffusion through hard tissues.

  14. The Shh signalling pathway in early tooth development.

    Science.gov (United States)

    Hardcastle, Z; Hui, C C; Sharpe, P T

    1999-07-01

    The Sonic Hedgehog (Shh) signalling pathway has been proposed to play an important role in mammalian tooth development. We describe the spatial and temporal expression of genes in this pathway during early tooth development and interpret these patterns in terms of the likely roles of Shh signalling. We show that the two putative receptors of the Shh ligand, Ptc and Ptch-2, localise in different cells, suggesting Shh may function in different ways as an epithelial and mesenchymal signal. Shh signalling has previously been shown, in other organs, to stimulate cell proliferation. In this paper we analyse the Fgf signalling pathway in Gli-2 mutants and propose a mechanism as to how Gli-2 may regulate cell proliferation in tooth development. PMID:10512189

  15. Tooth allotransplantation: Evaluation and report of 15 cases

    Directory of Open Access Journals (Sweden)

    AH. Fakhraie

    1994-07-01

    Full Text Available Tooth Transplantation from one individual to another is a method of replacing missing teeth. This method can be used as an applicable clinical treatment technique due to its numerous advantages .There are different methods of tooth transplantation. Among those, the safest and healthiest is transplantation of non-vital teeth or allostatic transplantation. In this method, the risk of antigenicity in recipient is low and also there is no risk of transmission of infectious diseases such as Hepatities or AIDS. The aim of this study was to evaluate the clinical results of tooth allotransplantation. Current study was conducted on 15 non-vital transplanted teeth within 18 months follow-up. Only one case of rejection was observed which was a Traumatic Rejection. Replacement resorption was found in all the cases while inflammatory resorption was recorded in only two cases. WBC Cross Match Test with pannel cell results were negative in all the cases.

  16. Effect of low-level laser therapy (LLLT) on orthodontic tooth movement.

    Science.gov (United States)

    Genc, Ghizlane; Kocadereli, Ilken; Tasar, Ferda; Kilinc, Kamer; El, Sibel; Sarkarati, Bahram

    2013-01-01

    The aim of this study is to evaluate the effects of low-level laser therapy (LLLT) on (1) the velocity of orthodontic tooth movement and (2) the nitric oxide levels in gingival crevicular fluid (GCF) during orthodontic treatment. The sample consisted of 20 patients (14 girls, six boys) whose maxillary first premolars were extracted and canines distalized. A gallium-aluminum-arsenide (Ga-Al-As) diode laser was applied on the day 0, and the 3rd, 7th, 14th, 21st, and 28th days when the retraction of the maxillary lateral incisors was initiated. The right maxillary lateral incisors composed the study group (the laser group), whereas the left maxillary lateral incisors served as the control. The teeth in the laser group received a total of ten doses of laser application: five doses from the buccal and five doses from the palatal side (two cervical, one middle, two apical) with an output power of 20 mW and a dose of 0.71 J /cm(2). Gingival crevicular fluid samples were obtained on the above-mentioned days, and the nitric oxide levels were analyzed. Bonferroni and repeated measures variant analysis tests were used for statistical analysis with the significance level set at p ? 0.05. The application of low-level laser therapy accelerated orthodontic tooth movement significantly; there were no statistically significant changes in the nitric oxide levels of the gingival crevicular fluid during orthodontic treatment. PMID:22350425

  17. Assessing the application of tooth cementum annulation relative to macroscopic aging techniques in an archeological sample.

    Science.gov (United States)

    Gauthier, J; Schutkowski, H

    2013-02-01

    The analysis of human skeletal remains is frequently impeded by the lack of adequately preserved morphological markers on which to base age estimation, particularly in archeological contexts. Therefore, histological methods such as tooth cementum annulation analysis can be useful for extracting reliable age estimates from poorly preserved skeletons, if they produce results corresponding to morphologically based, multifactorial assessments. In order to test this presumption, this study compares tooth cementum annulation (TCA) with macroscopic age estimation results incorporating the Brooks-Suchey pubic symphysis and the Buckberry-Chamberlain revised auricular surface methods, as well as Brothwell's guidelines for analyzing dental attrition. Undecalcified, polished, and unstained transverse thin sections viewed using standard light microscopy, with decentered phase contrast microscopy in cases of poorly delineated cementum annulations, were used for TCA counts. Age estimates were applied independently on the late medieval archeological Box Lane cemetery assemblage from Pontefract, England, to analyze their measure of correspondence and to assess whether data produced by a single histological technique are comparable to information pooled from multiple morphological age markers. Spearman's rank correlation tests resulted in a significant association between TCA and morphological age estimates. Further studies using larger samples of known age material would help to improve our understanding of TCA age estimation performance relative to macroscopic age assessment as well as continued refinement and standardization of cementum sectioning, which is suggested to impact annulation visibility. PMID:23218650

  18. Influence of remaining dentin wall thickness on the fracture strength of endodontically treated tooth

    Science.gov (United States)

    Haralur, Satheesh B.; Al-Qahtani, Ali Saad; Al-Qarni, Marie Mohammed; Al-Homrany, Rami Mohammed; Aboalkhair, Ayyob Ehsan

    2016-01-01

    Background: Remaining dentin wall thickness may influence the fracture resistance of tooth. Aims: To investigate the effect of various coronal dentin wall widths on the fracture strength of root canal treated teeth. Materials and Methods: Fifty recently extracted single canal mandibular premolars were used for the study. Ten unrestored teeth were used as control (Group 1); remaining teeth were root canal treated and divided into four groups (n = 10). The Groups 2a, 2b and 3a, 3b were having 2.5 mm, 1.5 mm remaining dentin with and without post, respectively. The samples fracture resistance was tested under the universal testing machine. The data were analyzed with one-way ANOVA and post-hoc Tukey test for comparative evaluation. Results: The mean fracture strength observed in Group 1 was (29.75 Mpa) followed by Group 2a (28.97 Mpa), Group 2b (27.70 Mpa), Group 3a (23.39 Mpa), and Group 3b (16.38 Mpa). There was no statistically significant difference between control and Groups 2a and 2b with P > 0.05. The post contributed significantly for fracture resistance in Group 3a. Conclusion: The endodontic post is not required in root canal treated teeth >2.5 mm coronal dentin wall width while the post is essential for a tooth with <1.5 mm dentin wall width to improve fracture resistance.

  19. Electron microscopy analysis of different orthodontic brackets and their adhesion to the tooth enamel.

    Science.gov (United States)

    Ciocan, Delia Ioana; Stanciu, Drago?; Popescu, Manuela Anca; Miculescu, Florin; Plotog, Ioan; V?rzaru, Gauden?iu; Ciocan, Lucian Toma

    2014-01-01

    This study proposed to evaluate the surface morphology of different types of orthodontic brackets and the characteristics of their adhesion to the tooth enamel. There have been taken into study six metallic, five ceramic and one polymeric bracket from different brands (Ormco, Lancer, Leone, Damon, 3M, Ultradent, American Orthodontics, Rocky Mountain). The surface base of the each bracket it have been ESEM analyzed using scanning electron microscope Phillips XL-30 ESEM. There have been investigated several parameters that have a potential influence of the bracket-bonding agent interface joint: chemical composition, roughness, surface morphology and wideness. After ESEM analysis, the same metallic and ceramic brackets have been afterwards collated on extracted teeth and subjected to mechanical tests. After the mechanical testing, the samples were once again ESEM investigated. All fractures occurred in the area of the adhesive system, recording adhesive fractures of the tooth-composite resin and composite-bracket, cohesive fractures and both. The metallic brackets surfaces that are optima for a good adhesion is that of a mesh sand blasted and acid etched. From the esthetic brackets, the ceramic ones are superior to polymeric ones regarding bonding to teeth. PMID:25178330

  20. Three dimensional mathematical model of tooth for finite element analysis

    Directory of Open Access Journals (Sweden)

    Puškar Tatjana

    2010-01-01

    Full Text Available Introduction. The mathematical model of the abutment tooth is the starting point of the finite element analysis of stress and deformation of dental structures. The simplest and easiest way is to form a model according to the literature data of dimensions and morphological characteristics of teeth. Our method is based on forming 3D models using standard geometrical forms (objects in programmes for solid modeling. Objective. Forming the mathematical model of abutment of the second upper premolar for finite element analysis of stress and deformation of dental structures. Methods. The abutment tooth has a form of a complex geometric object. It is suitable for modeling in programs for solid modeling SolidWorks. After analyzing the literature data about the morphological characteristics of teeth, we started the modeling dividing the tooth (complex geometric body into simple geometric bodies (cylinder, cone, pyramid,.... Connecting simple geometric bodies together or substricting bodies from the basic body, we formed complex geometric body, tooth. The model is then transferred into Abaqus, a computational programme for finite element analysis. Transferring the data was done by standard file format for transferring 3D models ACIS SAT. Results. Using the programme for solid modeling SolidWorks, we developed three models of abutment of the second maxillary premolar: the model of the intact abutment, the model of the endodontically treated tooth with two remaining cavity walls and the model of the endodontically treated tooth with two remaining walls and inserted post. Conclusion Mathematical models of the abutment made according to the literature data are very similar with the real abutment and the simplifications are minimal. These models enable calculations of stress and deformation of the dental structures. The finite element analysis provides useful information in understanding biomechanical problems and gives guidance for clinical research.

  1. Generation of gear tooth surfaces by application of CNC machines

    Science.gov (United States)

    Litvin, F. L.; Chen, N. X.

    1994-01-01

    This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

  2. Root canal treatment of mandibular second premolar tooth with taurodontism

    Directory of Open Access Journals (Sweden)

    Vujašković Mirjana

    2008-01-01

    Full Text Available INTRODUCTION Taurodontism is a morphoanatomical change in the shape of a tooth. An enlarged body of a tooth with smaller than usual roots is a characteristic feature. Internal tooth anatomy correlates with this appearance, which means that a taurodontal tooth has a large pulp chamber and apically positioned furcations. This dental anomaly may be associated with different syndromes and congenital discoders. CASE OUTLINE The case report presents the patient of a rare case of taurodontism in the mandibular second premolar with chronic periodontitis. Endodontic treatment was performed after dental history and clinical examination. Special care is required in all segments of endodontic treatment of a taurodontal tooth from the identification orifice, canal exploration, determining working length, cleaning and shaping and obturation of the root canal. Precurved K-file was used for canal exploration and location of the furcation. One mesial and one distal canal with the buccal position were identified in the apical third of the root canal. The working lengths of two canals were determined by radiographic interpretation with two K-files in each canal and verified with the apex locator. During canal instrumentation, the third canal was located in the disto-lingual position. The working length of the third canal was established using the apex locator. CONCLUSION Thorough knowledge of tooth anatomy and its variations can lead to lower percentage of endodontic failure. Each clinical case involving these teeth should be investigated carefully, clinically and radiographically to detect additional root canals. High quality radiographs from different angles and proper instrumentarium improve the quality of endodontic procedure.

  3. In Vitro Color Change of Three Dental Veneering Resins in Tea, Coffee and Tamarind Extracts

    Directory of Open Access Journals (Sweden)

    S. Muttagi

    2011-09-01

    Full Text Available Objective: To study the in vitro color changes of three dental resin veneering materials when immersed in tea, coffee and tamarind extracts.Materials and Methods: The color changes of heat polymerized tooth colored acrylic resin (Stellondetrey, B, F14, DPI Dental products of India Ltd, Mumbai, auto polymerized tooth colored acrylic resin (DPI, B, QV5, DPI Dental products of India Ltd, Mumbai andlight polymerized resin composite (Herculite XRV, Enamel A2, part no. 22860, lot no. 910437, Kerr Corporation, West Collins Avenue, Orange, CA, USA when immersed in water extracts of tea (Tata Tea Ltd. Bangalore, India, coffee (Tata Coffee Ltd. Coorg, Indiaand tamarind were evaluated using computer vision systems. The color images were recorded in R (red, G (green and B (blue form and converted into H (hue, S (saturationand V (value.Results: Significant color change occurred for auto polymerized tooth colored acrylic resin in tamarind extract, for heat polymerized tooth colored acrylic resin in tea extract andfor light polymerized resin composite in coffee extract. Auto polymerized tooth colored acrylic resin samples showed an overall higher color change. However, for all the material samples coffee extract produced more color change.Conclusion: These results suggest that the color stability of the resins is influenced by the presence of secondary metabolites such as tartaric acid, tannins, caffeine, saponins and phenols in tamarind, tea and coffee extracts.

  4. Dosimetric studies of gamma irradiated tooth enamel using XRD analyses

    International Nuclear Information System (INIS)

    The structure of bovine teeth enamel before and after gamma irradiation was investigated via X-ray diffraction (XRD) analyses. The irradiation doses were conducted at the values ranging from 5 Gy to 5 kGy, respectively. Tooth enamel contains, mainly, crystals of hexagonal form. The radiation induced creation of carbonated free radicals and their concentration grew in a proportional manner to the irradiation dose resulting in a decrease in the crystallinity. In addition, the unit cell volume increases as the gamma radiation dose increases due to the increasing in a- and c-axes. Also, the strain increases giving rise to the disordering in tooth enamel samples as gamma dose increases

  5. Anomalies of tooth formation in hypohidrotic ectodermal dysplasia

    DEFF Research Database (Denmark)

    Lexner, Michala Oron; Bardow, Allan

    2007-01-01

    The X-linked hypohidrotic ectodermal dysplasia (HED) is the most common type of ectodermal dysplasia. The clinical identification of possible heterozygous females can be difficult because of the varying degrees of clinical signs caused by X-chromosome inactivation. This study is the first to elaborate on anomalies of tooth formation found in a group of hemizygous males and heterozygous females with known ED1 mutations. These tooth anomalies may be used as dental biomarkers for heterozygous females, enabling an earlier diagnosis, and therefore, better treatment and genetic counselling.

  6. Melatonin Effects on Hard Tissues: Bone and Tooth

    Directory of Open Access Journals (Sweden)

    Hong-Wen He

    2013-05-01

    Full Text Available Melatonin is an endogenous hormone rhythmically produced in the pineal gland under the control of the suprachiasmatic nucleus (SCN and the light/dark cycle. This indole plays an important role in many physiological processes including circadian entrainment, blood pressure regulation, seasonal reproduction, ovarian physiology, immune function, etc. Recently, the investigation and applications of melatonin in the hard tissues bone and tooth have received great attention. Melatonin has been investigated relative to bone remolding, osteoporosis, osseointegration of dental implants and dentine formation. In the present review, we discuss the large body of published evidence and review data of melatonin effects on hard tissues, specifically, bone and tooth.

  7. Molar tooth carbonates and benthic methane fluxes in Proterozoic oceans

    Science.gov (United States)

    Shen, Bing; Dong, Lin; Xiao, Shuhai; Lang, Xianguo; Huang, Kangjun; Peng, Yongbo; Zhou, Chuanming; Ke, Shan; Liu, Pengju

    2016-01-01

    Molar tooth structures are ptygmatically folded and microspar-filled structures common in early- and mid-Proterozoic (~2,500-750 million years ago, Ma) subtidal successions, but extremely rare in rocks methane generation and methanethiol inhibited anaerobic oxidation of methane, resulting in the buildup of CH4, formation of degassing cracks in sediments and an increase in the benthic methane flux from sediments. Precipitation of crack-filling microspar was driven by methanogenesis-related alkalinity accumulation. Deep ocean ventilation and oxygenation around 750 Ma brought molar tooth structures to an end.

  8. Delayed Tooth Replantation after Traumatic Avulsion: A Case Report

    OpenAIRE

    Khalilak, Zohreh; Shikholislami, Mahshid; Mohajeri, Ladan

    2008-01-01

    Avulsion is a serious injury which causes damage to dental and supportive tissues, ranging from 1-16 % among dental injuries and it mostly occurs in maxillary incisors. This report presents a case of replantation of a traumatically avulsed central incisor. The left central incisor of an 8 year-old boy with open apex was avulsed and was left in unclean and dry conditions. Tooth was replaced after 270 min and splinted. After 24 hours, tooth was treated endodontically. The calcium hydroxide past...

  9. Metabolism in tooth enamel and reliability of retrospective dosimetry

    International Nuclear Information System (INIS)

    Most of the radiation centers in tooth enamel and bones are formed by the reactions COOH+??CO-2+H+, and CO2+e-?CO-2. These centers can be easily changed by metabolism and have a low stability in living organisms. The efficiency of CO-2 radical production by irradiation is substantially different for teeth and bones in living rat, dead rat, and teeth and bone removed from rat. It is shown that the suitability of tooth enamel for retrospective dosimetry can be evaluated from the anisotropy of its EPR signals

  10. Tooth enamel sample preparation using alkaline treatment in ESR dosimetry

    International Nuclear Information System (INIS)

    Tooth enamel sample preparation using alkaline treatment was studied and compared with traditional mechanical method in this paper. 20 adult teeth were used. Samples were placed into NaOH solution. This method requires 4-5 weeks and the enamel was separated from dentin. Experimental results show that 8M NaOH was appropriate for separating enamel from dentin and that there is no difference in background signal relative intensity between samples prepared by mechanical and by chemical methods. There is also no difference in radiosensitivity between samples prepared by two methods mentioned above. Dose response curve for tooth enamel samples isolated by 8M NaOH solution was obtained

  11. Restoration of noncarious tooth defects by dentists in The Dental Practice-Based Research Network

    DEFF Research Database (Denmark)

    Nascimento, Marcelle M; Gordan, Valeria V

    2011-01-01

    The authors conducted a study to quantify the reasons for restoring noncarious tooth defects (NCTDs) by dentists in The Dental Practice-Based Research Network (DPBRN) and to assess the tooth, patient and dentist characteristics associated with those reasons.

  12. Regeneration of tooth-like hydroxyapatite depended on amelogenin functional section monolayer: a new approach for tooth repair.

    Science.gov (United States)

    Tian, Kun; Peng, Min; Ren, Xiaohua; Liao, Chuhang; Fei, Wei

    2012-08-01

    Tooth defect due to caries, trauma, or acid corrosion are common in mankind. Ceramics, metal and resin were used to repaired tooth defect in the past hundred years, but they cannot instead enamel and dentin in depth in clinic usage for the difference in structure and element. So the formation of organized nanocrystals that resemble enamel is crucial for successful enamel remineralization. Now synthesizing a mimicking structure of human enamel using acellular methods has attracted much interest from research groups who have tried using recombinant enamel making proteins like amelogenin, surfactants, to mimic the biomineralization process to restore the enamel layer. Since amelogenin can be used in the assembly of functional nanostructures, we hypothesis that rationally designed ?-sheet-forming peptides that spontaneously form three-dimensional fibrillar scaffolds in response to specific environmental triggers may potentially be used in inducing tooth-like hydroxyapatite crystal ex vivo which important to treatment/prevention of dental caries, via bioactive surface groups. PMID:22564781

  13. Clinical evaluation of postradiation dental extraction

    International Nuclear Information System (INIS)

    Twenty-one patients who had undergone postradiation dental extraction were evaluated clinically. All patients had received irradiation for primary head and neck malignancies at doses ranging from 8 to 60 Gy (mean, 51.6 Gy). Time to dental extraction after irradiation ranged from 8 to 156 months (mean, 57.9 months). Of the 21 patients (80 teeth extracted, including 33 maxillary teeth and 47 mandibular teeth), one had delayed healing after wisdom tooth extraction due to postextraction irradiation. Thus, osteoradionecrosis after dental extraction did not develop. These results suggest that dental extraction after radiation is not contraindicated. To prevent complications, patients who have received radiation and require extractions should be cared for by oral and maxillofacial surgeons in close association with radiation oncologists. (author)

  14. Restoration of noncarious tooth defects by dentists in The Dental Practice-Based Research Network

    DEFF Research Database (Denmark)

    Nascimento, Marcelle M; Gordan, Valeria V; Qvist, Vibeke; Bader, James D; Rindal, D Brad; Williams, O Dale; Gewartowski, Daniel; Fellows, Jeffrey L; Litaker, Mark S; Gilbert, Gregg H

    2011-01-01

    The authors conducted a study to quantify the reasons for restoring noncarious tooth defects (NCTDs) by dentists in The Dental Practice-Based Research Network (DPBRN) and to assess the tooth, patient and dentist characteristics associated with those reasons.......The authors conducted a study to quantify the reasons for restoring noncarious tooth defects (NCTDs) by dentists in The Dental Practice-Based Research Network (DPBRN) and to assess the tooth, patient and dentist characteristics associated with those reasons....

  15. Tooth loss patterns in older adults with special needs: a Minnesota cohort

    OpenAIRE

    Chen, Xi; Clark, Jennifer J.

    2011-01-01

    This study was conducted to detail tooth loss patterns in older adults with special needs. A total of 491 elderly subjects with special needs were retrospectively selected and followed during 10/1999-12/2006. Medical, dental, cognitive, and functional assessments were abstracted from dental records and used to predict risk of tooth loss. Tooth loss events were recorded for subjects during follow-up. Chi-squared tests were used to study the association between tooth loss and the selected risk ...

  16. In vivo PIXE-PIGE study of enhanced retention of fluorine in tooth enamel after laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Demortier, Guy [Department of Physics, University of Namur, 61, rue de Bruxelles, B5000 Namur (Belgium)], E-mail: guy.demortier@tvcablenet.be; Nammour, Samir [Faculty of Medicine, University of Liege, 8, rue Paul Spaak, B-1000 Bruxelles (Belgium)

    2008-05-15

    The presence of fluoride in tooth enamel reduces the solubility of hydroxylapatite by acid attack. Fluoride presence (even at low concentration) in the oral cavity is efficient against caries process. We propose a new approach of the explanation of the increase of fluoride retention in the tooth enamel when low power laser irradiation is applied after the treatment with fluoride gel (fluoridation). External beam PIGE measurements of fluorine on extracted teeth have been made in order to determine the best sequence of the operations. The laser irradiation after fluoride application is more efficient than the reverse procedure. This observation is in agreement with previous observations that the fluorine penetration in the enamel takes place first in the soft organic material present between the polycrystalline (prismatic) structure before being integrated in the crystalline composition of hydroxylapatite in order to produce fluoro-apatite. As those in vitro measurements do not reflect the whole process in the saliva, in vivo PIGE measurements have been also performed. We have demonstrated, by repeating the PIGE measurements (at least five times at various time intervals) that a significant increase of the fluoride retention took place even 18 months after the unique laser treatment. The complete experimental procedure is described: fluoride application, laser irradiation, PIGE measurements with 2.7 MeV protons (repeated measurements at the same place on the same tooth in order to follow the evolution) and safety tests before in vivo analyses.

  17. The Effect of Diode Laser Treatment for Root Canal Disinfection on Fracture Resistance and Micro-hardness of the Tooth

    International Nuclear Information System (INIS)

    This study evaluated the effect of diode laser treatment for root canal disinfection on fracture resistance and micro-hardness of the tooth. Sixty freshly extracted mandibular and maxillary premolars were accessed under coolant then root canals were flared up to apical preparation size 40 MFA coupled with 5.25% NaOCl as an irrigant. Teeth were divided into two groups, control group (group I) and lased group (group II) that was lased by diode laser with average power 2 w through fibrooptic into the canal 2 mm shorter than the apex. Each tooth was embedded in acrylic block, and then subjected to the fracture resistance test. Each root was then sectioned transversely and polished to record dentin Vickers hardness. Data was analysed with student t-test then with linear regression test. The Lased samples presented a significantly higher resistance to fracture than unlased samples. There was no statistically significant differences found between Vickers hardness (HV) of lased and unlased samples and there was no relation between fracture resistance and microhardness. Diode laser (980 nm) treatment had no adverse effect on dentin microhardness, also it increased the fracture resistance of dentin. Diode laser (980 nm) treatment could attain better function ability and maintenance of tooth after endodontic treatment.

  18. Effect of Low Level Laser Therapy on Orthodontic Tooth Movement: A Review Article

    OpenAIRE

    Soghra Yassaei; Reza Fekrazad; Neda Shahraki

    2013-01-01

    Increased duration of fixed orthodontic treatments leads to increased tooth root degeneration, gum inflammation and tooth caries. To decrease the time period of orthodontic treatment, it is essential to facilitate tooth movement or in other words increase the speed of bone remodeling. Use of low level laser therapy is a method for achieving this goal.

  19. On optimization of internal/external spur gears tooth bending strength

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    Gear fatigue strength is primarily controlled by the durability and load capacity, the first is typically related to pitting damage and the second to tooth-breakage. The pitting is due to the tooth contact and the shape of the contacting surfaces, the tooth breakage is controlled by the stress...

  20. 21 CFR 872.3900 - Posterior artificial tooth with a metal insert.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Posterior artificial tooth with a metal insert... SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3900 Posterior artificial tooth with a metal insert. (a) Identification. A posterior artificial tooth with a metal insert is...

  1. 21 CFR 872.3910 - Backing and facing for an artificial tooth.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Backing and facing for an artificial tooth. 872.3910 Section 872.3910 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... artificial tooth. (a) Identification. A backing and facing for an artificial tooth is a device intended...

  2. Measurement accuracy and reliability of tooth length on conventional and CBCT reconstructed panoramic radiographs

    Scientific Electronic Library Online (English)

    Carlos, Flores-Mir; Mark R, Rosenblatt; Paul W., Major; Jason P., Carey; Giseon, Heo.

    2014-10-01

    Full Text Available INTRODUÇÃO: este estudo in vivo avaliou a precisão e a confiabilidade de medições do comprimento dentário realizadas em radiografias panorâmicas convencionais e em reconstruções panorâmicas de tomografias computadorizadas de feixe cônico (TCFC), comparando-as com medições feitas com um paquímetro [...] digital, consideradas o padrão-ouro. MÉTODOS: a amostra incluiu indivíduos que já tivessem realizado tanto exames imaginológicos de TCFC quanto radiografias panorâmicas, e cujo tratamento ortodôntico exigisse a extração de pré-molar superior. No total, 48 dentes extraídos, de 26 pacientes, foram mensurados diretamente com paquímetros digitais. As radiografias foram escaneadas e digitalmente avaliadas com a ajuda do software Dolphin 3D. Por meio da análise de variância simples com correção de Bonferroni e Coeficiente de Correlação Intraclasse simples, comparou-se a precisão das medições de comprimento dentário realizadas em reconstruções panorâmicas de TCFC, em radiografias panorâmicas convencionais e com paquímetro digital. RESULTADOS: medições repetidas de comprimento dentário feitas com o paquímetro digital, radiografias panorâmicas e reconstruções panorâmicas de TCFC foram todas consideradas, individualmente, altamente confiáveis. Em comparação ao paquímetro, as medidas obtidas por meio de radiografias panorâmicas convencionais foram, em média, 6,3 ± 2,0mm mais longas, enquanto as medidas obtidas por meio das reconstruções panorâmicas de TCFC foram, em média, 1,7 ± 1,2mm mais curtas. CONCLUSÕES: em comparação com o real comprimento dentário, as radiografias panorâmicas convencionais foram relativamente imprecisas e superestimaram o comprimento em 29%; já as reconstruções panorâmicas de TCFC subestimaram o comprimento em 4%. Abstract in english INTRODUCTION: This in vivo study assessed accuracy and reliability of tooth length measurements obtained from conventional panoramic radiographs and CBCT panoramic reconstructions to that of a digital caliper (gold standard). METHODS: The sample consisted of subjects who had CBCT and conventio [...] nal panoramic radiographic imaging and who required maxillary premolar extraction for routine orthodontic treatment. A total of 48 teeth extracted from 26 subjects were measured directly with digital calipers. Radiographic images were scanned and digitally measured in Dolphin 3D software. Accuracy of tooth length measurements made by CBCT panoramic reconstructions, conventional panoramic radiographs and digital caliper (gold standard) were compared to each other by repeated measures one-way ANOVA with Bonferroni correction and by single measures intraclass correlation coefficient. RESULTS: Repeated root length measures with digital calipers, panoramic radiographs and CBCT constructed panoramic-like images were all individually highly reliable. Compared to the caliper (gold standard), tooth measurements obtained from conventional panoramic radiographs were on average 6.3 mm (SD = 2.0 mm) longer, while tooth measurements from CBCT panoramic reconstructions were an average of 1.7 mm (SD = 1.2 mm) shorter. CONCLUSIONS: In comparison to actual tooth lengths, conventional panoramic radiographs were relatively inaccurate, overestimating the lengths by 29%, while CBCT panoramic reconstructions underestimated the lengths by 4%.

