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Tooth Extraction  

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... suppress the immune system. Wisdom teeth , also called third molars, are often extracted either before or after they ... root remains in the jaw — Your dentist usually removes the root to prevent infection, ... of an upper back tooth (molar) — A small hole usually will close up by ...

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Necessity of analgesics prescription after tooth extraction  

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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.

Tozoglu Sinan

2009-01-01

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Alveolar process reconstruction after tooth extraction by orthodontic indications  

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Full Text Available The objective of the study is to determine indications for alveolar bone reconstruction after tooth extraction according to orthodontic indications. Material and methods. 62 patients (first maturity level with dental arch asymmetry due to loss of a premolar on one side of the mouth were examined and treated. Frontal-diagonal coefficient of the dental arch was used to determine the correlation between tooth size and dental arch parameters. Results. It has been demonstrated that changes of the alveolar ridge following the extraction of the first premolars in patients of the experimental group were less significant as compared with the controls. Conclusion. It is reasonable to apply this method simultaneously with the removal of a tooth for orthodontic indications or when the alveolar ridge in the post-extraction socket leaves insufficient bone volume.

Kovalev ?.?.

2013-09-01

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Subcutaneous emphysema as a complication of tooth extraction  

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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 a...

Vaci? Aca

2004-01-01

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Osteitis pubis ameliorated after tooth extraction: a case report.  

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Osteitis pubis is a non-infective inflammation of the symphysis pubis, which is known to be associated with trauma, athletic exertion, urological or gynecological surgery, or with rheumatic conditions such as seronegative spondyloarthropathies. In this report, we describe a case of osteitis pubis whose symptoms were completely ameliorated following tooth extraction attributable to periodontitis. A 57-year-old female patient developed osteitis pubis, presenting with pain in the groin area with an elevated Creactive protein (CRP; 4.4 mg/dl) and radiological erosive changes in symphysis pubis. Prednisolone (5 mg/day) and etodolac were prescribed, but the patient's symptoms improved only partially and remained persistent. One year from the patient's first visit, three teeth were extracted due to severe chronic periodontitis, which she had been suffering from for years. Soon after the above tooth extraction, her symptoms appeared completely resolved, and the patient's CRP was decreased to nearly normal levels in 4 weeks. Human leukocyte antigen (HLA)-typing analysis revealed a positive result for HLA-A11, A24, and B54. Because HLA-B54 cross-reacts with HLA-B27, the patient's osteitis pubis was considered to be a form of reactive arthritis associated with periodontitis. PMID:23599946

Fukushi, Jun-ichi; Nakashima, Yasuharu; Iwamoto, Yukihide

2013-03-01

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Facial vertical changes among patients treated by Edgewise orthodontic technique along with tooth extraction  

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Statement of Problem: Tooth extraction is a common technique in orthodontics and most of the specialists believe that this technique is able to change the facial appearance. Purpose: The aim of this study was to investigate facial vertical changes in orthodontic patients following tooth extraction. Materials and Methods: Thirty patients, after their growth spurt, with CLI malocclusion all treated by a specific orthodontist through Edgewise technique along with the extraction of four first pre...

2004-01-01

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Safety analysis of tooth extraction in elderly patients with cardiovascular diseases  

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Background This study aimed to evaluate the safety of tooth extraction in elderly patients with cardiovascular diseases. Material/Methods A total of 13 527 patients underwent tooth extraction at the Affiliated Ninth People’s Hospital of Shanghai Jiaotong University. Age, sex, and diseases were analyzed. Cardiac monitoring during tooth extraction was performed in 7077 elderly patients with hypertension and other chronic diseases, and the influence of various factors on safety of tooth extraction was evaluated. Additionally, 89 patients with primary hypertension were recruited, and electrocardiogram was monitored with a general monitor or a Holter monitor, and the detection rate of cardiovascular events was compared between the 2 groups. Results The elderly accounted from 75.3%, and patients aged 70–79 years had highest proportion. The most frequent comorbidities were hypertension, coronary heart disease, arrhythmia, cerebrovascular accident, and diabetes. In analysis of factors influencing the safety of tooth extraction in the elderly, a significant difference was noted in systolic blood pressure at different time points. In addition, change in heart rate was different between males and females. Detection rate of cardiovascular events by use of a Holter monitor was significantly higher than with a general monitor. Conclusions Hypertension was the most common comorbidity in elderly patients undergoing tooth extraction, followed by coronary heart disease and arrhythmia. Advanced age and increased comorbidity may increase the risk of complications. Risk score can be used to rapidly determine risk for complications during tooth extraction. The Holter monitor is superior to the general monitor in identifying cardiovascular events in high-risk elderly patients undergoing tooth extraction, and can be used in this population.

Lu, Ping; Gong, Yiwen; Chen, Yi; Cai, Wenwei; Sheng, Jing

2014-01-01

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Clinical evaluation of two-stage mandibular wisdom tooth extraction method to avoid mental nerve paresthesia  

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Clinical courses following two-stage mandibular wisdom tooth extraction (TMWTE) carried out for preventing postoperative mental nerve paresthesia (MNP) were analyzed. When panoramic X-ray showed overlapping of wisdom tooth root on the superior 1/2 or more of the mandibular canal, interruption of the white line of the superior wall of the canal, or diversion of the canal, CT examination was facilitated. In cases where contact between the tooth root and canal was demonstrated in CT examination, TMWTE was then selected after gaining the patient's consent. TMWTE consisted of removing more than a half of the tooth crown and tooth root extraction at the second step after 2-3 months. The clinical features of wisdom teeth extracted and postoperative courses including tooth movement and occurrence of MNP during two-stage MWTE were evaluated. TMWTE was carried out for 40 teeth among 811 wisdom teeth (4.9%) that were extracted from 2007 to 2009. Among them, complete procedures were accomplished in 39 teeth, and crown removal was performed insufficiently at the first-stage operation in one tooth. Tooth movement was detected in 37 of 40 cases (92.5%). No postoperative MNP was observed in cases in which complete two-stage MWTE was carried out, but one case with insufficient crown removal was complicated by postoperative MNP. Seven mild complications (dehiscence, cold sensitivity, etc.) were noted after the first-stage operation. Therefore, we conclude that TMWTE for high-risk cases assessed by X-ray findings is useful to avoid MNP after MWTE. (author)

2011-09-01

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Forensic interpretation of the maxillary tuberosity fracture caused by tooth extraction  

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Background. Maxillary tuberosity during teeth extraction can occur in dental practice. The aim of this paper was to present a case of the maxillary tuberosity fracture occurred during tooth extraction, which was the subject of the forensic expertise. Case report. The maxillary tuberosity fracture created during the extraction of the upper molar was neither timely nor adequately managed by the doctor who started extraction. After the treatment at the specialist institution, the patient sued th...

Puzovi? Dragana; ?oli? Snježana

2010-01-01

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Late self-extraction of a traumatically displaced molar tooth from the maxillary sinus.  

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An unusual case of late self-extraction of an impacted left maxillary third molar that was displaced into the left maxillary sinus after a traffic accident is described. The patient had been operated on for a maxillofacial trauma after a traffic accident in a plastic and reconstructive surgery department 18 years ago. He was admitted to our clinic 1½ years ago for obstruction and periodically purulent drainage from the left side of the nose. A displaced tooth in the middle meatus was diagnosed, and the patient refused a surgical procedure to remove the tooth. The tooth was self-extracted from the nasal cavity 1 year later. One week after the extraction, the patient was mostly healed and had no complaints. PMID:22801180

Ertu?rul, Eylem Ertu?; Erkul, Evren; Velio?lu, Murat

2012-07-01

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Forensic interpretation of the maxillary tuberosity fracture caused by tooth extraction  

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Full Text Available Background. Maxillary tuberosity during teeth extraction can occur in dental practice. The aim of this paper was to present a case of the maxillary tuberosity fracture occurred during tooth extraction, which was the subject of the forensic expertise. Case report. The maxillary tuberosity fracture created during the extraction of the upper molar was neither timely nor adequately managed by the doctor who started extraction. After the treatment at the specialist institution, the patient sued the doctor for the criminal offense of negligent treatment. The task of the expert was to give a professional answer to the question whether the doctor, who caused a maxillary tuberosity fracture during the tooth extraction, acted negligently and applied inadequate treatment. Conclusion. The maxillary tuberosity fracture during molar extraction may be its complication. If it is diagnosed promptly, immediately and adequately managed, there is no possibility for negligence action.

Puzovi? Dragana

2010-01-01

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

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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.

Naidoo Sudeshni

2011-05-01

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

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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.

Kim, Mee Kyung; Hwang, Eui Hwan; Lee, Sang Rae [College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

2002-03-15

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

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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.

2002-03-01

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

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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.

Yugoshi Luciana Ibara

2002-01-01

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

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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.

Christopher C. Friedl

2012-06-01

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Facial vertical changes among patients treated by Edgewise orthodontic technique along with tooth extraction  

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Full Text Available Statement of Problem: Tooth extraction is a common technique in orthodontics and most of the specialists believe that this technique is able to change the facial appearance. Purpose: The aim of this study was to investigate facial vertical changes in orthodontic patients following tooth extraction. Materials and Methods: Thirty patients, after their growth spurt, with CLI malocclusion all treated by a specific orthodontist through Edgewise technique along with the extraction of four first premolars were chosen. Lateral cephalograms of patients, before and after treatment were compared and facial vertical changes and teeth were studied. Results: Anterior and posterior facial heights were increased during treatment. Despite the limited use of intermaxillary elastics, teeth were extruded. The most increase in facial heights was observed in the lower third of face. Patients with longer faces before treatment showed more extrusion of mandibular molars as well as more increase of mandibular slope. Conclusion: Tooth extraction in orthodontic treatments can not guarantee the decrease or even non-increase of facial height. Among patients with long faces, it is particularly suggested to refrain from the application of extrusive orthodontic forces.

Heravi F.

2004-08-01

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Intraseptal vs. periodontal ligament anaesthesia for maxillary tooth extraction: quality of local anaesthesia and haemodynamic response.  

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There is no data concerning the use of the intraseptal anaesthesia (ISA) for single tooth extraction. The aims of this study were to compare the clinical efficacy and haemodynamic responses of the ISA with the periodontal ligament anaesthesia (PLA) for single tooth extraction. Thirty-five randomly selected healthy patients (ASA I) undergoing maxillary lateral incisors extraction entered the study. Onset of anaesthesia, the width of the anaesthetic field and duration of anaesthesia were recorded by pinprick testing. Intensity of anaesthesia was evaluated on a visual analogue scale. Haemodynamic parameters were recorded simultaneously at different time points after anaesthesia injection. The two techniques of local anaesthesia did not show statistically significant differences regarding the success rate and onset of anaesthesia, while the duration of the ISA on the buccal site was significantly longer in comparison with the PLA. The intensity of the achieved anaesthesia, estimated by the experienced pain during procedure, pointed out that pain was recorded in 24% of cases in the ISA group, and in 19% in the PLA group without significant differences. Postoperative pain was found to be smaller in the ISA group (70.9% of treated sites) than in the PLA group (81.3% of treated sites); however, this difference was not significant. Although the heart rate increased in both groups, there were no significant differences in the patients' haemodynamic response between the ISA and the PLA. The results of the present study indicate that both techniques are useful and suitable for the routine tooth extraction. PMID:19902278

Brkovic, Bozidar M B; Savic, Miroslav; Andric, Miroslav; Jurisic, Milan; Todorovic, Ljubomir

2010-12-01

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Medical image of the week: tooth impaction and extraction  

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Full Text Available A 66-year-old gentleman with a history Friedreich’s ataxia underwent a dental extraction procedure just prior to 4 weeks of traveling abroad. He was seen in emergency room for increasing weakness, cough and low grade fevers. His chest x-ray revealed a foreign body in the right main bronchus (Figure 1. He underwent bronchoscopy with forceps and basket removal of partially impacted teeth from the bronchus intermedius (Figure 2.

Afaq T

2012-12-01

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Octacalcium phosphate (OCP) collagen composites enhance bone healing in a dog tooth extraction socket model.  

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The authors have reported that a scaffold constructed of synthetic octacalcium phosphate (OCP) and porcine atelocollagen sponge (OCP/Col) enhanced bone regeneration more than sintered beta-tricalcium phosphate collagen composite or sintered hydroxyapatite collagen composite with a rat calvarial defect model. To aim for clinical application, the present study investigated whether OCP/Col would enhance bone healing in a dog tooth extraction socket model. Six adult, male, beagle dogs were used. The tooth extraction socket model was made by extracting bilateral third maxillary incisors and the subsequent removal of buccal bone. Disks of OCP/Col were implanted into one side of the model and the other side was untreated. The specimens were fixed 1 or 3 months after implantation. In radiographic analysis, the OCP/Col-treated group showed a wider range of radiopacity than the untreated control. Histologically, the OCP/Col-treated group showed more abundant newly formed bone than untreated control, and the implanted OCP was gradually resorbed. In morphometrical analysis, enlargement of the buccal alveolus in the OCP/Col group was significantly greater than in the untreated control. This study showed that implanted OCP/Col would be replaced by newly formed bone and OCP/Col implantation would enhance bone healing in a tooth socket model. PMID:20060266

Iibuchi, S; Matsui, K; Kawai, T; Sasaki, K; Suzuki, O; Kamakura, S; Echigo, S

2010-02-01

 
 
 
 
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Sinus floor augmentation through a rotated palatal flap at the time of tooth extraction.  

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Rapid crestal bone resorption following maxillary tooth loss is further accentuated in the posterior regions because of pneumatization and enlargement of the maxillary sinuses. A treatment rationale that allows preservation and/or augmentation of vertical available bone at the time of posterior maxillary tooth extraction may offer numerous therapeutic benefits. The present study comprised 14 patients in whom 18 posterior maxillary teeth with no evident bone between the tooth apex and sinus floor, as estimated through preoperative radiographic analysis, were carefully extracted using a palatal approach. The empty alveolus was thoroughly debrided and incrementally filled with tricalcium phosphate. The graft material was gently pushed beyond the empty alveolus to elevate the sinus membrane using an osteotome. Primary soft tissue closure over the grafted sites was achieved by a rotated palatal flap. The distance between bone crest and sinus floor was radiographically estimated 6 to 7 months after the first procedure. Another procedure was then carried out to place the 10- to 14-mm implants, together with a bone-added osteotome sinus floor elevation. At uncovering, all implants were clinically stable, with no signs of infection. The presented surgical procedure performed at the time of extraction of posterior maxillary teeth in close proximity to the sinus floor allowed placement of implants of proper length and width, together with a bone-added osteotome sinus floor elevation during a second procedure. PMID:15119888

Nemcovsky, Carlos E; Winocur, Ephraim; Pupkin, Juan; Artzi, Zvi

2004-04-01

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Dry Socket following Tooth Extraction in an Iranian Dental Center: Incidence and Risk Factors Dry Socket following Tooth Extraction in an Iranian Dental Center: Incidence and Risk Factors  

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Full Text Available Introduction: Dry Socket (DS is a common post-surgical complication following extraction of permanent teeth. Various risk factors has been mentioned for this complication including gender, age, amount of trauma during extraction, difficulty of extraction, inappropriate irrigation, infection, smoking, and oral contraceptive use. The aim of this study was to evaluate the incidence of DS among permanent teeth extraction in an Iranian Oral and Maxillofacial clinic and also to identify risk factors. Methods: This cross-sectional study performed at Mashhad Faculty of Dentistry between January 2009 and June 2009. Total of 785 patients who underwent non-surgical extraction of permanent teeth included in this study. A questionnaire with two sections designed to collect demographic, medical, and extraction-related data along with data regarding cases returning with DS. Data were reported descriptively and analyzed using Chi-square test with 95% confidence interval. Results: Total of 1073 teeth included in this study. 46.11% of patients were male and 53.89% were female. The mean age of participants was 32.68 ± 17.63 years. Total of 31 patients (2.89% were diagnosed with dry socket. Smoking and oral contraceptives intake had significant association with incidence of DS. In contrast, age, gender, medical status, tooth location, number of anesthetic carpules, anesthetic technique, pre-extraction antibiotic consumption, and academic year of students had no significant association with the incidence of DS. All cases with DS treated and were followed until resolution of DS. Conclusion: it is recommended to identify high risk groups (smokers and oral contraceptive takers when performing extraction and to perform preventive measures in these group of patients to attenuate postoperative complications.

Majid Eshghpour

2013-07-01

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

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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)

2007-07-01

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A preliminary study of local administration of dexamethasone after tooth extraction: Better preservation of residual alveolar ridge?  

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Full Text Available Background/Aim. It is important that the height of the edentulous alveolar ridge after tooth extraction remains at a reasonable acceptable level for as long as possible. The aim of this study was to report preliminary results of the clinical effect of local oral submucous administration of dexamethasone after tooth extractions in order to prepare alveolar supporting tissues for acceptance of removable dentures. Methods. In a total of 15 patients (11 partially and 4 completely edentulous the quantity of 0.25 mL to 0.5 mL of dexamethasone was injected bucally and orally in the region of the tooth socket after complicated extractions. Results. Healing of extraction wounds was uneventful in all the patients, without pain or local inflammation. Conclusion. Dexamethasone can be locally applied to oral tissues to prevent post-extraction inflammation and extensive resorption of the residual alveolar ridge. The obtained results are promising for patients undergoing classic prosthodontic rehabilitation soon after tooth extraction, demonstrating that there are no adverse effects after local oral corticosteroids administration. [Projekat Ministarstva nauke Republike Srbije, br. 175021

Pošti? Sr?an D.

2014-01-01

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Inflammatory myofibroblastic tumor of maxilla showing sarcomatous change in an edentulous site with a history of tooth extraction following periodontitis: A case report with discussion.  

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Inflammatory myofibroblastic tumor (IMT) is a rare tumor of uncertain origin with variable biological behavior ranging from reactive lesions to highly aggressive malignancy. Oral IMTs are extremely rare and only 25 cases had been reported so far. A case of IMT with sarcomatous transformation in an extraction site with a history of tooth extraction following tooth mobility of an upper left molar tooth is presented here. The tooth was extracted following a complaint of gingival swelling and mobility of tooth. Though malignant transformation in IMTs had been documented in the extra oral sites, wide search of associated literature suggests, this is the first case of oral IMT showing malignant change associated with gingiva. The case report attempts to highlight the variant possibilities of tooth mobility other than periodontitis and the importance of assessing the primary cause of such conditions. PMID:25024554

Biniraj, K R; Janardhanan, Mahija

2014-05-01

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The use of aloe vera extract as a novel storage media for the avulsed tooth.  

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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. PMID:25031484

Badakhsh, Samaneh; Eskandarian, Tahereh; Esmaeilpour, Tahereh

2014-07-01

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

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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)

2013-09-01

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Autogenous tooth transplantation for replacing a lost tooth: case reports  

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The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site.

Kang, Ji-youn; Chang, Hoon-sang; Hwang, Yun-chan; Hwang, In-nam; Oh, Won-mann; Lee, Bin-na

2013-01-01

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Ectopic Intranasal Tooth  

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Full Text Available The intranasal tooth is a rare clinical phenomenon that has unclear etiology. It may result to rhinolith with deposition calcium and organic materials around the ectopic nasal tooth. In this report we presended 43-year-old female who had ectopic nasal tooth which seems to be rhinolith .Diagnose of ectopic nasal tooth was determined by radiological examination and it was extracted by endoscopically.

Ediz Yorganc?lar

2008-12-01

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Successful medical treatment for globe penetration following tooth extraction in a dog.  

Science.gov (United States)

A five-year-old entire male Tibetan Terrier was referred for left-sided periorbital swelling and blepharospasm 4 days following ipsilateral maxillary tooth extraction. Examination of the left eye revealed mild exophthalmos, pain on retropulsion, and absent menace response and pupillary light reflexes. Examination of the posterior segment was not possible owing to the anterior segment pathology. Differential diagnoses considered were iatrogenic globe penetration and peribulbar abscess/cellulitis. Ocular ultrasound was consistent with a penetrating wound to the globe. Treatment with systemic prednisolone and marbofloxacin, and topical atropine sulfate 1%, prednisolone acetate, and brinzolamide was started. Marked clinical improvement allowed visual confirmation of the perforation. Oral prednisolone was tapered over the following 10 weeks. At final re-examination (10 months), the patient was visual, and fundic examination revealed an additional chorioretinal scar, most likely an exit wound that was obscured by vitreal debris on initial examinations. Neither scar was associated with retinal detachment. To the authors' knowledge, this is the first reported case of successful medical management of iatrogenic globe penetration following exodontic procedures. PMID:23869648

Guerreiro, Cleo E; Appelboam, Helen; Lowe, Robert C

2014-03-01

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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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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.

Srinivas N CH

2011-04-01

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Dry Socket following Tooth Extraction in an Iranian Dental Center: Incidence and Risk Factors Dry Socket following Tooth Extraction in an Iranian Dental Center: Incidence and Risk Factors  

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Introduction: Dry Socket (DS) is a common post-surgical complication following extraction of permanent teeth. Various risk factors has been mentioned for this complication including gender, age, amount of trauma during extraction, difficulty of extraction, inappropriate irrigation, infection, smoking, and oral contraceptive use. The aim of this study was to evaluate the incidence of DS among permanent teeth extraction in an Iranian Oral and Maxillofacial ...

Majid Eshghpour; Amir Moradi; Amir Hossein Nejat

2013-01-01

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Effects of local and whole body irradiation on the appearance of osteoblasts during wound healing in tooth extraction sockets in rats  

International Nuclear Information System (INIS)

Irradiation before tooth extraction delays wound healing in the alveolar socket. This study examined the influences of local and whole body irradiation before tooth extraction on appearance of osteoblasts in the alveolar bone of rat maxillary first molars because bone formation is observed at the initial phase of wound healing. Several osteoblasts were generated 3 days after tooth extraction, and the number of cells increased day by day. Morphological studies showed there were little differences between local irradiation and non-irradiated controls. In contrast, the extraction wound in the whole body irradiation group showed delayed healing, and there was poor granulation tissue and very few osteoblasts at the bottom of the socket. An ultrastructural study showed that the osteoblasts in the extraction socket of whole body irradiation rats were smaller, and had poorly developed organelles. Injection of bone marrow cells to whole body-irradiated animals immediately after tooth extraction partially restored the number of osteoblasts. New periosteal bone formations outside of sockets showed little delay in the whole body irradiation group. These findings suggest that bone formation in the wound healing of extraction socket requires bone marrow cells from hematopoietic organs such as the bone marrow as well as local sources around the alveolar socket, during the initial phase of wound healing. (author)

2010-03-01

34

Tooth Discoloration  

Science.gov (United States)

Tooth Discoloration What Is It? Symptoms Diagnosis Expected Duration Prevention Treatment When To Call a Professional Prognosis ... on the surface or by changes inside the tooth. There are three main types of tooth discoloration: ...

35

Tooth Numbering  

Science.gov (United States)

Tooth Numbering If you were trying to tell your dentist which tooth was giving you problems, chances are you'd ... be 2 instead of 1, acknowledging the missing tooth. If you've had teeth removed or teeth ...

36

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

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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....

2006-01-01

37

Tooth Problems  

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MENU Return to Web version Tooth Problems See complete list of charts. A tooth that causes ongoing pain may be a sign of a serious problem. Use ... you have an injury that knocked out a tooth? Yes You have TOOTH LOSS. DENTAL EMERGENCY See ...

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EXTERNAL CAROTID ARTERY PSEUDOANEURYSM AND INTERNAL JUGULER VEIN THROMBOSIS FOLLOWING TOOTH EXTRACTION IN A CASE OF BEHÇET’S DISEASE  

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Full Text Available Behçet’s disease is a multisystemic inflammatory disease of unknown cause, presenting with vasculitis. Complications such as pseudoaneurysm or thrombosis may be seen due to major vein and artery involvement in addition to vasculitis causing clinical manifestations. Major artery complications are seen most commonly in the aorta, pulmonary, femoral, subclavian or carotid artery. The involvement of an extracranial artery, particularly the external carotid artery is uncommon in the literature. In our case, the clinical and radiologic findings of a young male Behçet patient with an external carotid artery pseudoaneurysm and internal jugular vein thrombosis following tooth extraction is presented together with the relevant literature. No such complication of Behçet’s disease following a dental manipulation has previously been reported in the literature. .

Arda Kayhan

2009-01-01

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Histomorphometric evaluation of the effect of systemic and topical ozone on alveolar bone healing following tooth extraction in rats.  

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The aim of this study was to investigate the effects of systemic and topical ozone applications on alveolar bone healing following tooth extraction. One hundred and twelve male Wistar rats were divided into eight groups of 14 rats each; seven groups were experimental (A-G) and one formed the control group (K). The experimental groups were further divided into two sub-groups, with seven rats in each - sacrificed on days 14 and 28 (subgroups 1 and 2). The maxillary right central incisors were extracted under general anaesthesia following the administration of local anaesthesia. After sacrifice, semi-serial histological sections were prepared, and mineralized and trabecular bone and osteoid and osteoblast surfaces were measured. Measurements of the trabecular bone showed statistically higher values in the groups treated with systemic ozone (D2: 50.01±2.12; E2: 49.03±3.03; F2: 48.76±2.61; G2: 50.24±3.37) than in the groups that underwent topical ozone administration (A2: 46.01±3.07; B2: 46.79±3.09; C2: 47.07±2.12; P=0.030 (G2-A2, G2-B2, G2-C2)). Within the limitations of the current study, it may be concluded that postoperative long-term systemic ozone application can accelerate alveolar bone healing following extraction. However, additional studies are required to clarify the effects of the different ozone applications on new bone formation. PMID:24491848

Erdemci, F; Gunaydin, Y; Sencimen, M; Bassorgun, I; Ozler, M; Oter, S; Gulses, A; Gunal, A; Sezgin, S; Bayar, G R; Dogan, N; Gider, I K

2014-06-01

40

X radiation effects on the wound healing process after tooth extraction. Histological study in rats  

International Nuclear Information System (INIS)

The X radiation effects on the wound healing process after teeth extractions are studied histologically. Albino rats are employed. After their right upper incisors were extracted, they were divided into groups of 20 animals each. With exception of the group I (control), 24 hours after teeth extractions the groups II, III and IV received X radiation, respectively, in the dosage of 75,125 and 175 R. The rats were sacrificed in group of 4, at 3, 6, 9,15 and 21 postoperative days and a histological study is done. (M.A.C.)

1988-01-01

 
 
 
 
41

Tooth Disorders  

Science.gov (United States)

... made of a hard, bonelike material. Inside the tooth are nerves and blood vessels. You need your ... These include eating, speaking and even smiling. But tooth disorders are nothing to smile about. They include ...

42

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

Science.gov (United States)

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. Conflict of interest:None declared. PMID:24385748

Kazanc?o?lu, Hakk? O?uz; Cak?r, Onur; Ak, Gülsüm; Zülfikar, Bülent

2013-03-01

43

Tooth ankylosis: Orthodontic implications.  

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Full Text Available Tooth ankylosis is a condition, which may lead to an occlusal abnormality. The etiology is unknown although different and often contradicting opinions have been presented. It prevails on primary teeth, characterized by progressive infraocclusion. Ankylosis on permanent teeth is less frequent and is associated with trauma and impaction. Management of the affected tooth ranges from simple observation to extraction. A protocol assisting in the proper diagnosis and treatment is presented.

P. Panos

2003-01-01

44

Implant treatment choice after extraction of a vertically fractured tooth. A proposal for a clinical classification of bony defects based on a systematic review of literature.  

Science.gov (United States)

OBJECTIVES: The objectives of this study were to propose a classification for the bone defects resulting after extraction of a vertically fractured tooth and to review the existing literature about the treatment of such kind of defects by means of dental implants in combination with regenerative procedures. MATERIALS AND METHODS: An electronic search was performed on biomedical databases using a combination of appropriated search terms combined through the use of Boolean operators. All articles concerning the treatment of peri-implant bone dehiscences and fenestrations through guided bone regeneration (GBR) with at least 6 months follow-up were eligible. Outcomes data extracted from the selected articles were summarized using descriptive tables. A classification of the bone defects associated with vertical root fracture (VRF) was also proposed. RESULTS: A total of 33 articles were included in the review. Twenty-three articles (814 implants) were about bone dehiscence treatment, ten articles presented the treatment of fenestrations, and ten (429 implants) adopted vertical bone augmentation. The percentage of bone filling was variable among different procedures and defect classification. The use of resorbable membrane was associated with better outcomes than the use of non-resorbable ones. CONCLUSIONS: Guided bone regeneration for the management of bone defects in the presence of a VRF of the extracted tooth is a viable treatment option. The assessment of bone defect geometry prior to a tooth extraction could be clinically relevant for evaluating the feasibility and the success of immediate implant placement as well as the need of GBR. PMID:23560723

Corbella, Stefano; Taschieri, Silvio; Samaranayake, Lakshman; Tsesis, Igor; Nemcovsky, Carlos; Del Fabbro, Massimo

2013-04-01

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Extrações dentárias em Ortodontia: avaliação de elementos de diagnóstico Tooth extraction in orthodontics: an evaluation of diagnostic elements  

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Full Text Available Algumas más oclusões exigem do ortodontista capacidade de diagnóstico para decidir pela melhor maneira de tratar o paciente. O objetivo dos autores deste artigo foi apresentar casos clínicos e discutir alguns elementos de diagnóstico utilizados na elaboração do plano de tratamento, auxiliando na decisão de extrair dentes. Foi dada ênfase em cada elemento de diagnóstico: aspectos relacionados à cooperação, discrepância de modelo, discrepância cefalométrica e perfil facial, idade esquelética (crescimento e relações anteroposteriores, assimetrias dentárias, padrão facial e patologias. Sugere-se que a associação dos aspectos citados é importante para a decisão correta. Todavia, algumas vezes, uma característica, por si só, pode definir o plano de tratamento.Certain malocclusions require orthodontists to be capable of establishing a diagnosis in order to determine the best approach to treatment. The purpose of this article was to present clinical cases and discuss some diagnostic elements used in drawing up a treatment plan to support tooth extraction. All diagnostic elements have been highlighted: Issues concerning compliance, model discrepancy, cephalometric discrepancy and facial profile, skeletal age (growth and anteroposterior relationships, dental asymmetry, facial pattern and pathologies. We suggest that sound decision-making is dependent on the factors mentioned above. Sometimes, however, one single characteristic can, by itself, determine a treatment plan.

Antônio Carlos de Oliveira Ruellas

2010-06-01

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Extrações dentárias em Ortodontia: avaliação de elementos de diagnóstico / Tooth extraction in orthodontics: an evaluation of diagnostic elements  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Algumas más oclusões exigem do ortodontista capacidade de diagnóstico para decidir pela melhor maneira de tratar o paciente. O objetivo dos autores deste artigo foi apresentar casos clínicos e discutir alguns elementos de diagnóstico utilizados na elaboração do plano de tratamento, auxiliando na dec [...] isão de extrair dentes. Foi dada ênfase em cada elemento de diagnóstico: aspectos relacionados à cooperação, discrepância de modelo, discrepância cefalométrica e perfil facial, idade esquelética (crescimento) e relações anteroposteriores, assimetrias dentárias, padrão facial e patologias. Sugere-se que a associação dos aspectos citados é importante para a decisão correta. Todavia, algumas vezes, uma característica, por si só, pode definir o plano de tratamento. Abstract in english Certain malocclusions require orthodontists to be capable of establishing a diagnosis in order to determine the best approach to treatment. The purpose of this article was to present clinical cases and discuss some diagnostic elements used in drawing up a treatment plan to support tooth extraction. [...] All diagnostic elements have been highlighted: Issues concerning compliance, model discrepancy, cephalometric discrepancy and facial profile, skeletal age (growth) and anteroposterior relationships, dental asymmetry, facial pattern and pathologies. We suggest that sound decision-making is dependent on the factors mentioned above. Sometimes, however, one single characteristic can, by itself, determine a treatment plan.

Antônio Carlos de Oliveira, Ruellas; Ricardo Martins de Oliveira, Ruellas; Fábio Lourenço, Romano; Matheus Melo, Pithon; Rogério Lacerda dos, Santos.

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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)

2006-01-01

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

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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.

Reza Birang

2012-06-01

49

Estudio de la prevalencia y causas de las exodoncias en una población infantil española / Study of prevalence and causes of tooth extractions in a Spanish infant population  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Introducción. Existe gran cantidad de estudios que examinan las razones que llevan a la extracción dental en adultos, pero poca información sobre la exodoncia en las poblaciones infantiles. Con este estudio se pretendió estudiar la frecuencia y distribución de las extracciones así como los motivos d [...] e las mismas en una muestra concreta. Material y Método. Se revisaron los expedientes de pacientes de 0 a 15 años, anotando la edad, sexo y el o los dientes extraídos, tomándose en consideración los motivos de extracción para cada diente. Resultados. De los 1062 expedientes revisados el 40,5% tenían historias de extracciones. Del total de las extracciones el 89,5% se realizaron en dentición temporal y el 10,5% en dentición permanente. El rango de edad donde se realizaron la mayor cantidad de exodoncias fue entre los 6-9 años (45,91%). El motivo más frecuente fue por causas ortodóncicas (44,75%). Los primeros molares temporales superiores fueron los dientes más extraídos. Conclusión. Podemos destacar que, las razones ortodóncicas y la caries, constituyen las causas más frecuentes para la indicación de exodoncias en esta población, los incisivos centrales, los primeros y segundos molares son los dientes más extraídos, y por último existen diferencias importantes entre los distintos grupos de edad. Abstract in english Introduction. There are many studies available examining the reasons for tooth extractions in adults, but little information exists on extractions in infant populations. This study examines the frequency and distribution of tooth extractions and the reasons for them in a specific sample. Materials a [...] nd methods. Files of patients from 0-15 years of age were studied regarding to age, gender, the extracted tooth or teeth and the reason for the extraction. Results. Of the 1,062 files studied, 40.5% had a history of extractions. Of the total number of extractions performed, 89.5% were related to temporary teeth and 10.5%, to permanent teeth. The age range in which the largest number of extractions were performed was between 6 and 9 years of age (45.91%). The most frequent motive was for orthodontic reasons (44.75%). The upper first temporary molars were the most frequently extracted teeth. Conclusion. Orthodontic reasons and caries are the most frequent causes for recommending extractions in this population. The central incisors and the first and second molars are the most frequently extracted teeth, with considerable differences between the different age groups.

Lucavechi-Alcayaga, Tania; Suárez-Clúa, Mª Cruz; Barbería-Leache, Elena.

50

Tooth Whitening  

Science.gov (United States)

... Used For Preparation How It's Done Follow-Up Risks When To Call a Professional What Is It? Tooth whitening lightens teeth and helps to remove stains ... This product contains some form of hydrogen peroxide. Tooth ... bleaching to happen faster. In-office whitening usually takes ...

51

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)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

52

Tooth in oropharynx  

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The incidence of ectopic teeth has increased. In many cases, the etiology of ectopic teeth cannot be identified. Ectopic tooth in deciduous dentition period is very rare and information is limited about its causes and characteristics. The conditions commonly associated with an increased prevalence of ectopic teeth include cleft lip and palate, cleidocranial dysplasia, and Gardner syndrome. The diagnosis is made by the clinical and radiological examinations. The indication for extraction in ec...

Nagarajappa, D.; Manjunatha, Bs

2011-01-01

53

Tooth Colored Fillings  

Science.gov (United States)

... Accredited and General Member Dental Patients ? Cosmetic Procedures ? Tooth Colored Fillings Tooth Colored Fillings In the past, teeth were filled ... becoming the preferred approach. Dentists are using more tooth-like materials (composite resins and porcelains) that are ...

54

Biocompatibility of Beta-tricalcium phosphate root replicas in porcine tooth extraction sockets - a correlative histological, ultrastructural, and x-ray microanalytical pilot study.  

Science.gov (United States)

This investigation studies porcine tissue response in tooth extraction sockets treated with root replicas made out of Beta-tricalcium phosphate (Beta-TCP; Beta-Ca(3)(PO(4))(2)) granules, molded and held together by thermal fusion of a thin film of polyglycolic-polylactic acid copolymer. Six left mandibular third incisors (n (1)/4 6) of experimental pigs are treated with the root replicas and four contralateral incisors are used as nontreated controls (n (1)/4 4). Two animals each were killed at 20, 40, and 60 weeks of observation periods. The mandibular jaw segments were prepared in toto for light microscopy by resin embedding and serial ground sectioning. Additionally, one Beta-TCP-treated socket at 60 weeks was thoroughly investigated by correlative light, electron microscopic and electron probe X-ray microanalysis to assess the bio-absorbability and host removal of the replica material from the implant site. The extraction wounds of the animals healed satisfactorily with very little histologically observable differences in the healing pattern of the test and control sites. The Beta-TCP was completely removed from extracellular sites, but at 60 weeks, remnants of it were found in the cytoplasm of multinucleated giant cells. The root replicas made out of Beta-TCP were biocompatible and bioabsorbable. Osseous healing occurred both in the test and control sockets, but the healing process was delayed due to the presence of Beta-TCP particles. PMID:16443623

Nair, P N Ramachandran; Luder, Hans-Ulrich; Maspero, Fabrizio A; Fischer, Jürgen H; Schug, Jens

2006-04-01

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A 5- Year Comparison of Marginal Bone Level Following Immediate Loading of Single-Tooth Implants Placed in Healed Alveolar Ridges and Extraction Sockets in the Maxilla.  

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Full Text Available AbstractPurpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol.Materials and Methods: Thirty-six patients in need of a single tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden. Implants were placed in healed ridges (group I or immediately into extraction sockets (group II. Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36 and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implantResults: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study and all remaining implants osseointegrated successfully after 5 years of functional loading. The mean change in marginal bone loss after implant placement was 0.267±0.161 for one year, and 0.265±0.171 for three years and 0.213±0.185 for five years in extraction sockets and was 0.266±0.176 for one year and 0.219±0.175 for three years and 0.194±0.172 for five years in healed ridges group. Significant reduction of marginal bone loss was more pronounced in implants inserted in healed ridges (P

AntoineNicolasBerberi

2014-01-01

56

A 5-year comparison of marginal bone level following immediate loading of single-tooth implants placed in healed alveolar ridges and extraction sockets in the maxilla.  

Science.gov (United States)

Purpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol. Materials and Methods: Thirty-six patients in need of a single-tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden). Implants were placed either in healed ridges (group I) or immediately into fresh extraction sockets (group II). Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36, and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implant. Results: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study. The mean change in marginal bone loss (MBL) after implant placement was 0.26 ± 0.161 mm for 1 year, and 0.26 ± 0.171 mm for 3 years, and 0.21 ± 0.185 mm for 5 years in extraction sockets and was 0.26 ± 0.176 mm for 1 year and 0.21 ± 0.175 mm for 3 years, and 0.19 ± 0.172 mm for 5 years in healed ridges group. Significant reduction of marginal bone was more pronounced in implants inserted in healed ridges (P < 0.041) compared to fresh surgical extraction sockets (P < 0.540). Significant MBL was observed on the mesial side of the implant after cementation of the provisional (P < 0.007) and after 12 months (P < 0.034) compared to the distal side which remained stable for 3 and 5 years observation period. Conclusions: Within the limitations of this study, responses of local bone to immediately loaded implants placed either in extraction sockets or healed ridges were similar. Functional loading technique by using prefabricated abutment placed during the surgery time seems to maintain marginal bone around implant in both healed and fresh extraction sites. PMID:24550840

Berberi, Antoine N; Sabbagh, Joseph M; Aboushelib, Moustafa N; Noujeim, Ziad F; Salameh, Ziad A

2014-01-01

57

Single-Tooth Modeling for 3D Dental Model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 acco...

Tianran Yuan; Wenhe Liao; Ning Dai; Xiaosheng Cheng; Qing Yu

2010-01-01

58

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

59

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)

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.

Schropp, Lars; Wenzel, Ann

2014-01-01

60

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)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

 
 
 
 
61

Single-Tooth Implants  

Science.gov (United States)

Single-Tooth Implants When Are They Used? How Do They Work? The Implant Process Caring for Your Implants What ... and right of the two front teeth. Single-tooth implants can be used in people who are ...

62

Surfaces of the Tooth  

Science.gov (United States)

... to the various sides and surfaces of a tooth. Learn them, and next time your dentist's words ... more sense. Here's how dentists refer to the tooth's surfaces: Buccal or facial or labial — This is ...

63

Replacing a Missing Tooth  

Science.gov (United States)

... Individuals Information for Parents & Individuals Replacing a Missing Tooth To download the PDF version of this factsheet, ... and palate are often born with a missing tooth, most often the lateral incisor (immediately next to ...

64

Tooth Abfraction Lesions  

Science.gov (United States)

Tooth Abfraction Lesions What Is It? Symptoms Diagnosis Expected Duration Prevention Treatment When To Call a Professional ... affect the enamel , the outer layer of the tooth. In severe cases, the dentin and cementum layers ...

65

Fractured tooth (image)  

Science.gov (United States)

A tooth can be chipped or fractured during an accident or a bad fall. A tooth that is chipped or not badly fractured can usually be handled on a nonemergency basis. A tooth that is badly fractured may have exposed nerve ...

66

Intracranial supernumerary tooth  

Energy Technology Data Exchange (ETDEWEB)

Case report of an accidentally diagnosed supernumerary tooth in the superior orbital fissure. Computed tomography (CT) contributed with a more precise localization of the tooth being situated between the orbit and the brain. CT also showed that there was no cyst or other pathological process around the supernumerary tooth, which is plausible and frequently reported in the literature.

Sjoeberg, S.; Loerinc, P.

1984-12-01

67

Effect of acemannan, an extracted polysaccharide from Aloe vera, on BMSCs proliferation, differentiation, extracellular matrix synthesis, mineralization, and bone formation in a tooth extraction model.  

Science.gov (United States)

Aloe vera is a traditional wound healing medicine. We hypothesized acemannan, a polysaccharide extracted from Aloe vera gel, could affect bone formation. Primary rat bone marrow stromal cells (BMSCs) were treated with various concentrations of acemannan. New DNA synthesis, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein, osteopontin expression, and mineralization were determined by [(3)H] thymidine incorporation assay, ELISA, biochemical assay, western blotting, and Alizarin Red staining, respectively. In an animal study, mandibular right incisors of male Sprague-Dawley rats were extracted and an acemannan treated sponge was placed in the socket. After 1, 2, and 4 weeks, the mandibles were dissected. Bone formation was evaluated by dual-energy X-ray absorptiometry and histopathological examination. The in vitro results revealed acemannan significantly increased BMSC proliferation, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein and osteopontin expression, and mineralization. In-vivo results showed acemannan-treated groups had higher bone mineral density and faster bone healing compared with untreated controls. A substantial ingrowth of bone trabeculae was observed in acemannan-treated groups. These data suggest acemannan could function as a bioactive molecule inducing bone formation by stimulating BMSCs proliferation, differentiation into osteoblasts, and extracellular matrix synthesis. Acemannan could be a candidate natural biomaterial for bone regeneration. PMID:23315202

Boonyagul, Sani; Banlunara, Wijit; Sangvanich, Polkit; Thunyakitpisal, Pasutha

2013-01-12

68

Tooth Retained Implant: No More an Oxymoron  

Directory of Open Access Journals (Sweden)

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.

Divya Bhat

2011-03-01

69

Automating digital leaf measurement: the tooth, the whole tooth, and nothing but the tooth.  

Science.gov (United States)

Many species of plants produce leaves with distinct teeth around their margins. The presence and nature of these teeth can often help botanists to identify species. Moreover, it has long been known that more species native to colder regions have teeth than species native to warmer regions. It has therefore been suggested that fossilized remains of leaves can be used as a proxy for ancient climate reconstruction. Similar studies on living plants can help our understanding of the relationships. The required analysis of leaves typically involves considerable manual effort, which in practice limits the number of leaves that are analyzed, potentially reducing the power of the results. In this work, we describe a novel algorithm to automate the marginal tooth analysis of leaves found in digital images. We demonstrate our methods on a large set of images of whole herbarium specimens collected from Tilia trees (also known as lime, linden or basswood). We chose the genus Tilia as its constituent species have toothed leaves of varied size and shape. In a previous study we extracted c.1600 leaves automatically from a set of c.1100 images. Our new algorithm locates teeth on the margins of such leaves and extracts features such as each tooth's area, perimeter and internal angles, as well as counting them. We evaluate an implementation of our algorithm's performance against a manually analyzed subset of the images. We found that the algorithm achieves an accuracy of 85% for counting teeth and 75% for estimating tooth area. We also demonstrate that the automatically extracted features are sufficient to identify different species of Tilia using a simple linear discriminant analysis, and that the features relating to teeth are the most useful. PMID:22870286

Corney, David P A; Tang, H Lilian; Clark, Jonathan Y; Hu, Yin; Jin, Jing

2012-01-01

70

Towards tooth friendly soft drinks.  

Science.gov (United States)

Most soft drinks contain high concentration of simple carbohydrates and have a pH of 3 or even lower. Therefore, they are harmful for tooth structure. A tooth friendly soft drink (T.F.S.D) should have the following characteristics and elements; fluoride (approximately 1 ppm), casein phosphopeptide-amorphous calcium phosphate (2%), xylitol (4-6g/serving), tea polyphenols (2-4 mg/ml), cranberry extract (250 mg/ml of the flavonoids quercetin and myricetin), sugar free, pH close to 5.5 and super oxygenation (240,000 ppm) vs. carbonation. T.F.S.D can be packaged in a container which gaseous oxygen is dissolved in a liquid in the form of bubbles. However, looking at opportunities for so-called sophisticated soft drinks, T.F.S.D will be an example for a functional and health oriented soft drink. PMID:19570614

Kolahi, Jafar; Fazilati, Mohamad; Kadivar, Mahdi

2009-10-01

71

Aesthetic replacement of an anterior tooth using the natural tooth as a pontic; an innovative technique  

Science.gov (United States)

This article presents a novel technique for replacing an anterior tooth. A new modification to the clinical technique of direct fabrication of a resin-bonded bridge was employed, in which the patient’s natural tooth was used as a pontic. Treatment with this modification led to overall improved aesthetics and reduced treatment cost. The natural tooth pontic was stabilized in the extraction socket with a resin-wire splint as a provisional restoration to maintain the gingival architecture while the permanent bridge was being constructed.

Purra, Aamir Rashid; Mushtaq, Mubashir

2013-01-01

72

Cracked Tooth Syndrome  

Science.gov (United States)

... tooth syndrome is one of the most difficult dental problems to diagnose because the pain is not predictable. Your dentist may refer you ... When To Call a Professional If you feel pain when you bite or chew, contact your dental office. Prognosis Treatment of cracked tooth syndrome is ...

73

Nasal tooth: case report  

Energy Technology Data Exchange (ETDEWEB)

Ectopic tooth is not uncommon and usually occurs in the palate and maxillary sinus. We report a case of ectopic tooth located in the nasal cavity, a rare site. The mass depicted by CT was highly attenuated, and central lucency was observed.

Park, Si Hyun; Kim, Ji Hye; Hwang, Hee Young; Yang, Dal Mo; Kim, Hyung Sik; Park, Chol Heui [Gachon Medical School, Inchon (Korea, Republic of)

2002-12-01

74

Nasal tooth: case report  

International Nuclear Information System (INIS)

Ectopic tooth is not uncommon and usually occurs in the palate and maxillary sinus. We report a case of ectopic tooth located in the nasal cavity, a rare site. The mass depicted by CT was highly attenuated, and central lucency was observed

2002-12-01

75

Single-Tooth Modeling for 3D Dental Model  

Directory of Open Access Journals (Sweden)

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.

Xiaosheng Cheng

2010-01-01

76

Cyst in the pulp of an intact human immature tooth: Case report  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this paper was to histologically present and analyze a cyst in the pulp of an intact human immature tooth as a rare case in dental practice. The cyst was discovered in the left upper first premolar of a 9 year old following tooth extraction for orthodontic reasons. Presence of this cyst in an immature tooth may impair the pulp integrity and the tooth on the whole, so early and adequate diagnosis is essential.

Vojinovi? Jovan

2004-01-01

77

Cyst in the pulp of an intact human immature tooth: Case report  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this paper was to histologically present and analyze a cyst in the pulp of an intact human immature tooth as a rare case in dental practice. The cyst was discovered in the left upper first premolar of a 9 year old following tooth extraction for orthodontic reasons. Presence of this cyst in an immature tooth may impair the pulp integrity and the tooth on the whole, so early and adequate diagnosis is essential.

Vojinovi? Jovan; Vojinovi? Olivera; Vu?eti? Mirjana

2004-01-01

78

Interactive tooth segmentation of dental models.  

Science.gov (United States)

The accurate segmentation of the teeth from the triangle mesh is an important step in computer-aided orthodontic. Because teeth come in different shapes and their arrangements vary substantially from one individual to another, tooth segmentation is difficult. This paper proposes a new method to accurately segment the teeth interactively. Based on curvature values of the triangle mesh, feature points are connected to feature regions. After feature lines are extracted from regions, feature contour can be obtained with the help of user supplied information. Using feature contour, the tooth are segmented accurately and individually. PMID:17282267

Zhao, Mingxi; Ma, Lizhuang; Tan, Wuzheng; Nie, Dongdong

2005-01-01

79

How a Tooth Decays  

Science.gov (United States)

... is the softer layer beneath the enamel. The pulp chamber contains nerves and blood vessels. It is considered the living part of the tooth. Bacteria that are exposed to sugars or carbohydrates can make acid. The ...

80

Fracture tooth fragment reattachment.  

Science.gov (United States)

Coronal fractures of the anterior teeth are a common form of dental trauma and its sequelae may impair the establishment and accomplishment of an adequate treatment plan. Among the various treatment options, reattachment of a crown fragment is a conservative treatment that should be considered for crown fractures of anterior teeth. This clinical case reports the management of two coronal tooth fracture cases that were successfully treated using tooth fragment reattachment using glass-fibre-reinforced composite post. PMID:23853012

Maitin, Nitin; Maitin, Shipra Nangalia; Rastogi, Khushboo; Bhushan, Rajarshi

2013-01-01

 
 
 
 
81

Acoustic tooth cleaner  

Science.gov (United States)

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.

Heyman, J. S. (inventor)

1982-01-01

82

Tooth regeneration: Current status  

Directory of Open Access Journals (Sweden)

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.

Dadu Shifali

2009-01-01

83

The rachitic tooth.  

Science.gov (United States)

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 newly identified factors involved in endocrine regulation of vitamin D, phosphate, and calcium, including phosphate-regulating endopeptidase homolog, X-linked, fibroblast growth factor 23, and dentin matrix protein 1. Systemic mineral metabolism intersects with local regulation of mineralization, and factors including tissue nonspecific alkaline phosphatase are necessary for proper mineralization, where rickets can result from loss of activity of tissue nonspecific alkaline phosphatase. Individuals suffering from rickets often bear the additional burden of a defective dentition, and transgenic mouse models have aided in understanding the nature and mechanisms involved in tooth defects, which may or may not parallel rachitic bone defects. This report reviews dental effects of the range of rachitic disorders, including discussion of etiologies of hereditary forms of rickets, a survey of resulting bone and tooth mineralization disorders, and a discussion of mechanisms, known and hypothesized, involved in the observed dental pathologies. Descriptions of human pathology are augmented by analysis of transgenic mouse models, and new interpretations are brought to bear on questions of how teeth are affected under conditions of rickets. In short, the rachitic tooth will be revealed. PMID:23939820

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

2014-02-01

84

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)

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.

Bashara, Haitham

2012-08-01

85

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

Energy Technology Data Exchange (ETDEWEB)

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 TE{sub 102} 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).

Ishii, Hiroshi; Ikeya, Motoji (Osaka Univ., Toyonaka (Japan). Dept. of Physics)

1990-05-01

86

Immediately loaded anterior single-tooth implants: two cases.  

Science.gov (United States)

Immediate loading of implants into fresh extraction sockets has the advantage of decreasing the period of healing, reducing the resorption of the alveolar bone, and achieving optimal esthetic results. These cases reveal the clinical success of immediate loaded single-tooth implants placed in fresh extraction sites. PMID:16160569

Tepret, Fulya; Sertgöz, Atilla; Basa, Selçuk

2005-09-01

87

The Human Sweet Tooth  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 techniq...

Reed Danielle R; McDaniel Amanda H

2006-01-01

88

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

"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 i...

Mh, Hosseini; Kamali A; Mahmoodzadeh Darbandi M

2010-01-01

89

Vertical tooth fracture: reunion with a miniature lag screw.  