  3. Association of physical properties and maintenance of sterility of primary teeth in human tooth bank

    Directory of Open Access Journals (Sweden)

    Nitika Bajaj

    2014-01-01

    Full Text Available Background: This study was carried out to evaluate the sterility and structural integrity of stored primary teeth in artificial saliva over a storage period of 12 weeks (3 months in human tooth bank (HTB. Materials and Methods: A total of 80 freshly extracted teeth were taken and were categorized into four groups of 20 each. The samples were stored at 4°C for 12 weeks (3 months in the refrigerator. During their storage time of 3 months, they were repetitively evaluated for their sterility, enamel hardness, calcium and phosphate solubility and color stability at regular intervals of 3 weeks. Observations and Results: That teeth stored in artificial saliva maintained their sterility throughout the storage time of 12 weeks, but changes in their physical and chemical properties occurred with an increase in storage time. Conclusion: Storage time not more than 9 weeks is recommended for deciduous teeth to be stored in artificial saliva in a HTB.

  4. Age-related peculiarities of tooth enamel as a natural EPR biodosimeter

    International Nuclear Information System (INIS)

    The influence of age on tooth enamel as an EPR dosimeter has been investigated using a big collection of teeth extracted from several tens of persons living in different regions of Ukraine. The study was focused on two groups of teeth. The first one represented the urban population while the second corresponded to residents of rural settlements. Age dependences of two above groups were quite different: for example, doses for the 65-75 year age group were approximately 200 mGy higher for urban population compared to habitants of rural settlements. This effect was explained by contribution of medical X-ray exposure: the comparison of corresponding lingual and buccal doses revealed the more frequent presence of X-ray dose for urban population. Another observed effect was the difference between average intensities of native signals for two studied groups. At present time, no correlation with age was seen for this effect

  5. ESR Dosimetry Below 1 Gy, in X-Ray Irradiated Tooth Enamel

    International Nuclear Information System (INIS)

    Tooth enamel, extracted from molars, was irradiated with 66keV X-rays, with doses up to 1Gy.The preparation of the powder samples is described, as well as the protocol for the acquisition and processing of the spectra.The radiation induced paramagnetism is measured, at room temperature, by ESR Spectroscopy.The ESR spectra is well described considering two paramagnetic species, with magnetic moments (in units of Bohr magnetons) g=2,0041, and g1=2,0018, g2=1,9972.The ESR data (peak-to-peak amplitude per mg, hpp/mg, vs dose D), for doses 0Gy2 =0,996) with the linear expression: [hpp/mg] = -0,2( 0,4)+14,9(0,5). D [Gy].The result supports the growing confidence in the use of this material, and method, in Retrospective Dosimetry

  6. Effect of bleaching gel in Ca, P and Zn content in tooth enamel evaluated by ?-EDXRF

    Science.gov (United States)

    Godinho, J.; Silveira, J.; Mata, A.; Carvalho, M. L.; Pessanha, S.

    2014-10-01

    The purpose of this in vitro study is to assess whether the elemental content of P, Ca and Zn in tooth enamel is altered when bleaching the teeth with bleaching gel. In order to perform this evaluation, sound vestibular surfaces of six anterior healthy teeth, extracted for periodontal or orthodontic reasons were used. Cuts were made in order to obtain 8 × 2 mm samples. Samples were then treated with the bleaching product (Opalescence PF 10%) accordingly to manufacturer instructions and stocked in artificial saliva between each application. The elemental content of each sample, before and after treatment was obtained by a portable micro Energy Dispersive X-ray Spectrometry (?-EDXRF), making use of a polycapillary optic to obtain a focal spot of 100 ?m for Fe-K?. Quantitative calculations were obtained by WinAXIL compare mode method, using four standard reference materials. The obtained results show that no significant statistic differences were observed for the studied elements.

  7. Dose estimation of two victims in a severe radiation accident by using tooth enamel

    International Nuclear Information System (INIS)

    Objective: To estimate the exposed dose levels of 2 two victims, who died one month after they were accidentally irradiated by Cobalt-60. Methods: Three teeth were extracted from 2 victims. The signal intensities of separated enamel samples were measured with ESR spectrometer. The accumulated exposed doses were reconstructed according to a calibration curve established using Cobalt-60 ?-rays. Results: A calibration curve between signal intensity and exposed dose was established. The estimated doses of 3 teeth were 26.1 ? 29.4 Gy, for victim A, 14.9 ? 18.3 Gy and 15.2 ? 18.5 Gy for victim B. The doses are close to the result of the other Laboratory. Conclusion: The application of ESR dosimetry in human tooth enamel could provide important information for a dose estimation of victims exposed to heavy doses of radiation. (authors)

  8. Study on the tooth enamel as a personal life-time dosimeter

    International Nuclear Information System (INIS)

    This paper is a summary of the results of basic and applied research on dental electron spin resonance (ESR) dosimetry for more than 15y. The material used in these experiments is enamel of human permanent teeth, which were extracted during normal dental treatment. The enamel was scrupulously separated from other parts of teeth with skillful techniques, pulverized in an agate mortar, and then sifted through several sieves to collect the uniform particle size. ESR measurements of the enamel samples were carried out at room temperature using an X-band spectrometer (JEOLRE1X). Although the limitations of ESR signal detection still remain, the study shows the useful application of dental ESR dosimetry not only in cases of radiation accidents and radiation therapy but also in cases of routine radiation work. The tooth enamel can be considered as a life-time dosimeter. (author)

  9. Patient satisfaction and esthetic outcome after immediate placement and provisionalization of single-tooth implants involving a definitive individual abutment

    DEFF Research Database (Denmark)

    Hartlev, Jens; Kohberg, Peter

    2014-01-01

    OBJECTIVES: To assess patient satisfaction and esthetic outcome after immediate placement and provisionalization of single-tooth implants involving a definitive individual abutment and a provisional crown followed by later placement of a definitive crown. MATERIALS AND METHODS: In private practice, a single-tooth implant was placed immediately after tooth extraction in the esthetic zone of 54 patients. A definitive individual abutment and a provisional crown were mounted in the same visit. The definitive crown was placed after a mean period of 7 months. After a mean follow-up period of 33 months, the subjective and professional evaluation of the total implant treatment, peri-implant soft tissues, and implant crown were assessed on a 10-cm visual analog scale (VAS). The professional esthetic treatment outcome was also evaluated using pink esthetic score (PES), white esthetic score (WES), and total score of PES/WES. RESULTS: The evaluation of total implant treatment, peri-implant soft tissues, and implant crown demonstrated a significantly higher subjective than professional score for all 3 parameters (P < 0.001), for example, for the overall treatment, the mean scores were 9.4 and 7.0, respectively. A significant positive correlation was revealed between the professional VAS scores and the PESs and WESs. CONCLUSIONS: Immediate placement and provisionalization of single-tooth implants involving a definitive individual abutment and provisional crown followed by later placement of a definitive crown demonstrated high subjective and professional satisfaction. Generally, the professionals seem to be more critical than the patients. A strong correlation was observed between the professional VAS scores and the PES and WES scoring systems.

  10. Functional convergence in bat and toothed whale biosonars

    DEFF Research Database (Denmark)

    Madsen, P T; Surlykke, A

    2013-01-01

    Echolocating bats and toothed whales hunt and navigate by emission of sound pulses and analysis of returning echoes to form a self-generated auditory scene. Here, we demonstrate a striking functional convergence in the way these two groups of mammals independently evolved the capability to sense with sound in air and water.

  11. Hair keratin mutations in tooth enamel increase dental decay risk.

    Science.gov (United States)

    Duverger, Olivier; Ohara, Takahiro; Shaffer, John R; Donahue, Danielle; Zerfas, Patricia; Dullnig, Andrew; Crecelius, Christopher; Beniash, Elia; Marazita, Mary L; Morasso, Maria I

    2014-12-01

    Tooth enamel is the hardest substance in the human body and has a unique combination of hardness and fracture toughness that protects teeth from dental caries, the most common chronic disease worldwide. In addition to a high mineral content, tooth enamel comprises organic material that is important for mechanical performance and influences the initiation and progression of caries; however, the protein composition of tooth enamel has not been fully characterized. Here, we determined that epithelial hair keratins, which are crucial for maintaining the integrity of the sheaths that support the hair shaft, are expressed in the enamel organ and are essential organic components of mature enamel. Using genetic and intraoral examination data from 386 children and 706 adults, we found that individuals harboring known hair disorder-associated polymorphisms in the gene encoding keratin 75 (KRT75), KRT75(A161T) and KRT75(E337K), are prone to increased dental caries. Analysis of teeth from individuals carrying the KRT75(A161T) variant revealed an altered enamel structure and a marked reduction of enamel hardness, suggesting that a functional keratin network is required for the mechanical stability of tooth enamel. Taken together, our results identify a genetic locus that influences enamel structure and establish a connection between hair disorders and susceptibility to dental caries. PMID:25347471

  12. Charcot-Marie-Tooth disease type 1A

    DEFF Research Database (Denmark)

    Hertz, Jens Michael; Børglum, A D; Brandt, C A; Flint, T; Bisgaard, C

    1994-01-01

    Charcot-Marie-Tooth disease type 1A (CMT1A) is an autosomal dominant peripheral neuropathy associated with a DNA duplication on chromosome 17p11.2-p12 in the majority of cases. Most of the sporadic cases are due to a de novo duplication. We have screened for this duplication in 11 Danish patients...

  13. Hand Involvement in Charcot-Marie-Tooth Disease 1A

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-12-01

    Full Text Available Hand strength, function and disease-related symptoms were determined in 84 children, aged 2-16 years, with Charcot-Marie-Tooth disease type 1A (CMT1A at University of Sydney, Children’s Hospital at Westmead, and Royal Children’s Hospital, Parkville, Australia.

  14. Hand Involvement in Charcot-Marie-Tooth Disease 1A

    OpenAIRE

    J. Gordon Millichap

    2008-01-01

    Hand strength, function and disease-related symptoms were determined in 84 children, aged 2-16 years, with Charcot-Marie-Tooth disease type 1A (CMT1A) at University of Sydney, Children’s Hospital at Westmead, and Royal Children’s Hospital, Parkville, Australia.

  15. Surgical treatments of the impacted canine tooth in young dogs

    International Nuclear Information System (INIS)

    Surgical treatments of the impacted canine tooth were carried out in 8 young dogs, and the results were successful in 12 out of 14 cases (85.7%). The treatments consisting of surgical correction by immediate tipping movement, fenestration of the gingiva, and removal of the impacted tooth, were applied to 14 cases radiographically showing the immature tooth root and no abnormalities in the tooth root or alveolar bone. Impacted teeth were seen in 8 regions of the maxilla and 6 regions of the mandible. Mesioversion was seen in almost all maxillary impacted teeth, while linguoversion or lingual mesioversion in all mandibular cases. Surgical correction was carried out by immediate tipping movement after removal of the retained deciduous canine with or without resection of the alveolar bone. Fixation of the moved teeth was done using a wedge made from the deciduous canine root, which was driven into the vacant alveolar cavity after moving. An additional fixation using a steel wire and/or self-curing resin was done, if necessary

  16. Contribution of the tooth bud mesenchyme to alveolar bone.

    Czech Academy of Sciences Publication Activity Database

    Diep, L.; Matalová, Eva; Mitsiadis, T. A.; Tucker, A. S.

    312B, ?. 5 (2009), 510-517. ISSN 1552-5007 R&D Projects: GA ?R GC524/08/J032; GA AV ?R KJB500450802 Institutional research plan: CEZ:AV0Z50450515 Keywords : tooth * alveolar bone * bud Subject RIV: FF - HEENT, Dentistry Impact factor: 2.938, year: 2009

  17. Tooth agenesis: from molecular genetics to molecular dentistry.

    Czech Academy of Sciences Publication Activity Database

    Matalová, Eva; Fleischmannová, Jana; Sharpe, P. T.; Tucker, A. S.

    2008-01-01

    Ro?. 87, ?. 7 (2008), s. 617-623. ISSN 0022-0345 R&D Projects: GA AV ?R KJB500450802; GA MŠk OC B23.001; GA ?R GC524/08/J032 Institutional research plan: CEZ:AV0Z50450515 Keywords : tooth agenesis Subject RIV: FF - HEENT, Dentistry Impact factor: 3.142, year: 2008

  18. Diagnostics of power transmissions system with tooth gear

    Directory of Open Access Journals (Sweden)

    Grzegorz WOJNAR

    2008-01-01

    Full Text Available This paper presents results of laboratory tests that were aimed at detecting early stages of various faults in toothed wheels by measurement and analysis of transverse vibration speed of the transmission gear shafts. In experimental investigation, cracking of the root tooth and chipping of the tooth were detected. The laser vibrometer Ometron VH300+ was used for non-contact measurement of shaft transversal vibration speed. Gear vibrations were recorded in selected points of gear housing and gear shafts at different speeds and gear loads. Results were analyzed and compared but in this paper is presented only selected examples. This paper shows that on the basis of the transverse vibration speed of transmission gear shafts, it is possible to detect defects at an earlier stage than on the basis of the housing vibration accelerations. In the case of measuring gear shaft vibration velocity, the way of the signal generated by the defect of a gear wheel (or bearing is shortened as well as the influence of composed transmittance of the bearing-gear housing system is eliminated. WV time-frequency analysis and complex continuous wavelet transformations were used for detection. The authors introduced a measure of local tooth damage, which was proportional to the size of damage. The results of research presented in this paperconfirmed that the defect's measure is very sensitive to the development of teeth faults.

  19. Pinion tooth surface generation strategy of spiral bevel gears

    Science.gov (United States)

    Liu, Guanglei; Fan, Hongwei

    2012-07-01

    Aviation spiral bevel gears are often generated by spiral generated modified (SGM) roll method. In this style, pinion tooth surface modified generation strategy has an important influence on the meshing and contact performances. For the optimal contact pattern and transmission error function, local synthesis is applied to obtain the machine-tool settings of pinion. For digitized machine, four tooth surface generation styles of pinion are proposed. For every style, tooth contact analysis (TCA) is applied to obtain contact pattern and transmission error function. For the difference between TCA transmission error function and design objective curve, the degree of symmetry and agreement are defined and the corresponding sub-objective functions are established. Linear weighted combination method is applied to get an equivalent objective function to evaluate the shape of transmission error function. The computer programs for the process above are developed to analyze the meshing performances of the four pinion tooth surface generation styles for a pair of aviation spiral bevel gears with 38/43 teeth numbers. The four analytical results are compared with each other and show that the incomplete modified roll is optimal for this gear pair. This study is an expansion to generation strategy of spiral bevel gears, and offers new alternatives to computer numerical control (CNC) manufacture of spiral bevel gears.

  20. Tooth bleaching--a critical review of the biological aspects

    DEFF Research Database (Denmark)

    Dahl, J E; Pallesen, Ulla

    2003-01-01

    Present tooth-bleaching techniques are based upon hydrogen peroxide as the active agent. It is applied directly, or produced in a chemical reaction from sodium perborate or carbamide peroxide. More than 90% immediate success has been reported for intracoronal bleaching of non-vital teeth, and in...

  1. Protection and Reinforcement of Tooth Structures by Dental Coating Materials

    Directory of Open Access Journals (Sweden)

    Toru Nikaido

    2012-10-01

    Full Text Available It has been proposed that a resin coating can serve as a means to protect dental structure after preparation of the tooth for indirect restorations, sealing the exposed dentin. The resin coating is applied on the cut surfaces immediately after tooth preparation and before making an impression by assembling a dentin bonding system and a flowable composite. Resin coatings minimize pulp irritation and improve the bond strength between a resin cement and tooth when bonding the restoration to tooth. Recently, thin-film coating dental materials based on all-in-one adhesive technology were introduced for resin coating of indirect restorations. The thin coating materials are applied in a single clinical step and create a barrier-like film layer on the prepared dentin. The thin coatings play an important role in protecting the dentin from physical, chemical, and biological irritation. In addition, these thin-film coating materials reportedly prevent marginal leakage beneath inlays or crown restorations. In light of the many benefits provided by such a protective layer, these all-in-one adhesive materials may therefore also have the potential to cover exposed root dentin surfaces and prevent caries formation. In this paper, recent progress of the dental coating materials and their clinical applications are reviewed.

  2. Functional convergence in bat and toothed whale biosonars

    DEFF Research Database (Denmark)

    Madsen, P T; Surlykke, A

    2013-01-01

    Echolocating bats and toothed whales hunt and navigate by emission of sound pulses and analysis of returning echoes to form a self-generated auditory scene. Here, we demonstrate a striking functional convergence in the way these two groups of mammals independently evolved the capability to sense...

  3. Caspase-7 tooth germ and hair follicle development and maintenance.

    Czech Academy of Sciences Publication Activity Database

    Veselá, Barbora; Matalová, Eva

    Rome : ECDO, 2012. 257-257. [Euroconference from Death to Eternity /20./ and Training course on Concepts and Methods in Programmed Cell Death /9./. 14.09.2012-17.09.2012, Rome] R&D Projects: GA ?R(CZ) GAP502/12/1285 Institutional support: RVO:67985904 Keywords : caspase-7 * hair follicle * tooth germ Subject RIV: EA - Cell Biology

  4. TLR signalling can modify the mineralization of tooth germ.

    Science.gov (United States)

    Papp, Tamas; Hollo, Krisztina; Meszar-Katona, Eva; Nagy, Zoltan; Polyak, Angela; Miko, Edit; Bai, Peter; Felszeghy, Szabolcs

    2016-05-01

    Objective The aim of this work is to investigate the possible role of Toll-like receptor 4 (TLR4) during the development of mouse tooth germ. TLR4 is well known to inhibit mineralization and cause inflammation in mature odontoblasts and dental pulp cells. However, unlike these pathological functions of TLR4, little is known about the developmental function(s) of TLR4 during tooth development. Materials and methods TLR4 expression was studied via Western blot in developing lower mouse incisors from E13.5 to E18.5. To generate functional data about the effects of TLR4, a specific agonist (LPS) was applied to the medium of in vitro tooth germ cultures, followed by Western blot, histochemical staining, ELISA assay, in situ hybridization and RT-qPCR. Results Increased accumulation of biotin-labelled LPS was detected in the enamel organ and in preodontoblasts. LPS treatment induced degradation of the inhibitor molecule (IκB) of the NF-κB signalling pathway. However, no morphological alterations were detected in cultured tissue after LPS addition at the applied dosage. Activation of TLR4 inhibited the mineralization of enamel and dentin, as demonstrated by alizarin red staining and as decreased levels of collagen type X. mRNA expression of ameloblastin was elevated after LPS administration. Conclusion These results demonstrate that TLR4 may decrease the mineralization of hard tissues of the tooth germ and may trigger the maturation of ameloblasts; it can give valuable information to understand better congenital tooth abnormalities. PMID:26763602

  5. Tooth engineering: searching for dental mesenchymal cells sources.

    Directory of Open Access Journals (Sweden)

    HervéLesot

    2011-03-01

    Full Text Available The implantation of cultured re-associations between embryonic dental mesenchymal cells and epithelial cells from mouse molars at ED14 allowed making full teeth with crown, root, periodontal ligament fibers and bone. Although representing valuable tools to set up methodologies embryonic cells are not easily available. This work thus aimed to replace the embryonic cells by dental mesenchymal cell lines or cultured expanded embryonic cells, and to test their ability to mediate tooth development in vitro when re-associated with a competent dental epithelium. Histology, immunostaining and RT-PCR allowed getting complementary sets of results. Two different immortalized cell lines from ED18 dental mesenchyme failed in mediating tooth formation. The potentialities of embryonic dental mesenchymal cells decreased from ED14 to ED16 and were lost at ED18. This is likely related to a change in the mesenchymal cell phenotype and/or populations during development. Attempts to cultivate ED14 or ED16 embryonic dental mesenchymal cells prior to re-association led to the loss of their ability to support tooth development. This was accompanied by a down-regulation of Fgf3 transcription. Supplementation of the culture medium with FGF2 allowed restoring Fgf3 expression, but not the ability of mesenchymal cells to engage in tooth formation. Altogether, these observations suggest that a competent cell population exists in the dental mesenchyme at ED14, progressively decreases during development, and cannot as such be maintained in vitro. This study evidenced the need for specific conditions to maintain the ability of dental mesenchymal cells to initiate whole tooth formation, when re-associated with an odontogenic epithelium. Efforts to improve the culture conditions will have to be combined with attempts to characterize the competent cells within the dental mesenchyme.

  6. Comparative Study of Streptococcus mutans Laboratory Strains and Fresh Isolates from Carious and Caries-Free Tooth Surfaces and from Subjects with Hereditary Fructose Intolerance

    OpenAIRE

    Vadeboncoeur, Christian; Trahan, Luc

    1983-01-01

    This study was undertaken to investigate and compare some biochemical and physiological properties related to sugar metabolism of 4 laboratory strains and 13 freshly isolated strains of Streptococcus mutans from carious and caries-free tooth surfaces and from subjects with hereditary fructose intolerance. Growth in Trypticase (BBL Microbiology Systems)-yeast extract in the presence of various sugars was almost the same for all of the fresh isolates, which grew generally better than the labora...

  7. In vitro color change of three dental veneering resins in tea, coffee and tamarind extracts

    OpenAIRE

    Muttagi, S.; J.K. Subramanya

    2011-01-01

    Objective: To study the in vitro color changes of three dental resin veneering materials when immersed in tea, coffee and tamarind extracts.Materials and Methods: The color changes of heat polymerized tooth colored acrylic resin (Stellondetrey, B, F14, DPI Dental products of India Ltd, Mumbai), auto polymerized tooth colored acrylic resin (DPI, B, QV5, DPI Dental products of India Ltd, Mumbai) andlight polymerized resin composite (Herculite XRV, Enamel A2, part no. 22860, lot no. 910437, Kerr...

  8. Computation of tooth axes of existent and missing teeth from 3D CT images.

    Science.gov (United States)

    Wang, Yang; Wu, Lin; Guo, Huayan; Qiu, Tiantian; Huang, Yuanliang; Lin, Bin; Wang, Lisheng

    2015-12-01

    Orientations of tooth axes are important quantitative information used in dental diagnosis and surgery planning. However, their computation is a complex problem, and the existing methods have respective limitations. This paper proposes new methods to compute 3D tooth axes from 3D CT images for existent teeth with single root or multiple roots and to estimate 3D tooth axes from 3D CT images for missing teeth. The tooth axis of a single-root tooth will be determined by segmenting the pulp cavity of the tooth and computing the principal direction of the pulp cavity, and the estimation of tooth axes of the missing teeth is modeled as an interpolation problem of some quaternions along a 3D curve. The proposed methods can either avoid the difficult teeth segmentation problem or improve the limitations of existing methods. Their effectiveness and practicality are demonstrated by experimental results of different 3D CT images from the clinic. PMID:25941910

  9. Impact of Local Application of Clindamycin in Preventing Dry Socket after Third Mandibular Molar Extraction

    OpenAIRE

    Vjosa Hamiti-Krasniqi; Zana Agani; Gafur Shtino; Mergime Loxha; Jehona Ahmedi; Aida Rexhepi

    2014-01-01

    Extraction of third mandibular tooth is one of the most commonly performed surgical procedures in oral surgery. One of the most common complications following the extraction of third mandibular molar teeth is dry socket (alveolar osteitis). Dry socket is the delayed healing of the wound of the alveolar bone after dental extractions. The purpose of this study was to determine if the intra-alveolar application of Clindamycin could reduce the incidence of dry socket following the extraction of t...

  10. [The inaccuracy of the panoramic radiograph as a tool to determine tooth inclination].

    Science.gov (United States)

    Brezniak, N; Birnboim-Blau, G; Bar-Hama, P; Zoizner, R; Dinbar, A; Wasserstein, A

    2012-01-01

    The panoramic radiograph is one of the most common radiographs in orthodontics. It is sometimes used as an aid for the decision which teeth should be extracted as part of the individual treatment plan. When treating patients with clear plates (for example, Invisalign), it is very important to know the inclination direction of the involved teeth. Tipping is more predictable and it takes less time than bodily movement. The objective of this paper is to demonstrate the limitations of the panoramic radiograph in the decision making process related extraction in orthodontics. An eleven years old girl with lower anterior crowding of about 5 mm was examined prior to her orthodontic treatment. One possible treatment plan, in order to relieve the crowding, was to extract two lower bicuspids. The other treatment plan was to extract one lower incisor. Clinically, both cuspids were acutely tipped mesially, but were imaged uprighted and parallel to their adjacent teeth in the panoramic radiograph. In order to better understand the cuspids position, a model of the lower arch was prepared, with a similar malocclusion demonstrated by the patient. In the model, the cuspids' metal teeth, invested in wax, were mesially angulated. A panoramic radiograph of the model was then taken. The radiograph of the model shows a parallel position of the incisors, the cuspids and the bicuspids, exactly as was shown in the patient's radiograph. It has been demonstrated that there is a discrepancy between the actual position of the teeth and roots and their position in the panoramic radiograph, especially in the mesiodistal angulation. It was concluded that we should be very cautious when trying to interpret the panoramic radiograph as a tool for root parallelism, and remember the inherent image distortions. This is especially true before deciding which teeth will be extracted, on the basis of "incorrect" tooth angulation. PMID:22991875

  11. DENTAL IMPLANTS: AS AN ALTERNATIVE FOR TOOTH REPLACEMENT

    Directory of Open Access Journals (Sweden)

    Banerjee Nandini

    2013-08-01

    Full Text Available A dental implant is an artificial tooth that replaces a tooth that has been taken out. Implants are natural-looking, can provide support for dentures and do not affect the teeth bordering them. They are as stable as your real teeth and protect you from the loss of jawbone, which occurs when you lose teeth. Endosseous dental implants have revolutionized the fields of implants and periodontics. During the last decade, a great deal of information has been generated concerning the effectiveness and predictability of endosseous implants. Implant placement is a viable option in the treatment of partial and full edentulism and has become an integral facet of periodontal therapy. The available implants are remarkably successful. This review discusses the different aspects of dental implant including its advantages over the contemporary removable implants, its procedure in detail and the financial outlook of the same. The review also has a small consideration on minidental implant.

  12. Characteristics of Rotary Electromagnet with Large Tooth-pitch Angle

    Directory of Open Access Journals (Sweden)

    Ruan Jian

    2012-10-01

    Full Text Available Since the conventional electro-mechanical converter of 2D valve had problems of step lose due to its small tooth-pitch angle, a novel rotary electromagnet with large tooth-pitch angle and coreless rotor structure was proposed. Combined with the approaches of magnetic circuit analysis, finite element simulation and experimental study, the static and dynamic characteristics of electromagnet including torque-angle characteristics, frequency response and step response were studied. The experimental results are in a close agreement with the simulated results. The electromagnet has sinusoidal torque-angle characteristics and good dynamic response. The maximum static torque is approximately 0.083N.M, and its frequency width is about 125Hz/-3dB, 130Hz/-90°, respectively, and the rise time is about 5.5 ms. It is appropriate to be used as the electro-mechanical converter of 2D proportional valve.

  13. Selective formation of metastable ferrihydrite in the chiton tooth.

    Science.gov (United States)

    Gordon, Lyle M; Román, Jessica K; Everly, R Michael; Cohen, Michael J; Wilker, Jonathan J; Joester, Derk

    2014-10-20

    Metastable precursors are thought to play a major role in the ability of organisms to create mineralized tissues. Of particular interest are the hard and abrasion-resistant teeth formed by chitons, a class of rock-grazing mollusks. The formation of chiton teeth relies on the precipitation of metastable ferrihydrite (Fh) in an organic scaffold as a precursor to magnetite. In?vitro synthesis of Fh under physiological conditions has been challenging. Using a combination of X-ray absorption and electron paramagnetic resonance spectroscopy, we show that, prior to Fh formation in the chiton tooth, iron ions are complexed by the organic matrix. In?vitro experiments demonstrate that such complexes facilitate the formation of Fh under physiological conditions. These results indicate that acidic molecules may be integral to controlling Fh formation in the chiton tooth. This biological approach to polymorph selection is not limited to specialized proteins and can be expropriated using simple chemistry. PMID:25196134

  14. Effect of Bleaching Agents on the Nanohardness of Tooth Enamel, Composite Resin, and the Tooth-Restoration Interface.

    Science.gov (United States)

    Abe, A T; Youssef, M N; Turbino, M L

    2016-01-01

    This in vitro study aimed to evaluate the nanohardness of tooth enamel, composite resin, dental adhesive, and enamel hybrid layer exposed to 35% hydrogen peroxide-based bleaching agents and analyze the tooth-restoration interface using scanning electron microscopy (SEM). This study used 40 crowns of bovine incisors, which were embedded in epoxy resin. A 2 × 2 × 2-mm cavity was prepared in the medial third of the flattened buccal surface of each tooth and restored (two-step etch-and-rinse Adper Single Bond 2 + nanocomposite resin Filtek Z350 XT). The specimens were polished and divided into four groups (n=10), corresponding to each bleaching agent used (TB: Total Blanc Office, pH=7.22-6.33; HPB: Whiteness HP Blue, pH=8.89-8.85; HP: Whiteness HP, pH=6.65-6.04; PO: Pola Office, pH=3.56-3.8), applied in accordance with manufacturer protocols. The nanohardness of the substrates was measured before and immediately after the bleaching procedure and after 7-day storage in artificial saliva with an Ultra-Microhardness Tester (DUH-211S, Shimadzu). Loads used were 100 mN for tooth enamel and composite resin and 10 mN for adhesive and enamel hybrid layer. For SEM analysis, epoxy replicas were prepared through high-precision impressions of the specimens. For nanohardness, the statistical tests two-way analysis of variance and Tukey (p<0.05) revealed that the agent with the lowest pH value (PO) was the only one to decrease the nanohardness of enamel and the enamel hybrid layer immediately after its application; however, after 7-day storage in artificial saliva, the nanohardness levels of these substrates returned to their original values. SEM analysis revealed small gaps between tooth enamel and adhesive after the exposure to all bleaching agents; however, the most evident gap in the tooth-restoration interface was observed immediately after application of agent PO. No bleaching agent used changed the nanohardness of the composite resin and adhesive layer. PMID:26266649

  15. An Invitro Evaluation of Coronal Microleakage in Strengthening of Weakend Teeth with Different Tooth-Coloured Material with

    Directory of Open Access Journals (Sweden)

    F - Shirani

    2006-01-01

    Full Text Available Introduction: The purpose of this in vitro study was to investigate coronal microlenkage in anterior weakend teeth after root canal therapy, reinforced with different tooth-coloured material and FRC post.Methods and Materials: A total 48 extracted intact central incisor were randomly divided into four experimental groups (n=12. All specimens were endodontically treated using lateral condensation and crowns were totally removed from 2mm of CEJ and were over flared to simulate weakened teeth . Control group (group I was restored only with gutta percha .In other groups root canal walls were prepared (etching, washing and gentle drying, bonding and the surface of the posts were cleaned with alcohol and after that covered with bonding agent and then light polymerized for 40 seconds. Finally post cementation was done durig reinforcing of weakened root canal walls with packable composite in group II, self-cure composite in group III and dual cure composite in group IV. All specimens were thermocycled for 500 cycles between 5ºc and 55ºc0 with a dowel time of 20 seconds before immersion in dye. Then all specimens were sealed with sticky wax and coated with two layer of nail polish & then they were placed in 0.5% fuchsine for 24 hours at room temperature and were sectioned longitudinally from the center of post with tooth cutter. Dye penetration in both sections of each tooth were evaluated using a stereomicroscope equipped with digital camera at original magnification of 32× and microleakage recorded in m. One-way analysis of variances (ANOVA and least square difference were used for statistical analysis.Result: The control group showed the maximum microleakage and the minimum was related to the third group .There was a significant difference among the average microleakage of all groups.Conclusion: Combination of FRC post and tooth-coloured materials did reinforce structurally compromised root and decreased microleakage and also the microleakage of root/bonding material is more than post/tooth-colored material. Microleakge in selfcure Group because of its polymerization was the least.

  16. Effect of Bisphosphonates on Orthodontic Tooth Movement—An Update

    OpenAIRE

    Krishnan, Sindhuja; Pandian, Saravana; Kumar S, Aravind

    2015-01-01

    Bisphosphonates are a synthetic class of pyrophosphate analogues that are powerful inhibitors of bone resorption which are commonly used as a medication for the prevention and therapy of osteoporosis and osteopenia, also used to treat tumor diseases. As it affects bone metabolism, it is said to have an influence on orthodontic treatment and tooth movement. Also, this review gives an insight into the reported effects of Bisphosphonate medication in literature highlighting the status quo of sci...

  17. ‘Eavesdropping’ in wild rough-toothed dolphins (Steno bredanensis)?

    OpenAIRE

    Götz, Thomas; Verfuß, Ursula Katharina; Schnitzler, Hans-Ulrich

    2005-01-01

    Several authors suggest that dolphins use information obtained by eavesdropping on echoes from sonar signals of conspecifics, but there is little evidence that this strategy is used by dolphins in the wild. Travelling rough-toothed dolphins (Steno bredanensis) either exhibit asynchronous movements or an extremely synchronized swimming behaviour in tight formations, which we expect to facilitate eavesdropping. Therefore, we determined, whether either one or more dolphins were echolocating in s...

  18. Application of numerical simulation on cast-steel toothed plate

    OpenAIRE

    Mi, Guofa; Li, Changyun; Gao, Zeng

    2014-01-01

    A three-dimensional Computer Aided Design (CAD) model is established by using Pro/E software. The finite volume method (FVM) numerical model and ViewCast simulation software are used to study both the casting solidification process and filling process of toothed-plate. Based on the simulation, the casting shrinkage and solidification process are forecast visually in the form of images. The mould-filling simulation verify whether the liquid metal pour the mould smoot...

  19. Towards unraveling the human tooth transcriptome: the dentome.

    Science.gov (United States)

    Hu, Shijia; Parker, Joel; Wright, John Timothy

    2015-01-01

    The goal of the study was to characterize the transcriptome profiles of human ameloblasts and odontoblasts, evaluate molecular pathways and advance our knowledge of the human "dentome". Laser capture microdissection was used to isolate odontoblasts and ameloblasts from human tooth buds (15-20week gestational age) from 4 fetuses. RNA was examined using Agilent 41k whole genome arrays at 2 different stages of enamel formation, presecretory and secretory. Probe detection was considered against the array negative control to control for background noise. Differential expression was examined using Significance Analysis of Microarrays (SAM) 4.0 between different cell types and developmental stages with a false discovery rate of 20%. Pathway analysis was conducted using Ingenuity Pathway Analysis software. We found that during primary tooth formation, odontoblasts expressed 14,802 genes, presecretory ameloblasts 15,179 genes and secretory ameloblasts 14,526 genes. Genes known to be active during tooth development for each cell type (eg COL1A1, AMELX) were shown to be expressed by our approach. Exploring further into the list of differentially expressed genes between the motile odontoblasts and non-motile presecretory ameloblasts we found several genes of interest that could be involved in cell movement (FN1, LUM, ASTN1). Furthermore, our analysis indicated that the Phospholipase C and ERK5 pathways, that are important for cell movement, were activated in the motile odontoblasts. In addition our pathway analysis identified WNT3A and TGFB1 as important upstream contributors. Recent studies implicate these genes in the development of Schimke immuno-osseous dysplasia. The utility of laser capture microdissection can be a valuable tool in the examination of specific tissues or cell populations present in human tooth buds. Advancing our knowledge of the human dentome and related molecular pathways provides new insights into the complex mechanisms regulating odontogenesis and biomineralization. This knowledge could prove useful in future studies of odontogenic related pathologies. PMID:25849153

  20. Joubert syndrome: congenital cerebellar ataxia with the “molar tooth”

    OpenAIRE

    Romani, Marta; Micalizzi, Alessia; Valente, Enza Maria

    2013-01-01

    Joubert syndrome (JS) is a congenital cerebellar ataxia with autosomal recessive or X-linked inheritance, which diagnostic hallmark is a unique cerebellar and brainstem malformation recognizable on brain imaging, the “molar tooth sign”. Neurological signs are present from neonatal age and include hypotonia evolving into ataxia, global developmental delay, ocular motor apraxia and breathing dysregulation. These are variably associated with multiorgan involvement, mainly of the retina, kidneys,...

  1. Toward in vivo OSL dosimetry of human tooth enamel

    International Nuclear Information System (INIS)

    The dose response and thermal stability characteristics of an adult human molar tooth to blue photon stimulation are reported. Statistically significant dose response OSL was observed for beta doses ?1.4Gy. However, fading studies indicate that measurements must be performed within 2 days of irradiation in order to be meaningful. Linearly modulated OSL response of the enamel and steps to make this method of practical application are discussed

  2. An interdisciplinary approach to treat crown-root-fractured tooth

    OpenAIRE

    Sun, Ying Chun; Li, Ying; Tong, Jian; Ping GAO

    2013-01-01

    Restoration of a crown-root subgingival fractured tooth, especially at anterior aesthetic zones is still a great challenge for restorative dentists. Crown lengthening procedure alone has the disadvantage of high gingival curve of the final restoration, which was not discontinuous to adjacent teeth and thus compromise cosmetic outcomes. The objective of this report is to display a new interdisciplinary approach which combining endodontic root canal treatment, orthodontic extrusion, periodontal...

  3. Classification of severe tooth discolorations and treatment options

    OpenAIRE

    Tran, Huy Quoc; Jenssen, Lotte

    2011-01-01

    In this literature study, a classification of severe discolorations and a summary over the options for different dental treatments have been described. Various causes of these severe discolorations are presented and how the mechanisms behind tooth discolorations affect the outcome of a treatment or treatment options. Finally, the aesthetic outcome of a possible bleaching treatment of the different classified discolorations is discussed. In the management of patients with stained teeth it i...

  4. Unicuspid and bicuspid tooth crown formation in squamates.

    Science.gov (United States)

    Handrigan, Gregory R; Richman, Joy M

    2011-12-15

    The molecular and developmental factors that regulate tooth morphogenesis in nonmammalian species, such as snakes and lizards, have received relatively little attention compared to mammals. Here we describe the development of unicuspid and bicuspid teeth in squamate species. The simple, cone-shaped tooth crown of the bearded dragon and ball python is established at cap stage and fixed in shape by the differentiation of cells and the secretion of dental matrices. Enamel production, as demonstrated by amelogenin expression, occurs relatively earlier in squamate teeth than in mouse molars. We suggest that the early differentiation in squamate unicuspid teeth at cap stage correlates with a more rudimentary tooth crown shape. The leopard gecko can form a bicuspid tooth crown despite the early onset of differentiation. Cusp formation in the gecko does not occur by the folding of the inner enamel epithelium, as in the mouse molar, but by the differential secretion of enamel. Ameloblasts forming the enamel epithelial bulge, a central swelling of cells in the inner enamel epithelium, secrete amelogenin at cap stage, but cease to do so by bell stage. Meanwhile, other ameloblasts in the inner enamel epithelium continue to secrete enamel, forming cusp tips on either side of the bulge. Bulge cells specifically express the gene Bmp2, which we suggest serves as a pro-differentiation signal for cells of the gecko enamel organ. In this regard, the enamel epithelial bulge of the gecko may be more functionally analogous to the secondary enamel knot of mammals than the primary enamel knot. PMID:21932327

  5. From Hopeless to Good Prognosis: Journey of a Failing Tooth

    OpenAIRE

    Gupta, Saurabh; Deshmukh, Jeevanand; Khatri, Richa; Kulkarni, Vinaya Kumar; Karthik, B

    2015-01-01

    Chronic periodontitis, along with associated clinical findings such as pathologic tooth migration, diastema, functional and aesthetic aberrations, poses an immense challenge to a dental professional. These findings convert clinical decision making into a daunting task and adversely affect the prognosis and the treatment plan for the presenting clinical problem. An interdisciplinary approach aimed at restoring functional and aesthetic needs of the affected individual within the limitations of ...

  6. Finite Element Residual Stress Analysis of Planetary Gear Tooth

    OpenAIRE

    Jungang Wang; Yong Wang; Zhipu Huo

    2013-01-01

    A method to simulate residual stress field of planetary gear is proposed. In this method, the finite element model of planetary gear is established and divided to tooth zone and profile zone, whose different temperature field is set. The gear’s residual stress simulation is realized by the thermal compression stress generated by the temperature difference. Based on the simulation, the finite element model of planetary gear train is established, the dynamic meshing process is simulated, and in...

  7. Mesenchymal Stem Cell-Mediated Functional Tooth Regeneration in Swine

    OpenAIRE

    Sonoyama, Wataru; Liu, Yi; Fang, Dianji; Yamaza, Takayoshi; Seo, Byoung-Moo; Zhang, Chunmei; Liu, He; Gronthos, Stan; Wang, Cun-Yu; Shi, Songtao; Wang, Songlin

    2006-01-01

    Mesenchymal stem cell-mediated tissue regeneration is a promising approach for regenerative medicine for a wide range of applications. Here we report a new population of stem cells isolated from the root apical papilla of human teeth (SCAP, stem cells from apical papilla). Using a minipig model, we transplanted both human SCAP and periodontal ligament stem cells (PDLSCs) to generate a root/periodontal complex capable of supporting a porcelain crown, resulting in normal tooth function. This wo...

  8. Associação na mesma família das doenças de Charcot-Marie-Tooth e de Friedreich / Association of Charcot-Marie-Tooth and Friedreich diseases in a family

    Scientific Electronic Library Online (English)

    Charles Peter, Tilbery; Décio Cassiani, Altimari; Luiz G., Gagliardi-Ferreira; José L., Alonso Nieto.

    1972-06-01

    Full Text Available Quatro irmãos com moléstias de Charcot-Marie-Tooth são estudados do ponto de vista clínico e genético. São ressaltadas, mediante análise da sintomatologia, as formas de transição no grande grupo de moléstias heredodegenerativas, sendo atribuída particular ênfase às formas entre a moléstia de Charcot [...] -Marie-Tooth e a de Friedreich. Nos casos apresentados havia sinais clínicos da amiotrofia de Charcot-Marie-Tooth e da degeneração espinocerebelar de Friedreich. No estudo genético foram observadas aberrações cromossômicas, fenômeno inédito na moléstia de Charcot-Marie-Tooth. Abstract in english Four brothers with Charcot-Marie-Tooth disease are studied clinically and genetically. By comparing the symptomatology, the mixed clinical forms within the great group of heredodegenerative diseases are enfazised, with special attention to the intermediate forms between Charcot-MarieTooth and Friedr [...] eich diseases. In the present cases there were signs of Charcot-Marie-Tooth's peroneal muscular atrophy and Friedreich's spinocerebelar degeneration. By the genetic study a cromosomal breakage, an unusual phenomenon in Charcot-Marie-Tooth disease, was observed.

  9. Associação na mesma família das doenças de Charcot-Marie-Tooth e de Friedreich Association of Charcot-Marie-Tooth and Friedreich diseases in a family

    Directory of Open Access Journals (Sweden)

    Charles Peter Tilbery

    1972-06-01

    Full Text Available Quatro irmãos com moléstias de Charcot-Marie-Tooth são estudados do ponto de vista clínico e genético. São ressaltadas, mediante análise da sintomatologia, as formas de transição no grande grupo de moléstias heredodegenerativas, sendo atribuída particular ênfase às formas entre a moléstia de Charcot-Marie-Tooth e a de Friedreich. Nos casos apresentados havia sinais clínicos da amiotrofia de Charcot-Marie-Tooth e da degeneração espinocerebelar de Friedreich. No estudo genético foram observadas aberrações cromossômicas, fenômeno inédito na moléstia de Charcot-Marie-Tooth.Four brothers with Charcot-Marie-Tooth disease are studied clinically and genetically. By comparing the symptomatology, the mixed clinical forms within the great group of heredodegenerative diseases are enfazised, with special attention to the intermediate forms between Charcot-MarieTooth and Friedreich diseases. In the present cases there were signs of Charcot-Marie-Tooth's peroneal muscular atrophy and Friedreich's spinocerebelar degeneration. By the genetic study a cromosomal breakage, an unusual phenomenon in Charcot-Marie-Tooth disease, was observed.

  10. Effect of experimental tooth clenching on the release of ?-endorphin

    DEFF Research Database (Denmark)

    Dawson, Andreas; Ljunggren, Lennart

    2014-01-01

    AIMS: To investigate the association between experimental tooth clenching and the release of ?-endorphin in patients with myofascial temporomandibular disorders (M-TMD) and healthy subjects. METHODS: Fifteen M-TMD patients and 15 healthy subjects were included and assigned an experimental tooth-clenching task. Venous blood was collected and pain intensity was noted on a visual analog scale. The masseter pressure pain threshold (PPT) was assessed 2 hours before the clenching task and immediately after. A mixed-model analysis of variance was used for statistical analyses. RESULTS: Significant main effects for time and group were observed for pain intensity and PPT, with significantly lower mean values of pain intensity (P < .001) and PPT (P < .01) after the clenching task compared with baseline. M-TMD patients had significantly higher pain intensity (P < .001) and significantly lower PPT (P < .05) than healthy subjects. No significant time or group effects were observed for the level of ?-endorphin. Neither pain intensity nor PPT correlated significantly with ?-endorphin levels. CONCLUSION: This experimental tooth-clenching task was not associated with significant alterations in ?-endorphin levels over time, but with mechanical hyperalgesia and low to moderate levels of pain in healthy subjects and M-TMD patients, respectively. More research is required to understand the role of the ?-endorphinergic system in the etiology of M-TMD.

  11. Equine Odontoclastic Tooth Resorption and Hypercementosis: Histopathologic Features.

    Science.gov (United States)

    Smedley, R C; Earley, E T; Galloway, S S; Baratt, R M; Rawlinson, J E

    2015-09-01

    Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a painful progressive condition of older horses that involves multiple teeth, including canines and incisors. EOTRH is uncommonly recognized by veterinary pathologists and in some cases may be misdiagnosed as cementoblastoma. The cause is unknown. The goals of this study were to describe the histopathologic features of EOTRH in 17 affected horses from the United States and to increase awareness of this condition. Samples ranged from affected tooth to the entire rostral mandible and maxilla. Affected teeth exhibited cemental hyperplasia and lysis. The marked proliferation of cementum in severe cases caused bulbous enlargement of the intra-alveolar portions of affected teeth. Several teeth contained necrotic debris, bacteria, and plant material in the regions of cemental lysis. All horses exhibited dentinal lysis in at least affected tooth, and several contained necrotic debris in these regions. Endodontic disease was often present with inflammation, lysis, necrotic debris, fibrosis, and/or a thin rim of atubular mineralized tissue in the pulp cavity. Periodontal disease was a common feature that was primarily characterized by moderate lymphoplasmacytic inflammation. Resorption with secondary hypercementosis appears to begin on the external surface of the teeth rather than within the pulp cavity. Distinguishing EOTRH from other diseases requires a complete history that includes the number and location of affected teeth, a gross description of regional hard/soft tissue health, and radiographic findings. PMID:26077784

  12. A radiological study on the tooth shape anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Karp Shik [Dept. of Oral Radiology, College of Dentistry, Kyungpook National University, Daegu (Korea, Republic of)

    1994-02-15

    The purpose of this study was to evaluate the prevalence and distribution according to the types of tooth shape anomalies in permanent teeth of 6,082 persons by means of analysis of the full mouth periapical radiographs. And the following results were obtained ; 1. Among tooth shape anomalies, the highest incidence was observed on dilaceration (20.14%), followed by dens invaginatus (3.02%), peg lateralis (1.48%), taurodontism (0.34%), dens evaginatus (0.33%), talon cusp (0.20%), fusion (0.07%) and gemination (0%) in descending order of frequency. 2. Peg lateralis, dens invaginatus and dilaceration occurred more prevalent in females, and other types of tooth shape anomalies occurred more prevalent in males. 3. Dens evaginatus and taurodontism occurred with bilateral tendency, but other anomalies occurred with unilateral tendency. 4. As to the involved teeth, maxillary lateral incisors were the most frequently involved teeth on peg lateralis, dens invaginatus and talon cusp. And the mandibular premolars were the most frequently involved teeth on dens evaginatus, the maxillary first molars were on taurodontism, the maxillary second premolars were on dilaceration, and the mandibular incisors and canines were on fusion.

  13. A radiological study on the tooth shape anomaly

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the prevalence and distribution according to the types of tooth shape anomalies in permanent teeth of 6,082 persons by means of analysis of the full mouth periapical radiographs. And the following results were obtained ; 1. Among tooth shape anomalies, the highest incidence was observed on dilaceration (20.14%), followed by dens invaginatus (3.02%), peg lateralis (1.48%), taurodontism (0.34%), dens evaginatus (0.33%), talon cusp (0.20%), fusion (0.07%) and gemination (0%) in descending order of frequency. 2. Peg lateralis, dens invaginatus and dilaceration occurred more prevalent in females, and other types of tooth shape anomalies occurred more prevalent in males. 3. Dens evaginatus and taurodontism occurred with bilateral tendency, but other anomalies occurred with unilateral tendency. 4. As to the involved teeth, maxillary lateral incisors were the most frequently involved teeth on peg lateralis, dens invaginatus and talon cusp. And the mandibular premolars were the most frequently involved teeth on dens evaginatus, the maxillary first molars were on taurodontism, the maxillary second premolars were on dilaceration, and the mandibular incisors and canines were on fusion.

  14. Evidence to support tooth brushing in critically ill patients.

    Science.gov (United States)

    Ames, Nancy J

    2011-05-01

    Tooth brushing in critically ill patients has been advocated by many as a standard of care despite the limited evidence to support this practice. Attention has been focused on oral care as the evidence accumulates to support an association between the bacteria in the oral microbiome and those respiratory pathogens that cause pneumonia. It is plausible to assume that respiratory pathogens originating in the oral cavity are aspirated into the lungs, causing infection. A recent study of the effects of a powered toothbrush on the incidence of ventilator-associated pneumonia was stopped early because of a lack of effect in the treatment group. This review summarizes the evidence that supports the effectiveness of tooth brushing in critically ill adults and children receiving mechanical ventilation. Possible reasons for the lack of benefit of tooth brushing demonstrated in clinical trials are discussed. Recommendations for future trials in critically ill patients are suggested. With increased emphasis being placed on oral care, the evidence that supports this intervention must be evaluated carefully. PMID:21532045

  15. Differential changes in gingival somatosensory sensitivity after painful electrical tooth stimulation

    DEFF Research Database (Denmark)

    Baad-Hansen, Lene; Lu, Shengyi

    2015-01-01

    We aimed to evaluate the effect of painful tooth stimulation on gingival somatosensory sensitivity of healthy volunteers in a randomized, controlled design. Thirteen healthy volunteers (six women, seven men; 28.4 ± 5.0 years) were included for two experimental sessions of electrical tooth stimulation: painful tooth stimulation and tooth stimulation below the sensory threshold (control). Eight of the human subjects participated in a third session without tooth stimulation. In all sessions, the somatosensory sensitivity of the gingiva adjacent to the stimulated tooth was evaluated with a standardized battery of quantitative sensory tests (QST) before, immediately after and 30 min after tooth stimulation. Painful tooth stimulation evoked significant decreases in warmth and heat pain thresholds (P 0.086). No QST changes were detected in the session without tooth stimulation (P > 0.060). In conclusion, modest increased gingival sensitivity to warmth, painful heat and pressure stimuli as well as desensitization to non-painful mechanical stimulation were demonstrated after tooth stimulation. This suggests involvement of competing heterotopic facilitatory and inhibitory mechanisms. Furthermore, stimulation below the sensory threshold induced similar thermal sensitization suggesting the possibility of activation of axon-reflex-like mechanisms even at intensities below the perception threshold. These findings may have implications for interpretation of somatosensory results in patients with chronic intraoral pain.

  16. TOOTH BRUSH - TOOTH PASTE OCULAR INJURY: A SEQUELAE TO FAST LIFE

    Directory of Open Access Journals (Sweden)

    Anil Kumar

    2015-01-01

    Full Text Available Toothbrush - tooth paste, widely used in every house hold, may cause irreversible injury to the eye especially cornea that comes into contact with this substance. We present two cases of toothbrush - toothpaste injury who accidentally injured their own eye. T hese were combination of chemical ( T oothpaste and trivial mechanical ( T oothbrush trauma. Ocular contact with toothpaste causes severe unbearable burning sensation. One of the cases developed suppurative corneal ulcer with hypopyon and lost vision in the affected eye. Toothpastes with more ph can cause blindness when it comes into contact with the eye if not treated urgently. The other patient ( O ne of the consultants in our institute reported immediately in the morning in emergency with complaints of seve re burning sensation in the involved eye after accidental injury with toothbrush - toothpaste. His eyes were washed with normal saline for 30 to 40 minutes. Because he was treated immediately, he recovered within one week. Clinicians should take adequate pre cautions to prevent serious complication. In case of an accidental contact of eye with toothpaste, it is important to wash the eye efficiently. We decided to estimate the ph of commonly used various brands of toothpaste in over biochemistry lab and it was found that ph of various toothpaste varies from 7 to 10. The pH of the brand of the toothpaste which was used by one of the case was (pH 9.6, which shows that it is a combination of mechanical and alkali injury. pH near to neutral (7.1 and 7.4 was detect ed in one of the herbal toothpaste and one the oldest brand of toothpaste ( W hich was not herbal. These cases are being reported to make aware the ophthalmologists and public that although rare but these cases should not be taken lightly and should be trea ted urgently to prevent the loss of vision in the involved eye. One of the risk factors, may be the hurried activities in the morning in this era of fast life a s one of the patients was working in a metropolitan city and the other a pathologist in our inst itution

  17. Molecular analysis of tooth enamel by Raman spectroscopy after treatment with bleaching agents at different concentrations

    International Nuclear Information System (INIS)

    The changes in the concentration of the v1 phosphate molecule of the surface of dentin enamel are treated and researched with bleaching agents of chemical activation to basis of hydrogen peroxide than 9,5% and 14% and carbamide peroxide than 38%, for a period of 28 days. Raman spectroscopy was used and 30 dental pieces extracted, of which, were to be free of blemishes and pigmentations, without possessing fractures of the enamel, decay nor any other type of defect. The Raman spectrum was obtained of each dental piece prior to the application of bleaching agents. The specimens were separated into three experimental groups according to the concentration of whitening. The concentration of the v1 phosphate molecule was measured in the tooth enamel to the second and fourth week of treatment. In addition, ANOVA was performed for respective measurements (p?0.05). A reduction of the v1 phosphate molecule were observed during and after the bleaching process in the experimental groups that have used of hydrogen peroxide to 14% and carbamide peroxide 38%. In the group of hydrogen peroxide to 9,5% has remained unproven a significant reduction. Within the limitations of this study is concluded that the bleaching agent causes a loss of v1 phosphate. This loss has been greater in the whitening of higher concentration. In spite, that the possible effect remineralizing of the saliva on a teeth whitening process has been unevaluated, it is recommended using during and after the treatment, toothpastes, mouthwashes, chewing gums, dental floss, among others, that contain ACP to help to cushion the potential loss of phosphate from tooth enamel. (author)

  18. Fracture toughness of zirconia ceramic crowns made by feather-edge tooth preparation design

    Directory of Open Access Journals (Sweden)

    Mirkovi? Nemanja

    2012-01-01

    Full Text Available Background/Aim. Fracture toughness determines functional crown strenght and prevents damages on ceramics during mastication. There is a lack of relevant literature data about fracture toughness of crowns made by feather-edge preparation. Mechanical testing of ceramic samples is supposed to show if feather-edge tooth preparation is a successful method for making ceramic crowns without any risk of reduction of their mechanical properties. This research was done to establish effects of feather-edge tooth preparation on fracture toughness of single zirconia ceramic crowns. Methods. The research was performed as an experimental study. Sixty (60 ceramic crowns were made on non-carious extracted human premolars. Thirty (30 crowns were made on the basis of feather-edge preparation (experimental group I. The group II included 30 crowns made on 1 mm rounded shoulder. Crowns fabrication was executed on a copy mill production system “Zirkonzahn” (Zirkonzahn GMBH, Gais, Germany. The spherical compression test was used to determine fracture toughness, using 6 mm diameter ceramic ball. Fracture load for damaging ceramic crown was recorded on a universal testing machine - Zwick, type 1464, with the speed of 0.05 mm/min. Results. The results of this research introduced significant differences between fracture toughness of ceramic samples in every examined group. However, fracture toughness of crowns from both group was above 2 000 N, what was double beyond a recommended value. The mean value of fracture toughness in the feather-edge group was 2 090 N, and in shoulder group it was 2 214 N. Conclusion. This research showed a high fracture toughness of zirconia crowns made on feather-edge preparation. The examined crowns showed a fracture resistance at a sufficient distance in relation to the minimum values of functional loads. Further research of functional loads of these crown is necessary, as well as research of marginal adaptation of cemented crowns and gingival inflammatory response.