Science.gov (United States)

The treatment and prognosis of teeth with crown root fracture are dictated solely by the extent of the fracture line. Vertical tooth fracture, a variant of crown root fracture, presents serious complications in management because of the extent of the fracture line to the full vertical length of the tooth. It is invariably followed by extraction of the entire or a segment of the tooth. Literature recommends various treatment possibilities for vertical tooth fracture, yet no predictable protocol with a long-term prognosis has been described. This case report details a multidisciplinary approach towards reunion of the fractured fragments of maxillary I premolar by providing interfragmentary compression with the use of a miniaturized lag screw. PMID:19722482

Rajan, R Mathan; Kandasamy, D; Kumar, P Suresh

2009-01-01

90

Electron paramagnetic resonance biophysical radiation dosimetry with tooth enamel  

International Nuclear Information System (INIS)

This thesis deals with the advancements made in the field of Electron Paramagnetic Resonance (EPR) for biophysical dosimetry with tooth enamel for accident, emergency, and retrospective radiation dose reconstruction. A methodology has been developed to measure retrospective radiation exposures in human tooth enamel. This entails novel sample preparation procedures with minimum mechanical treatment to reduce the preparation induced uncertainties, establish optimum measurement conditions inside the EPR cavity, post-process the measured spectrum with functional simulation of dosimetric and other interfering signals, and reconstruct dose. By using this technique, retrospective gamma exposures as low as 80±30 mGy have been successfully deciphered. The notion of dose modifier was introduced in EPR biodosimetry for low dose measurements. It has been demonstrated that by using the modified zero added dose (MZAD) technique for low radiation exposures, doses in 100 mGy ranges can be easily reconstructed in teeth that were previously thought useless for EPR dosimetry. Also, the use of a dose modifier makes robust dose reconstruction possible for higher radiation exposures. The EPR dosimetry technique was also developed for tooth samples extracted from rodents, which represent small tooth sizing. EPR doses in the molars, extracted from the mice irradiated with whole body exposures, were reassessed and shown to be correct within the experimental uncertainty. The sensitivity of human tooth enamel for neutron irradiation, obtained from the 3 MV McMaster K.N. Van de Graaff accelerator, was also studied. For the first time this work has shown that the neutron sensitivity of the tooth enamel is approximately 1/10th of the equivalent gamma sensitivity. Parametric studies for neutron dose rate and neutron energy within the available range of the accelerator, showed no impact on the sensitivity of the tooth enamel. Therefore, tooth enamel can be used as a dosimeter for both neutrons as well as gamma radiation. We will continue experiments to develop this end point as a sensitive accident or emergency tool for our response capabilities

2003-08-01

91

Learning about Charcot-Marie-Tooth Disease  

Science.gov (United States)

... Research 2003 News Release Learning About Charcot-Marie-Tooth Disease What do we know about Charcot-Marie- ... Disease What do we know about Charcot-Marie-Tooth disease? Charcot-Marie-Tooth disease (CMT) is an ...

92

The Human Sweet Tooth  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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,...

Reed, Danielle R.; Mcdaniel, Amanda H.

2006-01-01

93

Tooth loss in aggressive periodontitis: a systematic review.  

Science.gov (United States)

Aggressive periodontitis (AgP) is thought to have a faster rate of progression than chronic periodontitis (CP). However, there is a lack of studies systematically investigating disease progression and tooth loss in AgP. A systematic search of the literature was conducted by two independent reviewers for longitudinal studies including patients with AgP (previously known as 'periodontosis', 'juvenile' or 'early-onset' periodontitis) indicating measures of disease progression. Ovid MEDLINE(®) and Embase databases were searched for at least 5-year longitudinal human studies in AgP patients. In total, 16 studies were included in the review, from an initial search of 1,601 titles. Heterogeneity was detected for disease definition and clinical data reporting; hence meta-analysis was feasible only for the objective measure 'tooth loss'. The average tooth loss for all AgP cases was 0.09 (95% C.I. = 0.06-0.16) per patient-year. The corresponding values by diagnosis were 0.05, 0.14, and 0.12 tooth loss per patient-year, respectively, for LAgP, GAgP, and un-specified AgP. For studies reporting tooth loss during the 'observational period' (excluding extractions at initial therapy), the average tooth loss for AgP was 0.09 per patient-year. High heterogeneity was detected for these analyses. In conclusion, most studies report good long-term stability of treated AgP cases. PMID:23955159

Nibali, L; Farias, B C; Vajgel, A; Tu, Y K; Donos, N

2013-10-01

94

Role of multiple cusps in tooth fracture.  

Science.gov (United States)

The role of multiple cusps in the biomechanics of human molar tooth fracture is analysed. A model with four cusps at the bite surface replaces the single dome structure used in previous simulations. Extended finite element modelling, with provision to embed longitudinal cracks into the enamel walls, enables full analysis of crack propagation from initial extension to final failure. The cracks propagate longitudinally around the enamel side walls from starter cracks placed either at the top surface (radial cracks) or from the tooth base (margin cracks). A feature of the crack evolution is its stability, meaning that extension occurs steadily with increasing applied force. Predictions from the model are validated by comparison with experimental data from earlier publications, in which crack development was followed in situ during occlusal loading of extracted human molars. The results show substantial increase in critical forces to produce longitudinal fractures with number of cuspal contacts, indicating a capacity for an individual tooth to spread the load during mastication. It is argued that explicit critical force equations derived in previous studies remain valid, at the least as a means for comparing the capacity for teeth of different dimensions to sustain high bite forces. PMID:24755003

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

2014-07-01

95

Partial tooth gear bearings  

Science.gov (United States)

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.

Vranish, John M. (Inventor)

2010-01-01

96

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 pa [...] ra 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. Abstract in english 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.

Eleny, BALDUCCI-ROSLINDO; Karina Gonzales, SILVÉRIO; Daniela Mercaldi, MALAGOLI.

97

Tooth fragment reattachment technique on a pluri traumatized tooth  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This case report describes and analyses a tooth fragment reattachment technique used to resolve crown fractures of the anterior teeth. This treatment allows a conservative approach to traumatic coronal lesions offering a better possibility of maintaining aesthetics and function. The authors have illustrated here a clinical case of a fractured incisor. This case is characterized by several traumas on the same tooth that required different therapeutic solutions. We used an easy and ultra-conser...

Giudice, Giuseppe Lo; Lipari, Frank; Lizio, Angelo; Cervino, Gabriel; Cicciu?, Marco

2012-01-01

98

What Are Tooth Preservation Kits?  

Science.gov (United States)

... Visit KidsHealth in the Classroom What Other Parents Are Reading Checkups: What to Expect A Cold or ... Sports Breastfeeding FAQs Pregnant? Your Baby's Growth What Are Tooth Preservation Kits? KidsHealth > Parents > Sports Medicine Center > ...

99

Biomaterial Selection for Tooth Regeneration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Biomaterials are native or synthetic polymers that act as carriers for drug delivery or scaffolds for tissue regeneration. When implanted in vivo, biomaterials should be nontoxic and exert intended functions. For tooth regeneration, biomaterials have primarily served as a scaffold for (1) transplanted stem cells and/or (2) recruitment of endogenous stem cells. This article critically synthesizes our knowledge of biomaterial use in tooth regeneration, including the selection of native and/or s...

Yuan, Zhenglin; Nie, Hemin; Wang, Shuang; Lee, Chang Hun; Li, Ang; Fu, Susan Y.; Zhou, Hong; Chen, Lili; Mao, Jeremy J.

2011-01-01

100

NSAIDs in orthodontic tooth movement  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

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

2012-01-01

 
 
 
 
101

Fracture of tooth enamel from incipient microstructural defects.  

Science.gov (United States)

We present definitive evidence for crack growth from internal defects called 'tufts' in human enamel. Transverse slices (normal to the tooth axis) sawn from extracted human teeth are embedded in a polycarbonate sandwich configuration and tested in simple flexural loading. The evolution of ensuing cracks across the enamel sections is viewed in situ by a video camera. The observations unequivocally identify tufts as sources of internal tooth fracture. In sufficiently thin slices the enamel becomes translucent, allowing for through-thickness observations of the crack topography. Crack segments that appear to be disjointed on a section surface link up into a contiguous primary crack below the surface, suggesting some crack resistance by 'bridging' behind the advancing crack tip. The role of these and other microstructural factors in determining the resilience of tooth structures is considered. PMID:19878909

Chai, Herzl; Lee, James J-W; Lawn, Brian R

2010-01-01

102

The human sweet tooth.  

Science.gov (United States)

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, mice, cats and primates to understand the origins of sweet taste perception. Our studies demonstrate that there are two sweet receptor genes (TAS1R2 and TAS1R3), and alleles of one of the two genes predict the avidity with which some mammals drink sweet solutions. We also find a relationship between sweet and bitter perception. Children who are genetically more sensitive to bitter compounds report that very sweet solutions are more pleasant and they prefer sweet carbonated beverages more than milk, relative to less bitter-sensitive peers. Overall, people differ in their ability to perceive the basic tastes, and particular constellations of genes and experience may drive some people, but not others, toward a caries-inducing sweet diet. Future studies will be designed to understand how a genetic preference for sweet food and drink might contribute to the development of dental caries. PMID:16934118

Reed, Danielle R; McDaniel, Amanda H

2006-01-01

103

TOOTH-BASED IDENTIFICATION OF INDIVIDUALS  

Directory of Open Access Journals (Sweden)

Full Text Available The use of automated biometrics-based personal identification systems is an omnipresent procedure. Many technologies are no more secure, and they have certain limitations such as in cases when bodies are decomposed or burned. Dental enamel is one of the most mineralized tissues of an organism that have a post-mortem degradation resistance. In this article we describe the dental biometrics which utilizes dental radiographs for human identification. The dental radiographs provide information about teeth, including tooth contours, relative positions of neighboring teeth, and shapes of the dental work (crowns, fillings, and bridges. Then we propose a new system for the dental biometry that consists of three main stages: segmentation, features extraction and matching. The features extraction stage uses grayscale transformation to enhance the image contrast and a mixture of morphological operations to segment the dental work. The matching stage consists of the edge and the dental work comparison.

Charbel Fares

2013-01-01

104

Human tooth bank: sociocultural profile of a group of donors  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: To survey the sociocultural profile of a specific group of individuals who donated teeth to the Human Tooth Bank of Positivo University, Curitiba, Paraná, Brazil. Methods: The research consisted of a questionnaire containing the following information about: Patient’s age, sex, occupation, education, reason for tooth loss and intention to replace the missing tooth by means of prosthesis or implant. The questionnaire was filled out by 50 patients after having the extraction procedure performed and donating the dental organ. The data were compiled and analyzed by means of descriptive and multivariate statistics. Results: The sociocultural profile of the donor was basically composed of individuals in the age group between 30 and 50 years, with educational level ranging from zero to nine or more years of formal schooling. Caries disease was the most frequent reason for tooth loss (36%, followed by periodontal disease (34%. Of the donors analyzed, more than half did not intend to replace the tooth. Furthermore, according to the multivariate analysis, the most relevant factors for assessing the profile of donors were the variables age, orthodontic indication, caries and periodontal disease. Conclusion: This information was shown to be relevant for structuring the oral health care services, as well as in the strategy for obtaining teeth from the Public Health Units.

Mariane Moreira Poletto

2010-04-01

105

Development of transplanted pulp tissue containing epithelial sheath into a tooth-like structure.  

Science.gov (United States)

The aim of these studies was to find out whether intact neonatal pulp tissue containing residual epithelial cells can induce the development of a tooth-like structure in situ. First maxillary neonatal hamster molar pulps containing adhering undifferentiated epithelial cells were transplanted submucosally in the oral cavity of recipient mothers for periods ranging from 2-8 weeks and the tissues were then processed for light microscopy. Developing tooth-like structures containing mineralised tubular dentine, predentine and a vascularised pulp-like chamber lined with functional odontoblast-like cells were observed in the specimens within 2 weeks of transplantation. Enamel and root formation were not observed. These data indicate that neonatal dental pulp tissues containing epithelial cell remnants have the capacity to develop into tooth-like structures and that this could be the explanation for the development of tooth-like structures sometimes observed in infants after extraction of a natal tooth. PMID:10432194

Lyaruu, D M; van Croonenburg, E J; van Duin, M A; Bervoets, T J; Wöltgens, J H; de Blieck-Hogervorst, J M

1999-08-01

106

Safety controversies in tooth bleaching.  

Science.gov (United States)

Tooth bleaching using peroxide-based materials is an effective procedure in dentistry. Studies provide evidence on the safety of bleaching by dental professionals. However, concerns and controversy remain regarding the safety of bleaching systems that do not involve dental professionals, especially those available at mall kiosks, salons, spas, and cruise ships. Bleaching causes tooth sensitivity and/or gingival irritation in a significant portion of patients. Bleaching requires proper examination, diagnosis, and treatment plan, which can be performed appropriately only by dental professionals; therefore, involvement of dental professionals in bleaching is necessary to maximize the efficacy and minimize potential risks. PMID:21473992

Li, Yiming

2011-04-01

107

Biology of tooth replacement in amniotes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tooth replacement is a common trait to most vertebrates, including mammals. Mammals, however, have lost the capacity for continuous tooth renewal seen in most other vertebrates, and typically have only 1–2 generations of teeth. Here, we review the mechanisms of tooth replacement in reptiles and mammals, and discuss in detail the current and historical theories on control of timing and pattern of tooth replacement and development.

Whitlock, John A.; Richman, Joy M.

2013-01-01

108

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

Directory of Open Access Journals (Sweden)

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.

Jamileh Beygom Taheri

109

Accuracy of the orthopantomogram in assessment of tooth length in orthodontic patients.  

Science.gov (United States)

The orthopantomogram (OPG) provides as assessment of root length and characteristics before orthodontic tooth movement. This study determined the accuracy of the OPG in assessing tooth length. Investigators compared the radiographic and actual tooth lengths in permanent first premolars indicated for orthodontic extractions. Results showed that the mean lengths measured from OPG were consistently higher than the actual lengths by 22% (p < 0.001) for maxillary teeth and by 1% for mandibular teeth. This study found that there is elongation of root images in OPG. PMID:11699368

Lien, L C; Soh, G

2000-12-01

110

Tooth Avulsion in the School Setting  

Science.gov (United States)

Tooth avulsions occur when a tooth is displaced from its socket. Tooth avulsions are common dental injuries that may occur before, during, or after school. Therefore, it is essential that school nurses be well prepared to intervene when such a dental emergency arises. It is also imperative that school nurses and school personnel are fully equipped…

Krause-Parello, Cheryl A.

2005-01-01

111

Anterior fixed interim prosthesis with natural tooth crown as pontic subsequent to replantation failure  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Facial trauma resulting in tooth avulsion results in problems of physical and emotional nature for the patient and a challenge for the dentist. Avulsion accounts for 0.5–16% of traumatic injuries in the permanent dentition that can occur at any age and is most common in the young permanent dentition. As an emergency procedure, it is advisable to replant a traumatically avulsed tooth, but unfortunately long-term success is rather low. After unsuccessful replantation and subsequent extraction...

Nuvvula, Sivakumar; Mohapatra, Abinash; Kiranmayi, M.; Rekhalakshmi, K.

2011-01-01

112

A multidisciplinary approach to the management of a subgingivally fractured tooth: a clinical report.  

Science.gov (United States)

Anterior tooth fracture is the most common type of trauma occurring to the dental tissues. Teeth fracturing at or below the gingival level usually have a poor prognosis, with extraction of the tooth being the most probable outcome. Clinical crown lengthening followed by prosthetic rehabilitation is a promising approach toward such cases. The clinical report presented here explains in detail the various treatment modalities available for such cases with special emphasis on orthodontic extrusion/forced eruption. PMID:21284765

Goenka, Puneet; Marwah, Nikhil; Dutta, Samir

2011-04-01

113

Capacity of Dental Pulp Differentiation in Mouse Molars as Demonstrated by Allogenic Tooth Transplantation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dental pulp elaborates both bone and dentin under pathological conditions such as tooth replantation/transplantation. This study aims to clarify the capability of dental pulp to elaborate bone tissue in addition to dentin by allogenic tooth transplantation using immunohistochemistry and histochemistry. After extraction of the molars of 3-week-old mice, the roots and pulp floor were resected and immediately allografted into the sublingual region in a littermate. In addition, we studied the con...

Takamori, Yasuhiko; Suzuki, Hironobu; Nakakura-ohshima, Kuniko; Cai, Jinglei; Cho, Sung-won; Jung, Han-sung; Ohshima, Hayato

2008-01-01

114

Immediate Implant in Management of Anterior Missing Tooth  

Directory of Open Access Journals (Sweden)

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.

Harinath Reddy S

2010-04-01

115

Fluoridation and tooth wear in Irish adults.  

LENUS (Irish Health Repository)

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.

Burke, F M

2010-10-01

116

Charcot–Marie–Tooth disease  

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Charcot-Marie-Tooth (CMT) disease is a heterogeneous group of genetic disorders presenting with the phenotype of a chronic progressive neuropathy affecting both the motor and sensory nerves. During the last decade over two dozen genes have been identified in which mutations cause CMT. The disease illustrates a multitude of genetic principles, including diverse mutational mechanisms from point mutations to copy number variation (CNV), allelic heterogeneity, age-dependent penetrance and variabl...

Szigeti, Kinga; Lupski, James R.

2009-01-01

117

Periodontal regeneration after tooth autotransplantation.  

Czech Academy of Sciences Publication Activity Database

. Olomouc : -, 2008 - (Bezdi?ková, M.; Molíková, R.). s. 163-163 ISBN 978-80-244-2061-5.[Morphology 2008. Lojda Symposium on Histochemistry /45./. 08.09.2008-10.09.2008, Olomouc]Grant CEP: GA ?R GC524/08/J032Výzkumný zám?r: CEZ:AV0Z50450515Klí?ová slova: tooth autotransplantationKód oboru RIV: FF - ORL, oftalmologie, stomatologie

Štembírek, Jan; Kanovská, K.; Navrátil, M.; Pokorná, M.; Roubalíková, L.; Míšek, Ivan

118

Charcot-Marie-Tooth disease.  

LENUS (Irish Health Repository)

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.

Reilly, Mary M

2011-03-01

119

Prevalence and reasons for tooth loss in a sample from a dental clinic in Brazil.  

Science.gov (United States)

Purpose. To evaluate the prevalence and reasons for teeth extractions in a sample from a dental clinic in Brazil. Methods. The prevalence of teeth mortality was analyzed by gender, age, tooth type and reasons for extraction on 800 teeth of 439 subjects, whose data was collected in clinical records in a convenience sample. Results. The groups with range from 35 to 44 years, 45 to 54 years and 55 to 64 years revealed significantly greater number of teeth extractions than other age groups (P < 0.0001). The anterior teeth loss increased significantly with aging, while the tooth mortality of premolar and molar were higher in younger people. The caries was the more prevalent reason for tooth mortality among young and adults up to 44 years old, while the periodontal disease was the main reason for extractions from 45 years old until range of 81 years (P < 0.0001). Conclusions. It can be suggested that some reasons for tooth loss were age-dependent, but the caries and the periodontal diseases were the main reasons for tooth mortality in this Brazilian sample. PMID:22973312

Montandon, Andréia; Zuza, Elizangela; Toledo, Benedicto Egbert

2012-01-01

120

Prosthetic clone and natural human tooth comparison by speckle interferometry  

Science.gov (United States)

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.

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

2010-09-01

 
 
 
 
121

Bender-type tooth-movement transducer  

Energy Technology Data Exchange (ETDEWEB)

A tooth-movement transducer using bender-type piezoelectric ceramics was developed for the measurement probe of the Tooth Mobility tester. It is small, light and suitable for oral examination and it is possible to evaluate the tooth mobility of a molar in the direction of the tooth axis. The transducer utilizes a set of, long and rectangular ceramic beam. It includes two supporting points and it is possible to adjust the resonance frequency by moving two points. This frequency is applied as the measuring frequency. The basic characteristics of the transducer and clinical applicability of the measurement probe are confirmed using an artificial tooth model and human tooth. 10 refs., 7 figs., 1 tab.

Oka, H.; Shimizu, Y. [Osaka University, Osaka (Japan); Saratani, K.; Kawazoe, T. [Osaka Dental University, Osaka (Japan); Shi, S.

1997-12-20

122

Comparative analysis of aspartic acid racemization methods using whole-tooth and dentin samples.  

Science.gov (United States)

One way to estimate biological age is to use the aspartic acid (Asp) racemization method. Although this method has been performed mostly using enamel and dentin, we investigated whether an entire tooth can be used for age estimation. This study used 12 pairs of canines extracted from both sides of the mandible of 12 individuals of known age. From each pair, one tooth was used as a dentin sample and the other as a whole-tooth sample. Amino acids were extracted from each sample, and the integrated peak areas of D-Asp and L-Asp were determined using a gas chromatograph/mass spectrometer. Statistical analysis was performed using the D/L-Asp ratio. Furthermore, teeth from two unidentified bodies, later identified as Japanese and Brazilian, were examined in the same manner. Results showed that the D/L ratios of whole-tooth samples were higher overall than those of dentin samples. The correlation coefficient between the D/L ratios of dentin samples and their age was r=0.98, and that of the whole-tooth samples was r=0.93. The difference between estimated age and actual chronological age was -0.116 and -6.86 years in the Japanese and Brazilian cases, respectively. The use of whole teeth makes the racemization technique easier and can standardize the sampling site. Additionally, using only a few tooth samples per analysis made it possible to reanalyze known-age samples. Although the difficulty in obtaining a proper control sample has prevented racemization from being widely used, the method described here not only ensures the availability of a control tooth, but also enables the teeth to be used for other purposes such as DNA analysis. The use of a whole tooth will increase the application of the racemization technique for age determination. PMID:22989598

Sakuma, Ayaka; Ohtani, Susumu; Saitoh, Hisako; Iwase, Hirotaro

2012-11-30

123

Molecular Genetics of Supernumerary Tooth Formation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite advances in the knowledge of tooth morphogenesis and differentiation, relatively little is known about the aetiology and molecular mechanisms underlying supernumerary tooth formation. A small number of supernumerary teeth may be a common developmental dental anomaly, while multiple supernumerary teeth usually have a genetic component and they are sometimes thought to represent a partial third dentition in humans. Mice, which are commonly used for studying tooth development, only exhib...

Wang, Xiu-ping; Fan, Jiabing

2011-01-01

124

Asymmetric extractions in orthodontics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 Portugue...

Camilo Aquino Melgaço; Mônica Tirre de Souza Araújo

2012-01-01

125

Rock bit cutter tooth design and analysis  

Energy Technology Data Exchange (ETDEWEB)

The finite element method was used to analyze the stresses in a rock bit cutter tooth under applied loads. Detailed finite element models were constructed to allow accurate descriptions of the structural material properties of a tooth design which includes carburization and hard metal application. Numerical solutions were obtained for investigating stress concentrations and plastic region growths in a cutter tooth when loaded beyond its yield point. It was found that the finite element method can be a powerful tool for improving the performance of a cutter tooth. Design objectives can be achieved through parametric studies of stress level variations against geometry and material property changes on a computer system.

Feng, C.C.; Schumacher, P.W.

1983-01-01

126

[Mathematical investigations of the functional tooth axis].  

Science.gov (United States)

The functional tooth axis is--contrary of the anatomical tooth axis--defined as follows: The effect of force in its direction causes a maximum of desmodontal fibres being stressed on drawing. After measure of an upper caninus, an upper and a lower molar mathematical models of the teeth and the desmodont of force are calculated with a computer simulation. A variety of functional tooth axes which are not identical with the anatomical ones, result for each tooth. The possible functional axes yield a variety which signifies the biological tolerance. This tolerance causes that many individual forms of occlusion don't have any pathological effect on the desmodont. PMID:1816808

Reiber, T; Buchmann, F

1991-01-01

127

21 CFR 872.3590 - Preformed plastic denture tooth.  

Science.gov (United States)

...2010-04-01 false Preformed plastic denture tooth. 872.3590 Section 872.3590 Food...872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture tooth is a prefabricated device, composed...

2010-04-01

128

21 CFR 872.3580 - Preformed gold denture tooth.  

Science.gov (United States)

...2009-04-01 false Preformed gold denture tooth. 872.3580 Section 872.3580 Food...Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of austenitic...

2009-04-01

129

21 CFR 872.5525 - Preformed tooth positioner.  

Science.gov (United States)

...2009-04-01 2009-04-01 false Preformed tooth positioner. 872.5525 Section 872...Therapeutic Devices § 872.5525 Preformed tooth positioner. (a) Identification. A preformed tooth positioner is a plastic device that...

2009-04-01

130

About Kids' Teeth: Baby Tooth Decay is Real  

Medline Plus

Full Text Available ... Tooth Decay Thumb sucking Prevent Decay Nutrition Baby Tooth Decay Is Real As soon as teeth appear in ... news – decay is mostly preventable . What Are Cavities? Causes of Decay Tooth decay begins when cavity- ...

131

Tooth use in Aboriginal Australia  

Directory of Open Access Journals (Sweden)

Full Text Available The study of dental casts taken from living people avoids the ethical problems of research into human remains, while providing valuable information about diet and life styles. This article describes a study of tooth wear in dental casts of three different groups of Australian Aborigines. The authors describe their methods of recording and report differential patterns of wear in the different groups. Preliminary interpretation relates the wear patterns both to diet and to the use of teeth as tools in a range of cultural activities, results which are potentially relevant to other groups of hunter-gatherers, past and present.

Anna Clement

2008-09-01

132

Investigation of EPR signals on tooth enamel  

Science.gov (United States)

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.

Pavlenko, A.; Mironova-Ulmane, N.; Polakov, M.; Riekstina, D.

2007-12-01

133

Investigation of EPR signals on tooth enamel  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2007-12-15

134

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

2007-12-01

135

Controlling the Number of Tooth Rows  

Science.gov (United States)

The organization and renewal capacity of teeth vary greatly among vertebrates. Mammals have only one row of teeth that are renewed at most once, whereas many nonmammalian species have multirowed dentitions and show remarkable capacity to replace their teeth throughout life. Although knowledge on the genetic basis of tooth morphogenesis has increased exponentially over the past 20 years, little is known about the molecular mechanisms controlling sequential initiation of multiple tooth rows or restricting tooth development to one row in mammals. Mouse genetics has revealed a pivotal role for the transcription factor Osr2 in this process. Loss of Osr2 caused expansion of the expression domain of Bmp4, a well-known activator of tooth development, leading to the induction of supernumerary teeth in a manner resembling the initiation of a second tooth row in nonmammalian species.

Marja L. Mikkola (University of Helsinki;Institute of Biotechnology REV)

2009-08-25

136

A Radiographic method for determining the actual tooth length  

International Nuclear Information System (INIS)

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).