  19. The relationship between dental fluorosis and tooth fluoride concentration - a study in an endemic area - doi:10.5020/18061230.2011.p355

    Directory of Open Access Journals (Sweden)

    Marc Daniel Grynpas

    2012-01-01

    Full Text Available Objective: To determine the relationship between dental fluorosis (DF severity and fluoride [F] concentration in tooth and water in DF endemic areas. Methods: Life-long residents from two DF endemic communities were studied. Forty-five extracted teeth were collected and analyzed for DF severity and tooth [F]. Thylstrup-Ferjeskov Index (TFI was used to measure DF severity and instrumental neutron activation analysis (INAA for tooth [F] concentration. Water from regional wells was also collected (n=9 and analyzed for F content using specific ion F electrode. Results: Water [F] varied between 0.2ppm and 4.7ppm. TFI scores ranged from 0 to 6; [F] from 120ppm to 2,140ppm in enamel and 304ppm to 4,800ppm in dentin. No correlation was found between DF severity and [F] in enamel (rs=0.22,p=0.15 and dentin (rs=-0.19,p=0.20, nor between water [F] and [F] in enamel (rs=-0.09,p=0.65 and dentin (rs=-0.11,p=0.56. Weak correlation between DF severity and water [F] (rs=0.38,p=0.04 was found. Linear regression analysis showed that TFI couldn’t be predicted from a linear combination of the independent variables (age, enamel and dentin [F]. When enamel, dentin and water [F] were used as independent variables in the linear regression (predict DF severity, only water [F] showed influence in DF severity (p=0.013;t=2.67. Conclusion: Even in areas of endemic DF, tooth [F] didn’t correlate with DF severity and the relationship between water [F] and DF severity was very weak. Therefore, tooth [F] may not be a good predictor/indicator of DF severity.

  20. Phosphoproteomes of Strongylocentrotus purpuratus shell and tooth matrix: identification of a major acidic sea urchin tooth phosphoprotein, phosphodontin

    Directory of Open Access Journals (Sweden)

    Mann Matthias

    2010-02-01

    Full Text Available Abstract Background Sea urchin is a major model organism for developmental biology and biomineralization research. However, identification of proteins involved in larval skeleton formation and mineralization processes in the embryo and adult, and the molecular characterization of such proteins, has just gained momentum with the sequencing of the Strongylocentrotus purpuratus genome and the introduction of high-throughput proteomics into the field. Results The present report contains the determination of test (shell and tooth organic matrix phosphoproteomes. Altogether 34 phosphoproteins were identified in the biomineral organic matrices. Most phosphoproteins were specific for one compartment, only two were identified in both matrices. The sea urchin phosphoproteomes contained several obvious orthologs of mammalian proteins, such as a Src family tyrosine kinase, protein kinase C-delta 1, Dickkopf-1 and other signal transduction components, or nucleobindin. In most cases phosphorylation sites were conserved between sea urchin and mammalian proteins. However, the majority of phosphoproteins had no mammalian counterpart. The most interesting of the sea urchin-specific phosphoproteins, from the perspective of biomineralization research, was an abundant highly phosphorylated and very acidic tooth matrix protein composed of 35 very similar short sequence repeats, a predicted N-terminal secretion signal sequence, and an Asp-rich C-terminal motif, contained in [Glean3:18919]. Conclusions The 64 phosphorylation sites determined represent the most comprehensive list of experimentally identified sea urchin protein phosphorylation sites at present and are an important addition to the recently analyzed Strongylocentrotus purpuratus shell and tooth proteomes. The identified phosphoproteins included a major, highly phosphorylated protein, [Glean3:18919], for which we suggest the name phosphodontin. Although not sequence-related to such highly phosphorylated acidic mammalian dental phosphoproteins as phosphoryn or dentin matrix protein-1, phosphodontin may perform similar functions in the sea urchin tooth. More than half of the detected proteins were not previously identified at the protein level, thus confirming the existence of proteins only known as genomic sequences previously.

  1. Nrf2 activation attenuates both orthodontic tooth movement and relapse.

    Science.gov (United States)

    Kanzaki, H; Shinohara, F; Itohiya-Kasuya, K; Ishikawa, M; Nakamura, Y

    2015-06-01

    During orthodontic tooth movement, osteoclasts resorb the alveolar bone at the compress side of periodontium. Reactive oxygen species (ROS) works as intracellular signaling molecules of RANKL during osteoclastogenesis, although ROS has cytotoxicity against cells such as lipid oxidation. To deal with oxidative stress, cells have a defense system that is scavenging ROS by augmented antioxidative stress enzymes via transcriptional regulation with nuclear factor E2-related factor 2 (Nrf2). Previously, we reported that augmented antioxidative stress enzymes by Nrf2-gene transfer inhibited bone destruction. In the present study, we examined the effects of Nrf2 activation on osteoclastogenesis and, thereby, orthodontic tooth movement and orthodontic relapse. Mouse macrophage cell line RAW264.7 cells were used as osteoclast progenitor cells and stimulated with recombinant RANKL (100 ng/mL) with or without Nrf2 activator sulforaphane (SFN) and epigallocatechin gallate (EGCG) or ROS scavenger catechin. Osteoclastogenesis, resorption activity, and osteoclast marker gene expression were examined. Intracellular ROS was analyzed by flow cytometry. Maxillary first molars of C57BL6 male mice were moved palatally with 0.012-inch NiTi wire (100-mN force); SFN or EGCG was injected into the palatal gingiva once a week; and phosphate buffered saline was injected on the contralateral side. Tooth movement was monitored using a stone model with precise impression, and the amount of the tooth movement was compared among groups. SFN and EGCG significantly, but catechin weakly, inhibited RANKL-mediated osteoclastogenesis in vitro. Western blot analysis revealed that SFN and EGCG augmented the nuclear translocation of Nrf2 and the expression of anti-oxidative stress enzymes such as HO-1, although catechin did not. SFN and EGCG significantly, but catechin weakly, attenuated the intracellular ROS. Finally, animal experiment revealed that both SFN and EGCG successfully inhibited the orthodontic tooth movement. Additionally, SFN inhibited the relapse. These results suggest that Nrf2 activation could be therapeutic target for the anchorage enforcement in orthodontic treatment and pharmacologic retention against relapse. PMID:25795629

  2. Effect of tooth bleaching agents on protein content and mechanical properties of dental enamel.

    Science.gov (United States)

    Elfallah, Hunida M; Bertassoni, Luiz E; Charadram, Nattida; Rathsam, Catherine; Swain, Michael V

    2015-07-01

    This study investigated the effect of two bleaching agents, 16% carbamide peroxide (CP) and 35% hydrogen peroxide (HP), on the mechanical properties and protein content of human enamel from freshly extracted teeth. The protein components of control and treated enamel were extracted and examined on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Marked reduction of the protein matrix and random fragmentation of the enamel proteins after bleaching treatments was found. The mechanical properties were analyzed with Vickers indentations to characterize fracture toughness, and nanoindentation to establish enamel hardness, elastic modulus and creep deformation. Results indicate that the hardness and elastic modulus of enamel were significantly reduced after treatment with CP and HP. After bleaching, the creep deformation at maximum load increased and the recovery upon unloading reduced. Crack lengths of CP and HP treated enamel were increased, while fracture toughness decreased. Additionally, the microstructures of fractured and indented samples were examined with field emission gun scanning electron microscopy (FEG-SEM) showing distinct differences in the fracture surface morphology between pre- and post-bleached enamel. In conclusion, tooth bleaching agents can produce detrimental effects on the mechanical properties of enamel, possibly as a consequence of damaging or denaturing of its protein components. PMID:25841347

  3. [Dental tours de force 6. Autotransplantation in case of agenesis or traumatic tooth loss].

    Science.gov (United States)

    Carels, C E

    2004-03-01

    Autotransplantation of a tooth is probably the most natural method to replace a missing or lost tooth. This treatment has been performed successfully already for more than twenty years. The prognosis of a transplanted tooth is determined by tooth type, stage of root formation at the time of transplantation, surgical technique used, and duration and way of splinting. Determining the optimal stage of root formation of the tooth is very important in planning the autotransplantation. If the transplantation is carried out successfully, the transplanted tooth behaves at its new location just like before: it erupts, the root formation is continuing, it shows physiological mobility and it can be displaced by orthodontic forces. Most cases of autotransplantation require teamwork between oral surgeon, orthodontist, and dentist. PMID:15058244

  4. Tooth brushing among 11- to 15-year-olds in Denmark

    DEFF Research Database (Denmark)

    Bast, L. S.; Holstein, B. E.; Nordahl, Helene; Christensen, Lisa Bøge

    2015-01-01

    Objective: Regular tooth brushing in adolescence predicts stable tooth brushing habits later in life. Differences in tooth brushing habits by ethnic background and socioeconomic position have been suggested. We investigated migration status and social class in relation to infrequent tooth brushing...... both separately and combined. Methods: The study population was 11-15 year-olds chosen from a clustered random sample of schools. Univariate and multivariate logistic regression analyses estimated the separate and combined effects of migration status and social class on less than twice daily tooth...... brushing. Results: 10,607 respondents: a response rate of 88.3%. Boys of lower social class had higher odds ratio (OR) of infrequent tooth brushing than girls: 1.98 (95% confidence interval 1.62-2.41) vs 1.80 (1.53-2.24). Immigrants and descendants had higher odds compared to adolescents of Danish origin...

  5. Esthetic management of double tooth associated with talon cusp using a laminate veneer.

    Science.gov (United States)

    Cordeiro, Wayne José Batista; do Couto, Cintia Fernandes; Barros, Renata Nunes; Zarranz, Laila; Jorge, Mônica Zacharias; de Gouvêa, Cresus Vínicius Depes

    2014-01-01

    Double tooth and talon cusp are tooth shape anomalies with rare co-occurrences in a single tooth. Double tooth is a developmental anomaly that leads to the eruption of fused teeth and may contribute to compromised esthetics, pain, caries, and tooth crowding. Talon cusp is a rare developmental extra cusp-like projection on the cingulum area that may cause functional and esthetic problems. Differential diagnosis of these anomalies may be complicated. A multidisciplinary approach for the esthetic and functional rehabilitation of double teeth is important. Various treatment methods have been described in the literature for the different types and morphological variations of double teeth. The purpose of this paper is to report the case of an unusual combination of double tooth and talon cusp on a permanent maxillary incisor and describe its esthetic and functional rehabilitation using a porcelain laminate veneer. PMID:25514262

  6. A comparative study of two methods of dental pulp extraction for genetic fingerprinting.

    Science.gov (United States)

    Tilotta, Françoise; Brousseau, Philippe; Lepareur, Elise; Yasukawa, Kazutoyo; de Mazancourt, Philippe

    2010-10-10

    Extracting dental DNA for identification purposes is usually performed after crushing the tooth. The main disadvantage of this method is that the tooth is completely destroyed so further radiographic, anatomical or biochemical studies are no longer possible. We compared the quantities of DNA obtained by crushing the tooth and by removing pulp by standard endodontic access with trepanation of the occlusal surface and amplified DNA micro-satellites. In the series of crushed teeth, insufficient material for amplification was obtained in 78% of cases and a complete profile was obtained in only 9% of cases. Conversely, for the teeth prepared by trepanation, the profile was complete in 75% of cases and the DNA quantity was insufficient in only 3% of cases. Trepanation thus produced superior results in terms of quantity of DNA and the quality of the genetic profiles. Furthermore, it was a conservative procedure that allowed further analyses on the tooth. PMID:20663623

  7. Prospective Study of Serum 25-hydroxy Vitamin D and Tooth Loss

    OpenAIRE

    Zhan, Y.; Samietz, S.; Holtfreter, B.; Hannemann, A.; Meisel, P; Nauck, M; Völzke, H.; Wallaschofski, H.; Dietrich, T; Kocher, T.

    2014-01-01

    Vitamin D deficiency and oral diseases (periodontitis, caries, and tooth loss) are highly prevalent in Germany. Previous studies suggested that vitamin D might be a modifiable and protective factor for periodontitis, caries, and tooth loss. However, prospective studies investigating such associations are limited. We explored the association between the concentration of serum 25-hydroxy vitamin D (25OHD) and incidence of tooth loss, progression of clinical attachment loss (CAL) ? 3 mm, and pro...

  8. Social Determinants of Tooth Loss among a Group of Iranian Female Heads of Household

    OpenAIRE

    Taraneh Movahhed; Behjatalmolook Ajami; Mojtaba Dorri; Nima Biouki; Hadi Ghasemi; Mohammad Taghi Shakeri; Mahboobe Dehghani

    2015-01-01

    Background and aims. Tooth loss may lead to mastication disability, which in turn has important impact on individual’s quality of life. Social and psychological factors have been shown to be associated with tooth loss. This study aimed to in-vestigate the social determinants and prevalence of tooth loss, and presence of functional dentition among female heads of household under support of Welfare Organization in Mashhad, Iran. Materials and methods. In current study 556 participants aged 1...

  9. Professional and patient-based evaluation of oral rehabilitation in patients with tooth agenesis

    DEFF Research Database (Denmark)

    Dueled, Erik; Gotfredsen, Klaus; Trab Damsgaard, Mogens; Hede, Børge

    2009-01-01

    OBJECTIVES: The outcome of oral rehabilitation is usually monitored with clinical tests rather than by patient's perception of change. The aim of this study was to describe the objective measure and subjective perception of oral rehabilitation in patients with tooth agenesis. MATERIAL AND METHODS: The study included 129 patients with tooth agenesis rehabilitated with implant- or tooth-supported reconstructions, and a control group of 58 patients. Professional assessments included biological, tec...

  10. A 9 year follow-up of a fractured tooth fragment reattachment

    Directory of Open Access Journals (Sweden)

    Sharan S Sargod

    2010-01-01

    Full Text Available Coronal fractures of the anterior teeth are a common form of dental trauma that mainly affects children and adolescents. One of the options for managing coronal tooth fractures, when the tooth fragment is available, is reattachment of the dental fragment. Reattachment of fractured fragment can provide good and long lasting esthetics. This is a report of a 9 -year follow-up of a oronal fracture case successfully treated using tooth fragment reattachment.

  11. Prevalence of tooth wear among 16-year-old secondary school children in Kota Bharu, Kelantan

    Directory of Open Access Journals (Sweden)

    N.B. Saerah

    2006-09-01

    Full Text Available Tooth wear is the non-carious loss of tooth tissue due to attrition, erosion and/or abrasion. The amount of wear that accelerates physiological tooth wear is referred as pathological tooth wear. This study aims to determine the prevalence and mean scores according to mouth quadrant of raw tooth wear (RTW and pathological tooth wear (PTW and investigate sex association with PTW among 16-year-old secondary school children in Kota Bharu, Kelantan. This cross-sectional study involves 688 participants randomly selected from eight government secondary schools. The Smith and Knight Tooth Wear Index (TWI was used. Data were analyzed using a simplified Microsoft Excel program developed based on the index to quantify PTW. Bar graphs were plotted to highlight the mean scores according to mouth quadrant. About 44% of participants were male and 56% were female. The prevalence of RTW and PTW among subjects was 100% and 20.1% respectively. It was found that 32.8% of tooth surfaces were affected with RTW and 0.7% of study subjects already had exposed dentine. The most affected quadrant for RTW and PTW was the upper and lower incisal quadrant respectively. Males had 92% more odds of developing tooth wear compared to females. In conclusion, all subjects have some degree of wear. About one-fifth of the study subjects were affected by PTW. The patterns of wear were similar to those encountered in the Western societies. There was statistically significant association between sex and PTW.

  12. Mutations in the Myelin Protein Zero result in a spectrum of Charcot-Marie-Tooth phenotypes.

    Science.gov (United States)

    Kocha?ski, A

    2004-05-01

    Initially the Myelin Protein Zero gene was shown to be mutated in the demyelinating form of Charcot-Marie-Tooth disease (CMT1). The vast majority of the mutations in the Myelin Protein Zero gene have been detected in the Charcot-Marie-Tooth (1B) disease, however, some of them were found in patients suffering from congenital hypomyelinating neuropathy and axonal type Charcot-Marie-Tooth disease. In this study, a Charcot-Marie-Tooth disease phenotype diversity associated with different mutations in the MPZ gene, is described. PMID:15298082

  13. Dens evaginatus and dens invaginatus in a double tooth: A rare case report.

    Science.gov (United States)

    Sharma, Gaurav; Mutneja, Anudeep R; Nagpal, Archna; Mutneja, Puneet

    2015-01-01

    The presence of dens invaginatus (DI) and dens evaginatus (DE) on same tooth is a rare phenomenon. However, when these dental anomalies occur on a double tooth, it becomes an extremely rare phenomenon. The authors report a rare case of DI and DE on fused permanent maxillary central incisor with supernumerary tooth in a 40-year-old male. The present article also focuses on the differentiating fusion from gemination and also reviews preventive and management strategies for tooth with complex dental anatomy. PMID:26672430

  14. Comparison of hard tissue interrelationships at the cervical region of teeth based on tooth type and gender difference

    Directory of Open Access Journals (Sweden)

    Madhusudan Astekar

    2014-01-01

    Full Text Available Context: Cementoenamel junction (CEJ represents the anatomic limit between the crown and root surface. With advancing age and continuous eruption, this area becomes exposed in the oral media. Consequently, CEJ will be subjected to the action of various physical and chemical factors that might alter its morphology, with the cementum being affected in most cases. Aim: To identify the frequency of hard tissue interrelationships present at the CEJ in relation to different genders, positions and aspects of tooth using a light microscope. Materials and Methods: The cervical regions of 80 permanent teeth (40 male and 40 female, extracted for orthodontic or periodontal reasons, were analyzed after longitudinal ground sections were made in the mesio-distal plane. The CEJ of the prepared sections was then studied and their frequencies were categorized as: cementum overlapping enamel, enamel overlapping cementum, edge-to-edge relationship and the presence of gap junctions. Statistical Analysis: Chi-square test performed using SPSS 15 software. Results: Edge-to-edge contact of the cementum and enamel was most frequent, followed by gap junction and cementum overlapping the enamel, respectively. Chi-square test revealed no statistically significant differences with respect to the gender and tooth aspect, whereas the result was significant when the position of the tooth was studied. Conclusion: The observations of the study indicate a considerable morphological diversity in the anatomical pattern of CEJ. It can be concluded that the region should be protected against dentinal sensitivity, erosion, abrasion, abfraction and resorption, as it is more prone to cervical pathologies.

  15. A 3-year prospective study of implant-supported, single-tooth restorations of all-ceramic and metal-ceramic materials in patients with tooth agenesis

    DEFF Research Database (Denmark)

    Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten; Gotfredsen, Klaus

    2013-01-01

    OBJECTIVES: The purpose of this clinical study was to describe outcome variables of all-ceramic and metal-ceramic implant-supported, single-tooth restorations. MATERIALS AND METHODS: A total of 59 patients (mean age: 27.9 years) with tooth agenesis and treated with 98 implant-supported single-tooth restorations were included in this study. Two patients did not attend baseline examination, but all patients were followed for 3 years. The implants supported 52 zirconia, 21 titanium and 25 gold allo...

  16. Current issues on EPR dose reconstruction in tooth enamel

    International Nuclear Information System (INIS)

    This paper focuses on the opportunities to gain risk assessment information from populations exposed to ionizing radiation. Details are presented on the scale of the nuclear events in several areas within the former Soviet Union. An overview of the issues associated with dose reconstruction by electron paramagnetic resonance (EPR) is given. Principles and outline of the EPR tooth enamel dose assessment are described. Technical details, the latest achievements and the problems of each procedural step are analyzed. In addition, the present accuracy of the EPR dose reconstruction, its problems and cost are discussed

  17. [Accelerated tooth movement by alveolar corticotomy or piezocision].

    Science.gov (United States)

    Strippoli, Julien; Aknin, Jean-Jacques

    2012-06-01

    The relatively recent introduction of corticotomies and piezocision has made it possible for orthodontists to accelerate tooth movement and thereby to shorten the length of orthodontic treatment. Specialists emphasizing a mechanistic concept have been debating the underlying basic biological mechanics of these new therapeutic tools with opposing specialists who support a biological conception. Our analysis of different publications on the subject suggests that the biological explanation, with its emphasis on the Regional Acceleratory Phenomenon (RAP), is correct. However, the majority of studies in this field are not based on the principle of evidence based medicine (EBM). PMID:22717115

  18. Tooth mortality in an adult rural population in Kenya

    DEFF Research Database (Denmark)

    Manji, F; Baelum, V; Fejerskov, O

    1988-01-01

    This paper reports on the pattern of tooth loss in a random sample of 1131 adults aged from 15 to 65 years in a rural area of Kenya in which access to formal dental care is minimal. We found that the majority of the population retained most of their dentition in a functional state even up to the age of 65 years: In all age groups, more than 50% had at least 26 teeth present, and more than 90% had at least 16 teeth present. The prevalence of edentulousness was less than 0.3%. The principal cause ...

  19. Posteruptive tooth age and severity of dental fluorosis in Kenya

    DEFF Research Database (Denmark)

    Baelum, V; Manji, F; Fejerskov, O

    1986-01-01

    The purpose of the present study was to assess whether the degree of severity of enamel changes in a population exhibiting rather severe dental fluorosis may be related to posteruptive tooth age and to describe the clinical manifestations of the enamel destructions. All permanent teeth in 102 children aged 10-15 yr who were born and reared in a 2 ppm fluoride area of Kenya were examined for dental fluorosis using the TF-Index. Clinically, at time of eruption all teeth appeared chalky white, but ...

  20. [Ascorbic Acid and Charcot-Marie-Tooth Disease].

    Science.gov (United States)

    Noto, Yu-ichi

    2015-10-01

    Charcot-Marie-Tooth disease type 1A (CMT1A) is a disease for which no drug treatments are available. Passage et al. reported that ascorbic acid reduced the mRNA level of PMP22, improved motor function and increased the numbers of myelinated peripheral nerve axons in a mouse model of CMT1A. Based on these results, five clinical trials were undertaken at different centers worldwide. However, none of them demonstrated significant effectiveness. Although these outcomes were disappointing, these studies have provided many useful insights for conducting the next randomised controlled trial for CMT1A. PMID:26450076

  1. Charcot-Marie-Tooth Disease: Seventeen Causative Genes

    OpenAIRE

    Lee, Jung-Hwa; Choi, Byung-Ok

    2006-01-01

    Charcot-Marie-Tooth disease (CMT) is the most common form of inherited motor and sensory neuropathy. Moreover, CMT is a genetically heterogeneous disorder of the peripheral nervous system, with many genes identified as CMT-causative. CMT has two usual classifications: type 1, the demyelinating form (CMT1); and type 2, the axonal form (CMT2). In addition, patients are classified as CMTX if they have an X-linked inheritance pattern and CMT4 if the inheritance pattern is autosomal recessive. A l...

  2. Benign Cementoblastoma associated with a deciduous tooth: a case report

    Directory of Open Access Journals (Sweden)

    Hemant R Umarji

    2011-10-01

    Full Text Available Benign Cementoblastoma is an odontogenic neoplasm of cementoblasts, also known as true cementoma. Cementoblastoma rarely affects the deciduous teeth and its occurrence on the left side is much more uncommon. This case report is of a 13 year-old patient who presented with cementoblastoma associated with a deciduous second molar in the mandible. The objective of this case report is to add one more case of this rare odontogenic tumor to the academic literature. Key Words: Benign Cementoblastoma, odontogenic tumor, deciduous tooth

  3. The second international intercomparison on EPR tooth dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Wieser, A. E-mail: wieser@gsf.de; Mehta, K.; Amira, S.; Aragno, D.; Bercea, S.; Brik, A.; Bugai, A.; Callens, F.; Chumak, V.; Ciesielski, B.; Debuyst, R.; Dubovsky, S.; Duliu, O.G.; Fattibene, P.; Haskell, E.H.; Hayes, R.B.; Ignatiev, E.A.; Ivannikov, A.; Kirillov, V.; Kleschenko, E.; Nakamura, N.; Nather, M.; Nowak, J.; Onori, S.; Pass, B.; Pivovarov, S.; Romanyukha, A.; Scherbina, O.; Shames, A.I.; Sholom, S.; Skvortsov, V.; Stepanenko, V.; Tikounov, D.D.; Toyoda, S

    2000-12-15

    Eighteen international EPR laboratories participated in the second intercomparison programme. Each participant had to prepare enamel samples and evaluate the absorbed dose from molars that were irradiated in vitro in the range 0-1000 mGy. The objective of the programme was to bring together all methods which are currently applied by different laboratories for EPR dose reconstruction and to demonstrate the present state of dosimetry. An overview of the essential features of the different methods is presented. The current accuracy of EPR tooth enamel dosimetry under defined conditions of irradiation is evaluated.

  4. The second international intercomparison on EPR tooth dosimetry

    International Nuclear Information System (INIS)

    Eighteen international EPR laboratories participated in the second intercomparison programme. Each participant had to prepare enamel samples and evaluate the absorbed dose from molars that were irradiated in vitro in the range 0-1000 mGy. The objective of the programme was to bring together all methods which are currently applied by different laboratories for EPR dose reconstruction and to demonstrate the present state of dosimetry. An overview of the essential features of the different methods is presented. The current accuracy of EPR tooth enamel dosimetry under defined conditions of irradiation is evaluated

  5. Manufacture of Toothed Elements in Nanoausferritic Ductile Iron

    Directory of Open Access Journals (Sweden)

    Myszka D.

    2014-10-01

    Full Text Available The technology currently used for the fabrication of toothed wheels, gear couplings and chain drums involves the induction hardening process or hardening and tempering after carburising. All these processes take a long time and cause adverse changes in the dimensions and surface quality of products, requiring post-treatment machining to remove the resulting cavities. The paper proposes the implementation of gear elements made of ductile iron with nanoausferritic matrix obtained by a new appropriate heat treatment process. The new material offers good performance characteristics and nearly no need for the application of other technological processes commonly used in the manufacture of gears.

  6. Radicular cyst of primary tooth associated with maxillary sinus

    OpenAIRE

    Rakesh N. Bahadure; Khubchandani, Monika; Thosar, Nilima R; Rajeev Kumar SINGH

    2013-01-01

    Radicular cyst is one of the most common odontogenic cystic lesions found in the jaws. It is inflammatory in nature and found mostly in relation to a non-vital tooth. It usually presents at a later stage in life because the formation of the cyst is the last step in the progression of inflammatory events after a periapical infection. The cyst usually goes unnoticed because of its painless nature and small size. We present the clinical, radiographic and histological characteristics of a radicul...

  7. Tooth-surface-specific Effects of Xylitol: Randomized Trial Results

    OpenAIRE

    Ritter, A.V.; Bader, J.D.; Leo, M. C.; Preisser, J.S.; Shugars, D.A.; Vollmer, W.M.; Amaechi, B.T.; Holland, J.C.

    2013-01-01

    The Xylitol for Adult Caries Trial was a three-year, double-blind, multi-center, randomized clinical trial that evaluated the effectiveness of xylitol vs. placebo lozenges in the prevention of dental caries in caries-active adults. The purpose of this secondary analysis was to investigate whether xylitol lozenges had a differential effect on cumulative caries increments on different tooth surfaces. Participants (ages 21-80 yrs) with at least one follow-up visit (n = 620) were examined at base...

  8. Diagnóstico clínico de la enfermedad Charcot-Marie-Tooth

    Directory of Open Access Journals (Sweden)

    Yuselis Pérez Cid

    2014-08-01

    Full Text Available La enfermedad de Charcot-Marie-Tooth es un trastorno polineuropático genéticamente heterogéneo, en la que se han identificado más de 30 genes responsables; sin embargo, el diagnóstico es posible establecerlo sobre las bases de los estudios clínicos y electrofisiológicos. Constituye un reto en la práctica médica de los países del tercer mundo contar con la realización sistemática de estudios genéticos moleculares de las neuropatías hereditarias, por lo que en este trabajo se enfatiza en los estudios clínico-electrofisiológicos para la clasificación de la CMT

  9. The origin of remarkable resilience of human tooth enamel

    Science.gov (United States)

    Zhao, Xiaoli; O'Brien, Simona; Shaw, Jeremy; Abbott, Paul; Munroe, Paul; Habibi, Daryoush; Xie, Zonghan

    2013-12-01

    The mechanical properties of human tooth enamel depend not only on test locations but also on the indentation depth. However, it remains uncertain what roles the depth-dependant properties play in mechanical performance of enamel. Here we reveal that a change in the mechanical properties of enamel, in particular its strength, with increasing indentation depth promotes inelastic deformation in material. In doing so, the severity and extent of stress concentration is reduced. Furthermore, we observed that following unloading, self-recovery occurs in enamel. These findings improve our understanding of the underlying mechanisms responsible for the remarkable resilience of enamel.

  10. The Gap-Tooth Method in Particle Simulations

    CERN Document Server

    Gear, C W; Kevrekidis, Yu G; Li, Ju; Kevrekidis, Ioannis G.

    2003-01-01

    We explore the gap-tooth method for multiscale modeling of systems represented by microscopic physics-based simulators, when coarse-grained evolution equations are not available in closed form. A biased random walk particle simulation, motivated by the viscous Burgers equation, serves as an example. We construct macro-to-micro (lifting) and micro-to-macro (restriction) operators, and drive the coarse time-evolution by particle simulations in appropriately coupled microdomains (teeth) separated by large spatial gaps. A macroscopically interpolative mechanism for communication between the teeth at the particle level is introduced. The results demonstrate the feasibility of a closure-on-demand approach to solving hydrodynamics problems.

  11. Charcot-Marie-Tooth disease complicating type 2 diabetes.

    LENUS (Irish Health Repository)

    Win, Htet Htet Ne

    2012-02-01

    Although both conditions are relatively common, there are very few descriptions of type 2 diabetes mellitus coexisting with Charcot-Marie-Tooth disease (CMT). This case report and literature review describes a 53-year-old Irish man who presented with type 2 diabetes and significant neuropathy, and who was subsequently diagnosed with CMT type 1A. This case report will also discuss how to differentiate diabetic neuropathy from a progressive hereditary neuropathy and how coexistence aggravates the progression of neuropathy thus necessitating early diagnosis.

  12. Charcot-marie-tooth disease complicating type 2 diabetes.

    LENUS (Irish Health Repository)

    Win, Htet Htet Ne

    2011-07-01

    Although both conditions are relatively common, there are very few descriptions of type 2 diabetes mellitus coexisting with Charcot-Marie-Tooth disease (CMT). This case report and literature review describes a 53-year-old Irish man who presented with type 2 diabetes and significant neuropathy, and who was subsequently diagnosed with CMT type 1A. This case report will also discuss how to differentiate diabetic neuropathy from a progressive hereditary neuropathy and how coexistence aggravates the progression of neuropathy thus necessitating early diagnosis.

  13. Analysis of stress state of toothed ring of flexspline by means the BEM

    Directory of Open Access Journals (Sweden)

    P. Fol?ga

    2013-01-01

    Full Text Available Purpose: The paper presents an analysis of the influence of design features of the flexspline in a harmonic drive, such as the relative radial deformation, the relative coating thickness and the design features of the basic rack tooth profile, on stress values in the bottom lands of a toothed ring.Design/methodology/approach: In numerical calculations, the software developed at the Faculty of Transport of the Silesian University of Technology was used. The program automatically generates a profile of the flexspline and a boundary elements mesh on the grounds of the flexspline and working tool assigned parameters. In the analysis of the state of stress, the boundary element method (BEM was applied.Findings: A decreased value of the curve radius of the head of the basic rack tooth profile results in a change in the width of the tooth bottom land, shortening of the transition curve in the tooth base and a reduction of the tooth thickness at its base, which in turn leads to increased values of stress. Yet, the influence of the relative curve radius of the head of the basic rack tooth profile on the stress value is insignificant. The increase of the torque and relative coating thickness for different value of the curve radius of the head of the basic rack tooth profile cause an increase of stress in the bottom lands of the toothed ring.Research limitations/implications: The paper presents strength calculations for the teeth in toothed ring of a flexspline of a double harmonic drive by means of boundary elements method (BEM. The results of numerical calculations correspond in terms of their quality to the results presented in the literature, which were calculated by finite element method (FEM.Originality/value: In the analysis of the state of stress of toothed ring of flexspline, the boundary element method (BEM was applied.

  14. Comparison of the effect of thermal stresses on tooth-colored posts, cores and tooth structures by finite element analysis

    Directory of Open Access Journals (Sweden)

    Levent Nalbant

    2012-04-01

    Full Text Available Objectives: The aims of this study were to analyze the influence of cold heat flow in all ceramic crown material, composite core, zirconium and glass fiber reinforced composite post materials, resin based luting cement and root dentin; and to compare these two tooth-colored post systems about their temperature and thermal stress distributions.
    Materials and Methods: A 3-dimesional finite element model of maxillary left canine tooth was constructed. All ceramic crown, composite core, tooth dentin, post and bone were modeled. In the first part of this study, initial body temperature was assumed to be 36.5°C and the outer temperature was reduced to 0°C for 5 secs. In the second part, the thermal stress was calculated as a result of temperature change. For the analysis, 7 nodes of the finite element model were selected and heat flow, temperature and thermal stres on these nodes were evaluated.
    Results: Mean temperature value was 15.75 °C for GFRC post model and 15.47 °C for Zr post model. The maximum von Mises stress was obtained at the node C in both post systems. In general, thermal stress was observed on the cervical part of all-ceramic crown and there was an interface between root dentin-composite core and post material. The temperature gradient of the GFRC post was smaller than that of the zirconia post.
    Conclusions: Within the limitation of this study, zirconia posts produced greater stress than GFRC posts. Temperature changes had more effect on the post-cement interface and cervical areas than on the other areas.

  15. Anticariogenic and Hemolytic Activity of Selected Seed Protein Extracts In vitro conditions

    OpenAIRE

    Ishnava, Kalpesh B.; Pankit P Shah

    2014-01-01

    This study aimed to assess the anticariogenic and hemolytic activity of crude plant seed protein extracts against tooth decaying bacteria.The proteins from seeds of 12 different plants were extracted and used for antimicrobial assay against six different organisms. The extraction was carried out in 10mM of sodium phosphate buffer (pH 7.0). Protein concentrations were determined as described by Bradford method. Anticariogenic activity was studied by agar well diffusion method and Minimum Inhib...

  16. Effect of bisphosphonates on orthodontic tooth movement-an update.

    Science.gov (United States)

    Krishnan, Sindhuja; Pandian, Saravana; Kumar S, Aravind

    2015-04-01

    Bisphosphonates are a synthetic class of pyrophosphate analogues that are powerful inhibitors of bone resorption which are commonly used as a medication for the prevention and therapy of osteoporosis and osteopenia, also used to treat tumor diseases. As it affects bone metabolism, it is said to have an influence on orthodontic treatment and tooth movement. Also, this review gives an insight into the reported effects of Bisphosphonate medication in literature highlighting the status quo of scientific research regarding effects of Bisphosphonates on orthodontic tooth movement. A systematic literature search was done in Medline database (Pubmed) for the appropriate keywords. Manual handsearch was also done. From the available evidence it can be concluded that the duration of orthodontic treatment is increased for patients under Bisphosphonate therapy as they interfere with the osteoclastic resorption. However, they may be beneficial for anchorage procedures. Further long term prospective randomized controlled trials are required to assess possible benefits and adverse effects of bisphosphonate treatment, before Bisphosphonates can be therapeutically used in orthodontics. PMID:26023659

  17. Development of the canine tooth in the beagle

    International Nuclear Information System (INIS)

    The growth of the crown and root in the canine tooth of beagle dogs were observed macroscopically and radiographically, and changes of occlusion with age were investigated. Completion of growth in the crown of the canine tooth was observed in both mandible and maxilla, and its eruption was accompanied by development of the dental root. The permanent canine erupted on the lingual side of deciduous canine in the mandible, and on the mesial side of the deciduous canine in the maxilla. Movement of the permanent canine to normal occlusal position(buccal direction in mandibular canine, and distal direction in maxillary canine)was followed by the loss of the deciduous canine. Coexistence of the permanent and deciduous canines occurred for about 2.4 weeks in the maxilla and about 1.4 weeks in the mandible, on average. Macroscopically, the growth of the permanent canine was completed by 33 weeks of age in the mandible and about 34 weeks of age in the maxilla. The mature root of the permanent canine was recognized radiographically at about 43 weeks of age in the mandible and 47 weeks of age in the maxilla

  18. Unlocking evidence of early diet from tooth enamel.

    Science.gov (United States)

    Humphrey, Louise T; Dean, M Christopher; Jeffries, Teresa E; Penn, Malcolm

    2008-05-13

    Recent developments in microspatial analysis of enamel chemistry provide the resolution needed to reconstruct detailed chronological records of an individual's early life history. Evidence of nutritional history, residential mobility, and exposure to heavy metals can potentially be retrieved from archaeological and even fossil teeth. Understanding the pattern and timing of incorporation of each trace element or stable isotope into enamel is crucial to the interpretation of the primary data. Here, we use laser ablation inductively coupled plasma mass spectrometry and ArcGIS software to map variation in calcium-normalized strontium intensities across thin sections of enamel from exfoliated deciduous teeth. Differences in calcium-normalized strontium intensities across each tooth reflect variation in tooth mineralization, implying that sampling location must be taken into account in interpreting results. Chronologically consistent shifts in calcium-normalized strontium intensities in teeth from children with known nursing histories reflect the onset and duration of breastfeeding and the introduction of nonmaternal sources of food. This tool is likely to be valuable for studying weaning and nursing behavior in the past. The distribution of normalized strontium intensities presented here is consistent with a model for the differential incorporation of strontium and calcium into enamel during the secretory and maturational phases of formation. PMID:18458343

  19. Viscoplastic response of tooth enamel under cyclic microindentation.

    Science.gov (United States)

    Jia, Yunfei; Xuan, Fu-Zhen; Yang, Fuqian

    2015-10-01

    Cyclic microindentations were performed on the occlusal surface and axial section of tooth enamel, using the Berkovich indenter. Under the action of a cyclic indentation load, the indenter continuously penetrated into the tooth enamel and reached a quasi-steady state at which the penetration depth per cycle was a constant. At the quasi-steady state, both the amplitude of the indentation depth and the penetration depth per cycle for the cyclic indentation of the axial section are larger than those for the indentation of the occlusal section under the same loading condition. The energy dissipation per cycle consists of two contributions; one is the plastic energy dissipated per cycle due to the propagation of the plastic zone underneath the indentation and the other is the energy dissipation due to the viscous flow during the cyclic indentation. Both the penetration depth and the plastic energy dissipated per cycle at the quasi-steady state are independent of the maximum applied load and increase with increasing the amplitude of the cyclic indentation load. PMID:26117776

  20. Effect of Bisphosphonates on Orthodontic Tooth Movement—An Update

    Science.gov (United States)

    Pandian, Saravana; Kumar S, Aravind

    2015-01-01

    Bisphosphonates are a synthetic class of pyrophosphate analogues that are powerful inhibitors of bone resorption which are commonly used as a medication for the prevention and therapy of osteoporosis and osteopenia, also used to treat tumor diseases. As it affects bone metabolism, it is said to have an influence on orthodontic treatment and tooth movement. Also, this review gives an insight into the reported effects of Bisphosphonate medication in literature highlighting the status quo of scientific research regarding effects of Bisphosphonates on orthodontic tooth movement. A systematic literature search was done in Medline database (Pubmed) for the appropriate keywords. Manual handsearch was also done. From the available evidence it can be concluded that the duration of orthodontic treatment is increased for patients under Bisphosphonate therapy as they interfere with the osteoclastic resorption. However, they may be beneficial for anchorage procedures. Further long term prospective randomized controlled trials are required to assess possible benefits and adverse effects of bisphosphonate treatment, before Bisphosphonates can be therapeutically used in orthodontics. PMID:26023659

  1. The unicorn and the narwhal: a tale of the tooth.

    Science.gov (United States)

    Christen, Arden G; Christen, Joan A

    2011-01-01

    From as far back as the early Roman era, detailed descriptions and artistic images of the unicorn have been imagined. In Europe, the Mediterranean and the Far East, this creature became accepted as real. Although such an animal had never actually been seen, it was said to have the appearance of a horse, the beard and cloven hooves of a goat, the tail of a lion, and a single, spear-like horn protruding from the center of its forehead. The unicorn myth originated shortly after unidentified horn-like objects, from six to ten feet long, began to appear in ancient European marketplaces. Physicians quickly ascribed outlandish healing properties to these horns, pulverizing them for the treatment of various diseases. In 1638, a Danish zoologist challenged these claims and provided evidence that the so-called "unicorn horn" was actually the tusk (tooth) of the narwhal from the Arctic seas. However, his findings remained unheeded for the next 100 years. This paper explains how the myth of the unicorn and the purported powers contained within the substance of its magical horn evolved from the ages-old spoils of the Arctic fishing trade, where the narwhal was primarily speared for food and secondarily, for the export value of its ivory tusk. This unusually long, pointed and protruding single tooth, which breaks through the upper lip and the left jaw of each male narwhal, became a highly valuable commodity over the following centuries, due to its believed supernatural origins and curative qualities. PMID:22372187

  2. Disturbed tooth formation by 60Co-gamma-ray radiation

    International Nuclear Information System (INIS)

    The molar of guinea pigs was irradiated with 60Co-#betta# ray for daily observations of the manifestation of disturbed tooth formation by microradiography and the time registration by tetracycline-labelling. Irradiation first injured young blast cells of the dentin in the growth phase, dental pulp cells, and cells of the enamel. The portion composed of injured cells formed a depressed ''constriction'' from the dental pulp side toward the border between the enamel and dentin. The cells of the enamel injured by irradiation in the growth phase later formed a very thin irregular stroma. In contrast, cells in the differentiation or subsequent phase at the time of irradiation and cells probably having started to grow after irradiation proceeded with formation of a normal stroma and calcification. No uniform relation was obtained between the histological staining of the organic stroma of normal or abnormal dentin and calcification. Labelling with tetracycline revealed that the irradiation conditions in the present study provoked hardly any changes in the speed of tooth eruption. (Chiba, N.)

  3. Charcot-Marie-Tooth disease: genetic and rehabilitation aspects

    Directory of Open Access Journals (Sweden)

    Mariana CEVEI

    2008-05-01

    Full Text Available Charcot-Marie-Tooth hereditary motor and sensory neuropathy refers to a group of disorders characterized by a chronic motor and sensory polyneuropathy. Typical cases have distal muscle weakness and peroneal atrophy often associated with mild to moderate sensory loss, depressed tendon reflexes, and pes cavus. Hereditary neuropathies are categorized by mode of inheritance and chromosomal locus. The diagnosis is based on family history, characteristic findings on physical examination, EMG, nerve conduction velocity testing, and occasionally on nerve biopsy. The disorder shows allelic and non-allelic genetic heterogeneity, thus mutations of different genes leading to the same clinical features. Also, different mutations of the same gene may lead to different phenotypes. Molecular genetic testing is available in clinical laboratories for diagnosis of 7 subtypes of the disease. Genetic counseling and risk assessment depend on the inheritance. We present two cases with Charcot-Marie-Tooth type 1 and type 2 respectively. There is no cure for the disorder, although physical therapy and moderate activity are often recommended to maintain muscle strength and endurance.

  4. Application of thrombin powder after tooth extraction in patients receiving anticoagulant therapy

    Directory of Open Access Journals (Sweden)

    Marjanovi? Marjan

    2002-01-01

    Full Text Available Patients with extreme hypocoagulation, which occurs either as an effect of some diseases with coagulation deficiency or because of the anticoagulant therapy (ACT, are a risk group for oral surgery. In the last decades decision to change or interrupt ACT before and after the procedure was abandoned and more often local hemostasis was being achieved by combining chemical and biological substances. The success of the surgical hemostasis and thrombin powder combination was tested on the group of 20 patients with ACT. The results were satisfactory despite thrombin powder solubility in the moist oral environment.

  5. Evaluation of the effectiveness of the tooth whitening treatment associated with the immersion in coloring solutions

    Directory of Open Access Journals (Sweden)

    Giovani de Oliveira Correa

    2012-12-01

    Full Text Available Introduction: Tooth whitening or dental bleaching is a cosmetic procedure that has established itself in Dentistry; however, the staining because of the ingestion of some types of food may cause several factors leading to the failure of this treatment. Objective: This study aimed to evaluate in vitro the influence of the immersion of whitened teeth in solutions with a high degree of pigmentation on the efficacy of the bleaching performed with 16% hydrogen peroxide. Material and methods: Fifty-six human teeth were selected, bleached for 4 hours a day during 14 days and randomly divided into 7 groups (n = 8. The groups G1/G2 and G3 were immersed in coloring solutions immediately (IM after bleaching (AP: G1 – tooth whitening + coffee (IM, G2 – tooth whitening + cola-based soft drink (IM and G3 – tooth whitening + red wine (IM; G4/and G6 were immersed in the solutions for 2 hours (AP, G4 – tooth whitening + coffee (AP, G5 – tooth whitening + cola based soft drink (AP, G6 – tooth whitening + red wine and (AP G7 – control. After bleaching with an immersion time of 5 minutes, with the aid of a digital spectrophotometer, the final color (FC was measured 24 hours after the end of the bleaching treatment (day 15. Results: The results for ANOVA showed no statistical differences in all groups. Conclusion: There was no influence on the effectiveness of tooth whitening immersed in coloring solutions.

  6. Hippo pathway/Yap regulates primary enamel knot and dental cusp patterning in tooth morphogenesis.

    Science.gov (United States)

    Kwon, Hyuk-Jae Edward; Li, Liwen; Jung, Han-Sung

    2015-11-01

    The shape of an individual tooth crown is primarily determined by the number and arrangement of its cusps, i.e., cusp patterning. Enamel knots that appear in the enamel organ during tooth morphogenesis have been suggested to play important roles in cusp patterning. Animal model studies have shown that the Hippo pathway effector Yap has a critical function in tooth morphogenesis. However, the role of the Hippo pathway/Yap in cusp patterning has not been well documented and its specific roles in tooth morphogenesis remain unclear. Here, we provide evidence that Yap is a key mediator in tooth cusp patterning. We demonstrate a correlation between Yap localization and cell proliferation in developing tooth germs. We also show that, between the cap stage and bell stage, Yap is crucial for the suppression of the primary enamel knot and for the patterning of secondary enamel knots, which are the future cusp regions. When Yap expression is stage-specifically knocked down during the cap stage, the activity of the primary enamel knot persists into the bell-stage tooth germ, leading to ectopic cusp formation. Our data reveal the importance of the Hippo pathway/Yap in enamel knots and in the proper patterning of tooth cusps. PMID:26318014

  7. Symptoms and physiological responses to prolonged, repeated, low-level tooth clenching in humans

    DEFF Research Database (Denmark)

    Takeuchi, Tamiyo; Arima, Taro; Ernberg, Malin; Yamaguchi, Taihiko; Ohata, Noboru; Svensson, Peter

    2015-01-01

    BACKGROUND: The traditional view contends bruxism, such as tooth grinding/clenching, is part of the etiology of temporomandibular disorders (TMD) including some subtypes of headaches. The purpose of this study is to investigate if a low-level but long-lasting tooth-clenching task initiates TMD...

  8. Treatment of asymptomatic internal resorption of a maxillary premolar tooth in a military working dog.

    Science.gov (United States)

    Eikenberg, S; Loheide, H; Arens, F C

    1998-12-01

    An asymptomatic pink discoloration of a maxillary right fourth premolar tooth was discovered during a routine oral examination on a 9 year-old Belgian Malinois dog. A radiolucent lesion was seen in the pulpal chamber on radiographic examination. The lesion had perforated the mesiobuccal root of the tooth. The primary differential diagnosis was idiopathic internal resorption. The tooth was treated by partial resection (removal of the mesiobuccal root and associated crown). A vital pulpotomy and amalgam restoration was performed on the remaining tooth structure. A follow-up 1 year later demonstrated a successful treatment outcome. The animal was asymptomatic and able to perform military duties. Clinical and radiographic signs of healing were evident and the tooth was functional. PMID:10518874

  9. Uneven distribution of enamel in the tooth crown of a Plains Zebra (Equus quagga).

    Science.gov (United States)

    Winkler, Daniela E; Kaiser, Thomas M

    2015-01-01

    Unworn teeth of herbivorous mammals are not immediately functional. They have to be partially worn to expose enamel ridges which can then act as shear-cutting blades to break the food down. We use the Plains Zebra (Equus quagga) as a hypsodont, herbivorous model organism to investigate how initial wear of the tooth crown is controlled by underlying structures. We find that the enamel proportion is smaller at the apical half of the tooth crown in all upper tooth positions and suggest that lower enamel content here could promote early wear. Besides this uneven enamel distribution, we note that the third molar has a higher overall enamel content than any other tooth position. The M3 is thus likely to have a slightly different functional trait in mastication, resisting highest bite forces along the tooth row and maintaining functionality when anterior teeth are already worn down. PMID:26082860

  10. Uneven distribution of enamel in the tooth crown of a Plains Zebra (Equus quagga

    Directory of Open Access Journals (Sweden)

    Daniela E. Winkler

    2015-06-01

    Full Text Available Unworn teeth of herbivorous mammals are not immediately functional. They have to be partially worn to expose enamel ridges which can then act as shear-cutting blades to break the food down. We use the Plains Zebra (Equus quagga as a hypsodont, herbivorous model organism to investigate how initial wear of the tooth crown is controlled by underlying structures. We find that the enamel proportion is smaller at the apical half of the tooth crown in all upper tooth positions and suggest that lower enamel content here could promote early wear. Besides this uneven enamel distribution, we note that the third molar has a higher overall enamel content than any other tooth position. The M3 is thus likely to have a slightly different functional trait in mastication, resisting highest bite forces along the tooth row and maintaining functionality when anterior teeth are already worn down.

  11. The use of surrogate variables to reflect long-term tooth survivability.

    Science.gov (United States)

    Greenstein, Gary

    2005-08-01

    Clinical parameters used to monitor periodontal patients are usually measures of the disease process. They are considered surrogate variables because changes in their status are interpreted to have an impact on the ultimate goal of periodontal therapy, which is tooth retention. However, their ability to reflect tooth survivability has been questioned because there is a lack of long-term data to validate that stable or improved surrogates result in reduced tooth loss. Therefore, to clarify the utility of employing surrogates to reflect long-term tooth retention, a number of issues related to their use are discussed in this commentary: phraseology, benefits and shortcomings, biologic credibility, and their previous successful utilization in monitoring the effects of therapy. This commentary supports the reasonableness of using surrogates to monitor periodontal status and suggests that a combination of surrogates that represent "periodontal clinical health" should be considered a true endpoint of periodontal therapy, since this outcome provides a condition conducive to tooth retention. PMID:16101375

  12. Visualization of Tooth for Non-Destructive Evaluation from CT Images

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Hui; Chae, Ok Sam [Kyung Hee University, Seoul (Korea, Republic of)

    2009-06-15

    This paper reports an effort to develop 3D tooth visualization system from CT sequence images as a part of the non-destructive evaluation suitable for the simulation of endodontics, orthodontics and other dental treatments. We focus on the segmentation and visualization for the individual tooth. In dental CT images teeth are touching the adjacent teeth or surrounded by the alveolar bones with similar intensity. We propose an improved level set method with shape prior to separate a tooth from other teeth as well as the alveolar bones. Reconstructed 3D model of individual tooth based on the segmentation results indicates that our technique is a very conducive tool for tooth visualization, evaluation and diagnosis. Some comparative visualization results validate the non-destructive function of our method.

  13. Visualization of Tooth for Non-Destructive Evaluation from CT Images

    International Nuclear Information System (INIS)

    This paper reports an effort to develop 3D tooth visualization system from CT sequence images as a part of the non-destructive evaluation suitable for the simulation of endodontics, orthodontics and other dental treatments. We focus on the segmentation and visualization for the individual tooth. In dental CT images teeth are touching the adjacent teeth or surrounded by the alveolar bones with similar intensity. We propose an improved level set method with shape prior to separate a tooth from other teeth as well as the alveolar bones. Reconstructed 3D model of individual tooth based on the segmentation results indicates that our technique is a very conducive tool for tooth visualization, evaluation and diagnosis. Some comparative visualization results validate the non-destructive function of our method.

  14. On optimization of internal/external spur gears tooth bending strength

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2014-01-01

    Gear fatigue strength is primarily controlled by the durability and load capacity, the first is typically related to pitting damage and the second to tooth-breakage. The pitting is due to the tooth contact and the shape of the contacting surfaces, the tooth breakage is controlled by the stress level at the tooth root. As with most machine elements the design/geometry is defined in standards (ISO). The present work focuses on changing the tooth root design of both external and internal gears, in order to improve the stress concentration factor. The design changes made are compliant with the standard, i.e. the optimized gear design can mesh with a standard gear.

  15. Organ dose conversions from ESR measurements using tooth enamel of atomic bomb survivors

    International Nuclear Information System (INIS)

    Dose conversions were studied for dosimetry of atomic bomb survivors based upon electron spin resonance (ESR) measurements of tooth enamel. Previously analysed data had clarified that the tooth enamel dose could be much larger than other organ doses from a low-energy photon exposure. The radiation doses to other organs or whole-body doses, however, are assumed to be near the tooth enamel dose for photon energies which are dominant in the leakage spectrum of the Hiroshima atomic bomb assumed in DS02. In addition, the thyroid can be a candidate for a surrogate organ in cases where the tooth enamel dose is not available in organ dosimetry. This paper also suggests the application of new Japanese voxel phantoms to derive tooth enamel doses by numerical analyses. (authors)

  16. Retrospective dosimetry assessment using the 380 deg. C thermoluminescence peak of tooth enamel

    International Nuclear Information System (INIS)

    The thermoluminescence (TL) response to gamma-ray irradiation of tooth enamel is reported. The tooth enamel was separated from dentine by using mechanical and physico-chemical procedures followed by grinding (grain size ?100 ?m) and etching. The TL was attributed to the recombination of CO2- radicals incorporated into or attached to the surface of hydroxyapatite crystals. The growth of the ?380 deg. C TL peak with absorbed dose was examined with irradiated tooth enamel samples and reconstructed doses evaluated for tooth enamel samples from four human subjects. - Highlights: ? Thermoluminescence response after gamma-ray irradiation of tooth enamel was investigated. ? Thermoluminescence was attributed to the recombination of CO2- radicals. ? CO2- radicals are produced inside or at the surface of hydroxyapatite crystals. ? From the growth of the 380C peak reconstructed doses have been evaluated.