1995-08-01

137

EPR-dosimetry with tooth enamel for low doses  

International Nuclear Information System (INIS)

Results are presented for electron paramagnetic resonance (EPR) dosimetry with tooth enamel that focus on the dose region below 100 mGy. Three uncontaminated molars were gamma-irradiated in steps of 10-100 mGy and then in larger steps to 400 mGy. The spectra were evaluated using a deconvolution method including a simulated powder spectrum for extracting the dose related EPR signal of tooth enamel. The dose related signal intensity and the variability between samples were evaluated to investigate the feasibility to reconstruct irradiation doses below 100 mGy. Averaged signal amplitudes as well as the signal amplitudes for single sample were analysed. The performance parameters, critical dose and limit of detection, were calculated and compared with the averaged signal amplitudes of sets of five samples of a pool of mixed tooth samples originating from the same source but irradiated from 100 to 1500 mGy. The values of performance parameters were found to depend on the number and type of samples included in assessment. The evaluated critical dose varied between 131 and 50 mGy for measurements of single sample, and 73 and 33 mGy for average amplitudes of three and five samples, respectively. For exposures below 100 mGy the dose related EPR-signal amplitude was found to correlate with the applied dose only for one of three samples for which the evaluated critical dose was 50 mGy

2008-02-01

138

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

1992-01-01

139

Dynamic influences of changing gear tooth stiffness  

Energy Technology Data Exchange (ETDEWEB)

One of the principal sources of vibratory excitation of gear a system is due to the angular speed fluctuation of meshing gears due to non-linearities and profile errors and tooth and supporting bearings flexibility. The transmission error is also influenced by the varying force at the contact point of the meshing gear teeth. The varying contact force itself is influenced by the varying tooth stiffness due to change of orientation of teeth relative to each other, during the contact phase of each pair. This paper presents a simplified single degree of freedom gear system. It is assumed that one member of the gear pair is rigid and flexibility of the gear tooth is attributed only to one section of the gear system. This enables the equation to be simplified to a single degree of freedom system. The resulting non-linear equation is solved iteratively by employing a method which combines piecewise linearization for the stiffness and resulting contact orientation shift due to shaft and tooth flexibility. The contact shift will be referred as the phase shift in this report. The early finding indicates that there are significant differences between the response of the system incorporating three different tooth stiffness, namely, constant tooth stiffness, rectangular wave tooth stiffness and sinusoidal tooth stiffness. The results also implies that any design specification associated with gears has to include gear tooth influences, especially if the excitation is of a major concern. The rectangular stiffness variation which most accurately describes the tooth stiffness gives a response fluctuation, studied in the frequency domain shows that the effective natural frequencies fluctuates between certain upper and lower limits. Thus the paper suggest that any design study should consider these limits.

Morguel, O.K. [Sakarya Univ. (Turkey). Dept. of Mechanical Engineering; Esat, I. [Brunel Univ., Uxbridge (United Kingdom). Dept. of Mechanical Engineering

1997-07-01

140

Comparisons of debonding forces between different tooth types.  

Directory of Open Access Journals (Sweden)

Full Text Available Following the introduction of the direct bonding of orthodontic brackets to enamel, numerous studies were designed to investigate the bonding characteristics of various adhesive systems. In these studies, different tooth types were used for testing including, incisors, premolars and molars. A confounding factor was related to the effect of using different tooth types on bond strength. The purpose of the present study was to compare the shear bond strength of orthodontic brackets to the enamel surface of various tooth types, while eliminating the influence of other extraneous variables such as differences in the adhesive system used and variation in the bracket base design. Sixty freshly extracted human teeth including 20 molars, 20 premolars, and 20 incisors were similarly prepared for bonding. The same orthodontic bonding system was used to bond the same type of metal brackets to all the teeth. The teeth were then stored in distilled water for 48 hours. An Instron Testing Machine was used to measure shear bond strength in Megapascals. The Analysis of Variance was used to compare the three groups. The comparisons of the shear bond strength for incisors (x=12.4+6.5 MPa, premolars (x=11.9+5.2 MPa and third molars (x=13.1+6.2 MPa indicted that they were not significantly different (p=0.84. In conclusion, the findings indicate that in vitro testing of bond strength is not significantly agecte.9y the use of various tooth types namely, incisors, premolars and molars. This finding suggests that investigators can use teeth that are more readily available e.g. third molars to test bond strength.

S.E Bishara

1999-01-01

 
 
 
 
141

Establishment of quantitative diagnosis about radiopacity of tooth. Measurement of dentin mineral density by CT  

International Nuclear Information System (INIS)

In measuring the dentin mineral density (DMD), X-ray absorptiometry using slices of tooth after tooth extraction (the Slice method) is used conventionally. Because it takes time and must extract a tooth, these methods are limited to usable cases. Therefore we investigated a method to measure DMD by CT scan (the CT method). Cervical dentin in the alveolar bone was measured to avoid the influence by the beam hardening effect. The area where DMD value showed a plateau was measured to avoid the influence of the partial volume effect. DMD by CT method accorded with Slice method with a difference of 1.2%. Using this CT method, a difference of DMD among kind of tooth in the same individual was measured in 16 cases without metal restoration or prosthetic appliance in Ohu University Hospital. There were a few differences in DMD and the standard deviation of a measured value was about around 1.5%. Thus, it is suggested that all kind of tooth are useful as diagnostic standard and the CT value of dentine is effective if measured using the CT method. (author)

2004-06-01

142

Assessment of proprioceptive allodynia after tooth-clenching exercises  

DEFF Research Database (Denmark)

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.

Dawson, Andreas; List, Thomas

2012-01-01

143

Three Ways To Be a Saber-Toothed Cat  

Science.gov (United States)

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.

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

144

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

Directory of Open Access Journals (Sweden)

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.

Park Jun-Beom

2010-01-01

145

Impacted supernumerary tooth in coronoid process: a case report  

International Nuclear Information System (INIS)

Impaction of tooth is a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise located so that it cannot erupt normally. The supernumerary tooth is also called as hyperdontia and defined as the condition of having additional tooth to the regular number of teeth. The most common supernumerary tooth is a mesiodens, which is a mal-formed, peg-like tooth that occurs between the maxillary incisors. The supernumerary tooth is commonly impacted but they are frequently impacted on maxilla. Ectopic impaction of supernumerary tooth on mandibular condyle, coronoid process, ascending ramus, and pterygomandibular space is very rare condition. In this case, we report a case of impacted supernumerary tooth on mandibular sigmoid notch without definite pathologic change.

2010-06-01

146

Impacted supernumerary tooth in coronoid process: a case report  

Energy Technology Data Exchange (ETDEWEB)

Impaction of tooth is a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise located so that it cannot erupt normally. The supernumerary tooth is also called as hyperdontia and defined as the condition of having additional tooth to the regular number of teeth. The most common supernumerary tooth is a mesiodens, which is a mal-formed, peg-like tooth that occurs between the maxillary incisors. The supernumerary tooth is commonly impacted but they are frequently impacted on maxilla. Ectopic impaction of supernumerary tooth on mandibular condyle, coronoid process, ascending ramus, and pterygomandibular space is very rare condition. In this case, we report a case of impacted supernumerary tooth on mandibular sigmoid notch without definite pathologic change.

Park, Won Se; Lee, Je Ho; Park, Hyok; Jung, Ho Gul; Kim, Kee Deog [Yonsei University College of Dentistry, Seoul (Korea, Republic of)

2010-06-15

147

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

LENUS (Irish Health Repository)

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.

McNamara, C M

1997-09-01

148

Genetics And Tooth Anomalies - An Update  

Directory of Open Access Journals (Sweden)

Full Text Available Tooth development like the development of all epithelial appendages is regulated by inductive tissue interactions between epithelium and mesenchyme. Numerous genes interact, either act in conjunction or antagonize each other in odontogenesis. A number of different mesenchymal molecules and their receptors act as mediators in epithelial mesenchymal interactions. Several genes linked with early tooth positioning and developments belong to signaling pathways and have morphogenesis regulatory functions in morphogenesis of other organs. Their mutations often show pleiotropic effects beyond dental morphogenesis. In contrast, certain genes involved in enamel and dentin structures are highly specific for tooth. Mutations in these genes have been identified as causes of Amelogenesis Imperfecta (AI, Dentinogenesis Imperfecta (DI, Dentin Dysplasia (DD and anomalies in tooth number. This article focuses on genetic basis of inherited non-syndromic teeth disorders.

Aswathy Brahmanandan

2013-01-01

149

Lead levels among various deciduous tooth types  

Energy Technology Data Exchange (ETDEWEB)

The amount of lead in deciduous teeth has been used extensively as a marker for infant lead exposure and body burden. However, the pattern of lead abundances among the various tooth positions in a child's mouth appears to be non-uniform. Taken together these findings show an apparently inconsistent pattern among the tooth types. These comparisons are complicated by different research groups using different portions of the tooth. This issue is of significance to those who wish to compare the lead burden of children but have available teeth from different positions from the various children. By examining a large number of teeth from two different populations, the authors hope to explore the more universal aspects of any variability among tooth types.

Rabinowitz, M.B. (Children' s Hospital, Boston, MA (United States) National Taiwan Univ., Taipei (Taiwan)); Bellinger, D.; Leviton, A. (Children' s Hospital, Boston, MA (United States)); Jungder Wang (National Taiwan Univ., Taipei (Taiwan))

1991-10-01

150

Sports Safety: Avoiding Tooth and Mouth Injuries  

Science.gov (United States)

Sports Safety: Avoiding Tooth and Mouth Injuries A few years ago, a dental newsletter published what seemed ... the perfect dunk. In older children and adults, sports injuries are common. Dentists estimate that between 13% ...

151

Life of a Tooth: A Visual Timeline  

Medline Plus

Full Text Available ... InfoBites Quick Reference Learn more Sports and Oral Health What is Baby Bottle Tooth Decay? What is Dental Amalgam (Silver Filling)? Why is Oral Health Important for Men? Men: Looking for a Better ...

152

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)

2002-09-01

153

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

Energy Technology Data Exchange (ETDEWEB)

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 {gamma}-ray dose of {sup 60}Co 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)

Shiraishi, Kunio; Yonehara, Hidenori; Matsumoto, Masaki [National Inst. of Radiological Sciences, Chiba (Japan); Iwasaki, Midori; Miyazawa, Chyuzo [Ohu Univ., Koriyama, Fukushima (Japan). School of Dentistry

2002-09-01

154

Gene Expression Profiling during Murine Tooth Development  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this study was to describe the expression of genes, including ameloblastin (Ambn), amelogenin X chromosome (Amelx), and enamelin (Enam) during early (pre-secretory) tooth development. The expression of these genes has predominantly been studied at post-secretory stages. Deoxyoligonucleotide microarrays were used to study gene expression during development of the murine first molar tooth germ at 24?h intervals, starting at the 11th embryonic day (E11.5), and up to the 7th day afte...

Landin, Maria A. Dos Santos Silva; Shabestari, Maziar; Babaie, Eshrat; Reseland, Janne E.; Osmundsen, Harald

2012-01-01

155

Computer simulation of gear tooth manufacturing processes  

Science.gov (United States)

The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.

Mavriplis, Dimitri; Huston, Ronald L.

1990-01-01

156

Multivariate image analysis of laser-induced photothermal imaging used for detection of caries tooth  

Science.gov (United States)

Time-resolved photothermal imaging has been investigated to characterize tooth for the purpose of discriminating between normal and caries areas of the hard tissue using thermal camera. Ultrasonic thermoelastic waves were generated in hard tissue by the absorption of fiber-coupled Q-switched Nd:YAG laser pulses operating at 1064 nm in conjunction with a laser-induced photothermal technique used to detect the thermal radiation waves for diagnosis of human tooth. The concepts behind the use of photo-thermal techniques for off-line detection of caries tooth features were presented by our group in earlier work. This paper illustrates the application of multivariate image analysis (MIA) techniques to detect the presence of caries tooth. MIA is used to rapidly detect the presence and quantity of common caries tooth features as they scanned by the high resolution color (RGB) thermal cameras. Multivariate principal component analysis is used to decompose the acquired three-channel tooth images into a two dimensional principal components (PC) space. Masking score point clusters in the score space and highlighting corresponding pixels in the image space of the two dominant PCs enables isolation of caries defect pixels based on contrast and color information. The technique provides a qualitative result that can be used for early stage caries tooth detection. The proposed technique can potentially be used on-line or real-time resolved to prescreen the existence of caries through vision based systems like real-time thermal camera. Experimental results on the large number of extracted teeth as well as one of the thermal image panoramas of the human teeth voltanteer are investigated and presented.

El-Sherif, Ashraf F.; Abdel Aziz, Wessam M.; El-Sharkawy, Yasser H.

2010-08-01

157

Forty-five-year tooth survival probabilities among men in Oslo, Norway.  

Science.gov (United States)

Changes in tooth survival probabilities over a person's lifetime have remained largely unexplored. The goal of this study was to evaluate changes in the 45-year tooth survival probabilities in a cohort of 565 Norwegian males who were examined in 1969 as young adults, and followed up into mid-life (examination years and sample sizes (n): 1971 (n = 381), 1973 (n = 292), 1975 (n = 245), 1981 (n = 228), 1988 (n = 202), and 1995 (n = 223). The results indicated that the tooth survival probabilities varied considerably both (i) among teeth within individuals, and (ii) over time. The 45-year survival probabilities for the 28 teeth fell into the following ranges: larger than 95% for incisors and cuspids; between 84% and 92% for premolars; and between 59% and 96% for molars. Over the first 4 post-eruptive decades, the tooth mortality risks (excluding orthodontic extractions) were: 1st decade, 2.0% (from 1.7 to 2.4%); 2nd decade, 0.2% (from 0.1 to 0.4%); 3rd decade, 0.6% (from 0.4 to 0.8%); and 4th decade, 1.1% (from 0.8 to 1.5%). The tooth mortality risks in the 2nd, 3rd, and 4th decades were probably somewhat underestimated (due to dropout bias), suggesting that the true underlying tooth mortality hazard function may have been V-shaped. The conclusions were that the tooth mortality hazard during the first 4 post-eruptive decades was bathtub-shaped and that it varied considerably among teeth within individuals. PMID:9839791

Hujoel, P P; Löe, H; Anerud, A; Boysen, H; Leroux, B G

1998-12-01

158

Tooth design to avoid shearing stresses  

Energy Technology Data Exchange (ETDEWEB)

Teeth disposed on the bit face of a rotating bit are, angularly oriented on the sloping surface of the bit face such that a vertical loading force which is applied to each tooth vectorially sums with a wedging force exerted by the rock formation on each tooth to create a resultant force applied to the diamond cutting element included within the tooth. The angular orientation of the tooth is chosen such that the resultant force is applied to the diamond cutting element in a direction which minimizes shear stress on the element. For example, in the case where the diamond cutting element is an equilateral triangular prismatic element tangentially set on the bit face with one apical edge defined by two adjacent triangular sides outermost on the tooth, the orientation or inclination of the tooth with respect to the vertical loading force and wedge force is such that the resulting force lies near or on the disector of the dihedral angle formed by the apical edge. Similarly, the diamond cutting element is rearwardly raked in the longitudinal direction, generally parallel to the tangential motion during normal drilling as defined by the rotation of the bit, such that the vectorial sum of the vertical loading force in a reactive cutting force applies a resultant force on the diamond cutting element in a direction which minimizes shear stress, namely, in the example in a direction approximately perpendicular to one of the end faces of the triangular prismatic diamond cutting element.

Mengel, H. E.; Munzel, H.

1985-05-07

159

Prevalence of tooth transposition in Greek population.  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: To investigate the prevalence of tooth transposition in a sample of Greek dental patients. STUDY DESIGN: Epidemiological study. TIME AND PLACE OF ACTION: Prefecture of Drama, time period 2001-2006. MATERIALS AND METHODS: The first author examined in her private practice 2034 consecutive patients seeking dental treatment. Patients with nationality other than Greek, individuals below 13 years of age with primary or mixed dentitions, patients without panoramic radiographs, patients with syndromes, as well as those who had more than one permanent tooth missing were excluded from the initial sample. In total, 1113 patients were assessed (288 men, 825 women with a mean age of 36.1 years (range: 13.1-73.0 years. MAIN MEASUREMENTS: Tooth transposition was investigated my means of clinical examination through observation and palpation, as well as with radiographic examination using panoramic radiographs. Results were analyzed with descriptive statistics. RESULTS: In total, only one case was found with tooth transposition presenting complete bilateral transposition between canine - lateral incisor in the maxilla. The percentage of patients with tooth transposition in the total dental population examined was 0.09%. The prevalence of this phenomenon in females was 0.12%, whereas in males it was 0%. Men / women ratio was found 0:1. CONCLUSIONS: Tooth transposition in Greek population is rather rare, it is most often encountered in females and concerns mostly maxillary canines and lateral incisors.

Maria Hatzoudi

2006-01-01

160

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

2002-06-24

 
 
 
 
161

An Alternative Efficient Technique For Thin Tooth Sectioning  

Directory of Open Access Journals (Sweden)

Full Text Available Background: The importance of tooth sectioningis realized in disasters such as earthquake, airplanecrash investigation, terror, micro leakage studies, ageestimation etc. The objective of this study was to developa simple method to make thin sections (approximately100 mm from freshly extracted teeth.Methods: One hundred and twenty human premolarsrecently extracted for orthodontic purpose were used forthis study. The teeth were stored in 0.5% chorlaraminefor 2 weeks and were not allowed to dry at any stageof the experiment. The teeth were thoroughly washedin distilled water teeth and then were sectionedbuccolingually from crown to the root portion.Results: A detailed embedding-cutting-mountingprocedure is described. The prepared thin groundsections were then examined under a Polarised lightmicroscope for the enamel and the dentine, as well asthe caries lesions can clearly be distinguished.Conclusion: This is an effective and efficient methodfor preparation of ground sections in which the hardtissue details are preserved.

Muneer Gohar Babar

2011-06-01

162

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

Directory of Open Access Journals (Sweden)

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.

B. Rahsepar

2005-02-01

163

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)

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.

Kokovi? Vladimir

2011-01-01

164

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.

2009-04-01

165

Hydroxyapatite coating on damaged tooth surfaces by immersion  

Energy Technology Data Exchange (ETDEWEB)

Hydroxyapatite (HAp) was coated on scratched areas of a human tooth and HAp disks by the immersion method in a HAp colloidal solution (<=20{mu}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 Ca{sup 2+} 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 Ca{sup 2+} 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.

Lim, Byoung-Ki; Ryu, Su-Chak [Department of Nanomaterials Engineering, College of Nanoscience and Nanotechnology, Pusan National University, Miryang, 607-706 (Korea, Republic of); Sun, Fangfang; Koh, Kwangnak; Han, Dong-Wook; Lee, Jaebeom, E-mail: jaebeom@pusan.ac.k [Department of Nanomedical Engineering, College of Nanoscience and Nanotechnology, Pusan National University, Miryang, 607-706 (Korea, Republic of)

2009-04-15

166

Detecting Tooth Damage in Geared Drive Trains  

Science.gov (United States)

This paper describes a method that was developed to detect gear tooth damage that does not require a priori knowledge of the frequency characteristic of the fault. The basic idea of the method is that a few damaged teeth will cause transient load fluctuations unlike the normal tooth load fluctuations. The method attempts to measure the energy in the lower side bands of the modulated signal caused by the transient load fluctuations. The method monitors the energy in the frequency interval which excludes the frequency of the lowest dominant normal tooth load fluctuation and all frequencies above it. The method reacted significantly to the tooth fracture damage results documented in the Lewis data sets which were obtained from tests of the OH-58A transmission and tests of high contact ratio spiral bevel gears. The method detected gear tooth fractures in all four of the high contact ratio spiral bevel gear runs. Published results indicate other detection methods were only able to detect faults for three out of four runs.

Nachtsheim, Philip R.

1997-01-01

167

Kinematics of the tooth tapping movement.  

Science.gov (United States)

Electrical activity in the masseter muscles and tooth contact vibrations were recorded simultaneously from subjects tapping their teeth slowly into maximal intercuspidation and again with maximal frequency. High speed cinephotography was also used with four of the ten subjects. Three main parts could be distinguished on the obtained graphical representation of the tooth tapping movement: tooth contact phase (TCP), opening phase (OP) and closing phase (CP). Tapping frequency was increased by decreasing the jaw opening degree and the durations of TCP, OP and CP. The jaw velocity immediately before tooth contact, which may be of significance for the reflex response, was however not increased. The average jaw speed was nevertheless increased from 10 to 15 cm/s since the turning from OP to CP was more abrupt in high than in low frequency tapping. The duration of electrical activity after tooth contact was significantly shorter at tapping with high than with low frequency. The teeth maintained contact without detectable rebound between each open-close cycle. The OP started about 100 ms after the cessation of electrical activity both at low and high tapping frequency. The time between end of electrical activity and the start of a new OP was supposed to be dependent upon the relaxation time of the masseter muscles. PMID:268419

Widmalm, S E; Hedegård, B

1977-07-01

168

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)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 statisticall

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

169

PKA regulatory subunit expression in tooth development.  

Science.gov (United States)

Protein kinase A (PKA) plays critical roles in many biological processes including cell proliferation, cell differentiation, cellular metabolism and gene regulation. Mutation in PKA regulatory subunit, PRKAR1A has previously been identified in odontogenic myxomas, but it is unclear whether PKA is involved in tooth development. The aim of the present study was to assess the expression of alpha isoforms of PKA regulatory subunit (Prkar1a and Prkar2a) in mouse and human odontogenesis by in situ hybridization. PRKAR1A and PRKAR2A mRNA transcription was further confirmed in a human deciduous germ by qRT-PCR. Mouse Prkar1a and human PRKAR2A exhibited a dynamic spatio-temporal expression in tooth development, whereas neither human PRKAR1A nor mouse Prkar2a showed their expression in odontogenesis. These isoforms thus showed different expression pattern between human and mouse tooth germs. PMID:24755349

de Sousa, Sílvia Ferreira; Kawasaki, Katsushige; Kawasaki, Maiko; Volponi, Ana Angelova; Gomez, Ricardo Santiago; Gomes, Carolina Cavaliéri; Sharpe, Paul T; Ohazama, Atsushi

2014-05-01

170

Roentgenologic investigations for the anterior tooth length  

International Nuclear Information System (INIS)

The author measured the length of crown, root and tooth on the films which was taken by intraoral bisecting technic with mesh plate on the films. The films were taken from the dry skulls, dentiform, same patients who had to be removed their upper incisors, and the other patients who admitted for dental care. From this serial experiment the results were made as follows: 1. By using the film and mesh plate in the oral cavity, the real tooth length can be measured easily on the film surfaces. 2. The film distortion in the oral cavity can be avoided when taking the film using the mesh plate and film together. 3. When measuring the film, length of crown was elongated and length of root was shortened. 4. When using the well-trained bisecting technic, the real tooth length can be measured directly on the intraoral film.

1972-11-01

171

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 CO_3"3"- 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)

1985-01-01

172

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

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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.

A Moghareh Abed

2010-01-01

173

Do we really know how to evaluate tooth prognosis? A systematic review and suggested approach.  

Science.gov (United States)

Periodontal treatment is based on tooth prognosis evaluation. Different approaches for determining tooth prognosis have been described in the literature. The vast majority are based on clinical and radiographic findings, as well as patient-related factors. The availability of various systems for assigning tooth prognosis complicates both the assignment process and the communication between clinicians regarding patient status and treatment plan. In addition, performance evaluation of several systems reveals that the accuracy of prediction differs between teeth of various conditions in most methods, as well as the factors providing significant predictive power. As a standardized prognostic classification system is still lacking, an overall evaluation based on a uniform dataset could provide an objective comparison of all methods, and help progress towards developing novel approaches. The main features of such approaches should include the selection of predictive factors, their assigned weights in accordance with different tooth conditions, and the estimated period of time applicable for reevaluation of prognosis. In this paper, we propose a different approach for prognosis evaluation, suggesting reevaluating tooth prognosis at several time points during the treatment plan, and taking into consideration some of the most important issues of patient compliance, oral hygiene, and plaque control. The suggested approach attempts to address prognosis from a different perspective, viewing the process as a dynamic and recurring evaluation embedded within each step of the treatment plan. Due to the fact that accurate tooth prognosis evaluation is still (and might forever be) unavailable, a more humble and less aggressive approach should be adopted, trying to preserve more and extract less. PMID:23479586

Halperin-Sternfeld, Michal; Levin, Liran

2013-05-01

174

Clinical, radiological and histological diagnoses of periapical periodontitis spreading to the adjacent tooth: A case of endodontic failure  

Directory of Open Access Journals (Sweden)

Full Text Available 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-treatment of 4.5 and endodontic treatment of 4.4 were performed in a single visit. A large amount of endodontic sealer squeezed mesially from the root of tooth 4.5, where a partial horizontal root fracture was hypothesized. 6-, 12-, and 18-month radiographic follow-ups, by both periapical and cone-beam computed tomography (CBCT analyses, showed incomplete osseous healing. CBCT excluded root fracture on 4.5. Local symptoms were still present. Clinical and radiological conditions led to extractions, and a cystic lesion was enucleated for histopathologic analyses. Histopathologic diagnosis was a periapical cyst. The supposed partial horizontal root fracture of 4.5 was actually a large lateral canal. Although the root canal treatments followed high standards in terms of quality, a persistent chronic infection developed histologically. The cystic lesion was one consistent reason for the unsuccessful healing of 4.5.

Luigi Cianconi

2013-07-01

175

Investigation of crack propagation scatter in a gear tooth's root  

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This paper describes the problem of determining crack initiation location and its influence on crack propagation in a gear tooth's root. Three different load positions on the gear tooth's flank were considered for this investigation of crack initiation and propagation. A special test device was used for the single tooth test. It can be concluded from the measurements thata crack can be initiated at very different locations in a tooth's root and then propagate along its own paths. A numerical ...

Pehan, Stanislav; Kramberger, Janez; Flas?ker, Joz?e; Zafos?nik, Bos?tjan

2012-01-01

176

Root canal treatment of mandibular second premolar tooth with taurodontism  

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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...

2008-01-01

177

Tooth Wear Prevalence and Sample Size Determination : A Pilot Study  

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Tooth wear is the non-carious loss of tooth tissue, which results from three processes namely attrition, erosion and abrasion. These can occur in isolation or simultaneously. Very mild tooth wear is a physiological effect of aging. This study aims to estimate the prevalence of tooth wear among 16-year old Malay school children and determine a feasible sample size for further study. Fifty-five subjects were examined clinically, followed by the completion of self-administered questionnaires. Qu...

Abd Karim, Nama Bibi Saerah; Ismail, Noorliza Mastura; Naing, Lin; Ismail, Abdul Rashid

2008-01-01

178

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

1995-08-01

179

An inductive signalling network regulates mammalian tooth morphogenesis with implications for tooth regeneration.  