  17. Relationship between human tooth enamel free radical concentration and radiation dose

    International Nuclear Information System (INIS)

    Free radical concentrations of 25 adult tooth enamel samples were measured by electron spin resonance (ESR) technique in this paper, and the relationship between free radical concentration of tooth enamel and radiation dose was also investigated. In the 25 adult enamel samples they are 16 male samples and 9 female samples, Ages of tooth donors range from 18-41 years. Difference in background ESR signal intensity between male and female samples was no observed; free radical concentration (or increment of radiation-induced free radical concentration) in tooth enamel increases linearly with increasing of radiation dose. In the case of radiation accident, the study results of this paper could be applied to dose estimation when conditions of ESR measurement of exposed individual tooth enamel are similar to measurement conditions of dose-effect calibration curve in this paper

  18. Craniomandibular Trauma and Tooth Loss in Northern Dogs and Wolves: Implications for the Archaeological Study of Dog Husbandry and Domestication

    OpenAIRE

    Losey, Robert J; Jessup, Erin; Nomokonova, Tatiana; Sablin, Mikhail

    2014-01-01

    Archaeological dog remains from many areas clearly show that these animals suffered tooth fractures, tooth loss, trauma, and dental defects during their lives. Relatively little research has explored the meanings of these patterns, particularly for ancient dog remains from small-scale societies of the North. One limiting issue is the lack of comparative data on dental health and experiences of trauma among northern wolves and dogs. This paper examines tooth loss, tooth fracture, enamel hypopl...

  19. Comparison between observed children's tooth brushing habits and those reported by mothers

    Directory of Open Access Journals (Sweden)

    Pordeus Isabela A

    2011-09-01

    Full Text Available Abstract Background Information bias can occur in epidemiological studies and compromise scientific outcomes, especially when evaluating information given by a patient regarding their own health. The oral habits of children reported by their mothers are commonly used to evaluate tooth brushing practices and to estimate fluoride intake by children. The aim of the present study was to compare observed tooth-brushing habits of young children using fluoridated toothpaste with those reported by mothers. Methods A sample of 201 mothers and their children (aged 24-48 months from Montes Claros, Brazil, took part in a cross-sectional study. At day-care centres, the mothers answered a self-administered questionnaire on their child's tooth-brushing habits. The structured questionnaire had six items with two to three possible answers. An appointment was then made with each mother/child pair at day-care centres. The participants were asked to demonstrate the tooth-brushing practice as usually performed at home. A trained examiner observed and documented the procedure. Observed tooth brushing and that reported by mothers were compared for overall agreement using Cohen's Kappa coefficient and the McNemar test. Results Cohen's Kappa values comparing mothers' reports and tooth brushing observed by the examiner ranged from poor-to-good (0.00-0.75. There were statistically significant differences between observed tooth brushing habits and those reported by mothers (p Conclusions In general, there was low agreement between observed tooth brushing and mothers' reports. Moreover, the different methods of estimation resulted in differences in the frequencies of tooth brushing habits, indicative of reporting bias. Data regarding children's tooth-brushing habits as reported by mothers should be considered with caution in epidemiological surveys on fluoridated dentifrice use and the risk of dental fluorosis.

  20. Diabetes and Tooth Loss in a National Sample of Dentate Adults Reporting Annual Dental Visits

    Directory of Open Access Journals (Sweden)

    Julie M. Kapp, PhD, MPH

    2007-07-01

    Full Text Available IntroductionPeriodontal disease has been associated with tooth loss and reported as more prevalent among people with diabetes than among those without diabetes. Having an annual dental examination is a national goal of Healthy People 2010. Our objective was to examine whether an association exists between diabetes and tooth loss among a population reporting an annual dental visit.MethodsWe used data from the 2004 Behavioral Risk Factor Surveillance System to examine the association between self-reported diabetes and tooth removal due to decay or periodontal disease among 155,280 respondents reporting a dental visit within the past year. We calculated prevalence estimates, odds ratios, and 95% confidence intervals. Multiple logistic regression allowed for adjustment.ResultsThe overall prevalence of tooth removal among the people in the study was 38.3%. People with diabetes had a significantly higher prevalence of tooth removal. In a multivariable model adjusting for selected covariates, respondents with diabetes were 1.46 times as likely (95% CI, 1.30–1.64 to have at least one tooth removed than respondents without diabetes. A stronger association between diabetes and tooth loss was observed among people in the younger age groups than among those in the older age groups.ConclusionEven among people reporting a recent dental visit, diabetes was independently associated with tooth loss. Multidisciplinary efforts are needed to raise awareness of the risk of tooth loss among younger people with diabetes. Good oral hygiene as well as annual dental examinations are important for preventing tooth loss.

  1. Comparison of Intact dental pulp tissue characteristics, Comparison between primary and permanent tooth in dog

    Directory of Open Access Journals (Sweden)

    SE Jabbarifar

    2007-01-01

    Full Text Available Introduction: Responses of dental pulp in primary and permanent tooth are different to pulp therapy, trauma, caries, dehydration, pulp tester and dental materials. The reactions of primary dental pulp in compare with permanent dental pulp are different.Can these various reactions be attributed to different histological characteristics in two groups of teeth? The aim of this study is comparison of histological characteristics between dental pulps in two groups of teeth of dog.Methods and Materials: 20 primary and 20 permanent teeth of two dogs were selected. Forty teeth were extracted under general anesthesia. 1-2 millimeter of apices of roots were cut and immersed in 10% formaldehyde solution. Then the samples were sent to oral histological lab for staining and sliding. Oral pathologist examined the histology of dental pulps and reported the results. The data of study were analyzed by SPSS software 11.5. Then data were compared with Mann-Whitney and t-test. Finally findings were reported.Results: The relative frequency of fibroblasts, mesenchymal undifferentiating cells, blood vessels, collagen and nerve fibers and immune cells in primary and permanent dental pulp in dog had no significant difference (p value

  2. Effect of fluorides from various restorative materials on remineralization of adjacent tooth: An in vitro study

    Directory of Open Access Journals (Sweden)

    Baliga M

    2010-06-01

    Full Text Available The aim of the study was to evaluate the extent of surface zone remineralization and the effect of fluoride at the inter-proximal adjacent tooth surface, using restorative materials FusionAlloy, Ketac-Fil and Heliomolar. Ninety extracted molar teeth were used of which 45 were placed in artificial caries for 10 weeks. The remaining 45 teeth were filled with the respective restorative materials, mounted with the artificial carious teeth in proximal contact with plaster and placed in artificial saliva for a period of 28 days. Finally, sectioning of artificially carious teeth was done mesio-distally and observed under the optical microscope and scanning electron microscope. Comparison among the groups was done by one-way analysis of variance [ANOVA] and Fischer?s F test. Intercomparison between the groups was done by using Dunnett?s t-test. Results obtained from transmitted electron microscopic and scanning electron microscopic observations were almost similar with the Ketac-Fil and Heliomolar showing better results in surface zone remineralization compared to FusionAlloy. Also, Ketac-Fil is a good material in releasing fluoride to remineralize enamel when compared to Heliomolar and FusionAlloy. Thus, it can be used mainly in class II cavity restorations of primary and permanent dentitions due to the potential ability of fluoride containing glass ionomer cements and composite resins to remineralize incipient carious lesions on adjacent teeth.

  3. Tooth enamel electron spin resonance dosimetry of people living in the area with lime tobacco custom

    International Nuclear Information System (INIS)

    Objective: To study the effect of the custom of long term chewing lime tobacco on human tooth enamel electron spin resonance (ESR) dosimetry. Methods: A total of 20 enamel samples from lingual parts of adults teeth collected in Bombay, India were obtained by mechanical method. Some enamel samples from Japanese adults were extracted and 10 mixed samples were prepared. Enamel samples were exposed to different doses of 60Co ?-rays several times, and ESR spectra were measured after exposure. Results: ESR background signals of 9 Bombay samples were found 1.5-3.3 times higher than those of Japanese mixed samples. The ?-ray dose responses of dosimetric signal with higher background level were a little lower, and the average sensitivity was (0.42±0.03) mGy, which was close to that of Japanese mixed samples. Conclusions: The average level of background signals of Bombay samples was much higher than that of other non-chewing tobacco area, which was possibly caused by tobacco area, which was possibly caused by tobacco lime, the main component in chewing tobacco productions, and it would help to explore its special influences on ESR, and improve dose reconstruction in accuracy. (authors)

  4. Placement of single tooth implant in healed socket with immediate temporization: Clinical study

    Directory of Open Access Journals (Sweden)

    Jeevan Lata

    2012-01-01

    Full Text Available Introduction: Edentulous condition inadequately compensated for, by dentures, impair oral function and is accompanied by reduced self–confidence. In a continued effort to achieve these goals, implant dentistry was introduced. Immediate temporization is somehow a recent concept, which allows the maintenance of soft tissue contours, along with interdental alveolar contours. Aims and Obectives: Aims of the present study were to study the placement of implant in the post-extracted healed tooth socket of anterior maxilla and to evaluate the feasibility of early function on implants placed. Materials and Methods: In the present study, HI-TECH IMPLANTS TRX-OP one-piece immediate loading implant system with the built on abutment has been used.Immediate temporisation has been done and results have been evaluated in terms of stability, gingival health, esthetics, marginal bone loss, patient?s psychological attitude, and satisfaction.?Results: Out of eight implants, 6 successfully healed whereas 2 implants suffered failure?Conclusion: Overall conclusion drawn from the study is, immediate temporization is a successful method providing psychological, financial and emotional benefits to the patient.

  5. Genome-wide association study of primary tooth eruption identifies pleiotropic loci associated with height and craniofacial distances

    DEFF Research Database (Denmark)

    Fatemifar, Ghazaleh; Hoggart, Clive J; Paternoster, Lavinia; Kemp, John P; Prokopenko, Inga; Horikoshi, Momoko; Wright, Victoria J; Tobias, Jon H; Richmond, Stephen; Zhurov, Alexei I; Toma, Arshed M; Pouta, Anneli; Taanila, Anja; Sipila, Kirsi; Lähdesmäki, Raija; Pillas, Demetris; Geller, Frank; Feenstra, Bjarke; Melbye, Mads; Nohr, Ellen A; Ring, Susan M; St Pourcain, Beate; Timpson, Nicholas J; Davey Smith, George; Jarvelin, Marjo-Riitta; Evans, David M

    2013-01-01

    Twin and family studies indicate that the timing of primary tooth eruption is highly heritable, with estimates typically exceeding 80%. To identify variants involved in primary tooth eruption, we performed a population-based genome-wide association study of 'age at first tooth' and 'number of tee...

  6. Tooth fracture risk analysis based on a new finite element dental structure models using micro-CT data.

    Science.gov (United States)

    Chen, G; Fan, W; Mishra, S; El-Atem, A; Schuetz, M A; Xiao, Y

    2012-10-01

    The finite element (FE) analysis is an effective method to study the strength and predict the fracture risk of endodontically-treated teeth. This paper presents a rapid method developed to generate a comprehensive tooth FE model using data retrieved from micro-computed tomography (?CT). With this method, the inhomogeneity of material properties of teeth was included into the model without dividing the tooth model into different regions. The material properties of the tooth were assumed to be related to the mineral density. The fracture risk at different tooth portions was assessed for root canal treatments. The micro-CT images of a tooth were processed by a Matlab software programme and the CT numbers were retrieved. The tooth contours were obtained with thresholding segmentation using Amira. The inner and outer surfaces of the tooth were imported into Solidworks and a three-dimensional (3D) tooth model was constructed. An assembly of the tooth model with the periodontal ligament (PDL) layer and surrounding bone was imported into ABAQUS. The material properties of the tooth were calculated from the retrieved CT numbers via ABAQUS user's subroutines. Three root canal geometries (original and two enlargements) were investigated. The proposed method in this study can generate detailed 3D finite element models of a tooth with different root canal enlargements and filling materials, and would be very useful for the assessment of the fracture risk at different tooth portions after root canal treatments. PMID:22901677

  7. Tooth wear in patients submitted to bariatric surgery

    Scientific Electronic Library Online (English)

    Maria do Socorro Coêlho, Alves; Fernando Alberto Costa Cardoso da, Silva; Stephanie Gomes, Araújo; Antônio Cláudio Almeida de, Carvalho; Alcione Miranda, Santos; Andrea Lúcia Almeida de, Carvalho.

    2012-04-01

    Full Text Available Cirurgia bariátrica pode provocar freqüentes episódios de vômito e refluxo gastroesofágico o que promove o contato dos ácidos gástricos com os dentes fazendo que haja perda irreversível de estrutura dental. Este estudo teve como objetivo avaliar a prevalência de desgaste dentário em pacientes bariát [...] ricos. Foram examinados 125 pacientes em um Hospital Público de São Luís, MA no período de julho a outubro de 2010, distribuídos em pacientes que já tinham sidos submetidos à cirurgia bariátrica há pelo menos 6 meses (Grupo bariátrico), obesos mórbidos que estavam na lista de espera para esta cirurgia (Grupo obeso) e por pacientes que esperavam por consulta médica ambulatorial em outros setores (Grupo controle). Os pacientes responderam a um questionário investigativo e foram examinados clinicamente utilizando o “Basic Erosive Wear Examination” - BEWE (Índice Básico do Desgaste Erosivo) que permite a classificação da severidade das lesões não-cariosas e avaliação de risco. Todos os pacientes apresentaram algum grau de desgaste dentário em diferentes níveis. No entanto, a presença de LDNC (lesão dental não-cariosa) estava associada ao grupo que o paciente pertencia. O grupo bariátrico apresentou maior prevalência e nível de risco em relação às LDNC’s estatisticamente significante quando comparado aos outros grupos, seguido pelo grupo de obeso e controle. Refluxo e vômito parecem não influenciar positivamente nas LDNC. Abstract in english Bariatric surgery may cause frequent vomiting episodes and gastroesophageal reflux, which promote the contact of gastric acids with the teeth leading to irreversible loss of tooth structure. The aim of this study was to assess prevalence of tooth wear in bariatric patients. One hundred and twenty-fi [...] ve patients were examined at a Public Hospital in São Luis, MA, Brazil, between July and October 2010, being patients who had already been submitted to the bariatric surgery at least 6 months previously (Bariatric group), morbidly obese patients who were on the waiting list for this surgery (Obese group) and patients who were waiting for ambulatory medical care in other sectors (Control group). The patients answered an investigative questionnaire and were clinically examined using the Basic Erosive Wear Examination (BEWE) scoring system, which allows the classification of the severity of noncarious dental lesions (NCDL) and evaluation of risk. All patients presented some degree of tooth wear at different levels. However, the presence of NCDL was associated with the group to which the patient belonged. The bariatric patients showed higher prevalence and a statistically significant level of risk with regard to NCDLs when compared with the other patients, followed by the obese and control groups. Reflux and vomiting did not seem to influence NCDL positively.

  8. A novel image processing and measurement system applied to quantitative analysis of simulated tooth root canal shape

    Science.gov (United States)

    Yong, Tao; Yong, Wei; Jin, Guofan; Gao, Xuejun

    2005-02-01

    Dental pulp is located in root canal of tooth. To modern root canal therapy, "Root canal preparation" is the main means to debride dental pulp infection. The shape of root canal will be changed after preparation, so, when assessing the preparation instruments and techniques, the root canal shaping ability especially the apical offset is very important factor. In this paper, a novel digital image processing and measurement system is designed and applied to quantitative analysis of simulated canal shape. By image pretreatment, feature extraction, registration and fusion, the variation of the root canals' characteristics (before and after preparation) can be accurately compared and measured, so as to assess the shaping ability of instruments. When the scanning resolution is 1200dpi or higher, the registration and measurement precision of the system can achieve 0.021mm or higher. The performance of the system is tested by a series of simulated root canals and stainless steel K-files.

  9. Filling of extraction sockets of feline maxillary canine teeth with autogenous bone or bioactive glass

    Scientific Electronic Library Online (English)

    Adelina Maria da, Silva; Rafael Dias, Astolphi; Sílvia Helena Venturoli, Perri; Marion Burkhardt de, Koivisto.

    2013-12-01

    Full Text Available PURPOSE: To evaluate bone healing in the extraction socket of the feline maxillary canine tooth after grafting. METHODS: Eighteen adult cats were submitted to unilateral extraction of maxillary canine tooth and divided into three groups. In group 1 (n=6), control, the extraction socket was left empt [...] y. In group 2 (n=6), the extraction socket was filled with autogenous cancellous bone from the iliac crest and in group 3 (n=6), with bioactive glass particulate material. Cats were euthanized at four weeks postoperative. RESULTS: The radiographic examinations performed four weeks after surgery showed that in all groups the healing process converged to a radiopacity similar to that observed in the surrounding bones. Histological examination showed formation of woven bone within the extraction socket. The percentage of newly formed bone within the extraction socket, measured by the histometry, showed no statistically significant difference among the values of the three groups (Kruskal-Wallis'test p>0.05) (group 1: 63.96 ± 5.85, group 2: 66.84 ± 11.67, group 3: 59.28 ± 15.50). CONCLUSION: The bone regeneration observed in the extraction sockets filled with autogenous cancellous bone or bioactive glass was similar to that observed in the control sites, given an observation period of four weeks after extraction of the maxillary canine tooth.

  10. Scanning Electron Microscope (SEM) Evaluation of Tooth Surface Irradiated by Different Parameters of Erbium: Yttrium Aluminium Garnet (Er:YAG) Laser

    OpenAIRE

    Abbas Monzavi; Sima Shahabi; Nasim Chiniforush; Hanieh Nokhbatolfoghahaie

    2012-01-01

    INTRODUCTION: The aim of this study was to investigate the Scanning Electron Microscope (SEM) analysis of tooth surface irradiated by different parameters of Er:YAG laser.METHODS: 15 caries-free extracted human third molars were used in this study. The teeth were put into 5 groups for laser irradiation as follows: Group 1 (power: 2.5 W, Energy: 250 mJ); Group 2(power: 3 W, Energy: 300 mJ); Group 3 (power: 3.5 W, Energy: 350 mJ); Group 4 (power: 4 W, Energy: 400 mJ); Group 5 (power: 4.5 W, Ene...

  11. Experimental Model for Retrospective Assessment of X-Ray Exposures in Dento-Maxillary Radiology Measured by Electron Paramagnetic Resonance in Tooth Enamel

    Directory of Open Access Journals (Sweden)

    Ioana Costina DÂN?OREANU

    2009-12-01

    Full Text Available Electron paramagnetic resonance (EPR dosimetry of human tooth enamel has been widely used in measuring radiation doses in various scenarios. For experimental purposes in X-ray diagnostic or therapy human persons can not be involved. For such cases we have developed an EPR dosimetry technique making use of enamel of molars extracted from pigs. The method can evaluate doses and dose-profiles of irradiated teeth at low level as 50 – 100 mGy (in air. EPR-spectra acquisition, data processing and dose assessment were done using non-dedicated equipment, devices and software.

  12. Control of erosive tooth wear: possibilities and rationale

    Scientific Electronic Library Online (English)

    Mônica Campos, Serra; Danielle Cristine Furtado, Messias; Cecilia Pedroso, Turssi.

    2009-06-01

    Full Text Available Dental erosion is a type of wear caused by non bacterial acids or chelation. There is evidence of a significant increase in the prevalence of dental wear in the deciduous and permanent teeth as a consequence of the frequent intake of acidic foods and drinks, or due to gastric acid which may reach th [...] e oral cavity following reflux or vomiting episodes. The presence of acids is a prerequisite for dental erosion, but the erosive wear is complex and depends on the interaction of biological, chemical and behavioral factors. Even though erosion may be defined or described as an isolated process, in clinical situations other wear phenomena are expected to occur concomitantly, such as abrasive wear (which occurs, e.g, due to tooth brushing or mastication). In order to control dental loss due to erosive wear it is crucial to take into account its multifactorial nature, which predisposes some individuals to the condition.

  13. Interactive simulation of tooth cleaning with an interdental brush.

    Science.gov (United States)

    Salb, T; Ghanai, S; Burgert, O; Dillmann, R

    2000-01-01

    Proper cleaning of tooth interspaces is significant to sufficient caries prophylaxis. In this article we present a system for the simulation of this cleaning procedure using an interdental brush. Various application areas for the simulation are presented and the purpose of our work is explained. Simulation methods are shown, including data acquisition and preprocessing, an editor for the design of simulated interdental brushes and the mathematical methods on which the simulation of flexible parts of the brush is based. The presentation of the haptic user interface and a glance on the overall simulation system complete the chapter on methods. Afterwards we show first results of our work, and the article ends with a conclusion and a view on further work to be done in future. PMID:10977560

  14. Control of erosive tooth wear: possibilities and rationale

    Directory of Open Access Journals (Sweden)

    Mônica Campos Serra

    2009-06-01

    Full Text Available Dental erosion is a type of wear caused by non bacterial acids or chelation. There is evidence of a significant increase in the prevalence of dental wear in the deciduous and permanent teeth as a consequence of the frequent intake of acidic foods and drinks, or due to gastric acid which may reach the oral cavity following reflux or vomiting episodes. The presence of acids is a prerequisite for dental erosion, but the erosive wear is complex and depends on the interaction of biological, chemical and behavioral factors. Even though erosion may be defined or described as an isolated process, in clinical situations other wear phenomena are expected to occur concomitantly, such as abrasive wear (which occurs, e.g, due to tooth brushing or mastication. In order to control dental loss due to erosive wear it is crucial to take into account its multifactorial nature, which predisposes some individuals to the condition.

  15. Radicular cyst of primary tooth associated with maxillary sinus

    Science.gov (United States)

    Bahadure, Rakesh N; Khubchandani, Monika; Thosar, Nilima R; Singh, Rajeev Kumar

    2013-01-01

    Radicular cyst is one of the most common odontogenic cystic lesions found in the jaws. It is inflammatory in nature and found mostly in relation to a non-vital tooth. It usually presents at a later stage in life because the formation of the cyst is the last step in the progression of inflammatory events after a periapical infection. The cyst usually goes unnoticed because of its painless nature and small size. We present the clinical, radiographic and histological characteristics of a radicular cyst along with its management. Cystic sac was removed surgically under general anaesthesia after the elevation of the mucoperiosteal flap. Histopathologically, the cystic sac was consistent with the features of a radicular cyst. Follow-up period of 21?months showed improved radiographical appearance on Coned Beam CT. Vestibular deepening was planned as a future treatment in the same region. PMID:23833085

  16. Dynamin 2 in Charcot-Marie-Tooth Disease

    Directory of Open Access Journals (Sweden)

    Tanabe,Kenji

    2012-06-01

    Full Text Available Charcot-Marie-Tooth disease (CMT is an inherited neuronal disorder, and is induced by mutations of various genes associated with intracellular membrane traffic and cytoskeleton. A large GTPase, dynamin, which is known as a fission protein for endocytic vesicles, was identified as a gene responsible for dominant-intermediate CMT type 2B (DI-CMT2B. Of these mutants, the PH domain, which is required for interaction with phosphoinositides, was mutated in several families. Interestingly, the expression of a deletion mutant, 551?3, did not impair endocytosis, but induced abnormal accumulation of microtubules. Recent evidence has shown that dynamin 2 regulates the dynamic instability of microtubules, and 551?3 lacks this function. We propose a model for the regulation of the dynamic instability of microtubules by dynamin 2 and discuss the relationship between dynamin 2 and CMT.

  17. An interdisciplinary approach to treat crown-root-fractured tooth

    Directory of Open Access Journals (Sweden)

    Ying Chun Sun

    2013-01-01

    Full Text Available Restoration of a crown-root subgingival fractured tooth, especially at anterior aesthetic zones is still a great challenge for restorative dentists. Crown lengthening procedure alone has the disadvantage of high gingival curve of the final restoration, which was not discontinuous to adjacent teeth and thus compromise cosmetic outcomes. The objective of this report is to display a new interdisciplinary approach which combining endodontic root canal treatment, orthodontic extrusion, periodontal crown lengthening surgery and prosthodontic post-core-crown restoration procedures to restore a crown-root subgingival fractured maxillary central incisor and achieved a satisfied cosmetic result. Computer-based spectrophotometer was also used to accurately select colour without objective interference to achieve ideal cosmetic effects.

  18. Solitary osteochondroma of the trapezoid disguised as a tooth fragment.

    Science.gov (United States)

    Baumann, Andreas; Pereira, Daniela; Baldwin, Katy; Weusten, Axel

    2015-01-01

    Fight bite injuries of the hand are common presentations in A&E departments and usually result from a fist blow to the mouth. The authors report a case of a 24-year-old man who presented 6 weeks after an injury to his right wrist following an altercation. Radiographic examination and CT scans were in keeping with a tooth fragment embedded in the trapezoid. However, post excision histology subsequently revealed the lesion to be a solitary osteochondroma of the trapezoid. Osteochondromas are benign lesions of bony or cartilaginous origin and are usually found in the metaphyseal region of long bones. They represent by far the most common primary bone tumours. However, osteochondromas arising from the carpal bones are extremely rare with very few cases reported in the literature. This case illustrates the need to include 'tumour' as a differential diagnosis in every unusual appearing bony lesion, even if there is a history of trauma. PMID:26240108

  19. Tooth enamel EPR dosimetry: sources of errors and their correction

    International Nuclear Information System (INIS)

    Some of the most important sources of systematic errors in dose determination using tooth enamel EPR spectroscopy and ways of reducing those errors are discussed. Enamel from the outside of the front teeth should not be used for dose determination because of induction of paramagnetic centers by solar light. The accuracy of the method in the low dose range is limited by variation in the shape of the EPR signal of unirradiated enamel, which can be described by an initial intrinsic signal and which varies for different samples with standard deviation of 20-30 mGy. The energy dependence of enamel sensitivity should be taken into account in the form of a correction factor. The value of this factor is estimated at 1.1-1.3 for real radiation fields in radiation contaminated territories. Variation in enamel sensitivity for different samples is shown to be within limits of 10-15% of the average value

  20. Hand weakness in Charcot-Marie-Tooth disease 1X.

    LENUS (Irish Health Repository)

    Arthur-Farraj, P J

    2012-07-01

    There have been suggestions from previous studies that patients with Charcot-Marie-Tooth disease (CMT) have weaker dominant hand muscles. Since all studies to date have included a heterogeneous group of CMT patients we decided to analyse hand strength in 43 patients with CMT1X. We recorded handedness and the MRC scores for the first dorsal interosseous and abductor pollicis brevis muscles, median and ulnar nerve compound motor action potentials and conduction velocities in dominant and non-dominant hands. Twenty-two CMT1X patients (51%) had a weaker dominant hand; none had a stronger dominant hand. Mean MRC scores were significantly higher for first dorsal interosseous and abductor pollicis brevis in non-dominant hands compared to dominant hands. Median nerve compound motor action potentials were significantly reduced in dominant compared to non-dominant hands. We conclude that the dominant hand is weaker than the non-dominant hand in patients with CMT1X.

  1. Multiple microscopy modalities applied to a sea urchin tooth fragment.

    Science.gov (United States)

    Stock, S R; Ignatiev, K; Dahl, T; Barss, J; Fezzaa, K; Veis, A; Lee, W K; De Carlo, F

    2003-09-01

    Two synchrotron X-ray microscopy methods, phase-contrast microradiography (the propagation method) and absorption microCT (high-resolution computed tomography or microtomography), and laser-scanning confocal microscopy (visible wavelength) were used to study a fragment of the keel of a tooth of the sea urchin Lytechinus variegatus. Stripes observed in the phase-contrast images of the fragment were also seen in confocal micrographs. MicroCT showed that the stripes were due to two parallel planar arrays of low-absorption channels within the bulk of the keel. In the phase microradiographs, maximum contrast stripes appear when a channel image from one row coincides with a channel image from the second row; otherwise, contrast is minimal. Long channels do not appear to have been observed previously in keels of sea urchin teeth. PMID:12944629

  2. An interdisciplinary approach to treat crown-root-fractured tooth.

    Science.gov (United States)

    Sun, Ying Chun; Li, Ying; Tong, Jian; Gao, Ping

    2013-07-01

    Restoration of a crown-root subgingival fractured tooth, especially at anterior aesthetic zones is still a great challenge for restorative dentists. Crown lengthening procedure alone has the disadvantage of high gingival curve of the final restoration, which was not discontinuous to adjacent teeth and thus compromise cosmetic outcomes. The objective of this report is to display a new interdisciplinary approach which combining endodontic root canal treatment, orthodontic extrusion, periodontal crown lengthening surgery and prosthodontic post-core-crown restoration procedures to restore a crown-root subgingival fractured maxillary central incisor and achieved a satisfied cosmetic result. Computer-based spectrophotometer was also used to accurately select colour without objective interference to achieve ideal cosmetic effects. PMID:24249958

  3. Proteins, Pathogens, and Failure at the Composite-Tooth Interface

    Science.gov (United States)

    Spencer, P.; Ye, Q.; Misra, A.; Goncalves, S.E.P.; Laurence, J.S.

    2014-01-01

    In the United States, composites accounted for nearly 70% of the 173.2 million composite and amalgam restorations placed in 2006 (Kingman et al., 2012), and it is likely that the use of composite will continue to increase as dentists phase out dental amalgam. This trend is not, however, without consequences. The failure rate of composite restorations is double that of amalgam (Ferracane, 2013). Composite restorations accumulate more biofilm, experience more secondary decay, and require more frequent replacement. In vivo biodegradation of the adhesive bond at the composite-tooth interface is a major contributor to the cascade of events leading to restoration failure. Binding by proteins, particularly gp340, from the salivary pellicle leads to biofilm attachment, which accelerates degradation of the interfacial bond and demineralization of the tooth by recruiting the pioneer bacterium Streptococcus mutans to the surface. Bacterial production of lactic acid lowers the pH of the oral microenvironment, erodes hydroxyapatite in enamel and dentin, and promotes hydrolysis of the adhesive. Secreted esterases further hydrolyze the adhesive polymer, exposing the soft underlying collagenous dentinal matrix and allowing further infiltration by the pathogenic biofilm. Manifold approaches are being pursued to increase the longevity of composite dental restorations based on the major contributing factors responsible for degradation. The key material and biological components and the interactions involved in the destructive processes, including recent advances in understanding the structural and molecular basis of biofilm recruitment, are described in this review. Innovative strategies to mitigate these pathogenic effects and slow deterioration are discussed. PMID:25190266

  4. Magnesium stable isotope ecology using mammal tooth enamel.

    Science.gov (United States)

    Martin, Jeremy E; Vance, Derek; Balter, Vincent

    2015-01-13

    Geochemical inferences on ancient diet using bone and enamel apatite rely mainly on carbon isotope ratios (?(13)C) and to a lesser extent on strontium/calcium (Sr/Ca) and barium/calcium (Ba/Ca) elemental ratios. Recent developments in nontraditional stable isotopes provide an unprecedented opportunity to use additional paleodietary proxies to disentangle complex diets such as omnivory. Of particular relevance for paleodietary reconstruction are metals present in large quantity in bone and enamel apatite, providing that biologically mediated fractionation processes are constrained. Calcium isotope ratios (?(44)Ca) meet these criteria but exhibit complex ecological patterning. Stable magnesium isotope ratios (?(26)Mg) also meet these criteria but a comprehensive understanding of its variability awaits new isotopic data. Here, 11 extant mammal species of known ecology from a single locality in equatorial Africa were sampled for tooth enamel and, together with vegetation and feces, analyzed for ?(26)Mg, ?(13)C, Sr/Ca, and Ba/Ca ratios. The results demonstrate that ?(26)Mg incorporated in tooth enamel becomes heavier from strict herbivores to omnivores/faunivores. Using data from experimentally raised sheep, we suggest that this (26)Mg enrichment up the trophic chain is due to a (26)Mg enrichment in muscle relative to bone. Notably, it is possible to distinguish omnivores from herbivores, using ?(26)Mg coupled to Ba/Ca ratios. The potential effects of metabolic and dietary changes on the enamel ?(26)Mg composition remain to be explored but, in the future, multiproxy approaches would permit a substantial refinement of dietary behaviors or enable accurate trophic reconstruction despite specimen-limited sampling, as is often the case for fossil assemblages. PMID:25535375

  5. Mercury speciation and selenium in toothed-whale muscles.

    Science.gov (United States)

    Sakamoto, Mineshi; Itai, Takaaki; Yasutake, Akira; Iwasaki, Toshihide; Yasunaga, Genta; Fujise, Yoshihiro; Nakamura, Masaaki; Murata, Katsuyuki; Man Chan, Hing; Domingo, José L; Marumoto, Masumi

    2015-11-01

    Mercury accumulates at high levels in marine mammal tissues. However, its speciation is poorly understood. The main goal of this investigation was to establish the relationships among mercury species and selenium (Se) concentrations in toothed-whale muscles at different mercury levels. The concentrations of total mercury (T-Hg), methylmercury (MeHg), inorganic mercury (I-Hg) and Se were determined in the muscles of four toothed-whale species: bottlenose dolphins (n=31), Risso's dolphins (n=30), striped dolphins (n=29), and short-finned pilot whales (n=30). In each species, the MeHg concentration increased with increasing T-Hg concentration, tending to reach a plateau. In contrast, the proportion of MeHg in T-Hg decreased from 90-100% to 20-40%. The levels of T-Hg and Se showed strong positive correlations. Se/I-Hg molar ratios rapidly decreased with the increase of I-Hg and reached almost 1 in all species. These results suggested that the demethylated MeHg immediately formed Se/I-Hg equimolar complex of mercury selenide (HgSe) in their muscles. In addition, an X-ray absorption fine structure analysis (XAFS) of a bottlenose dolphin muscle confirmed that the dominant chemical form of the Se/I-Hg equimolar complex was HgSe. HgSe was mainly localized in cells near the endomysium using electron probe microanalysis (EPMA). These results suggested that the demethylated MeHg finally deposits within muscle cells of bottlenose dolphin as an inert HgSe. PMID:26436307

  6. Proteins, pathogens, and failure at the composite-tooth interface.

    Science.gov (United States)

    Spencer, P; Ye, Q; Misra, A; Goncalves, S E P; Laurence, J S

    2014-12-01

    In the United States, composites accounted for nearly 70% of the 173.2 million composite and amalgam restorations placed in 2006 (Kingman et al., 2012), and it is likely that the use of composite will continue to increase as dentists phase out dental amalgam. This trend is not, however, without consequences. The failure rate of composite restorations is double that of amalgam (Ferracane, 2013). Composite restorations accumulate more biofilm, experience more secondary decay, and require more frequent replacement. In vivo biodegradation of the adhesive bond at the composite-tooth interface is a major contributor to the cascade of events leading to restoration failure. Binding by proteins, particularly gp340, from the salivary pellicle leads to biofilm attachment, which accelerates degradation of the interfacial bond and demineralization of the tooth by recruiting the pioneer bacterium Streptococcus mutans to the surface. Bacterial production of lactic acid lowers the pH of the oral microenvironment, erodes hydroxyapatite in enamel and dentin, and promotes hydrolysis of the adhesive. Secreted esterases further hydrolyze the adhesive polymer, exposing the soft underlying collagenous dentinal matrix and allowing further infiltration by the pathogenic biofilm. Manifold approaches are being pursued to increase the longevity of composite dental restorations based on the major contributing factors responsible for degradation. The key material and biological components and the interactions involved in the destructive processes, including recent advances in understanding the structural and molecular basis of biofilm recruitment, are described in this review. Innovative strategies to mitigate these pathogenic effects and slow deterioration are discussed. PMID:25190266

  7. Using a Novel Absolute Ontogenetic Age Determination Technique to Calculate the Timing of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis.

    Science.gov (United States)

    Wysocki, M Aleksander; Feranec, Robert S; Tseng, Zhijie Jack; Bjornsson, Christopher S

    2015-01-01

    Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age determination for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month). Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates absolute ontogenetic age ranges of tooth development and eruption in S. fatalis. The timing of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo). Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for absolute ontogenetic age determination can be replicated in other ancient species, including non-saber-toothed taxa, as long as the timing of growth initiation and growth rate can be determined for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation. PMID:26132165

  8. Finite element-based force/moment-driven simulation of orthodontic tooth movement.

    Science.gov (United States)

    Geiger, M

    2013-01-01

    The objectives of this study were to develop a numerically controlled experimental set-up to predict the movement caused by the force systems of orthodontic devices and to experimentally verify this system. The presented experimental set-up incorporated an artificial tooth fixed via a 3D force/moment sensor to a parallel kinematics robot. An algorithm determining the initial movement of the tooth in its elastic embedding controlled the set-up. The initial tooth movement was described by constant compliances. The constants were obtained prior to the experiment in a parameterised finite element (FE) study on the basis of a validated FE model of a human molar. The long-term tooth movement was assembled by adding up a multiple of incremental steps of initial tooth movements. A pure translational movement of the tooth of about 8 mm resulted for a moment to force ratio of - 8.85 mm, corresponding to the distance between the bracket and the centre of resistance. The correct behaviour of this linear elastic model in its symmetry plane allows for simulating single tooth movement induced by orthodontic devices. PMID:22292517

  9. The timing of tooth eruption and root development of permanent canine and premolars in Korean children

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Shin; Jung, Yun Hoa; Cho, Bong Hae [Department of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Pusan (Korea, Republic of)

    2010-09-15

    The aim of this study was to investigate the timing and sequence of eruption of permanent canine and premolars, and to evaluate tooth calcification stage on emergence in Korean children. The sample was comprised of 1,266 children (male 720, female 546) aged from 7-13 years. Tooth eruption and calcification stages were determined through oral and panoramic radiographic examination, respectively. Probit analysis was used to calculate the timing of tooth eruption and tooth calcification stage from these cross-sectional data. In both males and females, eruption occurred around the time when one third of tooth root or more was formed. The sequence was as follows: first premolar, canine, and second premolar in maxilla, and canine, first premolar and second premolar in mandible. Tooth eruption occurred earlier in girls compared with boys, averaging 0.63 years. Eruption sequence is identical in males and females with a trend for females to erupt earlier than males. Tooth eruption becomes earlier over the past decades in Korean children.

  10. The timing of tooth eruption and root development of permanent canine and premolars in Korean children

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the timing and sequence of eruption of permanent canine and premolars, and to evaluate tooth calcification stage on emergence in Korean children. The sample was comprised of 1,266 children (male 720, female 546) aged from 7-13 years. Tooth eruption and calcification stages were determined through oral and panoramic radiographic examination, respectively. Probit analysis was used to calculate the timing of tooth eruption and tooth calcification stage from these cross-sectional data. In both males and females, eruption occurred around the time when one third of tooth root or more was formed. The sequence was as follows: first premolar, canine, and second premolar in maxilla, and canine, first premolar and second premolar in mandible. Tooth eruption occurred earlier in girls compared with boys, averaging 0.63 years. Eruption sequence is identical in males and females with a trend for females to erupt earlier than males. Tooth eruption becomes earlier over the past decades in Korean children.

  11. Tooth germ invagination from cell-cell interaction: Working hypothesis on mechanical instability.

    Science.gov (United States)

    Takigawa-Imamura, Hisako; Morita, Ritsuko; Iwaki, Takafumi; Tsuji, Takashi; Yoshikawa, Kenichi

    2015-10-01

    In the early stage of tooth germ development, the bud of the dental epithelium is invaginated by the underlying mesenchyme, resulting in the formation of a cap-like folded shape. This bud-to-cap transition plays a critical role in determining the steric design of the tooth. The epithelial-mesenchymal interaction within a tooth germ is essential for mediating the bud-to-cap transition. Here, we present a theoretical model to describe the autonomous process of the morphological transition, in which we introduce mechanical interactions among cells. Based on our observations, we assumed that peripheral cells of the dental epithelium bound tightly to each other to form an elastic sheet, and mesenchymal cells that covered the tooth germ would restrict its growth. By considering the time-dependent growth of cells, we were able to numerically show that the epithelium within the tooth germ buckled spontaneously, which is reminiscent of the cap-stage form. The difference in growth rates between the peripheral and interior parts of the dental epithelium, together with the steric size of the tooth germ, were determining factors for the number of invaginations. Our theoretical results provide a new hypothesis to explain the histological features of the tooth germ. PMID:26188369

  12. Analysis of tooth decay data in Japan using asymmetric statistical models

    Directory of Open Access Journals (Sweden)

    Tomizawa S

    2012-11-01

    Full Text Available Kouji Yamamoto,1 Sadao Tomizawa21Department of Medical Innovation, Osaka University Hospital, Osaka, 2Department of Information Sciences, Faculty of Science and Technology, Tokyo University of Science, Noda City, Chiba, JapanBackground: The aim of the present paper was to develop two new asymmetry probability models to analyze data for tooth decay from 363 women and 349 men aged 18–39 years who visited a dental clinic in Sapporo City, Japan, from 2001 to 2005.Methods: We analyzed the probability relationship between grade of upper and lower tooth decay for men and women using the two new models, and tested goodness-of-fit for the models.Results: The probability that a woman's (man's grade of lower tooth decay is i (i = 1,2 and her (his grade of upper tooth decay is j(>i, (j = 2,3 is estimated to be at most 13.52 (10.23 times higher than the probability that the woman's (man's grade of upper tooth decay is i and grade of lower tooth decay is j.Conclusion: From the data on tooth decay, decay of the upper teeth is worse than of the lower teeth in women and men, and the tendency becomes stronger as the numbers of decayed upper and lower teeth increase.Keywords: distance-proportional symmetry, asymmetry, square contingency table, teeth

  13. Evaluation of the force applied by the tongue and lip on the maxillary central incisor tooth

    Scientific Electronic Library Online (English)

    Amanda Freitas, Valentim; Renata Maria Moreira Moraes, Furlan; Tatiana Vargas de Castro, Perilo; Monalise Costa Batista, Berbert; Andréa Rodrigues, Motta; Estevam Barbosa de Las, Casas.

    2014-06-01

    Full Text Available PURPOSE: To describe the development and testing of a system that measures forces exerted by the tongue and upper lip on a tooth during rest and during swallowing. METHODS: Twenty-eight subjects, aged 19-31 years (mean: 23.2 years) were submitted to measurement of forces exerted by the upper l [...] ip and tongue on the maxillary right central incisor tooth. Flexiforce resistive sensors were fixed on the labial and lingual surfaces of the tooth. They were connected to an amplifier circuit and a data acquisition board for processing and transmitting information to a computer. RESULTS: At rest, the tongue force on the tooth was 0.00±0.00 N and the lip force on tooth was 0.02±0.02 N. The difference between them was significant. During swallowing, the values were 0.31±0.38 N and 0.15±0.14 N, for the tongue and lip, respectively. This difference was not significant. CONCLUSION: At rest, the lip exerts a larger force than the tongue on the maxillary right central incisor tooth. During swallowing, there was no difference between lip and tongue force on the tooth.

  14. Relationship between free radical content in child tooth enamel and radiation dose

    International Nuclear Information System (INIS)

    Free radical contents of the tooth enamel in 25 children permanent tooth and 35 milk tooth samples were measured by electron spin resonance (ESR) technique, and the relationship between free radical content of the tooth enamel and radiation dose was also investigated. Of the 25 children tooth samples there are 13 male samples and 12 female samples respectively, 20 male samples and 15 female samples. In 35 milk tooth samples permanent and milk tooth samples were divided into 5 dose groups each, and irradiated with 60Co ? ray at dose rate of 0.48 Gy/min. Radiation doses of 5 groups were 0.30, 0.50, 1.00, 3.00 and 5.00 Gy, respectively. Results indicated that there was no significant difference in background ESR signal intensity between male and female samples for both children permanent teeth and milk teeth. And also no significant difference in background ESR signal intensity between children permanent teeth and milk teeth was observed. Free radical content of teeth enamel increased linearly with increasing of radiation dose. The results could be applied to dose estimation of exposed individual in the case of radiation accident. Two methods of ESR dosimetry were also discussed

  15. Extraction '90

    International Nuclear Information System (INIS)

    Over the past few years there has been a change in liquid-liquid solvent extraction from a process used mainly for metal recovery to more diverse areas such as pharmaceutical drug production. The conference reported here was organised by the Scottish Branch of the IChemE in association with AEA Technology Dounreay. The papers presented address the recent advances in solvent extraction, both industrial and academic, carried out in both the nuclear and non-nuclear fields. The broad areas covered are: extraction fundamentals, extraction from dilute solutions, sorption, extraction of biological products, and processes and equipment. (author)

  16. Extraction process

    International Nuclear Information System (INIS)

    A process is described for extracting at least two desired constituents from a mineral, using a liquid reagent which produces the constituents, or compounds thereof, in separable form and independently extracting those constituents, or compounds. The process is especially valuable for the extraction of phosphoric acid and metal values from acidulated phosphate rock, the slurry being contacted with selective extractants for phosphoric acid and metal (e.g. uranium) values. In an example, uranium values are oxidized to uranyl form and extracted using an ion exchange resin. (U.K.)

  17. Clinical, radiological and histological diagnoses of periapical periodontitis spreading to the adjacent tooth: A case of endodontic failure

    OpenAIRE

    Luigi Cianconi; Manuele Mancini

    2013-01-01

    Aims: This article describes the apical infection in endodontically treated tooth 4.5 that spread to adjacent tooth 4.4. Case Report: A 52-year-old woman was referred for the presence of radiolucency extending from tooth 4.5 and mental foramen. Spontaneous symptoms were present. Tooth 4.5 showed poor-quality endodontics. The vitality of tooth 4.4 was negative, even though no mechanical trauma had been reported, nor was caries present. Both teeth were sensitive to percussion. Endodontic re-tr...

  18. Tooth brushing, tongue cleaning and snacking behaviour of dental technology and therapist students

    Directory of Open Access Journals (Sweden)

    Clement C. Azodo

    2010-08-01

    Full Text Available Objective: To determine the tooth brushing, tongue cleaning and snacking behaviour of dental technology and therapist students. Methods: A descriptive cross-sectional study of students of Federal School of Dental Therapy and Technology Enugu, Nigeria. Self-administered questionnaire was used to obtain information on demography, frequency, duration and technique of tooth brushing and tongue cleaning as well as information on consumption of snacks. Results: A total of 242 students responded. Dental technology students made up 52.5% of the respondents and dental therapist in training made up 47.5%. Majority (63.2% of the respondents considered the strength of tooth brush when purchasing a tooth brush and 78.9% use tooth brushes with medium strength. Seven-tenth (71.9% of the respondents brush their teeth twice daily and 52.1% brush for 3–5 minutes. About one-third (30.2% brush their teeth in front of a mirror. Chewing stick was used by 51.7% of respondents in addition to the use of tooth brush. Tongue cleaning was done by 94.2% with only 9.5% using a tongue cleaner. Only 20.2% reported regular snacks consumption. Nine-tenth (90.4% of respondents were previously involved in educating others, apart from their colleagues, on tooth brushing. Conclusion: This survey revealed that most of the dental therapy and technology students had satisfactory tooth-brushing behaviour. The zeal to educate others about proper tooth brushing revealed in this study suggests that the students may be helpful in oral health promotion.

  19. Surgical management with intentional replantation on a tooth with palato-radicular groove.

    Science.gov (United States)

    Forero-López, Jorge; Gamboa-Martínez, Luis; Pico-Porras, Laura; Niño-Barrera, Javier Laureano

    2015-05-01

    A palato-radicular groove (PRG) is a developmental anomaly primarily found in the maxillary lateral incisors. It is a potential communication path between the root canal and the periodontium that decreases the survival prognosis of the affected tooth, therefore compromising the stability of the dental structure in the oral cavity. The aim of this case report is to present an original technique where a PRG was treated by means of intracanal disinfection, PRG sealing with glass ionomer, replantation with intentional horizontal 180 degree rotation of the tooth, and an aesthetic veneer placed to provide adequate tooth morphology. The clinical and biological benefits of this novel technique are presented and discussed. PMID:25984480

  20. Uneven distribution of enamel in the tooth crown of a Plains Zebra (Equus quagga)

    OpenAIRE

    Winkler, Daniela E.; Kaiser, Thomas M.

    2015-01-01

    Unworn teeth of herbivorous mammals are not immediately functional. They have to be partially worn to expose enamel ridges which can then act as shear-cutting blades to break the food down. We use the Plains Zebra (Equus quagga) as a hypsodont, herbivorous model organism to investigate how initial wear of the tooth crown is controlled by underlying structures. We find that the enamel proportion is smaller at the apical half of the tooth crown in all upper tooth positions and suggest that lowe...

  1. Dependencies of the radiation sensitivity of human tooth enamel in EPR dosimetry

    International Nuclear Information System (INIS)

    The EPR dose response of tooth enamel was determined for human molars collected in Egypt. The influence of age, gender and residence of the tooth donors as well as tooth position and sample preparation on EPR sensitivity and its variability over the enamel samples was investigated. The EPR sensitivity and its variability were found to depend only on the sample preparation procedure. The variability in EPR sensitivity of enamel from Egyptian teeth was maximally 10% and the mean sensitivity was in good agreement with that of German teeth

  2. Retrospective Dosimetry: Dose Analysis From Tooth Enamel Using Electron Spin Resonance (ESR)

    International Nuclear Information System (INIS)

    The radiation dose should be accurately measured in order to relate its effect to the cells. The assessment of dose usually performed using biological dosimetry techniques. However, the reduction of lymphocytes (white blood cells) after the time period results in inaccuracy of dose measurement. An alternative method used is the application of Electron Spin Resonance (ESR) using tooth enamel. In this study, tooth enamels were evaluated and used to measure the individual absorbed dose from the background. The basic tooth features that would affect dose measurement were discussed. The results show this technique is capable and effective for retrospective dose measurement and useful for the study of radiation effect to human. (author)

  3. Replantation of an avulsed tooth with an extended extra oral period

    Directory of Open Access Journals (Sweden)

    Girish Kubasad

    2012-01-01

    Full Text Available In this study, we have reported a case of the replantation of a maxillary incisor with an extended extraoral period following a traumatic avulsion. After storage in normal saline, the root surface of the avulsed tooth was conditioned with citric acid and treated with a triple antibiotic solution. The tooth socket was filled with Emdogain before replantation. A 12 month, 18 month and a 5 year follow-up clinical examination revealed the patient to be asymptomatic, and the tooth was functional. The recall radiograph showed no evidence of renewed periradicular breakdown and apical root resorption.

  4. Charcot Marie Tooth Disease Type 1 - Rare but Commonest Hereditary Neuropathy

    Directory of Open Access Journals (Sweden)

    Shakya Bhattacharjee

    2012-01-01

    Full Text Available Objective: To present a case of Charcot Marie Tooth Disease. Backgrounds: A 22 years old boy presented with very slowly progressive symmetrical weakness of both lower limbs with distal muscular atrophy. He has a family member with similar problem. Methods: The patient was clinically examined and investigations done accordingly like Nerve Conduction Velocity studies (NCV. Results: The patient was diagnosed to be a case of Charcot Marie Tooth disease type 1 with classical features like” inverted Champagne bottle” like legs. Conclusion: Charcot Marie Tooth disease is rare and often undiagnosed yet it is the commonest hereditary neuropathy worldwide and India is not an exception

  5. Analysis of EPR tooth enamel spectra exposed to combined radiation and mechanical effects

    International Nuclear Information System (INIS)

    In the EPR spectra of tooth enamel samples exposed to sequential radiation and mechanical effect, the intensity of the signal in the spectra of tooth enamel samples exposed to sequential mechanical and radiation effects exceeded the amplitude of a signal in enamel samples that were only exposed to radiation. The increased dosimetric signal can be explained by superposition of mechanically and radiation-induced signals. The contribution of the mechanically induced component to the individual dose load reconstructed by EPR-spectra of tooth enamel has been evaluated

  6. Deconvolution of complex EPR spectrum of tooth enamel into three components: native, dosimetric and mechanical

    International Nuclear Information System (INIS)

    A software was developed on the base of non-linear simulation, which allowed the deconvolution of EPR spectra of tooth enamel into three components: native, radiation- and mechanically induced. The software was designed for the reconstruction of individual absorbed doses by EPR spectra of tooth enamel using the method of additive irradiation of samples. It has been demonstrated with the help of this program that the presence of mechanically induced paramagnetic centers in enamel samples led to an excessive individual absorbed dose reconstructed by EPR spectra of tooth enamel.

  7. Extraction method

    International Nuclear Information System (INIS)

    Definitions of the basic terms and of relations are given and the knowledge is described of the possibilities of the extraction of elements, oxides, covalent-bound halogenides and heteropolyacids. Greatest attention is devoted to the detailed analysis of the extraction of chelates and ion associates using diverse agents. For both types of compounds detailed conditions are given of the separation and the effects of the individual factors are listed. Attention is also devoted to extractions using mixtures of organic agents, the synergic effects thereof, and to extractions in non-aqueous solvents. The effects of radiation on extraction and the main types of apparatus used for extractions carried out in the laboratory are described. (L.K.)

  8. Comparative analysis of the effect of autoclaving and 10% formalin storage on extracted teeth: A microleakage evaluation

    OpenAIRE

    Attam Kanika; Talwar Sangeeta; Yadav Seema; Miglani Sanjay

    2009-01-01

    Aim: This study compares the effect of formalin and autoclaving the tooth samples by evaluating microleakage in-vitro . Materials and Methods: Forty-five extracted human permanent incisor teeth were taken and randomly divided into three groups (with different methods of storage and disinfection) with 15 teeth each: Group 1: Control-extracted teeth in this group were stored in normal saline, Group 2: the extracted teeth in this group were stored in 10 % formalin for two weeks and Gr...

  9. New therapeutic modalities to modulate orthodontic tooth movement

    Scientific Electronic Library Online (English)

    Ildeu, Andrade Jr; Ana Beatriz dos Santos, Sousa; Gabriela Gonçalves da, Silva.

    2014-12-01

    Full Text Available A modulação do movimento dentário ortodôntico (MDO) é desejável para os pacientes, pois reduz o tempo de tratamento, e também para ortodontistas, uma vez que a duração do tratamento tem sido associada a um aumento do risco de inflamação gengival, descalcificação, cárie dentária e reabsorção radicula [...] r. O crescente foco sobre os mecanismos biológicos da movimentação dentária levou a Ortodontia a ser uma especialidade mais abrangente, que hoje incorpora aspectos de todas as áreas da Medicina. Com o conhecimento atual, o uso de novas modalidades terapêuticas que visam a modulação da MDO, como a corticotomia, terapia a laser de baixa intensidade e vibração (ultrassom pulsátil de baixa intensidade) já são uma realidade clínica. Outras, como injeções locais de biomoduladores e a terapia genética, serão utilizadas em breve. Elas destinam-se a aumentar ou inibir o recrutamento, à diferenciação e/ou ativação das células ósseas, a acelerar ou reduzir a MDO, a aumentar a estabilidade dos resultados ortodônticos, bem como auxiliar na prevenção da reabsorção radicular. Esse artigo resume os estudos mais recentes sobre cada uma dessas novas modalidades terapêuticas, fornecendo informações aos leitores a respeito de como afetam a MDO e aponta futuras perspectivas clínicas. Abstract in english Modulation of orthodontic tooth movement (OTM) is desirable not only to patients because it shortens treatment time, but also to orthodontists, since treatment duration is associated with increased risk of gingival inflammation, decalcification, dental caries, and root resorption. The increased focu [...] s on the biological basis of tooth movement has rendered Orthodontics a more comprehensive specialty that incorporates facets of all fields of medicine. Current knowledge raises the possibility of using new therapeutic modalities for modulation of OTM, such as corticotomy, laser therapy, vibration (low-intensity pulsed ultrasound), local injections of biomodulators and gene therapy; with the latter being applicable in the near future. They are intended to enhance or inhibit recruitment, differentiation and/or activation of bone cells, accelerate or reduce OTM, increase stability of orthodontic results, as well as assist with the prevention of root resorption. This article summarizes recent studies on each one of these therapeutic modalities, provides readers with information about how they affect OTM and points out future clinical perspectives.