Science.gov (United States)

Sequential and reciprocal epithelial-mesenchymal interactions, essential throughout such aspects of tooth morphogenesis as patterning, size and number of teeth, involves a well-ordered series of inductive and permissive signals that exert global control over cell proliferation, differentiation and organogenesis. In particular, growth factors, transcription factors and their corresponding receptors, as well as other soluble morphogens, make up a regulatory network at the molecular level that synergistically or antagonistically controls intra-/inter-cellular signal transduction during odontogenesis. This review summarizes recent advances in the study of crucial signalling pathways, for example of BMPs, Wnt, Notch, Shh and FGF, with emphasis on the potential integrated signalling network responsible for tooth formation. Our work probes into the complexity of these inductive signalling pathways to promote the understanding of tooth regeneration. Additionally, our study provides further insights into therapeutic strategies for various dental abnormalities in patterning and number, such as tooth agenesis and supernumerary teeth. PMID:23952789

Li, Z; Yu, M; Tian, W

2013-10-01

180

EPR dosimetry with tooth enamel: A review  

Energy Technology Data Exchange (ETDEWEB)

When tooth enamel is exposed to ionizing radiation, radicals are formed, which can be detected using electron paramagnetic resonance (EPR) techniques. EPR dosimetry using tooth enamel is based on the (presumed) correlation between the intensity or amplitude of some of the radiation-induced signals with the dose absorbed in the enamel. In the present paper a critical review is given of this widely applied dosimetric method. The first part of the paper is fairly fundamental and deals with the main properties of tooth enamel and some of its model systems (e.g., synthetic apatites). Considerable attention is also paid to the numerous radiation-induced and native EPR signals and the radicals responsible for them. The relevant methods for EPR detection, identification and spectrum analyzing are reviewed from a general point of view. Finally, the needs for solid-state modelling and studies of the linearity of the dose response are investigated. The second part is devoted to the practical implementation of EPR dosimetry using enamel. It concerns specific problems of preparation of samples, their irradiation and spectrum acquisition. It also describes how the dosimetric signal intensity and dose can be retrieved from the EPR spectra. Special attention is paid to the energy dependence of the EPR response and to sources of uncertainties. Results of and problems encountered in international intercomparisons and epidemiological studies are also dealt with. In the final section the future of EPR dosimetry with tooth enamel is analyzed.

Fattibene, Paola, E-mail: paola.fattibene@iss.i [Istituto Superiore di Sanita, Department of Technology and Health, Viale Regina Elena 299, I-00161 Rome (Italy); Callens, Freddy, E-mail: freddy.callens@ugent.b [Ghent University, Department of Solid State Sciences, Krijgslaan 281-S1, B-9000 Gent (Belgium)

2010-11-15

 
 
 
 
181

Is it possible to change tooth boundaries?.  

Czech Academy of Sciences Publication Activity Database

. Ghent, 2004. s. 7.[Oral Facial Development and Regeneration, WG1 - WG3 meeting COST B23. 19.03.2004-20.03.2004, Ghent]Grant CEP: GA ?R GA304/02/0448; GA MŠk OC B23.002Klí?ová slova: tooth boundariesKód oboru RIV: EB - Genetika a molekulární biologie

Peterková, Renata; Lesot, H.; Kristenová, Pavlína; Peterka, Miroslav

182

EPR dosimetry with tooth enamel: A review  

International Nuclear Information System (INIS)

When tooth enamel is exposed to ionizing radiation, radicals are formed, which can be detected using electron paramagnetic resonance (EPR) techniques. EPR dosimetry using tooth enamel is based on the (presumed) correlation between the intensity or amplitude of some of the radiation-induced signals with the dose absorbed in the enamel. In the present paper a critical review is given of this widely applied dosimetric method. The first part of the paper is fairly fundamental and deals with the main properties of tooth enamel and some of its model systems (e.g., synthetic apatites). Considerable attention is also paid to the numerous radiation-induced and native EPR signals and the radicals responsible for them. The relevant methods for EPR detection, identification and spectrum analyzing are reviewed from a general point of view. Finally, the needs for solid-state modelling and studies of the linearity of the dose response are investigated. The second part is devoted to the practical implementation of EPR dosimetry using enamel. It concerns specific problems of preparation of samples, their irradiation and spectrum acquisition. It also describes how the dosimetric signal intensity and dose can be retrieved from the EPR spectra. Special attention is paid to the energy dependence of the EPR response and to sources of uncertainties. Results of and problems encountered in international intercomparisons and epidemiological studies are also dealt with. In the final section the future of EPR dosimetry with tooth enamel is analyzed.

2010-11-01

183

Epithelio-Mesenchymal Transformation During Tooth Development.  

Czech Academy of Sciences Publication Activity Database

. Bruges : EACMFS, 2010. s. 198-198.[Congress of the European Association for Cranio-Maxillo-Facial Surgery /20./. 14.09.2010-17.09.2010, Bruges]Výzkumný zám?r: CEZ:AV0Z50450515Klí?ová slova: tooth developmentKód oboru RIV: FF - ORL, oftalmologie, stomatologie

Štembírek, Jan; Buchtová, Marcela; Matalová, Eva; Stránský, J.; Míšek, Ivan

184

Impacted Primary Tooth and Tooth Agenesis: A Case Report of Monozygotic Twins  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the present report, a case of 19 year-old monozygotic twin brothers with similar tooth agenesis and impacted primary teeth is presented. Both twins (HDH, DHH) had agenesis of ten and eleven teeth (respectively), third molars excluded, consistent with oligodontia and both had four impacted primary teeth and the permanent successors of all these primary teeth were congenitally missing. The occurrence of similarly located tooth agenesis and primary impacted teeth in monozygotic twins may sugg...

Zengin, A. Zeynep; Sumer, A. Pinar; Karaarslan, Emine

2008-01-01

185

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

Directory of Open Access Journals (Sweden)

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

Gavrila Ion

2009-12-01

186

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

LENUS (Irish Health Repository)

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.

Harding, M A

2010-03-01

187

Environmental lead pollution and its possible influence on tooth loss and hard dental tissue lesions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bacground/Aim. Environmental lead (Pb) pollution is a global problem. Hard dental tissue is capable of accumulating lead and other hard metals from the environment. The aim of this study was to investigate any correlation between the concentration of lead in teeth extracted from inhabitants of Pan?evo and Belgrade, Serbia, belonging to different age groups and occurrence of tooth loss, caries and non-carious lesions. Methods. A total of 160 volunteers were chosen consecutively from Pan...

Ceni?-Miloševi? Desanka; Mileusni? Ivan; Kolak Veljko; Pejanovi? ?or?e; Risti? Tamara; Jakovljevi? Ankica; Popovi? Milica; Peši? Dragana; Melih Irena

2013-01-01

188

Detection of tooth fractures in CBCT images using attention index estimation  

Science.gov (United States)

The attention index (𝜑) is a number from zero to one that indicates a possible fracture is detected inside a selected tooth. The higher the 𝜑 number, the greater the likelihood for needed attention in the visual examination. The method developed for the 𝜑 estimation extracts a connected component with image properties that are similar to those of a typical tooth fracture. That is, in cone-beam computed tomography (CBCT) images, a fracture appears as a dark canyon inside the tooth. In order to start the visual examination process, the method provides a plane across the geometric center of the suspicious fracture component, which maximizes the number of pixels from that component inside the plane. During visual examination, the user (doctor) can change plane orientations and locations, by manipulating the mouse toward different graphical elements that represent the plane on a 3-D rendition of the tooth, while the corresponding image of the plane is shown at its side. The visual examination aims at confirming or disproving the fracture-detection event. We have designed and implemented these algorithms using the image-foresting transform methodology.

Souza, Andre; Falcão, Alexandre; Ray, Lawrence

2014-03-01

189

In-air micro-PIGE measurement system for fluorine analysis of the tooth  

International Nuclear Information System (INIS)

An in-air micro-PIGE and micro-PIXE measurement system for fluorine analysis of tooth have been developed at the Wakasa Wan Energy Research Center. A proton microbeam is extracted through a thin silicon nitride window into the air and used to irradiate a tooth sample mounted on a sample stage set in air. Gamma-rays from a 19F(p,??)16O reaction and characteristic X-rays are detected with a BGO detector and a Ge X-ray detector, simultaneously. The sample stage and beam scanner allow us to analyze the tooth sample over a range of 20 mm at maximum. Spot sizes of a proton beams in air at an energy of 2.5 MeV was 4 ?m, in the case of a distance between the silicon nitride window and the sample of 0.2 mm and 13 ?m in the case of 1.7 mm. Fluorine analysis was performed over an area of about 3 mm x 3 mm of the tooth sample. One- and two-dimensional distributions of fluorine and calcium were obtained successfully. Quantitative analysis was also performed using data for measurements of reference materials Ca10(PO4)6(OH)2-2xF2x

2007-07-01

190

[Recent advances in molecular mechanisms of supernumerary tooth formation].  

Science.gov (United States)

Despite advances in the knowledge of tooth morphogenesis and differentiation, little is relatively known about the aetiology and molecular mechanisms underlying supernumerary tooth formation. Mice, which are commonly used for studying tooth development, only exhibit one dentition. However, a number of mouse models are now starting to provide some insight into the mechanisms that control overall tooth number within the dentition. This review describes recent advances in our understanding of the molecular mechanisms of supernumerary tooth formation. Indeed, many of the molecular signaling pathways known to be involved in normal development of the tooth germ can also give rise to supernumerary teeth if inappropriately regulated. These include components of the Hedgehog, FGF, Wnt and BMP families, which may potentially play a role in human supernumerary tooth formation. PMID:23939184

Ge, Li-hong; Wang, Xu

2013-08-18

191

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)

2011-08-01

192

Investigating tooth loss and associated factors among older Taiwanese adults.  

Science.gov (United States)

The aim of this study was to evaluate factors associated with tooth loss in older Taiwanese adults with different numbers of remaining teeth. This study evaluated oral health status and tooth loss among 2286 adults aged over 65. Subjects were classified according to number of teeth (Group 1 Tooth loss and oral health data were collected from the National Health Interview Survey (NHIS), compared between groups and analyzed by multivariate modeling. Group 1 subjects were older and had more partial dentures. Tooth loss was associated with self-limited food choices due to oral health status, and malnutrition. Tooth loss in Group 2 subjects was significantly associated with lower mental status. Tooth loss may predict cognitive status (odds ratio (OR) 1.30) and physical-disability (OR 1.79). Our results suggested that tooth loss was associated with age, more partial dentures, self-limited food choices, malnutrition, and lower mental and cognitive status and physical disability. PMID:24568967

Wang, Tze-Fang; Chen, Ying-Yu; Liou, Yiing-Mei; Chou, Chyuan

2014-01-01

193

Blood lead--tooth lead relationship among Boston children  

Energy Technology Data Exchange (ETDEWEB)

The amount of lead in deciduous teeth has been used extensively as a marker for infant lead exposure and body burden. Elevated tooth lead levels have been seen in children who had lead poisoning. Also, on a population wide basis tooth lead levels appear to vary according to housing status and presumably lead exposure. This exposure index has been applied using varying techniques in Denmark, and the United Kingdom. Because of the neurotoxicity of lead, the tooth lead levels of retarded and normal children have been compared. Most recently, in research of lead and child development, tooth lead levels have been used as markers of past lead exposure. Despite the widespread use of tooth lead values, very little is known about the exact time course of lead deposition in tooth from blood. This report compares blood lead levels at different ages to tooth lead levels in a group of Boston children.

Rabinowitz, M.B.; Leviton, A.; Bellinger, D.C. (Children' s Hospital, Boston, MA (USA))

1989-10-01

194

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.

2011-09-01

195

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

196

New method of control of tooth whitening  

Science.gov (United States)

New methods of control of tooth bleaching stages through simultaneous measurements of a reflected light and a fluorescence signal are proposed. It is shown that the bleaching process leads to significant changes in the intensity of a scattered signal and also in the shape and intensity of the fluorescence spectra. Experimental data illustrate that the bleaching process causes essential changes in the teeth discoloration in short time as 8-10 min from the beginning of the application procedure. The continuation of the treatment is not necessary moreover the probability of the enamel destroy increases considerably. The proposed optical back control of tooth surface is a base for development of a practical set up to control the duration of the bleaching procedure.

Angelov, I.; Mantareva, V.; Gisbrecht, A.; Valkanov, S.; Uzunov, Tz.

2010-10-01

197

A Radiographic Study of Fused and Geminated Tooth  

International Nuclear Information System (INIS)

The incidence and several characteristic features of fused and geminated teeth were studied radiographically, with full mouth periapical radiogram and pantomogram, in 4201 patients of mixed dentition and 5358 patients of permanent dentition. The obtained results were as follows: 1. The prevalence was revealed to 2.86%, 0.32%, 0.33%, and 0.06% in deciduous fused tooth, permanent fused tooth, deciduous geminated tooth and permanent geminated tooth respectively, and these anomalies were occurred in female more than male. 2. Fused teeth were observed predominantly in lower anterior teeth area, especially in lateral incisor and canine region, and many cases of deciduous geminated tooth were observed in upper central incisor region. 3. Congenital missing rates of succedaneous tooth in deciduous fused teeth were 57.1%, 85.7%, 71.0%, 69.0% in upper right and left central-lateral incisor regions, lower right and left lateral incisor-canine regions, respectively. 4. Prevalence of dental caries was 42.3%, 18.8% and 5.6% in deciduous fused, deciduous geminated and permanent fused tooth, respectively. 5. In classifying of fused and geminated teeth into 9 type, by following appearance such as number of crown, root, pulp chamber and pulp canal of those teeth, it was more favorable that Type I (2 crown, 2 root, 2 pulp chamber, 2 pulp canal) in deciduous fused tooth and Type IX (1 crown, 1 root, 1 pulp chamber, 1 pulp canal) in permanent used tooth, deciduous and permanent geminated tooth.

1990-02-01

198

Unusual intraosseous transmigration of impacted tooth  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 transmigr...

Kumar, Santosh; Urala, Arun Srinivas; Kamath, Abhay Taranath; Jayaswal, Priyanka; Valiathan, Ashima

2012-01-01

199

Diagnosis of Charcot-Marie-Tooth Disease  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Charcot-Marie-Tooth (CMT) disease or hereditary motor and sensory neuropathy (HMSN) is a genetically heterogeneous group of conditions that affect the peripheral nervous system. The disease is characterized by degeneration or abnormal development of peripheral nerves and exhibits a range of patterns of genetic transmission. In the majority of cases, CMT first appears in infancy, and its manifestations include clumsiness of gait, predominantly distal muscular atrophy of the limbs, and deformit...

Banchs, Isabel; Casasnovas, Carlos; Alberti?, Antonia; Jorge, Laura; Povedano, Mo?nica; Montero, Jordi; Marti?nez-matos, Juan Antonio; Volpini, Victor

2009-01-01

200

Update on Charcot-Marie-Tooth Disease  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Charcot-Marie-Tooth disease (CMT) disease encompasses a genetically heterogeneous group of inherited neuropathies, also known as hereditary motor and sensory neuropathies. CMT results from mutations in more than 40 genes expressed in Schwann cells and neurons causing overlapping phenotypes. The classic CMT phenotype reflects length-dependent axonal degeneration characterized by distal sensory loss and weakness, deep tendon reflex abnormalities, and skeletal deformities. Recent articles have p...

Patzko?, A?gnes; Shy, Michael E.

2011-01-01

 
 
 
 
201

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

2000-12-15

202

Digital Computer Matching of Tooth Color  

Directory of Open Access Journals (Sweden)

Full Text Available This study aimed to determine the validity of the digital photocolorimetric (PCM method in matching the color of human teeth. First, two Vitapan Classical shade guides, each containing 16 shade guide teeth, were visually shade matched, and digital photographs of each three pair of shade guide teeth were taken in a color matching booth. Secondly, visual shade matching of the upper central incisors of 48 subjects was performed by two prosthodontists independently in a chair, using the Vitapan Classical shade guide. The three closest shade guide teeth were visually selected and ranked in order of preference, for which digital photographs were taken under ceiling daylight-corrected fluorescent lighting. All digital images were analyzed on a computer screen using software to calculate the color difference between the reference tooth and other teeth in the same digital image. The percent color matching for the shade guide teeth and human teeth was 88% and 75%, respectively. There was no statistically significant difference in matching the tooth color between the shade guide teeth and human teeth. The digital PCM method is valid for the range of human teeth based on the Vitapan Classical shade guide. This method enhances communication with the laboratory personnel in matching the tooth color.

Won-suk Oh

2010-06-01

203

Radiosterilization of tooth pastes EF, MB, LK  

International Nuclear Information System (INIS)

The effect of decontaminating doses of gamma rays (60Co, 10 Kr - 1.5 Mr) on the quality and biological activity of tooth pastes is studied. The radioresistance factors D10 of the dominating microorganisms in the studied pastes, namely Bac. subtilis, Staph. epidermidis, S. lutea, Ps. aeruginosa, Pen. notatum, Pen. chrysogenum, Asp. niger, C. parapsilosis, are determined. Ps aeruginosa appears to show the highest radiosensitivity - D10 = 20 Kr. The irradiation in the range 500 Kr - 1.5 Mr reveals that Ps. aeruginosa are inactivated with doses of 750 Kr while the inactivation of sporebearing bacteria and grampositive microorganisms starts at doses above 1 Mr. The lower values of radioresistance factors observed as compared to that established by the authors for cosmetic preparations henna and starch are due to radiosensitizing of microorganisms in a medium with higher water content. The radiolytic effect of water causes changes in consistency, odour, taste and colour of the tooth pastes and for that reason the radiosterilization of tooth pastes is not recommended. A mathematical model for irradiation of products contaminated with a variety of microorganisms is developed. Bac. subtilis - the most frequent and radioresistant pollutant - is suggested as a standard in selecting the proper sterilization procedure and in checking the efficiency of irradiation. 3 tabs, 3 figs, 6 refs

1989-01-01

204

Tooth Whitening And Temperature Rise With Two Bleaching Activation Methods  

International Nuclear Information System (INIS)

To measure the tooth whitening and the surface and Intrapulpal temperature increase in vitro on freshly extracted upper human central incisors after chemical, Zoom AP light and diode laser activated bleaching. Thirty caries-free upper human incisors were selected. Teeth were divided into three equal groups according to the methods of activation of the bleaching agent (n = 10). A whitening gel containing hydrogen peroxide was applied to the buccal surface of all teeth. Group I was bleached using chemically activated hydrogen peroxide gel, for three applications of 15 min each. Group II was bleached with high intensity advanced power Zoom activation light (Zoom AP), for three applications of 15 min each. Group III was bleached with diode laser activation technique, where the teeth were irradiated with 2 Watt diode laser for three applications of 30 sec each. The whitening degree was assessed using an image analysis system, while temperature rise was recorded using a thermocouple on the external tooth surface and Intrapulpal. The degree of whitening increased significantly in all groups. However, the percentage of whitening was not statistically significantly different between the three groups. In addition, group II showed statistically significant higher mean rise in both surface and pulp temperatures than group I and group III. Chemical bleaching produces the same whitening effect as Zoom AP light and laser, with no surface or pulpal temperature rise. Laser application is faster and produces less surface and pulp temperature increase than Zoom AP light. Diode laser used to activate bleaching gels is not considered dangerous to the vitality of dental pulp using power settings of 2 W.

2009-09-27

205

Tooth Whitening And Temperature Rise With Two Bleaching Activation Methods  

Science.gov (United States)

To measure the tooth whitening and the surface and Intrapulpal temperature increase in vitro on freshly extracted upper human central incisors after chemical, Zoom AP light and diode laser activated bleaching. Thirty caries-free upper human incisors were selected. Teeth were divided into three equal groups according to the methods of activation of the bleaching agent (n = 10). A whitening gel containing hydrogen peroxide was applied to the buccal surface of all teeth. Group I was bleached using chemically activated hydrogen peroxide gel, for three applications of 15 min each. Group II was bleached with high intensity advanced power Zoom activation light (Zoom AP), for three applications of 15 min each. Group III was bleached with diode laser activation technique, where the teeth were irradiated with 2 Watt diode laser for three applications of 30 sec each. The whitening degree was assessed using an image analysis system, while temperature rise was recorded using a thermocouple on the external tooth surface and Intrapulpal. The degree of whitening increased significantly in all groups. However, the percentage of whitening was not statistically significantly different between the three groups. In addition, group II showed statistically significant higher mean rise in both surface and pulp temperatures than group I and group III. Chemical bleaching produces the same whitening effect as Zoom AP light and laser, with no surface or pulpal temperature rise. Laser application is faster and produces less surface and pulp temperature increase than Zoom AP light. Diode laser used to activate bleaching gels is not considered dangerous to the vitality of dental pulp using power settings of 2 W.

Abu-Elmagd, D. M.; El-Sayad, I. I.; Abd El-Gawad, L. M.

2009-09-01

206

Dental extractions using improvised equipment.  

Science.gov (United States)

Extracting a tooth is the final treatment for multiple dental problems. Persons who are not dentists, however, have little experience with tooth extractions. When a remote setting makes it impossible to send a patient for optimal dental treatment, the clinician may need to extract teeth, sometimes using improvised equipment. The following cases of two patients with three carious, painful molars describe such a situation. The non-dental clinicians had to improvise not only appropriate dental tools, but also personal protective equipment, a functional suction machine, medications for a dental block, a dental chair, and dental consent forms and follow-up instructions in the patients' language. In these cases, they also communicated with their patients through a translator. To prepare to do tooth extractions in remote settings, clinicians should learn and practice dental blocks and review extraction techniques before they deploy. If they must do an extraction, clinicians should use the closest approximation available to the appropriate dental tools. When done correctly, a dental extraction can take some time and should not be rushed. PMID:24076092

Iserson, Kenneth V

2013-12-01

207

Results of tooth enamel EPR dosimetry for population living in the vicinity of the Semipalatinsk nuclear test site  

International Nuclear Information System (INIS)

The method of electron paramagnetic resonance (EPR) dosimetry was used on human tooth enamel to obtain individual absorbed doses of residents of settlements in the vicinity of the Nuclear Test Site (SNTS) in Semipalatinsk region, Kazakhstan. Measured teeth were extracted according to medical indications. In total, 105 tooth enamel samples were analyzed, including eight tooth samples from control settlement Kokpekty, which is located 400 km to the Southeast from SNTS and was not subjected to any radioactive contamination. It was found that the excess doses obtained after subtraction of the contribution of natural background radiation ranged up to about 440 mGy for residents of Dolon, whose tooth enamel was formed before 1949, and do not exceed 100 mGy for younger residents. For residents of Mostik, excess doses do not exceed 100 mGy for all ages except in one resident, for whom an extremely high dose of 1250 mGy was registered. For Bodene settlement, excess doses higher than 100 mGy were obtained for two samples from the residents having enamel formed before 1949. An extremely high dose (2800±400 mGy) was obtained for one resident of Semipalatinsk City. The average excess dose for Semipalatinsk samples with enamel formation before 1949 was determined close to the average excess dose for tooth enamel samples from Dolon village

2006-07-10

208

Results of tooth enamel EPR dosimetry for population living in the vicinity of the Semipalatinsk nuclear test site  

Energy Technology Data Exchange (ETDEWEB)

The method of electron paramagnetic resonance (EPR) dosimetry was used on human tooth enamel to obtain individual absorbed doses of residents of settlements in the vicinity of the Nuclear Test Site (SNTS) in Semipalatinsk region, Kazakhstan. Measured teeth were extracted according to medical indications. In total, 105 tooth enamel samples were analyzed, including eight tooth samples from control settlement Kokpekty, which is located 400 km to the Southeast from SNTS and was not subjected to any radioactive contamination. It was found that the excess doses obtained after subtraction of the contribution of natural background radiation ranged up to about 440 mGy for residents of Dolon, whose tooth enamel was formed before 1949, and do not exceed 100 mGy for younger residents. For residents of Mostik, excess doses do not exceed 100 mGy for all ages except in one resident, for whom an extremely high dose of 1250 mGy was registered. For Bodene settlement, excess doses higher than 100 mGy were obtained for two samples from the residents having enamel formed before 1949. An extremely high dose (2800{+-}400 mGy) was obtained for one resident of Semipalatinsk City. The average excess dose for Semipalatinsk samples with enamel formation before 1949 was determined close to the average excess dose for tooth enamel samples from Dolon village.

Zhumadilov, K. [Research Institute for Radiation Biology and Medicine, Hiroshima University, 734-8553 (Japan)], E-mail: kassym@hiroshima-u.ac.jp; Ivannikov, A. [Research Institute for Radiation Biology and Medicine, Hiroshima University, 734-8553 (Japan); Medical Radiological Research Center, Obninsk, 249036 (Russian Federation); Apsalikov, K. [Scientific-Research Institute for Radiation Medicine and Ecology, Semipalatinsk 490050 (Kazakhstan); Zhumadilov, Zh. [Semipalatinsk State Medical Academy, Semipalatinsk 490050 (Kazakhstan); Zharlyganova, D. [Research Institute for Radiation Biology and Medicine, Hiroshima University, 734-8553 (Japan); Stepanenko, V.; Skvortsov, V. [Medical Radiological Research Center, Obninsk, 249036 (Russian Federation); Berekenova, G. [Scientific-Research Institute for Radiation Medicine and Ecology, Semipalatinsk 490050 (Kazakhstan); Toyoda, S. [Department of Applied Physics Faculty of Science Okayama University of Science, 700-0005 (Japan); Endo, S.; Tanaka, K. [Research Institute for Radiation Biology and Medicine, Hiroshima University, 734-8553 (Japan); Miyazawa, C. [School of Dentistry, Ohu University, Koriyama-shi, Fukushima Pref. 963-8611 (Japan); Hoshi, M. [Research Institute for Radiation Biology and Medicine, Hiroshima University, 734-8553 (Japan)

2007-07-15

209

Maxillary Dentigerous Cyst and Supernumerary Tooth. Is it a Frequent Association?  

Science.gov (United States)

Dentigerous cysts, also known as follicular cysts, are a relatively common pathology in our field. They are associated with unerupted or semi-erupted teeth and are usually not related to supernumerary teeth. Objective: To describe a dentigerous cyst case associated to a supernumerary tooth. Case-report: A large-sized dentigerous cyst is described, associated with a supernumerary tooth, affecting the whole maxillary anterior area. Appropriate treatment consists of performing root canals and a Partsch II procedure with a cystectomy, extracting the unerupted teeth, carrying out an apicoectomy and retro-filling the affected teeth. The defect is filled with a bone xenograft. Possible therapeutic alternatives and the connection between the dentigerous cysts and supernumerary teeth are considered in the discussion. PMID:24603929

Navarro, Beatriz González; Jané Salas, Enric; Olmo, Ivette Teixidor; I Muñoz, Aura Font; Juarez Escalona, Inma; López-López, José

2014-03-01

210

ESR Dosimetry for Atomic Bomb Survivors Using Shell Buttons and Tooth Enamel  

Science.gov (United States)

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.

Ikeya, Motoji; Miyajima, Junko; Okajima, Shunzo

1984-09-01

211

Primary impaction of a primary in incisor tooth: a case report  

Directory of Open Access Journals (Sweden)

Full Text Available The primary impaction is the situation in which a tooth is retained inthe mouth and remains unerupted for a period upper six months whencompared to teeth of the other side. It is a very rare condition in primary teeth especially in maxillary anterior teeth. The purpose of this article is to present a case of a 2-year and 11-month old female child with an impacted primary upper central incisor. The main complaint was the absence of the anterior tooth in the mouth. There was a previous history of trauma when the child was four months old. Clinical and radiographic examinations are described. The treatment consisted of a period of clinical and radiographic control, with the extraction of the impacted primary upper central incisor and a follow-up until the eruption of the permanent successor. This case emphasizes the possible relationship between previous trauma and primary impaction.

Maria Naira Pereira FRIGGI

2007-05-01

212

Protection and Reinforcement of Tooth Structures by Dental Coating Materials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

2012-01-01

213

Instrumental selection of tooth color in prosthodontic rehabilitation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tooth color selection in prosthodontics is a very important factor for successful rehabilitation. The aim of this paper was to present different instruments for tooth color selection in prosthodontic rehabilitation. Knowledge of basic principles of a complex psychophysical phenomenon such as color is of essential interest in prosthodontic therapy. Furthemore, the mechanism of physiological perception of color and available methods for an objective determination of tooth color are also present...

?uriši? Slobodan; Mili?-Lemi? Aleksandra; Obradovi?-?uri?i? Kosovka; Popovi? Olga

2007-01-01

214

Instrumental selection of tooth color in prosthodontic rehabilitation  

Directory of Open Access Journals (Sweden)

Full Text Available Tooth color selection in prosthodontics is a very important factor for successful rehabilitation. The aim of this paper was to present different instruments for tooth color selection in prosthodontic rehabilitation. Knowledge of basic principles of a complex psychophysical phenomenon such as color is of essential interest in prosthodontic therapy. Furthemore, the mechanism of physiological perception of color and available methods for an objective determination of tooth color are also presented in the paper.

?uriši? Slobodan

2007-01-01

215

Tooth-shaped plasmonic waveguide filters with nanometeric sizes  

CERN Multimedia

A novel nanometeric plasmonic filter in a tooth-shaped Metal-Insulator-Metal waveguide is proposed and demonstrated numerically. An analytic model based on the scattering matrix method is given. The result reveals that the single tooth-shaped filter has a wavelength filtering characteristic and an ultra-compact size in the length of a few hundred nanometers, compared to grating-like SPPs filters. Both analytic and simulation results show that the wavelength of the trough of the transmission has linear and nonlinear relationships with the tooth depth and the tooth width, respectively. The waveguide filter could be utilized to develop ultra-compact photonic filters for high integration.

Lin, Xianshi; 10.1364/OL.33.002874

2009-01-01

216

Tooth-marked small theropod bone: an extremely rare trace  

DEFF Research Database (Denmark)

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.

Jacobsen, Aase Roland

2001-01-01

217

Restoration of a vertical tooth fracture and a badly mutilated tooth using canal projection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Management of vertically fractured tooth or a perforation frequently poses problem during endodontic management. Such teeth often need a pre-endodontic restoration prior to initiation of root canal therapy to aid in the placement of rubber dam clamp. This paper describes a simple method of placement of a pre-endodontic restoration using the canal projection technique using hollow metallic needles as sleeves.

Velmurugan N; Bhargavi N; Neelima Lakshmi; Kandaswamy D

2007-01-01

218

Restoration of the Severely Decayed Tooth Using Crown Lengthening with Simultaneous Tooth-Preparation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This clinical case describes a treatment approach that combines, in a single appointment, a crown lengthening procedure and the final crown preparation for the restoration of a severely decayed tooth. This approach allows for a more accurate placement of the crown margin in relation to the bone crest while reducing treatment time.

Park, Jun-beom

2010-01-01

219

Gene Expression Profiling during Murine Tooth Development.  

Science.gov (United States)

The aim of this study was to describe the expression of genes, including ameloblastin (Ambn), amelogenin X chromosome (Amelx), and enamelin (Enam) during early (pre-secretory) tooth development. The expression of these genes has predominantly been studied at post-secretory stages. Deoxyoligonucleotide microarrays were used to study gene expression during development of the murine first molar tooth germ at 24?h intervals, starting at the 11th embryonic day (E11.5), and up to the 7th day after birth (P7). The profile search function of Spotfire software was used to select genes with similar expression profile as the enamel genes (Ambn, Amelx, and Enam). Microarray results where validated using real-time reverse transcription-polymerase chain reaction (real-time RT-PCR), and translated proteins identified by Western-blotting. In situ localization of the Ambn, Amelx, and Enam mRNAs were monitored from E12.5 to E17.5 using deoxyoligonucleotide probes. Bioinformatics analysis was used to associate biological functions with differentially expressed (DE; p???0.05) genes. Microarray results showed a total of 4362 genes including Ambn, Amelx, and Enam to be significant DE throughout the time-course. The expression of the three enamel genes was low at pre-natal stages (E11.5-P0) increasing after birth (P1-P7). Profile search lead to isolation of 87 genes with significantly similar expression to the three enamel proteins. These mRNAs were expressed in dental epithelium and epithelium derived cells. Although expression of Ambn, Amelx, and Enam were lower during early tooth development compared to secretory stages enamel proteins were detectable by Western-blotting. Bioinformatic analysis associated the 87 genes with multiple biological functions. Around 35 genes were associated with 15 transcription factors. PMID:22866057

Landin, Maria A Dos Santos Silva; Shabestari, Maziar; Babaie, Eshrat; Reseland, Janne E; Osmundsen, Harald

2012-01-01

220

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Science.gov (United States)

...2009-04-01 2009-04-01 false Bracket adhesive resin and tooth conditioner... Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth...

2009-04-01

 
 
 
 
221

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Science.gov (United States)

...2009-04-01 false Bracket adhesive resin and tooth conditioner. 872...872.3750 Bracket adhesive resin and tooth conditioner. ...Identification. A bracket adhesive resin and tooth conditioner is a...polymethylmethacrylate, intended to cement an orthodontic bracket to...

2009-04-01

222

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Science.gov (United States)

... false Bracket adhesive resin and tooth conditioner. 872.3750 Section...872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a device composed...

2009-04-01

223

Measurement of Gear Tooth Dynamic Friction  

Science.gov (United States)

Measurements of dynamic friction forces at the gear tooth contact were undertaken using strain gages at the root fillets of two successive teeth. Results are presented from two gear sets over a range of speeds and loads. The results demonstrate that the friction coefficient does not appear to be significantly influenced by the sliding reversal at the pitch point, and that the friction coefficient values found are in accord with those in general use. The friction coefficient was found to increase at low sliding speeds. This agrees with the results of disc machine testing.

Rebbechi, Brian; Oswald, Fred B.; Townsend, Dennis P.

1996-01-01

224

Reconstruction of 3D Tooth Images  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We describe a novel approach to obtain a good estimate of the complete 3D representation of a tooth given only the crown. The technique is based on the use of statistical model derived from 3D-images of teeth constructed by microtomography. The root is constructed by matching the respective crowns of the two models, defining the optimal registration, and optimizing the statistical model parameters. This method allows us to generate the root efficiently due to the small number of parameters to...

Buchaillard, Ste?phanie; Ong, Sim Heng; Payan, Yohan; Foong, Kelvin

2004-01-01

225

The endodontic consequences of tooth bleaching procedures  

Directory of Open Access Journals (Sweden)

Full Text Available Tooth bleaching is a treatment modality that raises great interest, due to the important role played by aesthetics in current life style. To perform such procedure, nowadays, there are several bleaching substances at several concentrations, as well as, diverse clinical techniques. When suggesting this procedure, the dentist should take into consideration several factors related to the patient to determine which will be the most appropriate technique/material combination for solving the clinical problem. The procedure indication should not only be based on the expectations exhibited by the patient, but also on respecting the biological principles to maintain the integrity of both the endodontic and periodontal tissues.

Edson Alves de Campos

2011-04-01

226

Filling of extraction sockets with autogenous bone in cats Preenchimento de alvéolos dentais de gatos com osso autógeno  

Digital Repository Infrastructure Vision for European Research (DRIVER)

PURPOSE: To evaluate bone healing in the extraction socket of the feline mandibular canine tooth after grafting. METHODS: Eighteen adult cats were submitted to unilateral extraction of mandibular canine tooth and divided into three groups. In group 1 (n=6), control, the extraction socket was left empty. In group 2 (n=6), the extraction socket was filled with autogenous cancelous bone from the iliac crest and in group 3 (n=6), with cortical bone chips from the iliac crest. Cats were euthanized...

Adelina Maria da Silva; Wilson Machado Souza; Nair Trevizan Machado de Souza; Marion Burkhardt Koivisto; Patrícia de Athayde Barnabé; Tatiane da Silva Poló

2012-01-01

227

Clinical and histologic healing of human extraction sockets filled with calcium sulfate.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

PURPOSE: The aim of this investigation was to evaluate whether the placement of medical-grade calcium sulfate hemihydrate (MGCSH) in fresh extraction sockets might affect the quality of newly formed bone and influence crestal bone changes. MATERIALS AND METHODS: Forty patients who needed maxillary single-tooth extraction followed by implant insertion were enrolled in the study. Alveoli were required to have four remaining intact walls. After tooth extraction, 22 patients received MGCSH in the...

Aimetti, Mario; Romano, Federica

2009-01-01

228

In vitro investigation of heat transfer in human tooth  

Science.gov (United States)

The understanding of heat transfer in human teeth is important for optimizing clinical practice protocols and daily intake instructions. However, it is technically challenging to study the in vitro thermal behavior of human tooth due to its small size and complex biological/geometrical structure. The currently widely used method is based on thermocouples, which has several limitations such as low spatial resolution, contact measurement and, in particular, lack of whole-field information. To address these challenges, an experimental system was developed to measure the whole-field temperature distribution in human tooth in vitro. The human tooth sample was heated at the tooth crown with flowing hot water (60 °C) for 10 s and then cooled down by natural convection of air. The temperature of the whole sectioned sample surface was recorded using an infrared camera. The results demonstrate that the developed system is capable of measuring temperature evolution in small human tooth samples. The biological junction of tooth (e.g., dental-enamel junction) is shown to have great influence on its heat transfer behavior. The present study could open the door for several future applications, e.g., systemic investigation of heat transfer in intact/restored tooth heated with clinical methods for treatment optimization, and measurement of thermal properties for different tooth layers.

Lin, Min; Liu, Q. Da; Xu, Feng; Bai, B. Feng; Lu, T. Jian

2009-12-01

229

3D-Geomorphometrics tooth shape analysis in hypodontia  

Science.gov (United States)

Assessment of tooth morphology is an important part of the diagnosis and management of hypodontia patients. Several techniques have been used to analyze tooth form in hypodontia patients and these have shown smaller tooth dimensions and anomalous tooth shapes in patients with hypodontia when compared with controls. However, previous studies have mainly used 2D images and provided limited information. In the present study, 3D surface-imaging and statistical shape analysis were used to evaluate tooth form differences between hypodontia and control patients. Eighteen anatomical landmarks were recorded on the clinical crown of the lower left first permanent molar of 3D scanned study models of hypodontia and control subjects. The study sample group comprised of 120 hypodontia patients (40 mild, 40 moderate, and 40 severe hypodontia patients) and 40 age- and sex-matched controls. Procrustes coordinates were utilized to scale and superimpose the landmark coordinate data and then were subjected to principal component analysis (PCA). Subsequently, differences in shape as well as size were tested statistically using allometric analysis and MANOVA. Significant interaction was found between the two factor variables “group” and “sex” (p tooth crown shape were also found between sexes (p tooth form was proportional to the degree of the severity of the hypodontia. Thus, quantitative measurement of tooth shape in hypodontia patients may enhance the multidisciplinary management of those patients.

Al-Shahrani, Ibrahim; Dirks, Wendy; Jepson, Nicholas; Khalaf, Khaled

2014-01-01

230

Intrauterine hormone effects on tooth dimensions.  

Science.gov (United States)

The human dentition is a complex adaptive system that is influenced by genetic, epigenetic, and environmental factors. Within this system, is sexual dimorphism related to the growth promotion of the Y chromosome, or to hormonal influences, or both? This study is the first to investigate both primary and permanent tooth sizes in females from opposite-sex dizygotic (DZOS) twin pairs compared with females from dizygotic same-sex (DZSS) and monozygotic (MZ) twin pairs to indicate the influence of intrauterine male hormone, including the initial testosterone surge, on dental development. Serial dental models of the primary, mixed, and permanent dentitions of 134 females from DZOS, DZSS, and MZ twins were examined. Mesiodistal, buccolingual, crown height, and intercuspal dimensions of all primary teeth and selected permanent teeth were determined by image analysis. Univariate and multivariate analyses showed statistically significantly larger crown size in DZOS females in both dentitions, with the crown height dimensions displaying the greatest increase in size. These findings strongly support the Twin Testosterone Transfer (TTT) hypothesis. We propose that the growth-promoting effects of the Y chromosome and intrauterine male hormone levels influence different tooth dimensions and contribute differentially to the sexual dimorphism of human teeth. PMID:23549090

Ribeiro, D C; Brook, A H; Hughes, T E; Sampson, W J; Townsend, G C

2013-05-01

231

Microhardness and chemical composition of human tooth  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 thr [...] ough 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.

Gutiérrez-Salazar, Maria del Pilar; Reyes-Gasga, Jorge.

232

Microhardness and chemical composition of human tooth  

Directory of Open Access Journals (Sweden)

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.

Maria del Pilar Gutiérrez-Salazar

2003-06-01

233

The challenges of treating a fused tooth.  

Science.gov (United States)

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 maxillary 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. PMID:22814696

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

2012-01-01

234

Reattachment of complicated tooth fracture: An alternative approach.  

Science.gov (United States)

Trauma to the anterior teeth is relatively a common occurrence. There are several treatment modalities for such condition, one of which is reattachment of fractured fragment itself. Reattachment of fractured fragment provides immediate treatment with better esthetics, restoration of function, and is a faster and less complicated procedure. Reattachment of tooth fragment should be the first choice and is a viable alternative to conventional approaches because of simplicity, natural esthetics, and conservation of tooth structure. Patient cooperation and understanding of the limitations of the treatment is of utmost importance for good prognosis. The present case report describes management of a complicated fracture of maxillary right central incisor treated endodontically, followed by reattachment of the same fragment. Reattachment of fractured tooth fragments offers a viable restorative alternative, immediately restores tooth function for the clinician because it restores tooth function and esthetics with the use of a very conservative and cost-effective approach. PMID:22919235

Kumari, Nujella B P Surya; Sujana, V; Sunil, C H Ram; Reddy, P Satyanarayana

2012-04-01

235

Effect of root surface treatment with propolis and fluoride in delayed tooth replantation in rats.  

Science.gov (United States)

Replantation is an acceptable option for treatment of an avulsed permanent tooth. Nevertheless, an extended extraoral period damages the periodontal ligament and results in external root resorption. The purpose of this study was to assess by histologic and histometric analysis, the influence of propolis 15% (natural resinous substance collected by Apis mellifera bees from various plants) and the fluoride solution used as root surface treatment on the healing process after delayed tooth replantation. Thirty Wistar (Rattus norvegicus albinus) rats were submitted to extraction of their upper right incisor. The teeth were maintained in a dry environment for 60 min. After this, the pulp was extirpated and the papilla, enamel organ and periodontal ligament were removed with scalpel. The teeth were divided into three experimental groups: Group I - teeth immersed in 20 ml of physiologic saline; Group II - teeth immersed in 20 ml of 2% acidulated phosphate sodium fluoride; Group III - teeth immersed in 20 ml of 15% propolis. After 10 min of immersion in the solutions, the root canals were dried and filled with calcium hydroxide paste and the teeth were replanted. The animals were euthanized 60 days after replantation. The results showed that similar external root resorption was seen in the propolis and fluoride groups. Teeth treated with physiologic saline tended to have more inflammatory root resorption compared with those treated with fluoride or propolis. However, the comparative analysis did not reveal statistically significant differences (P > 0.05) between the treatment modalities when used for delayed tooth replantation. PMID:18721196

Gulinelli, Jéssica Lemos; Panzarini, Sônia Regina; Fattah, Cristiane Mara Ruiz de Sousa; Poi, Wilson Roberto; Sonoda, Celso Koogi; Negri, Márcia Regina; Saito, Célia Tomiko Matida Hamata

2008-12-01

236

The 4th international comparison on EPR dosimetry with tooth enamel  

Energy Technology Data Exchange (ETDEWEB)

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.

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

237

The 4th international comparison on EPR dosimetry with tooth enamel  

International Nuclear Information System (INIS)

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.

2011-09-01

238

In vitro efficacy and risk for adverse effects of light-assisted tooth bleaching.  

Science.gov (United States)

The use of optical radiation in the so-called light-assisted tooth bleaching procedures has been suggested to enhance the oxidizing effect of the bleaching agent, hydrogen peroxide. Documentation is scarce on the potential adverse effects of bleaching products and on optical exposure risks to eyes and skin. The efficacy of seven bleaching products with or without simultaneous use of seven different bleaching lamps was investigated using extracted human teeth. The bleaching effect was determined immediately after treatment and one week later. Tooth surfaces were examined for adverse alterations after bleaching using a scanning electron microscope. Source characteristics of eight lamps intended for tooth bleaching were determined. International guidelines on optical radiation were used to assess eye and skin exposure hazards due to UV and visible light emission from the lamps. Inspection of teeth one week after bleaching showed no difference in efficacy between teeth bleached with or without irradiation for any of the products. Scratches, probably from the cleaning procedure were frequently seen on bleached enamel irrespective of irradiation. Maximum permissible exposure time (t(max)) and threshold limit values were exceeded for about half the bleaching lamps investigated. One lamp exceeded t(max) even for reflected blue light within the treatment time. This lamp also exceeded t(max) values for UV exposure. The lamps were classified as "low risk" and as borderline to "moderate risk" according to a relevant lamp standard. PMID:19255679

Bruzell, Ellen M; Johnsen, Bjørn; Aalerud, Tommy Nakken; Dahl, Jon E; Christensen, Terje

2009-03-01

239

Terfenol-D tooth phone performance characterization and optimization  

Science.gov (United States)

A Terfenol-D transducer has been developed for use as a tooth phone with both sensing and actuating capabilities by Audiodontics, Inc. This research focuses on characterizing the sensitivity of the tooth phone's magnetostrictive Terfenol-D rod performance in both sensor and actuator modes to changes in the initial prestress of the device. A test apparatus was designed to allow prestress variability while operating the transducer as either a sensor or an actuator. To assess the sensor-mode performance, a force-feedback loop control system was used to excite the tooth phone with a constant force from a mechanical shaker at the tooth-tooth phone interface surface while measuring the voltage generated in the transducer's coil. The shaker was driven with a 200 Hz to 7 kHz swept sine at various dynamics force loadings for prestresses ranging from 0.25 to 3.5 ksi. The results indicate a prestress of 2 ksi offers the best sensor-mode performance. To assess the actuator performance, a accelerometer was attached to the tooth-tooth phone interface surface and output acceleration was recorded while sweeping the tooth phone excitation frequency from 200 Hz to 7 kHz with zero-to-peak voltages of 0.1, 0.3, and 0.5 V. The prestress settings were varied from 0.3 to 3.25 ksi. As an actuator, no prestress offered a significant broadband performance advantage. Finally, comparisons were made of the tooth phone and an accelerometer for measuring tooth vibrations induced during humming. They perform similarly and capture much of the frequency content found in concurrently recorded microphone data.

Staley, Mark E.; Flatau, Alison B.

2005-05-01

240

Fast image processing on chain board of inverted tooth chain  

Science.gov (United States)

Discussed ordinary image processing technology of inverted tooth chain board, including noise reduction, image segmentation, edge detection and contour extraction etc.. Put forward a new kind of sub-pixel arithmetic for edge orientation of circle. The arithmetic first did edge detection to image by Canny arithmetic, so as to enhance primary orientation precision of edge, then calculated gradient direction, and then interpolated gradient image (image that was detected by Sobel arithmetic) along gradient direction, last obtained sub-pixel orientation of edge. Performed two kinds of least-square fitting methods for line edge to getting its sub-pixel orientation, from analysis and experiments, the orientation error of improved least-square linear fitting method was one quarter of ordinary least-square linear fitting error under small difference of orientation time. The sub-pixel orientation of circle made resolution of CCD increase 42 tines, which enhanced greatly orientation precision of image edge. For the need of quick on-line inspection next step, integrated the whole environment containing image preprocess, Hough conversion of line, setting orientation & direction of image, sub-pixel orientation of line and circle, output of calculation result. The whole quick processing course performed without operator, processing tine of single part is less than 0.3 second. The sub-pixel orientation method this paper posed fits precision orientation of image, and integration calculation method ensure requirement of quick inspection, and lays the foundations for on-line precision visual measurement of image.

Liu, Qing-min; Li, Guo-fa

2007-11-01

 
 
 
 
241

Allogenic tooth transplantation inhibits the maintenance of dental pulp stem/progenitor cells in mice.  

Science.gov (United States)

Our recent study suggested that allogenic tooth transplantation may affect the maintenance of dental pulp stem/progenitor cells. This study aims to elucidate the influence of allograft on the maintenance of dental pulp stem/progenitor cells following tooth replantation and allo- or auto-genic tooth transplantation in mice using BrdU chasing, immunohistochemistry for BrdU, nestin and Ki67, in situ hybridization for Dspp, transmission electron microscopy and TUNEL assay. Following extraction of the maxillary first molar in BrdU-labeled animals, the tooth was immediately repositioned in the original socket, or the roots were resected and immediately allo- or auto-grafted into the sublingual region in non-labeled or the same animals. In the control group, two types of BrdU label-retaining cells (LRCs) were distributed throughout the dental pulp: those with dense or those with granular reaction for BrdU. In the replants and autogenic transplants, dense LRCs remained in the center of dental pulp associating with the perivascular environment throughout the experimental period and possessed a proliferative capacity and maintained the differentiation capacity into the odontoblast-like cells or fibroblasts. In contrast, LRCs disappeared in the center of the pulp tissue by postoperative week 4 in the allografts. The disappearance of LRCs was attributed to the extensive apoptosis occurring significantly in LRCs except for the newly-differentiated odontoblast-like cells even in cases without immunological rejection. The results suggest that the host and recipient interaction in the allografts disturbs the maintenance of dense LRCs, presumably stem/progenitor cells, resulting in the disappearance of these cell types. PMID:24671256

Saito, Kotaro; Nakatomi, Mitsushiro; Kenmotsu, Shinichi; Ohshima, Hayato

2014-05-01

242

Collagen analysis in human tooth germ papillae  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

243

Enfermedad de Charcot Marie Tooth en un niño Charcot-Marie-Tooth disease in a child  

Directory of Open Access Journals (Sweden)

Full Text Available Se presenta el caso clínico de un niño de 7 años de edad con enfermedad de Charcot Marie Tooth, atendido en el Servicio de Rehabilitación del Hospital Infantil Norte Docente "Dr. Juan de la Cruz Martínez Maceira" de Santiago de Cuba para recibir tratamiento rehabilitador. Luego del programa terapéutico aplicado el paciente mejoró el trofismo y la fuerza muscular, disminuyeron las deformidades del pie y ocurrieron importantes cambios en la marcha, de modo que la rehabilitación oportuna evitó el tratamiento quirúrgico.The case of a 7 year-old boy with Charcot- Marie-Tooth disease, who was attended at the Rehabilitation Department of "Dr. Juan de la Cruz Martínez Maceira" Northern Teaching Children Hospital in Santiago de Cuba for rehabilitation treatment is reported. After receiving a therapeutic program the patient improved his muscle strenght and trophism, foot deformities decreased and significant changes occurred in gait, so that timely rehabilitation prevented surgical treatment.

Teresa Vidal Pérez

2012-11-01

244

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Janczewski, D. N.; Yuhki, N.; Gilbert, D. A.; Jefferson, G. T.; O Brien, S. J.

1992-01-01

245

Restoration of a vertical tooth fracture and a badly mutilated tooth using canal projection  

Directory of Open Access Journals (Sweden)

Full Text Available Management of vertically fractured tooth or a perforation frequently poses problem during endodontic management. Such teeth often need a pre-endodontic restoration prior to initiation of root canal therapy to aid in the placement of rubber dam clamp. This paper describes a simple method of placement of a pre-endodontic restoration using the canal projection technique using hollow metallic needles as sleeves.

Velmurugan N

2007-01-01

246

Restoration of a vertical tooth fracture and a badly mutilated tooth using canal projection.  

Science.gov (United States)

Management of vertically fractured tooth or a perforation frequently poses problem during endodontic management. Such teeth often need a pre-endodontic restoration prior to initiation of root canal therapy to aid in the placement of rubber dam clamp. This paper describes a simple method of placement of a pre-endodontic restoration using the canal projection technique using hollow metallic needles as sleeves. PMID:17502715

Velmurugan, N; Bhargavi, N; Lakshmi, Neelima; Kandaswamy, D

2007-01-01

247

Morphological characterization of the tooth/adhesive interface  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Este estudo teve o objetivo de observar a morfologia da interface dente-restauração de diferentes sistemas adesivos em cavidades MOD, por microscopia eletrônica de varredura (MEV). A hipótese do estudo foi de que a morfologia da interface adesiva poderia variar nas diferentes regiões da cavidade MOD [...] , para algum dos 3 sistemas adesivos estudados. Preparos tipo MOD foram confeccionados em 12 terceiros molares humanos hígidos e restaurados com resina composta Filtek Z250 e os seguintes sistemas adesivos: ABF (n=4), Clearfil SE Bond (n=4) (sistemas adesivos autocondicionantes) e Single Bond (n=4) (sistema adesivo de condicionamento ácido total). Após 24 h de armazenamento em água destilada a 37ºC, os dentes foram secionados e preparados para MEV. A morfologia da interface de união variou com o sistema adesivo e com a região analisada. A hipótese do estudo foi aceita, pois a morfologia da interface de união refletiu as características do substrato dental e dos sistemas adesivos testados. Abstract in english The purpose of this study was to assess the morphological characteristics of the tooth/adhesive interface using different adhesive systems in MOD restorations under scanning electron microscopy (SEM). The tested hypothesis was that the morphology of the bonding interface would vary in different area [...] s of MOD restorations for the three adhesive systems. MOD cavities were prepared in 12 sound extracted human third molars and restored with Filtek Z250 composite resin and one of the following adhesive systems: Experimental ABF (n=4), Clearfil SE Bond (n=4) self-etching primers and Single Bond etch-and-rinse adhesive system (n=4). After 24-h storage in distilled water at 37ºC, teeth were sectioned and prepared for SEM. The interfacial morphology varied depending on the adhesive system and also on the evaluated area. The null hypothesis was accepted because the morphology of the tooth/adhesive interface reflected the characteristics of both the dental substrate and the adhesive systems.