  10. Finite element analysis of tooth load distribution on P-110S conic threaded connections

    International Nuclear Information System (INIS)

    Based on elastic mechanics and by use of thick cylinder theory, this paper presents a finite element analysis model with interference fit and axial load on P-110S conic threaded connections and the tooth load distributions on contact threaded surfaces were investigated. A 2D finite element model with elastic-plastic axisymmetric contact threaded surfaces was established and the tooth load distributions on its thread teeth were analyzed under different interference fit and axial load. Results for the loads on every engaged tooth are obtained. These indicate that the load distribution on the engaged teeth is not uniform, with the maximum tooth load concentrated on the first three pairs or the farthest two pairs of engaged teeth from the pin end and the middle teeth only bear a very small load. Such results are identical to the practical situation and indicate that the finite element model proposed in this paper is reasonable.

  11. Differential changes in gingival somatosensory sensitivity after painful electrical tooth stimulation

    DEFF Research Database (Denmark)

    Baad-Hansen, Lene; Lu, Shengyi; Kemppainen, Pentti; List, Thomas; Zhang, Zhenting; Svensson, Peter

    2015-01-01

    standardized battery of quantitative sensory tests (QST) before, immediately after and 30 min after tooth stimulation. Painful tooth stimulation evoked significant decreases in warmth and heat pain thresholds (P < 0.001) as well as pressure pain thresholds (increased sensitivity) (P = 0.024) and increases in...... mechanical detection thresholds (decreased sensitivity) (P < 0.050). Similar thermal threshold changes (P < 0.019) but no mechanical changes were found after tooth stimulation below the sensory threshold (P > 0.086). No QST changes were detected in the session without tooth stimulation (P > 0.060). In......, stimulation below the sensory threshold induced similar thermal sensitization suggesting the possibility of activation of axon-reflex-like mechanisms even at intensities below the perception threshold. These findings may have implications for interpretation of somatosensory results in patients with chronic...

  12. Gender differences in tooth loss among Chilean adolescents: socio-economic and behavioral correlates

    DEFF Research Database (Denmark)

    López, Rodrigo; Baelum, Vibeke

    2006-01-01

    OBJECTIVE: To investigate gender differences in tooth loss among Chilean adolescents and its association with selected socio-economic indicators and oral-health-related behaviors. MATERIAL AND METHODS: Data on 9,163 Chilean adolescents obtained using multistage random cluster procedures. Clinical...... recordings included information on missing teeth and the participants provided information on socio-demographic factors and oral-related behaviors. Two eruption-time-adjusted logistic regression analyses were used to investigate the associations between gender, tooth loss and socio-economic position....../oral-health-related behaviors. RESULTS: The association between gender and tooth loss remained after adjusting for age, eruption times in both the socio-economic position regression model and the oral-health-related behaviors model. Tooth loss followed social gradients for the variables paternal income and achieved parental...

  13. Gender differences in tooth loss among Chilean adolescents: socio-economic and behavioral correlates

    DEFF Research Database (Denmark)

    López, Rodrigo; Baelum, Vibeke

    2006-01-01

    OBJECTIVE: To investigate gender differences in tooth loss among Chilean adolescents and its association with selected socio-economic indicators and oral-health-related behaviors. MATERIAL AND METHODS: Data on 9,163 Chilean adolescents obtained using multistage random cluster procedures. Clinical recordings included information on missing teeth and the participants provided information on socio-demographic factors and oral-related behaviors. Two eruption-time-adjusted logistic regression analyses were used to investigate the associations between gender, tooth loss and socio-economic position/oral-health-related behaviors. RESULTS: The association between gender and tooth loss remained after adjusting for age, eruption times in both the socio-economic position regression model and the oral-health-related behaviors model. Tooth loss followed social gradients for the variables paternal income and achieved parental education, with students reporting a paternal income

  14. Relationship between microhardness and fluorine contents on tooth enamel determined by PIGE analysis

    International Nuclear Information System (INIS)

    The remineralization effect of fluoride has been measured by surface microhardness on tooth enamel. The purpose of this study was to investigate the relationship between microhardness and fluorine concentration on tooth enamel. Twelve sound bovine enamel specimens were prepared and immersed in 0.05% NaF solution for 1, 3, 6, 24 and 36 hours, respectively. The concentration of fluorine in specimens were measured by PIGE analysis and surface microhardness of each specimen was measured by surface microhardness tester. Fluorine concentration was increased by immersing time. There was no change in microhardness of each specimen by fluorine content. The results of this study suggest that there was no relationship between the fluorine concentration and surface microhardness in sound tooth enamel. PIGE analysis can be used effectively to assess the remineralization effect of fluorine content in tooth enamel. (author)

  15. Cigarette smoking and tooth loss experience among young adults: a national record linkage study

    Directory of Open Access Journals (Sweden)

    Tanaka Keiko

    2007-11-01

    Full Text Available Abstract Background Various factors affect tooth loss in older age including cigarette smoking; however, evidence regarding the association between smoking and tooth loss during young adulthood is limited. The present study examined the association between cigarette smoking and tooth loss experience among adults aged 20–39 years using linked data from two national databases in Japan. Methods Two databases of the National Nutrition Survey (NNS and the Survey of Dental Diseases (SDD, which were conducted in 1999, were obtained from the Ministry of Health, Labor and Welfare with permission for analytical use. In the NNS, participants received physical examinations and were interviewed regarding dietary intake and health practices including cigarette smoking, whereas in the SDD, participants were asked about their frequency of daily brushing, and received oral examinations by certified dentists. Among 6,805 records electronically linked via household identification code, 1314 records of individuals aged 20 to 39 years were analyzed. The prevalence of 1+ tooth loss was compared among non-, former, and current smokers. Multiple logistic regression models were constructed including confounders: frequency of tooth brushing, body mass index, alcohol consumption, and intake of vitamins C and E. Results Smoking rates differed greatly in men (53.3% and women (15.5%. The overall prevalence of tooth loss was 31.4% (31.8% men and 31.1% women. Tooth loss occurred more frequently among current smokers (40.6% than former (23.1% and non-smokers (27.9%. Current smoking showed a significant association with 1+ tooth loss in men (adjusted OR = 2.21 [1.40–3.50], P = 0.0007 and women (1.70 [1.13–2.55], P = 0.0111. A significant positive exposure-related relationship between cigarette smoking status and tooth loss was observed (P for trend Conclusion An association between cigarette smoking and tooth loss was evident among young adults throughout Japan. Due to limitations of the available variables in the present databases, further studies including caries experience and its confounders should be conducted to examine whether smoking is a true risk of premature tooth loss in young adults.

  16. Professional and patient-based evaluation of oral rehabilitation in patients with tooth agenesis

    DEFF Research Database (Denmark)

    Dueled, Erik; Gotfredsen, Klaus

    2009-01-01

    OBJECTIVES: The outcome of oral rehabilitation is usually monitored with clinical tests rather than by patient's perception of change. The aim of this study was to describe the objective measure and subjective perception of oral rehabilitation in patients with tooth agenesis. MATERIAL AND METHODS: The study included 129 patients with tooth agenesis rehabilitated with implant- or tooth-supported reconstructions, and a control group of 58 patients. Professional assessments included biological, technical and aesthetic variables. An aesthetic index score included mucosal discoloration, crown morphology, crown color match, occlusal harmony, and papilla level. The Oral Health Impact Profile (OHIP) questionnaire was used to evaluate the patient-based outcomes. Six OHIP questions were subtracted to evaluate the patient-based aesthetic outcomes. RESULTS: Severe root resorption was observed in 36% of the patients in whom orthodontic treatment had been performed. Twelve percent of patients had implants with 5-7 mm peri-implant bone defects. Mucosal discoloration was recorded in 57% of the patients. Twelve percent of the patients had metal visible on the buccal side. The median scores for all five aesthetic variables were acceptable in 92% of the implant reconstructions and for 83% of the tooth-supported fixed dental prostheses (FDPs). The total OHIP score was inferior in rehabilitated patients with tooth agenesis to that of the control group without tooth agenesis. The total OHIP score after rehabilitation was <50 for 95% of the patients with tooth agenesis. The six OHIP questions concerning aesthetics demonstrated patient-based aesthetic problems in 41% of patients treated with implant-supported reconstructions and 47% of patients treated with tooth-supported FDPs. Ninety-eight percent of the group treated with implant-supported reconstructions and 84% of the patients in the tooth-supported FDP group were very satisfied or satisfied with the treatment outcome. CONCLUSIONS: Patients with tooth agenesis had a high risk ofsevere root resorption after orthodontic treatment. A better aesthetic outcome was obtained with implant-supported reconstructions than with tooth-supported reconstructions. A positive but not significant correlation was observed between the professional and patient-based evaluations of aesthetic outcomes.

  17. Severe tooth wear in Prader-Willi syndrome. A case–control study

    Directory of Open Access Journals (Sweden)

    Saeves Ronnaug

    2012-05-01

    Full Text Available Abstract Background Prader-Willi syndrome (PWS is a rare complex multsystemic genetic disorder characterized by severe neonatal hypotonia, endocrine disturbances, hyperphagia and obesity, mild mental retardation, learning disabilities, facial dysmorphology and oral abnormalities. The purpose of the present study was to explore the prevalence of tooth wear and possible risk factors in individuals with Prader-Willi syndrome. Methods Forty-nine individuals (6-40?years with PWS and an age- and sex-matched control group were included. Tooth wear was evaluated from dental casts and intraoral photographs and rated by four examiners using the Visual Erosion Dental Examination (VEDE scoring system and the individual tooth wear index IA. In accordance with the VEDE scoring system, tooth wear was also evaluated clinically. Whole saliva was collected. Results Mean VEDE score was 1.70?±?1.44 in the PWS group and 0.46?±?0.36 in the control group (p?A was 7.50 (2.60-30.70 in the PWS group and 2.60 (0.90-4.70 among controls (p?A; r?=?0.82, p?A; r?=?0.43, p?=?0.002. Tooth grinding was also associated with tooth wear in the PWS group, as indicated by the mean VEDE 2.67?±?1.62 in grinders and 1.14?±?0.97 in non-grinders (p?=?0.001 and median IA values 25.70 (5.48-68.55 in grinders and 5.70 (1.60-9.10 in non-grinders (p?=?0.003. Multivariate linear regression analysis was performed with tooth wear as the dependent variable and PWS (yes/no, age, tooth grinding and saliva secretion as independent variables. PWS (yes/no, age and tooth grinding retained a significant association with tooth wear, VEDE (p?A (p? Conclusions Our study provides evidence that tooth wear, in terms of both erosion and attrition, is a severe problem in Prader-Willi syndrome. There is therefore considerable need for prosthodontic rehabilitation in young adults with PWS.

  18. Dose response of hydrazine - Deproteinated tooth enamel under blue light stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Yuece, Ulkue Rabia, E-mail: ulkuyuce@hotmail.co [Ankara University, Faculty of Engineering, Department of Engineering Physics, 06100, Tandogan - Ankara (Turkey); Meric, Niyazi, E-mail: meric@ankara.edu.t [Ankara University, Faculty of Engineering, Department of Engineering Physics, 06100, Tandogan - Ankara (Turkey); Atakol, Orhan, E-mail: atakol@science.ankara.edu.t [Ankara University, Science Faculty, Department of Chemistry, 06100, Tandogan - Ankara (Turkey); Yasar, Fusun, E-mail: ab121310@adalet.gov.t [Council of Forensic Medicine, Ankara Branch, Ankara (Turkey)

    2010-08-15

    The beta dose response and Optically Stimulated Luminescence (OSL) signal stability characteristics of human tooth enamel deproteinated by hydrazine reagent under blue photon stimulation are reported. Removal of the protein organic component of tooth enamel resulted in a higher OSL sensitivity and slower fading of OSL signals. The effect of chemical sample preparation on the enamel sample sensitivity is discussed and further steps to make this deproteinization treatment suitable for in vitro dose reconstruction studies are suggested.

  19. Coexistent partial anodontia and supernumerary tooth in the mandibular arch: A rare case

    Directory of Open Access Journals (Sweden)

    Das G

    2006-05-01

    Full Text Available Coexistent partial anodontia and supernumerary tooth in the lower jaw is a very uncommon condition. Very few cases have been reported in the literature of this condition, etiology of which is still obscure. Presented here is a rare case of simultaneous presence of single supernumerary tooth together with missing permanent central incisor teeth in the lower jaw without any associated systemic condition or syndrome.

  20. Clinical Study Monitoring the pH on Tooth Surfaces in Patients with and without Erosion

    OpenAIRE

    Lussi, Adrian; von Salis-Marincek, Maya; Ganss, Carolina; Hellwig, Elmar; Cheaib, Zeinab; Jaeggi, Thomas

    2012-01-01

    The aim of this study was to compare tooth surface pH after drinking orange juice or water in 39 patients with dental erosion and in 17 controls. The following investigations were carried out: measurement of pH values on selected tooth surfaces after ingestion of orange juice followed by ingestion of water (acid clearance), measurement of salivary flow rate and buffering capacity. Compared with the controls, patients with erosion showed significantly greater decreases in pH after drinking ora...

  1. Mathematical Model for the Contact Stress Calculation of Fluoropolymerized Toothed Wheels

    Directory of Open Access Journals (Sweden)

    Ion-Cornel Mituletu

    2010-10-01

    Full Text Available In this paper is presented a contact stress calculation algorithm for a new type of cylindrical toothed wheel. This new type consists in the application of a Xylan 1052 fluoropolymer film on the surface of a metal toothed wheel. Due to the fact that the steel strength, in any case is better than the plastic strength, the main issue which appears is at the contact between the two homologous flank surfaces.

  2. Studies of the chronological course of wisdom tooth eruption in a Black African population

    OpenAIRE

    Olze, Andreas; Van Niekerk, Piet; Schulz, Ronald; Schmeling, Andreas

    2007-01-01

    The importance of forensic age estimation in living subjects has grown over the last few years. In dental age estimation, tooth eruption is a parameter of developmental morphology that can be analyzed by either clinical examination or by evaluation of dental X-rays. In the present study, we determined the stage of wisdom tooth eruption in 410 male and 106 female black South African subjects of known age (12–26 years) based on radiological evidence from 516 conventional orthopantomograms. Four...

  3. Copy Number Variations in a Population-Based Study of Charcot-Marie-Tooth Disease

    OpenAIRE

    Helle Høyer; Braathen, Geir J; Eek, Anette K.; Nordang, Gry B. N.; Camilla F. Skjelbred; Russell, Michael B.

    2015-01-01

    Copy number variations (CNVs) are important in relation to diversity and evolution but can sometimes cause disease. The most common genetic cause of the inherited peripheral neuropathy Charcot-Marie-Tooth disease is the PMP22 duplication; otherwise, CNVs have been considered rare. We investigated CNVs in a population-based sample of Charcot-Marie-Tooth (CMT) families. The 81 CMT families had previously been screened for the PMP22 duplication and point mutations in 51 peripheral neuropathy gen...

  4. Evaluation of Algesimetric Parameters on the Basis of Tooth Pulp Stimulation in Humans

    OpenAIRE

    Rohdewald, P.; Keuth, V.

    1990-01-01

    Investigations concerning the validity and sensitivity of algesimetric parameters were performed on 23 healthy volunteers on the basis of electrical tooth pulp stimulation. Bipolar tooth pulp stimulation has been proved to be superior to monopolar stimulation in respect to the reproducibility of threshold of sensation. Verbal numerical scale (VNS) was found to discriminate better between stimulus intensities than visual analogue scale in terms of sensitivity and reproducibility. The long-term...

  5. Digital Radiography for Determination of Primary Tooth Length: In Vivo and Ex Vivo Studies

    OpenAIRE

    Basso, Maria D.; Jeremias, Fabiano; Cordeiro, Rita C. L.; Santos-Pinto, Lourdes

    2015-01-01

    Background. Methods for determining the root canal length of the primary tooth should yield accurate and reproducible results. In vitro studies show some limitations, which do not allow their findings to be directly transferred to a clinical situation. Aim. To compare the accuracy of radiographic tooth length obtained from in vivo digital radiograph with that obtained from ex vivo digital radiograph. Method. Direct digital radiographs of 20 upper primary incisors were performed in teeth (2/3 ...

  6. Uranium-series disequilibrium data for tooth fragments from the fossil hominid site at Ternifine, Algeria.

    Science.gov (United States)

    Szabo, B. J.

    1982-01-01

    I report here analyses of elephant molar-tooth fragments that were submitted by the late K.P.Oakley for uranium-series dating. The tooth fragments were collected by the late C. Arambourg from Pleistocene sand in association with the hominid fossils of Ternifine Man, Algeria. Of the results reported the minimum age of over 360 000 yr BP for the enamel appears to be the most reliable. -Authors

  7. Tooth apatite as a bone substitute: an experimental study and clinical applications

    International Nuclear Information System (INIS)

    The purpose of this study is to evaluate the usefulness of calcined teeth powder as biological apatite. The animal experiment was performed in 36 rabbits aging 6 weeks and weighing 1.6 kg. In experimental group, tooth apatite powder was implanted to 10 mm bony defects in diameter made on the cranial bone of the rabbits. As control groups, synthetic porous hydroxyapatite and resorbable type calcium carbonate were implanted to the defects of same size. Each group was sacrificed in 1, 2, 4, 6, 8, 12 weeks after the surgery. Specimens were prepared for decalcified samples and observed by a light microscope. And we also performed quantitative analysis of new bone formation through image analysis using computer. In clinical applications, we used tooth apatite alone or mixed with decalcified freeze-dried bone for reconstruction of bony defects in 15 patients undergone enucleation of cyst or ameloblastoma. The obtained results were as follows; 1) The powder of the calcined teeth was called as 'tooth apatite' and it seemed to have biocompatibility in rabbits and human. 2) In group of tooth apatite, after 4 weeks of operation, new bone directly bonded to the particles was observed. And in 12 weeks of it, new bone occupied most of the bony defects. In 6 weeks, resorption of the tooth apatite particles was observed. Thus the tooth apatite was regarded as one of resorbable apatite. 3) The group of tooth apatite showed new bone formation similar to the group of porous hydroxyapatite, but they were inferior to the group of resorbable calcium carbonate. 4) In clinical application, tooth apatite had biocompatibility and new bone formation was observed without any complication except for 1 case. So we think it is a useful bone substitute with osteoconductivity

  8. Effect of repeated immersion solution cycles on the color stability of denture tooth acrylic resins

    Scientific Electronic Library Online (English)

    Paulo Maurício Batista da, Silva; Emílio José Tabaré Rodríguez, Acosta; Matheus, Jacobina; Luciana de Rezende, Pinto; Vinícius Carvalho, Porto.

    2011-12-01

    Full Text Available OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected [...] the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm) were fabricated from two different brands (Artiplus and Trilux) of denture tooth acrylic resin. The specimens from each brand (n=30) were randomly divided into 6 groups (n=5) and immersed in the following solutions: distilled water (control group) and 5 disinfecting solutions (1% sodium hypochlorite, 2% sodium hypochlorite, 5.25% sodium hypochlorite, 2% glutaraldehyde, and 4% chlorhexidine gluconate). Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (?E*) were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA) followed by Tukey tests. The significance level was set at 5%. RESULTS: There were statistically significant differences in ?E* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ?E* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ?E* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

  9. Effect of repeated immersion solution cycles on the color stability of denture tooth acrylic resins

    Directory of Open Access Journals (Sweden)

    Paulo Maurício Batista da Silva

    2011-12-01

    Full Text Available OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm were fabricated from two different brands (Artiplus and Trilux of denture tooth acrylic resin. The specimens from each brand (n=30 were randomly divided into 6 groups (n=5 and immersed in the following solutions: distilled water (control group and 5 disinfecting solutions (1% sodium hypochlorite, 2% sodium hypochlorite, 5.25% sodium hypochlorite, 2% glutaraldehyde, and 4% chlorhexidine gluconate. Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (?E* were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA followed by Tukey tests. The significance level was set at 5%. RESULTS: There were statistically significant differences in ?E* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ?E* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ?E* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

  10. Permeability of Human Tooth Surfaces Studied In Vitro by Electrochemical Impedance Spectroscopy

    OpenAIRE

    Pita, Marcos

    2012-01-01

    Electrochemical Faradaic impedance spectroscopy was applied to evaluate dependence of the electrical resistance on human teeth. The experiments were performed using iodide anions as a redox probe to model permeability of teeth for fluoride upon an iontophoresis process. Tooth molars were used - as these are teeth most affected by tooth decay processes in vivo. Teeth compared included sound molars - with no evidence of pit and fissure decay, teeth with pits and fissures regarded 'clinically' a...

  11. Intrusion Injury of Deciduous Tooth sequeling Ectopic Eruption of a Permanent Successor

    OpenAIRE

    Hema Sirisha K; Rajajee KTSS

    2010-01-01

    Intrusive luxation of primary teeth carries a high risk of damage to underlying permanent tooth germs. Ectopic eruption of permanent incisors is an unusual outcome of traumatic injury to their predecessors. In this case report, we describe the multidisciplinary management of the consequences of a primary tooth intrusion that led to severe impaction of the permanent left central incisor in a vertical position at the level of the labial sulcus.

  12. Future dentistry: cell therapy meets tooth and periodontal repair and regeneration

    OpenAIRE

    Catón, Javier; Bostanci, Nagihan; Remboutsika, Eumorphia; De Bari, Cosimo; Mitsiadis, Thimios A

    2011-01-01

    Cell-based tissue repair of the tooth and – tooth-supporting – periodontal ligament (PDL) is a new attractive approach that complements traditional restorative or surgical techniques for replacement of injured or pathologically damaged tissues. In such therapeutic approaches, stem cells and/or progenitor cells are manipulated in vitro and administered to patients as living and dynamic biological agents. In this review, we discuss the clonogenic potential of human dental and periodontal tissue...

  13. X-linked Charcot-Marie-Tooth disease with myokymia: Report of a family

    Directory of Open Access Journals (Sweden)

    Chakravarty A

    2003-07-01

    Full Text Available The clinical and electrophysiologic profiles of two brothers suffering from Charcot-Marie-Tooth disease are presented. Both had widespread muscle twitching in the legs which showed electrophysiologic features of myokymia. Pedigree analysis suggested an x-linked recessive form of inheritance. This appears to be the first report of an Indian family with x-linked Charcot-Marie-Tooth disease.

  14. Use of computed tomography to investigate cheek tooth abnormalities in chinchillas (Chinchilla laniger)

    International Nuclear Information System (INIS)

    Computerised tomographic scanning was used to investigate tooth structure in chinchillas (Chinchilla laniger), both cheek tooth crown and root abnormalities being common in this species. This paper describes a common form of dental disease affecting species with continuously growing teeth, with particular reference to the chinchilla, and confirms the potential role of computed tomography (CT) in its early diagnosis. CT imaging is compared with previously available methods of investigation which frequently fail to detect early pathological changes

  15. Platelet-rich fibrin-mediated revitalization of immature necrotic tooth

    OpenAIRE

    Navin Mishra; Isha Narang; Neelam Mittal

    2013-01-01

    Contemporary studies have shown that the regeneration of tissues and root elongation is possible in necrotic immature permanent teeth. The purpose of this case report is to add a new vista in regenerative endodontic therapy by using platelet rich fibrin for revitalization of immature non vital tooth. An 11year old boy with the history of trauma was diagnosed with the pulpal necrosis and symptomatic apical periodontitis in tooth #21. Intra oral periapical radiograph showed open apex and associ...

  16. Platelet-rich fibrin-mediated revitalization of immature necrotic tooth.

    Science.gov (United States)

    Mishra, Navin; Narang, Isha; Mittal, Neelam

    2013-07-01

    Contemporary studies have shown that the regeneration of tissues and root elongation is possible in necrotic immature permanent teeth. The purpose of this case report is to add a new vista in regenerative endodontic therapy by using platelet rich fibrin for revitalization of immature non vital tooth. An 11year old boy with the history of trauma was diagnosed with the pulpal necrosis and symptomatic apical periodontitis in tooth #21. Intra oral periapical radiograph showed open apex and associated immature supernumerary tooth with respect to tooth #21. Access preparation and minimal instrumentation was done to remove necrotic debris under copious irrigation with 2.5% sodium hypochlorite. Triple antibiotic paste was packed in the canal for four weeks. During second visit, 5 mL of whole blood was drawn from the medial cubital vein of the patient and blood was then subjected to centrifugation at 2400 rpm for 12 minutes for the preparation of Platelet rich fibrin (PRF) utilizing Choukroun's method. Triple antibiotic paste was removed and canal was dried. PRF clot was pushed to the apical region of tooth #21 using hand pluggers. Three milimetres of Mineral trioxide (MTA) was placed in cervical part of the root canal and permanent restoration was done three days later. Clinical examination at 6 and 12 months revealed no sensitivity to percussion and palpation in tooth #21and it responded positively to both electric pulp and cold tests. Radiographic examination showed resolution of periapical rarefaction, further root development and apical closure of the tooth #21 and its associated supernumerary tooth. On the basis of successful outcome of the present case it can be stated that PRF clot may serve as a scaffold for regeneration of necrotic immature teeth. PMID:24124320

  17. Platelet-rich fibrin-mediated revitalization of immature necrotic tooth

    Directory of Open Access Journals (Sweden)

    Navin Mishra

    2013-01-01

    Full Text Available Contemporary studies have shown that the regeneration of tissues and root elongation is possible in necrotic immature permanent teeth. The purpose of this case report is to add a new vista in regenerative endodontic therapy by using platelet rich fibrin for revitalization of immature non vital tooth. An 11year old boy with the history of trauma was diagnosed with the pulpal necrosis and symptomatic apical periodontitis in tooth #21. Intra oral periapical radiograph showed open apex and associated immature supernumerary tooth with respect to tooth #21. Access preparation and minimal instrumentation was done to remove necrotic debris under copious irrigation with 2.5% sodium hypochlorite. Triple antibiotic paste was packed in the canal for four weeks. During second visit, 5 mL of whole blood was drawn from the medial cubital vein of the patient and blood was then subjected to centrifugation at 2400 rpm for 12 minutes for the preparation of Platelet rich fibrin (PRF utilizing Choukroun?s method. Triple antibiotic paste was removed and canal was dried. PRF clot was pushed to the apical region of tooth #21 using hand pluggers. Three milimetres of Mineral trioxide (MTA was placed in cervical part of the root canal and permanent restoration was done three days later. Clinical examination at 6 and 12 months revealed no sensitivity to percussion and palpation in tooth #21and it responded positively to both electric pulp and cold tests. Radiographic examination showed resolution of periapical rarefaction, further root development and apical closure of the tooth #21 and its associated supernumerary tooth. On the basis of successful outcome of the present case it can be stated that PRF clot may serve as a scaffold for regeneration of necrotic immature teeth.

  18. Triclosan-loaded Tooth-binding Micelles for Prevention and Treatment of Dental Biofilm

    OpenAIRE

    Chen, Fu; Rice, Kelly C; Liu, Xin-ming; Reinhardt, Richard A.; Bayles, Kenneth W.; Wang, Dong

    2010-01-01

    The purpose of the present study was to develop tooth-binding micelle formulations and evaluate their ability to both inhibit initial biofilm formation as well as decrease the viability of preformed biofilm using an in vitro dental biofilm model. Alendronate (ALN, a bisphosphonate) was covalently attached to the ends of different Pluronic copolymers to confer tooth-binding ability to the micelles, and triclosan was used as a model drug. Based on different micelle preparation methods, Pluronic...

  19. Study of New Type Herringbone Gear with Narrow Tooth Width and Beveloid Teeth

    OpenAIRE

    Chao Lin; Zheng Guo; Bingkui Chen; Caichao Zhu

    2013-01-01

    New narrow herringbone gear, a new kind of transmission, is derived from traditional herringbone gear and broadens its application range. Based on the theories of differential geometry and gear meshing principles, the author describes the tooth and the transmission characteristics of the gear and deduces the equations of tooth face and fillet. According to the theories of material mechanics and gear strength check, the author deduces the equations of gear f...

  20. Analysis of stress state of toothed ring of flexspline by means the BEM

    OpenAIRE

    P. Fol?ga

    2013-01-01

    Purpose: The paper presents an analysis of the influence of design features of the flexspline in a harmonic drive, such as the relative radial deformation, the relative coating thickness and the design features of the basic rack tooth profile, on stress values in the bottom lands of a toothed ring.Design/methodology/approach: In numerical calculations, the software developed at the Faculty of Transport of the Silesian University of Technology was used. The program automatically generates a pr...