Sandra Kiss, Moura; José Fortunato Ferreira, Santos; Rafael Yagüe, Ballester.

248

Autotransplantation of a Supernumerary Tooth to Replace a Misaligned Incisor with Abnormal Dimensions and Morphology: 2-Year Follow-Up  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Autotransplantation is a viable treatment option to restore esthetics and function impaired by abnormally shaped teeth when a suitable donors tooth is available. This paper describes the autotransplantation and 2-year follow-up of a supernumerary maxillary incisor as a replacement to a misaligned maxillary incisor with abnormal crown morphology and size. The supernumerary incisor was immediately autotransplanted into the extraction site of the large incisor and was stabilized with a bonded se...

Tirali, R. Ebru; Sar, Cagla; Ates, Ufuk; Kizilkaya, Metin; Cehreli, S. Burcak

2013-01-01

249

Unusual intraosseous transmigration of impacted tooth  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2012-03-15

250

Unusual intraosseous transmigration of impacted tooth  

International Nuclear Information System (INIS)

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.

2012-03-01

251

Abrasive Wear of Digger Tooth Steel  

Directory of Open Access Journals (Sweden)

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.

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

2011-08-01

252

Tooth structure and fracture strength of cavities  

DEFF Research Database (Denmark)

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 (Groups 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

Mondelli, José; Sene, Fábio

2007-01-01

253

Tooth loss and obstructive sleep apnoea  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Complete tooth loss (edentulism produces anatomical changes that may impair upper airway size and function. The aim of this study was to evaluate whether edentulism favours the occurrence of obstructive sleep apnoea (OSA. Methods Polysomnography was performed in 48 edentulous subjects on two consecutive nights, one slept with and the other without dentures. Upper airway size was assessed by cephalometry and by recording forced mid-inspiratory airflow rate (FIF50. Exhaled nitric oxide (eNO and oral NO (oNO, were measured as markers of airway and oropharyngeal inflammation. Results The apnoea/hypopnoea index (AHI without dentures was significantly higher than with dentures (17·4 ± 3·6 versus 11·0 ± 2·3. p = 0·002, and was inversely related to FIF50 (p = 0·017 and directly related to eNO (p = 0·042. Sleeping with dentures, 23 subjects (48% had an AHI over 5, consistent with OSA, but sleeping without dentures the number of subjects with abnormal AHI rose to 34 (71%. At cephalometry, removing dentures produced a significant decrease in retropharyngeal space (from 1·522 ± 0·33 cm to 1·27 ± 0·42 cm, p = 0·006. Both morning eNO and oNO were higher after the night slept without dentures (eNO 46·1 ± 8·2 ppb versus 33·7 ± 6·3 ppb, p = 0·035, oNO 84·6 ± 13·7 ppb versus 59·2 ± 17·4 ppb, p = 0·001. Conclusion These findings suggest that complete tooth loss favours upper airway obstruction during sleep. This untoward effect seems to be due to decrease in retropharyngeal space and is associated with increased oral and exhaled NO concentration.

Gai Valerio

2006-01-01

254

Mesiodistal tooth angulation to segmental occlusal plane in panoramic radiography  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2005-03-15

255

Comprehensive intermaxillary tooth width proportion of Bangkok residents  

Directory of Open Access Journals (Sweden)

Full Text Available Proper occlusion depends on the correct width ratio between upper and lower teeth, known as Bolton's ratio. In fact, this ratio can be calculated for each pair of teeth from the central incisor to the first permanent molar. This set of ratios, known as comprehensive cumulative percentage ratios (CPRs, can be used not only to determine which tooth or teeth have a tooth width discrepancy, but can also enable the partial graphical analysis of tooth width discrepancy when there is agenesis of certain permanent teeth. Although CPRs have been calculated for Caucasians, tooth width is known to vary depending on racial origin. Therefore, a test of differences between racial groups should be carried out. If these ratios of the Caucasians and Bangkokians are significantly different, the ratio of the Bangkokians is recommended. The objective of this study was to measure tooth size disproportion for Thai patients and to calculate a corresponding set of CPRs. Thirty-seven pairs of dental models were made from a group of Bangkok residents with normal occlusion. Mesiodistal tooth width was measured for each model. The intra- and inter-examiner measurement errors were ascertained as insignificant (p > 0.05. CPRs were then calculated and compared to those derived from other studies. Ten of thirteen CPRs were significantly different from corresponding values derived from Caucasians. We conclude that tooth width ratios vary between different racial groups, and therefore that these should be calculated specifically for each patient racial group.

Somchai Manopatanakul

2011-04-01

256

ATTITUDE AND KNOWLEDGE TOWARDS TOOTH AVULSION AMONG SPORTS TEACHERS  

Directory of Open Access Journals (Sweden)

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.

FARHEEN USTAD

2013-05-01

257

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.

2005-03-01

258

Supernumerary tooth in lower incisor region: A case report  

Directory of Open Access Journals (Sweden)

Full Text Available Supernumerary teeth are defined as any supplementary tooth in addition to usual configuration of twenty deciduous and thirty-two permanent teeth. They are most commonly found in the anterior maxilla and mandibular bicuspid region. Although supernumerary teeth have been reported in the incisor region of the mandible, they are very rare. It has been confirmed that approximately 25% of permanent supernumerary teeth appear in the mouth, the rest remains unerupted. The aim of this study was to present a case of single, erupted, supernumerary tooth in the right incisal region of the mandible. A patient showed up at the dental office complaining about aesthetic problem caused by a supernumerary tooth in mandibular incisal region. On intraoral examination, a supernumerary tooth, conical in shape and labially positioned, between the tooth 42 and 43, was observed. On previously taken panoramic radiogram, six months ago, the supernumerary tooth was undetected. Because the supernumerary tooth was masked by the denser overlying cortical bone, it was difficult to interpret the radiogram correctly. It should be noted that panoramic radiography does not guarantee accurate diagnosis of supernumerary teeth, therefore additional diagnostic methods are required.

Grga ?urica

2010-01-01

259

Anomalies of tooth formation in hypohidrotic ectodermal dysplasia.  

DEFF Research Database (Denmark)

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

Lexner, Michala O; Bardow, Allan

2007-01-01

260

Functional constraints on tooth morphology in carnivorous mammals  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The range of potential morphologies resulting from evolution is limited by complex interacting processes, ranging from development to function. Quantifying these interactions is important for understanding adaptation and convergent evolution. Using three-dimensional reconstructions of carnivoran and dasyuromorph tooth rows, we compared statistical models of the relationship between tooth row shape and the opposing tooth row, a static feature, as well as measures of mandibular motion during chewing (occlusion, which are kinetic features. This is a new approach to quantifying functional integration because we use measures of movement and displacement, such as the amount the mandible translates laterally during occlusion, as opposed to conventional morphological measures, such as mandible length and geometric landmarks. By sampling two distantly related groups of ecologically similar mammals, we study carnivorous mammals in general rather than a specific group of mammals. Results Statistical model comparisons demonstrate that the best performing models always include some measure of mandibular motion, indicating that functional and statistical models of tooth shape as purely a function of the opposing tooth row are too simple and that increased model complexity provides a better understanding of tooth form. The predictors of the best performing models always included the opposing tooth row shape and a relative linear measure of mandibular motion. Conclusions Our results provide quantitative support of long-standing hypotheses of tooth row shape as being influenced by mandibular motion in addition to the opposing tooth row. Additionally, this study illustrates the utility and necessity of including kinetic features in analyses of morphological integration.

Smits Peter D

2012-08-01

 
 
 
 
261

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)

2007-01-01

262

Tooth bleaching--a critical review of the biological aspects  

DEFF Research Database (Denmark)

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 the period of 1-8 years' observation time, from 10 to 40% of the initially successfully treated teeth needed re-treatment. Cervical root resorption is a possible consequence of internal bleaching and is more frequently observed in teeth treated with the thermo-catalytic procedure. When the external tooth-bleaching technique is used, the first subjective change in tooth color may be observed after 2-4 nights of tooth bleaching, and more than 90% satisfactory results have been reported. Tooth sensitivity is a common side-effect of external tooth bleaching observed in 15%-78% of the patients, but clinical studies addressing the risk of other adverse effects are lacking. Direct contact with hydrogen peroxide induced genotoxic effects in bacteria and cultured cells, whereas the effect was reduced or abolished in the presence of metabolizing enzymes. Several tumor-promoting studies, including the hamster cheek pouch model, indicated that hydrogen peroxide might act as a promoter. Multiple exposures of hydrogen peroxide have resulted in localized effects on the gastric mucosa, decreased food consumption, reduced weight gain, and blood chemistry changes in mice and rats. Our risk assessment revealed that a sufficient safety level was not reached in certain clinical situations of external tooth bleaching, such as bleaching one tooth arch with 35% carbamide peroxide, using several applications per day of 22% carbamide peroxide, and bleaching both arches simultaneously with 22% carbamide peroxide. The recommendation is to avoid using concentrations higher than 10% carbamide peroxide when one performs external bleaching. We advocate a selective use of external tooth bleaching based on high ethical standards and professional judgment.

Dahl, J E; Pallesen, Ulla

2003-01-01

263

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

Science.gov (United States)

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 the period of 1-8 years' observation time, from 10 to 40% of the initially successfully treated teeth needed re-treatment. Cervical root resorption is a possible consequence of internal bleaching and is more frequently observed in teeth treated with the thermo-catalytic procedure. When the external tooth-bleaching technique is used, the first subjective change in tooth color may be observed after 2-4 nights of tooth bleaching, and more than 90% satisfactory results have been reported. Tooth sensitivity is a common side-effect of external tooth bleaching observed in 15%-78% of the patients, but clinical studies addressing the risk of other adverse effects are lacking. Direct contact with hydrogen peroxide induced genotoxic effects in bacteria and cultured cells, whereas the effect was reduced or abolished in the presence of metabolizing enzymes. Several tumor-promoting studies, including the hamster cheek pouch model, indicated that hydrogen peroxide might act as a promoter. Multiple exposures of hydrogen peroxide have resulted in localized effects on the gastric mucosa, decreased food consumption, reduced weight gain, and blood chemistry changes in mice and rats. Our risk assessment revealed that a sufficient safety level was not reached in certain clinical situations of external tooth bleaching, such as bleaching one tooth arch with 35% carbamide peroxide, using several applications per day of 22% carbamide peroxide, and bleaching both arches simultaneously with 22% carbamide peroxide. The recommendation is to avoid using concentrations higher than 10% carbamide peroxide when one performs external bleaching. We advocate a selective use of external tooth bleaching based on high ethical standards and professional judgment. PMID:12907697

Dahl, J E; Pallesen, U

2003-01-01

264

Objective human tooth colour measurements as a means of determining chronologic age in vivo and ex vivo.  

Science.gov (United States)

Colour is a subjective sensation and as such is difficult to use in a quantitative study. However a number of clinical studies on extracted teeth have shown a good correlation between tooth colour and age. The purpose of this study was to examine the usefulness of a specific spectrophotometer in determining tooth colour on extracted and non- extracted teeth and to look for a possible age relationship. There were two parts in this study. An ex vivo study concentrated on collected tooth material. Single rooted teeth were selected out of each of the 5- year-age groups (ages ranged from 15-89 years). Colour measurements were performed on the mesial and vestibular aspects of the roots as well on the mid-vestibular aspects of the enamel crown. An in vivo study concentrated on the use of this specific shade taking system in living patients (n=70). Statistical analysis of the results revealed regression formulas for both ex vivo and in vivo situations displaying adjusted R-squares between 0.48 and 0.56. It may be concluded that age related trends were found. Having its shortcomings, the shade taking system was found to perform well as a convenient adjunct to dental age estimation in both the living and the deceased. PMID:22785092

Devos, N; Willems, G; Wood, R

2009-12-01

265

Unique case of a geminated supernumerary tooth with trifid crown  

Energy Technology Data Exchange (ETDEWEB)

Gemination, a relatively uncommon dental anomaly, is characterized by its peculiar representation as a tooth with a bifid crown and a common root and root canal. It usually occurs in primary dentition. To come across gemination in a supernumerary tooth is a rare phenomenon. The purpose of this paper is to present a unique case of hyperdontia wherein gemination in an impacted supernumerary tooth resulted in a trifid crown unlike the usual bifid crown. The role of conventional radiographs as well as computed tomography, to accurately determine the morphology and spatial location, and to arrive at a diagnosis, is also emphasized in this paper.

Ather, Amber; Ather, Hunaiza; Sheth, Sanket Milan; Muliya, Vidya Saraswathi [Manipal College of Dental Sciences, Manipal (Korea, Republic of)

2012-09-15

266

Unique case of a geminated supernumerary tooth with trifid crown  

International Nuclear Information System (INIS)

Gemination, a relatively uncommon dental anomaly, is characterized by its peculiar representation as a tooth with a bifid crown and a common root and root canal. It usually occurs in primary dentition. To come across gemination in a supernumerary tooth is a rare phenomenon. The purpose of this paper is to present a unique case of hyperdontia wherein gemination in an impacted supernumerary tooth resulted in a trifid crown unlike the usual bifid crown. The role of conventional radiographs as well as computed tomography, to accurately determine the morphology and spatial location, and to arrive at a diagnosis, is also emphasized in this paper.

2012-09-01

267

Effect of Cervical Lessions on the Tooth FEM Study  

Directory of Open Access Journals (Sweden)

Full Text Available The approach used until recently concerning the phenomena of dental abfraction points to the conclusion that the cervical area of the tooth, were this type of lesion usually occur, concentrates the stress resulted from the action of the forces applied on various areas on the crown. Moreover, any lesion in the cervical area facilitates the possibility of its advance into the tooth, ultimately fracturing it. Our paper presents a FEM (finite element method study on the results of a mechanical analysis of the phenomena involving the tooth damaged by cervical lesions.

Gabriela Bere?escu

2010-12-01

268

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

2001-11-01

269

Anti cariogenic efficacy of herbal and conventional tooth pastes - a comparative in-vitro study.  

Science.gov (United States)

Background: An upsurge of herbal products in various catalogues of fast moving consumer goods is evident. Dental creams or pastes which have numerous brands since years, have addition of many more herbal tooth pastes. Main claim of these herbal tooth pastes being effective reduction in cavities and plaque control. Proven fact is that proper brushing with a tooth brush and tooth paste brings down the caries incidence, and there is a substantial amount of contribution made by indispensable ingredient i.e, tooth pastes and their antibacterial component. Aim: To evaluate the antibacterial efficacy of various herbal tooth pastes available in the market and compare it with a conventional tooth paste with known antibacterial effect. Materials & Methods: The antibacterial efficacy of five herbal tooth pastes and two conventional tooth pastes with different ingredients was evaluated by the zone of inhibition created around the disc on the culture plates against streptococcus mutans and lactobacillus acidophilus. Results: The herbal tooth pastes showed similar efficacy as that of the conventional tooth pastes. One herbal tooth paste with multiple herbal ingredients had greater zone of inhibition compared to the conventional tooth pastes and other herbal tooth pastes. Conclusion: Herbal tooth pastes have similar antibacterial effect as conventional tooth pastes. Tooth paste with multiple herbal ingredients is more efficient than the tooth pastes with fewer herbal ingredients in an anticariogenic property. Key words: Anti-carcinogenicity, Herbal tooth pastes, Plaque Control. How to cite this article: Mohan Kumar K P, Priya N K, Madhushankari G S. Anti Cariogenic Efficacy of Herbal and Conventional Tooth Pastes - A Comparative In-Vitro Study. J Int Oral Health 2013; 5(2):8-13. PMID:24155585

K P, Mohankumar; N K, Priya; G S, Madhushankari

2013-04-01

270

Silica nanoparticles to polish tooth surfaces for caries prevention.  

Science.gov (United States)

Although silica particles have been used for tooth polishing, polishing with nanosized particles has not been reported. Here we hypothesize that such polishing may protect tooth surfaces against the damage caused by cariogenic bacteria, because the bacteria can be easily removed from such polished surfaces. This was tested on human teeth ex vivo. The roughness of the polished surfaces was measured with atomic force microscopy (AFM). A considerably lower nanometer-scale roughness was obtained when silica nanoparticles were used to polish the tooth surfaces, as compared with conventional polishing pastes. Bacterial attachment to the dental surfaces was studied for Streptococcus mutans, the most abundant cariogenic bacteria. We demonstrated that it is easier to remove bacteria from areas polished with silica nanoparticles. The results demonstrate the advantage of using silica nanoparticles as abrasives for tooth polishing. PMID:18809755

Gaikwad, R M; Sokolov, I

2008-10-01

271

About Kids' Teeth: Baby Tooth Decay is Real  

Medline Plus

Full Text Available ... sure they spit out the toothpaste. Baby Teeth Are Important Kids need strong, healthy baby teeth to ... good news – decay is mostly preventable . What Are Cavities? Causes of Decay Tooth decay begins when ...

272

About Kids' Teeth: Baby Tooth Decay is Real  

Medline Plus

Full Text Available ... sucking Prevent Decay Nutrition Baby Tooth Decay Is Real As soon as teeth appear in your baby’s ... may drift into the empty space. When it's time for the other permanent teeth to come in, ...

273

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)

2002-08-01

274

About Kids' Teeth: Baby Tooth Decay is Real  

Medline Plus

Full Text Available ... the teeth can decay. Pacifiers dipped in sugar, honey or sweetened liquids can also lead to tooth decay since the sugar or honey can provide food for the bacteria’s acid attacks.

275

About Kids' Teeth: Baby Tooth Decay is Real  

Medline Plus

Full Text Available ... baby teeth. Keep Baby’s Gums and Teeth Clean Begin cleaning your baby's mouth during the first few ... What Are Cavities? Causes of Decay Tooth decay begins when cavity-causing bacteria is passed to an ...

276

About Kids' Teeth: Baby Tooth Decay is Real  

Medline Plus

Full Text Available ... Learn about Thumb Sucking and Pacifiers 6 – 12 Years Old From around ages 6 - 12, children ... to arrive. Learn about Preventing Kids' Tooth Decay 12 – 17 Years Old Cavities aren’t just ...

277

Retrospective individual dosimetry using EPR of tooth enamel  

International Nuclear Information System (INIS)

The results of joint investigations (in the framework of ECP-10 program) aimed on the improvement of the sensitivity and accuracy of the procedure of dose measurement using tooth enamel EPR spectroscopy are presented. It is shown, what the sensitivity of method may be increased using special physical-chemical procedure of the enamel samples treatment, which leads to the reducing of EPR signal of organic components in enamel. Tooth diseases may have an effect on radiation sensitivity of enamel. On the basis of statistical analysis of the results of more then 2000 tooth enamel samples measurements it was shown, what tooth enamel EPR spectroscopy gives opportunity to register contribution into total dose, which is caused by natural environmental radiation and by radioactive contamination. EPR response of enamel to ultraviolet exposure is investigated and possible influences to EPR dosimetry is discussed. The correction factors for EPR dosimetry in real radiation fields are estimated

1996-03-18

278

Wisdom teeth extraction in a patient with moyamoya disease  

Science.gov (United States)

Moyamoya disease is a rare neurovascular disorder that involves constriction of certain arteries in the brain. In patients with moyamoya disease, it is very important to prevent cerebral ischemic attacks and intracerebral bleeding caused by fluctuating blood pressure and increased respiration. A 40-year-old woman with moyamoya disease was scheduled for extraction of her right upper and lower impacted wisdom teeth. Her lower impacted wisdom tooth was situated close to the inferior alveolar nerve. We decided to continue her oral antiplatelet therapy and planned intravenous sedation with analgesic agents administered approximately five minutes prior to extraction of the root of the mandibular wisdom tooth. Oral analgesic medications were regularly administered postoperatively to alleviate pain and anxiety. During the perioperative period, no cerebrovascular event occurred, and the wisdom teeth were successfully extracted as per the planned procedure. It is thought that the perioperative risks of wisdom tooth extraction in patients with moyamoya disease can be minimized with the use of our protocols.

Aoyagi, Naoko; Koga, Sayo; Kikuta, Toshihiro

2013-01-01

279

Development of a device to simulate tooth mobility  

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Objectives: The testing of new materials under simulation of oral conditions is essential in medicine. For simulation of fracture strength different simulation devices are used for test set-up. The results of these in vitro tests differ because there is no standardization of tooth mobility in simulation devices. The aim of this study is to develop a simulation device that depicts the tooth mobility curve as accurately as possible and creates reproducible and scalable mobility curves. Material...

Erdelt, Kurt-juergen; Lamper, Timea

2010-01-01

280

3D-Geomorphometrics tooth shape analysis in hypodontia.  

Science.gov (United States)

Assessment of tooth morphology is an important part of the diagnosis and management of hypodontia patients. Several techniques have been used to analyze tooth form in hypodontia patients and these have shown smaller tooth dimensions and anomalous tooth shapes in patients with hypodontia when compared with controls. However, previous studies have mainly used 2D images and provided limited information. In the present study, 3D surface-imaging and statistical shape analysis were used to evaluate tooth form differences between hypodontia and control patients. Eighteen anatomical landmarks were recorded on the clinical crown of the lower left first permanent molar of 3D scanned study models of hypodontia and control subjects. The study sample group comprised of 120 hypodontia patients (40 mild, 40 moderate, and 40 severe hypodontia patients) and 40 age- and sex-matched controls. Procrustes coordinates were utilized to scale and superimpose the landmark coordinate data and then were subjected to principal component analysis (PCA). Subsequently, differences in shape as well as size were tested statistically using allometric analysis and MANOVA. Significant interaction was found between the two factor variables "group" and "sex" (p < 0.002). Overall expected accuracies were 66 and 56% for females and males, respectively, in the cross-validated discriminant-analysis using the first 20 PCs. Hypodontia groups showed significant shape differences compared with the control subjects (p < 0.0001). Significant differences in tooth crown shape were also found between sexes (p < 0.0001) within groups. Furthermore, the degree of variation in tooth form was proportional to the degree of the severity of the hypodontia. Thus, quantitative measurement of tooth shape in hypodontia patients may enhance the multidisciplinary management of those patients. PMID:24795649

Al-Shahrani, Ibrahim; Dirks, Wendy; Jepson, Nicholas; Khalaf, Khaled

2014-01-01

 
 
 
 
281

Moxel: A molar tooth voxel model for dosimetric studies  

International Nuclear Information System (INIS)

Stylized numerical models of the tooth are usually employed in qualification procedure related to Electronic Paramagnetic Resonance in long-term accidental contamination dose reconstruction. In this work a voxel model was developed from the microCT image data set of a human non contaminated molar tooth. A stylized model, reproducing the characteristics of the voxel model, was also created in order to investigate the level of accuracy that can be obtained in this kind of study.

2010-02-01

282

Interdisciplinary Treatment of a Fused Lower Premolar with Supernumerary Tooth  

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The objective of this report is to describe combined orthodontic and endodontic treatment of a fused mandibular premolar with supernumerary tooth. The patient was a 15 year old girl seeking orthodontic treatment for the correction of maxillary and mandibular crowding. Cephalometric examination revealed skeletally Class I relationship. The panoramic radiograph showed a fused tooth with two separate pulp chambers and two separate root canals connecting in apical third. After the endodontic trea...

Gadimli, Cengiz; Sari, Zafer

2011-01-01

283

Ectopic Supernumerary Tooth in Nasal Septum: A Case Study  

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Introduction: Nasal teeth eruption is a rare phenomenon. The variability of symptoms and generic history makes the diagnosis difficult. This difficulty is more challenging when the tooth is placed in the depth of septum.   Case Report: Our case is an example of this problem. Herein, we present a case of intraseptal tooth with nasal obstruction and septal deviation and recurrent sinusitis. We present preoperative imaging.   Conclusion: Great suspicion may helpful for preoperative diagnosis a...

Saleh Mohebbi; Oveis Salehi; Sedighe Ebrahimpoor

2013-01-01

284

A conservative approach toward restoration of fractured anterior tooth  

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Reattachment of the fractured anterior tooth is a highly conservative and aesthetic treatment that has gained popularity in the recent past. Presented here is one such case in which a combination of external enamel bevel and internal dentinal groove has been used to enhance the bonding between the fractured fragment and the remaining tooth. The treatment was found to be successful both functionally and aesthetically at the 18-month follow-up.

Goenka, Puneet; Sarawgi, Aditi; Dutta, Samir

2012-01-01

285

Burried broken extraction instrument fragment  

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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...

Balaji, S. M.

2013-01-01

286

Is there a link between ovarian cancer and tooth agenesis?  

Science.gov (United States)

An epidemiologic study from the year 2008 found a highly significant increase of congenital tooth agenesis in women with ovarian cancer suggesting that a common genetic etiology may predispose women to both conditions. The finding was reminiscent of a previously described family harboring an AXIN2 mutation which could be shown to segregate with both the tooth agenesis and the predisposition to colon cancer transmitted in this family. Since tooth agenesis as a marker for susceptibility to ovarian cancer would be of great relevance to both oncologists and women with inborn missing teeth, the relationship between the two disorders requires a thorough assessment. We examined DNA samples from the ovarian cancer patients who participated in the original study, to look for a possible genetic connection between their ovarian malignancies and tooth agenesis. MSX1, PAX9, AXIN2, EDA, WNT10A, BARX and BRCA1 genes were selected for sequence analysis as they may cause tooth agenesis, are expressed in the female reproductive system, and/or are involved in tumorigenesis in general or specifically in the ovary. Our study revealed evidence that one half of the dually affected patients had an independent causation of the two conditions, thus reducing the previously estimated ovarian cancer risk for women with congenital tooth agenesis quite significantly. PMID:24631698

Bonds, John; Pollan-White, Sarah; Xiang, Lilin; Mues, Gabriele; D'Souza, Rena

2014-04-01

287

R-spondins/Lgrs expression in tooth development.  

Science.gov (United States)

Background: Tooth development is highly regulated in mammals and it is regulated by networks of signaling pathways (e. g. Tnf, Wnt, Shh, Fgf and Bmp) whose activities are controlled by the balance between ligands, activators, inhibitors and receptors. The members of the R-spondin family are known as activators of Wnt signaling, and Lgr4, Lgr5, and Lgr6 have been identified as receptors for R-spondins. The role of R-spondin/Lgr signaling in tooth development, however, remains unclear. Results: We first carried out comparative in situ hybridization analysis of R-spondins and Lgrs, and identified their dynamic spatio-temporal expression in murine odontogenesis. R-spondin2 expression was found both in tooth germs and the tooth-less region, the diastema. We further examined tooth development in R-spondin2 mutant mice, and although molars and incisors exhibited no significant abnormalities, supernumerary teeth were observed in the diastema. Conclusions: R-spondin/Lgr signaling is thus involved in tooth development. Developmental Dynamics 243:844-851, 2014. © 2014 Wiley Periodicals, Inc. PMID:24616052

Kawasaki, Maiko; Porntaveetus, Thantrira; Kawasaki, Katsushige; Oommen, Shelly; Otsuka-Tanaka, Yoko; Hishinuma, Mitsue; Nomoto, Takato; Maeda, Takeyasu; Takubo, Keiyo; Suda, Toshio; Sharpe, Paul T; Ohazama, Atsushi

2014-06-01

288

Young's modulus and hardness of shark tooth biomaterials.  

Science.gov (United States)

To date, the majority of studies on feeding mechanics in sharks have focused on the movement of cranial components and muscle function, with little attention to tooth properties or function. Attributes related to mechanical properties, such as structural strength, may also be subjected to natural selection. Additionally it is necessary to characterize these properties in order to construct biomechanical models of tooth function. The goal of this study was to determine hardness and elastic modulus for the shark tooth materials enameloid, osteodentine, and orthodentine. Five teeth each from one carcharhiniform species, the bonnethead Sphyrna tiburo, and one lamniform, the sand tiger shark Carcharias taurus, were utilized for nanoindentation testing. Each tooth was sectioned transversely, air-dried, and polished. Both enameloid and dentine were tested on each tooth via a Berkovich diamond tip, with nine 2 microm deep indentations per material. t-Tests were used to determine if there were differences in hardness and Young's modulus between the tooth materials of the two species. There was no significant difference between the two species for the material properties of enameloid, however both hardness and Young's modulus were higher for osteodentine than for orthodentine. This may be due to differences in microanatomy and chemical composition, however this needs to be studied in greater detail. PMID:20102762

Whitenack, Lisa B; Simkins, Daniel C; Motta, Philip J; Hirai, Makoto; Kumar, Ashok

2010-03-01

289

The relat ionship between denta l fluorosis and tooth fluoride concentrat ion – A study in an endemic area  

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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 DFseverity, 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 goodpredictor/indicator of DF severity.

Marc Daniel Grynpas

2011-12-01

290

Tooth cementum annulation method: accuracy and applicability.  

Science.gov (United States)

Tooth cementum annulation (TCA) technique has been a frequently discussed method for the individual age estimation. Conflicting statements on its accuracy and applicability in previous publications have provoked our research. The accuracy and bias of the TCA age estimates were examined in a sample of 116 teeth from 65 individuals of known age and sex from the anatomical collection of the University of Tubingen (Germany). Incremental lines were counted on enhanced digital images of undecalcified, unstained, 60-80 microm thick cross-sections from the middle third of the root of single-rooted teeth. Maximal line counts resulted in age estimates that correlated best with the real age of the specimens. In this sample, this argument is supported by the observation that the mean number of lines increased significantly from the most cervical to the most apical section. Reasonably accurate age estimates based on TCA counts were only obtained in young adults. Both accuracy and bias continuously decreased with the increasing age of the individuals. A considerable underestimation of age occurred in individuals older than 40 years. Due to the conflicting results on the accuracy of the TCA technique this method should be used for age estimation only in association with the macroscopic examination. PMID:19828994

Obertová, Zuzana; Francken, Michael

2009-01-01

291

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

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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 cor...

Ferhan Egilmez; Levent Nalbant

2012-01-01

292

Effects of KTP Laser Bleaching on Traumatized Tooth Enamel  

Science.gov (United States)

Background: Bleaching of traumatized discolored teeth is considered an important issue in esthetic dentistry. Various methods have been introduced for bleaching, some of which may have adverse effects on soft or hard tissues of the tooth. Objectives: The objective of the study was to evaluate the effects of KTP laser bleaching on enamel of traumatized teeth. Materials and Methods: A square of 36 mm2 was chosen on the labial surface of 32 extracted teeth. The corners were drilled in order to indicate the location precisely. The shade of each sample was recorded and the teeth were divided into four groups, each with eight teeth: group A (Smartbleach with KTP laser for 30 seconds), group B (Smartbleach with G-Light for 5 minutes), group C (only Smartbleach for 10 minutes) and group D (control group with no bleaching). After one session of bleaching, shade assessment was performed again. In another experiment on nine teeth, Smartbleach with KTP laser was used for 150 seconds to 1500 seconds. The samples were critically processed and observed by using scanning electron microscope (SEM) to assess enamel damage. Data was statistically analyzed using Kruskal-Wallis test (confidence interval level were set at 95%). Results: Smartbleach was highly effective when used with KTP laser (P = 0.0419). Enamel damage was observed after frequent KTP bleaching and 750 seconds of KTP bleaching was recognized as the limit by morphological evaluation via SEM, indicating a major difference between under and over 750 seconds of bleaching. Conclusions: Application of KTP laser may increase the bleaching effect of Smartbleach, nevertheless it may cause some enamel damage.

Kinoshita, Jun-Ichiro; Jafarzadeh, Hamid; Manabe, Atsufumi; Nozawa, Miki; Uchida, Tokiko; Abbott, Paul Vincent

2014-01-01

293

Use of ultrasound Doppler to determine tooth vitality in a discolored tooth after traumatic injury: its prospects and limitations.  

Science.gov (United States)

When a tooth shows discoloration and does not respond to the cold test or electric pulp test (EPT) after a traumatic injury, its diagnosis can be even more difficult due to the lack of proper diagnostic methods to evaluate its vitality. In these case reports, we hope to demonstrate that ultrasound Doppler might be successfully used to evaluate the vitality of the tooth after trauma, and help reduce unnecessary endodontic treatments. In all three of the present cases, the teeth were discolored after traumatic injuries and showed negative responses to the cold test and EPT. However, they showed distinctive vital reactions in the ultrasound Doppler test during the whole observation period. In the first case, the tooth color returned to normal, and the tooth showed a positive response to the cold test and EPT at 10 wk after the injury. In the second case, the tooth color had returned to its normal shade at 10 wk after the traumatic injury but remained insensitive to the cold test and EPT. In the third case, the discoloration was successfully treated with vital tooth bleaching. PMID:24516833

Cho, Yong-Wook; Park, Sung-Ho

2014-02-01

294

Pattern of tooth loss in recipients of free dental treatment at the University Hospital of Amman, Jordan.  

Science.gov (United States)

The aim of this study is to document reasons for tooth loss in disadvantaged Jordanians who seek free dental care at the University Hospital/Dental Clinics. A 4-year (1998-2001) prospective study was undertaken involving 2200 randomly selected patients from this subpopulation. Of their 3069 lost teeth, 46.9% were lost due to caries and its sequel; 18% were lost because of periodontal disease; 8% were lost for a combination of caries and periodontal disease; 19.4% for pre-prosthetic reasons; 4% for orthodontic reasons; 2.8% for eruption problems and 0.7% due to trauma. Logistic regression analysis for reasons of tooth loss in this sector revealed that caries and its sequel was the predominant cause of tooth loss in patients periodontal extractions were predominant for the above 40-year-old group. In addition, the most frequently extracted teeth, due to caries, were lower first and second molars while lower incisors were most commonly extracted for periodontal disease. Premolars were extracted for orthodontic reasons, upper incisors for trauma, third molars for eruption problems and canines for pre-prosthetic reasons. In conclusion, dental caries was the main reason for removal of teeth in adults attending the University of Jordan free dental casualty clinic. Therefore, in order to reduce the rate of dental extractions in this sector of the Jordanian population, efforts should focus on prevention and treatment of caries. Efforts should also be made to change the values and beliefs of this sector towards the importance of natural dentition. PMID:15009595

Sayegh, A; Hilow, H; Bedi, R

2004-02-01

295

Enfermedad de Charcot Marie Tooth en un niño / Charcot-Marie-Tooth disease in a child  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se presenta el caso clínico de un niño de 7 años de edad con enfermedad de Charcot Marie Tooth, atendido en el Servicio de Rehabilitación del Hospital Infantil Norte Docente "Dr. Juan de la Cruz Martínez Maceira" de Santiago de Cuba para recibir tratamiento rehabilitador. Luego del programa terapéut [...] ico aplicado el paciente mejoró el trofismo y la fuerza muscular, disminuyeron las deformidades del pie y ocurrieron importantes cambios en la marcha, de modo que la rehabilitación oportuna evitó el tratamiento quirúrgico. Abstract in english The case of a 7 year-old boy with Charcot- Marie-Tooth disease, who was attended at the Rehabilitation Department of "Dr. Juan de la Cruz Martínez Maceira" Northern Teaching Children Hospital in Santiago de Cuba for rehabilitation treatment is reported. After receiving a therapeutic program the pati [...] ent improved his muscle strenght and trophism, foot deformities decreased and significant changes occurred in gait, so that timely rehabilitation prevented surgical treatment.

Vidal Pérez, Teresa; Ragolta Mógrave, Katiuska; Jhones Cabrales, Hilda Alicia; Perdomo Veranes, Pastor; Uriarte Gómez, Manuel.

296

Experimental Investigation of Sprocket Tooth Form Effect on Dynamic Tension of Silent Chain  

Directory of Open Access Journals (Sweden)

Full Text Available The study's aim was to get ANSI sprocket tooth profile and involute sprocket tooth profile for effects on dynamic tension of chains in the silent chain drive, and analyse and compare the advantages and disadvantages of the different tooth profiles to choose more practical tooth profile from the two sprockets. Current collector was used to test the dynamic tension when straight sprocket and involute sprocket engaged with the same silent chain. And experimental data measured were analyzed in the amplitude domain and frequency domain. Test results indicate that the probability of tension appearing in the different numerical size and power spectral densities of load in the different frequencies of the involute tooth form are better than of straight tooth form, which show that the involute sprocket has been good working properties. In addition, taking the advantages of involute tooth profile into account in the process, the involute tooth form is recommended in universal sprocket tooth form of the actual use.

Wei Sun

2012-04-01

297

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

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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.

Kakoei S.

2012-02-01

298

Comprehensive intermaxillary tooth width proportion of Bangkok residents  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Proper occlusion depends on the correct width ratio between upper and lower teeth, known as Bolton's ratio. In fact, this ratio can be calculated for each pair of teeth from the central incisor to the first permanent molar. This set of ratios, known as comprehensive cumulative percentage ratios (CPR [...] s), can be used not only to determine which tooth or teeth have a tooth width discrepancy, but can also enable the partial graphical analysis of tooth width discrepancy when there is agenesis of certain permanent teeth. Although CPRs have been calculated for Caucasians, tooth width is known to vary depending on racial origin. Therefore, a test of differences between racial groups should be carried out. If these ratios of the Caucasians and Bangkokians are significantly different, the ratio of the Bangkokians is recommended. The objective of this study was to measure tooth size disproportion for Thai patients and to calculate a corresponding set of CPRs. Thirty-seven pairs of dental models were made from a group of Bangkok residents with normal occlusion. Mesiodistal tooth width was measured for each model. The intra- and inter-examiner measurement errors were ascertained as insignificant (p > 0.05). CPRs were then calculated and compared to those derived from other studies. Ten of thirteen CPRs were significantly different from corresponding values derived from Caucasians. We conclude that tooth width ratios vary between different racial groups, and therefore that these should be calculated specifically for each patient racial group.

Manopatanakul, Somchai; Watanawirun, Narumon.

299

The challenges of treating a fused tooth  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

300

Tooth structure and fracture strength of cavities  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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

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

 
 
 
 
301

Metabolism in tooth enamel and reliability of retrospective EPR dosimetry connected with Chernobyl accident  

International Nuclear Information System (INIS)

It is shown that the results of retrospective EPR dosimetry by tooth enamel are essentially determined by the fact that tooth enamel is the mineral of biological origin. The structure of tooth enamel, properties of radiation defects and the role of metabolism in tooth enamel are discussed. It is shown that at deep metamorphic modifications tooth enamel don't save information about its radiation history. The reliability and accuracy of retrospective EPR dosimetry are discussed. Because after Chernobyl accident have passed 10 years the application of tooth enamel for reconstruction of doses which are connected with Chernobyl accident need care and additional investigations

1996-03-18

302

Gingival crevicular fluid flow rate and alkaline phosphatase level as potential marker of active tooth movement.  

Science.gov (United States)

Background: Gingival Crevicular Fluid (GCF) changes occur during orthodontic tooth movement and this could serve as a potential indicator to the response to active treatment. Aim: The objective of the study is to assess the changes in the GCF volume and the levels of Alkaline Phosphatase (ALP) during early phase of tooth movement. Methods: 20 patients requiring all first premolar extractions were selected and treated with conventional straight wire mechanotherapy. Canine retraction was done using Nitinol closed coil springs. Maxillary canine on one side acted as experimental site while the contralateral canine acted as control. GCF was collected from around the canines before initiation of retraction, 1 hour after initiating canine retraction, 1 day, 7 days, 14 days and 21 days. GCF volume and the ALP levels were estimated and compared with the control side. Results: The results showed statistically significant changes in the GCF volume and ALP levels on the 7(th), 14(th) and 21(st) days at the experimental sides. The peak in the activity occurred on the 14(th) day of initiation of retraction. The GCF volume and ALP levels did not show any significant variations at the control sites where no retraction was done. Conclusions: It can be concluded that GCF volume and ALP levels may serve as an indicator to assess tooth movement dynamics in orthodontic therapy. Based on the available data and further studies, ALP levels in GCF may aid in developing a reliable non-invasive chair side test for assessing the prognosis and progress of orthodontic therapy. PMID:24984665

Alfaqeeh, S A; Sukumaran, Anil

2014-06-01

303

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

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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.

Beheshteh Malekafzali Malekafzali

2013-01-01

304

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

Science.gov (United States)

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 (?SBS) 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 ?SBS to primary tooth dentin.

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

2013-01-01

305

Dento-Alveolar distraction osteogenesis using rigid intra-oral tooth borne distraction device.  

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Background: The aim of this clinical prospective study is to apply and evaluate an approach to reduce the overall orthodontic treatment time, by means of dentoalveolar distraction osteogenesis to achieve rapid canine retraction using an indigenously developed intra-oral tooth-borne distraction device. Materials & Methods: This study was carried out in the Department of Orthodontics and Dentofacial Orthopedics. Four patients selected for the purpose of Maxillary and/or Mandibular canine distraction with a rigid custom-made, intra-oral distraction device made of stainless steel and were scheduled for orthodontic treatment with bilateral first premolar extraction and then subsequent bilateral canine teeth distalization. Results: In all the patients the canine teeth moved distally and made contact with the second premolars within 14-16 days range after which they were kept passive, with the appliance for a week of consolidation. The amount of canine retraction was in 7-7.5mms range, in all the patients, in each of the four quadrants studied. Bodily movement, tipping and buccal flaring of the canine teeth were noticed in all the cases. Conclusion: Combination of newer orthodontic appliances and the principles of biomechanics to maintain the control over rapid tooth movement, rapid canine distalization using distraction osteogenesis awaits further development before routine application, of this innovative and exciting approach. How to cite the article: Nair A, Kumar JP, Venkataramana V, Yuvaraj A, Reddy VS, Kumar SK. Dento-Alveolar distraction osteogenesis using rigid intra-oral tooth borne distraction device. J Int Oral Health 2014;6(2):106-13. PMID:24876710

Nair, Arvind; Kumar, J Phani; Venkataramana, V; Yuvaraj, A; Reddy, V Sridhar; Kumar, S Kishore

2014-04-01

306

Dento-Alveolar distraction osteogenesis using rigid intra-oral tooth borne distraction device  

Science.gov (United States)

Background: The aim of this clinical prospective study is to apply and evaluate an approach to reduce the overall orthodontic treatment time, by means of dentoalveolar distraction osteogenesis to achieve rapid canine retraction using an indigenously developed intra-oral tooth-borne distraction device. Materials & Methods: This study was carried out in the Department of Orthodontics and Dentofacial Orthopedics. Four patients selected for the purpose of Maxillary and/or Mandibular canine distraction with a rigid custom-made, intra-oral distraction device made of stainless steel and were scheduled for orthodontic treatment with bilateral first premolar extraction and then subsequent bilateral canine teeth distalization. Results: In all the patients the canine teeth moved distally and made contact with the second premolars within 14-16 days range after which they were kept passive, with the appliance for a week of consolidation. The amount of canine retraction was in 7-7.5mms range, in all the patients, in each of the four quadrants studied. Bodily movement, tipping and buccal flaring of the canine teeth were noticed in all the cases. Conclusion: Combination of newer orthodontic appliances and the principles of biomechanics to maintain the control over rapid tooth movement, rapid canine distalization using distraction osteogenesis awaits further development before routine application, of this innovative and exciting approach. How to cite the article: Nair A, Kumar JP, Venkataramana V, Yuvaraj A, Reddy VS, Kumar SK. Dento-Alveolar distraction osteogenesis using rigid intra-oral tooth borne distraction device. J Int Oral Health 2014;6(2):106-13.

Nair, Arvind; Kumar, J Phani; Venkataramana, V; Yuvaraj, A; Reddy, V Sridhar; Kumar, S Kishore

2014-01-01

307

Tooth wear among patients suffering from mental disorders  

Science.gov (United States)

Summary Aim Assess oral health, treatment needs and the correlation between tooth wear and medications in patients with psychiatric disease. Methodology 92 patients (40 male and 52 female) admitted in the Department of Neurology and Psychiatry of the Umberto I Hospital of Rome underwent an oral and dental clinical examination in accordance according to World Health Organization Basic Methods Criteria. One dentist performed all clinical examinations, training and calibration was carried out by an experienced clinical examiner. To measure the degree of inter-examiner agreement Kappa statistics was calculated. Level of tooth wear was assessed using the tooth wear classification of Johansson et al. Exact psychiatric pathology and medications of each patient were registrated. The Statistical Package for the Social Sciences (SPSS Inc., Chicago, Ill.) was used to analyze the data. A value of P < 0.05 was considered statistically significant. Results 34.78% of the sample regarding tooth wear demonstrated score 2. Men demonstrated 30% score 2, and 20% score 3 and 4 whereas female patients 38.46% score 2, 7.69% score 3 and none score 4. Conclusions Chronic exposure to neuroleptic drugs can cause phenomena of bruxism. There is a direct correlation between tooth wear, psychiatric disorders and administration of certain drugs. Poor oral hygiene and extensive unmet needs for dental treatment were widespread among psychiatric patients.

Piccoli, Luca; Besharat, Laith Konstantinos; Cassetta, Michele; Migliau, Guido; Di Carlo, Stefano; Pompa, Giorgio

2014-01-01

308

Delayed tooth replantation after traumatic avulsion: a case report.  

Science.gov (United States)

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 paste was applied as intracanal medicament. After one year the calcium hydroxide was not replaced and was maintained in the canal, permanently. The tooth followed for 5 years. During follow up, the tooth kept stable. However, the resulted dent alveolar ankylosis prevented growth of the alveolar process. Spite of the fact that in children, replacement resorption leads to the loss of ankylosed teeth within 1-5 years; this tooth has remained in a stable, infra-position for 5 year and in functional position after coronal restoration. However, in such cases other treatments such as decoronation should be considered. PMID:24146677

Khalilak, Zohreh; Shikholislami, Mahshid; Mohajeri, Ladan

2008-01-01

309

3D - Geomorphometrics tooth shape analysis in hypodontia  

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Full Text Available Assessment of tooth morphology is an important part of the diagnosis and management of hypodontia patients. Several techniques have been used to analyze tooth form in hypodontia patients and these have shown smaller tooth dimensions and anomalous tooth shapes in patients with hypodontia when compared with controls. However, previous studies have mainly used 2D images and provided limited information. In the present study, 3D surface-imaging and statistical shape analysis were used to evaluate tooth form differences between hypodontia and control patients. Eighteen anatomical landmarks were recorded on the clinical crown of the lower left first permanent molar of 3D scanned study models of hypodontia and control subjects. The study sample group comprised of 120 hypodontia patients (40 mild, 40 moderate and 40 severe hypodontia patients and 40 age- and sex-matched controls. Procrustes coordinates were utilized to scale and superimpose the landmark coordinate data and then were subjected to principal component analysis (PCA. Subsequently, differences in shape as well as size were tested statistically using allometric analysis and MANOVA. Significant interaction was found between the two factor variables “group” and “sex” (p

WendyDirks

2014-04-01

310

Initial observations of cheek tooth abnormalities in sheep in Slovenia.  

Science.gov (United States)

Observations were made on a small flock of 50 sheep of the native Slovenian Jezersko-Solcava breed by investigators with dental training. The aim was to determine the range of naturally occurring dental diseases, so postmortem examinations were performed on animals slaughtered for meat or culled due to disease. Additional data were obtained by examination of 25 specimens submitted for investigation of unexplained death at a pathology centre. Seventeen (34 per cent) of the flock had incisor disease but only five became clinically ill; all these five had advanced cheek tooth disease (gingival recession, periodontal pocketing, diastemata, missing teeth, occlusal wear abnormalities, food impaction, tooth mobility, tooth fracture, tooth loss and/or jaw abscessation). Advanced cheek tooth disease was found in 21 (84 per cent) of the sheep submitted to the pathology laboratory, while only seven (28 per cent) had advanced incisor disease. The results show that, as in other countries, dental disease is a serious problem for sheep in Slovenia. PMID:20656992

Erjavec, V; Crossley, D

2010-07-24

311

Monte Carlo modeling of human tooth optical coherence tomography imaging  

Science.gov (United States)

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.

Shi, Boya; Meng, Zhuo; Wang, Longzhi; Liu, Tiegen

2013-07-01

312

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

2004-08-01

313

Relation of Birth Weight with Time of First Deciduous Tooth  

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Full Text Available The deciduous teeth play a very important role in proper alignment, placing and occlusion of permanent teeth. Calcification of deciduous teeth begins during the fourth month of fetal life, and by the end of sixth month all of the deciduous teeth have begun calcification. Eruption date is variable and timing of eruption "runs in families". Delay of deciduous teeth eruption, especially the first teeth cause nutritional problem for infant and some worries for family. In this study we compare the time of eruption of first deciduous teeth in infant with their birth weight. A total of 148 infant who born at Shariati Hospital in Tehran in 2004- 2005 consecutively entered the study. Other data such as sex, birth weight, gestational age and time of first tooth eruption were collected. The mean birth weight was 3220 ± 420 grams. 5.5% of cases were less than 2500 grams and 19.9% were over 3500 grams. The patients were followed weekly since third month of birth till the time of their first tooth eruption and the data was analyzed. The mean age of eruption of first tooth was 7.68 ± 1.84 months. The results showed a reverse linear relationship between first deciduous tooth eruption and birth weight. So delayed tooth eruption may relate to birth weight.

Sajjadian Negar

2009-10-01

314

The development of complex tooth shape in reptiles  

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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.

AbigailSaffronTucker

2014-02-01

315

Detecting Gear Tooth Fatigue Cracks in Advance of Complete Fracture  

Science.gov (United States)

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.

Zakrajsek, James J.; Lewicki, David G.

1996-01-01

316

Study on the effect of x-ray radiation on the dental extraction wounds  

Energy Technology Data Exchange (ETDEWEB)

Male Donryu rats were irradiated with 1,500 rad (group 2) or 2,000 rad (group 3) with a 10 MeV electron beam. Seven days later their first left upper molar (M1) was extracted, and the dental extraction wound was examined histopathologically 3, 7, 14, 21, 35, 49 and 90 days later (5 rats each day). The findings were compared with those obtained on nonirradiated rats whose M1 were also removed (group 1). Covering by epithelium was seen on all the rats in group 1 on the 7th day after tooth extraction, in group 2 on the 21st day, and in group 3 on the 49th day. The bone absorption of tooth extraction lacuna in group 2 and 3 was prominent, increasing with time, as compared with group 1. Sequester formation was particularly prominent in group 3, and in many cases the extraction lacuna was malformed. Restoration by regenerated bone was detected in group 1 on the 14th day after tooth extraction, and in group 2 on the 35th day, but it was only slight in group 3 even on the 90th day. Therefore, it was clear that irradiation of the upper jaw of rats before tooth extraction caused delayed healing of the lacuna of the extracted tooth, and that the effect was dose dependent.

Shimizu, Takefumi (Nihon Univ., Tokyo. School of Dentistry)

1982-03-01

317

A study on the effect of x-ray radiation on the dental extraction wounds  

International Nuclear Information System (INIS)

Male Donryu rats were irradiated with 1,500 rad (group 2) or 2,000 rad (group 3) with a 10 MeV electron beam. Seven days later their first left upper molar (M1) was extracted, and the dental extraction wound was examined histopathologically 3, 7, 14, 21, 35, 49 and 90 days later (5 rats each day). The findings were compared with those obtained on nonirradiated rats whose M1 were also removed (group 1). Covering by epithelium was seen on all the rats in group 1 on the 7th day after tooth extraction, in group 2 on the 21st day, and in group 3 on the 49th day. The bone absorption of tooth extraction lacuna in group 2 and 3 was prominent, increasing with time, as compared with group 1. Sequester formation was particularly prominent in group 3, and in many cases the extraction lacuna was malformed. Restoration by regenerated bone was detected in group 1 on the 14th day after tooth extraction, and in group 2 on the 35th day, but it was only slight in group 3 even on the 90th day. Therefore, it was clear that irradiation of the upper jaw of rats before tooth extraction caused delayed healing of the lacuna of the extracted tooth, and that the effect was dose dependent. (Kaihara, S.)

1982-01-01

318

Patient Discomfort Following Single-Tooth Implant Placement: A Randomized Controlled Trial of Immediate vs. Conventional Tooth Restoration.  

Science.gov (United States)

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 delivered three months after implantation. Pain (first three days), bleeding (first day) and swelling (first seven days) were assessed using a questionnaire with Visual Analogue Scales (VAS). Results: Treatment time was longer for IR than for CR (57 ± 14 and 33 ± 8 min, respectively; ppain, bleeding, and swelling were low for both groups at the first postoperative day. VAS scores for pain and swelling decreased continuously over the time period in both groups. Conclusions: The longer treatment time in IR didn't increase patients' perception of pain, bleeding and swelling, compared to CR. The impact of immediate tooth restoration on patients' esthetic outcome should be further considered. PMID:24984662

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

2014-06-01

319

Patient Discomfort Following Single-Tooth Implant Placement : A Randomized Controlled Trial of Immediate vs. Conventional Tooth Restoration  

DEFF Research Database (Denmark)

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 delivered three months after implantation. Pain (first three days), bleeding (first day) and swelling (first seven days) were assessed using a questionnaire with Visual Analogue Scales (VAS). Results: Treatment time was longer for IR than for CR (57 ± 14 and 33 ± 8 min, respectively; p<0.0001). Mean VAS scores for pain, bleeding, and swelling were low for both groups at the first postoperative day. VAS scores for pain and swelling decreased continuously over the time period in both groups. Conclusions: The longer treatment time in IR didn't increase patients' perception of pain, bleeding and swelling, compared to CR. The impact of immediate tooth restoration on patients' esthetic outcome should be further considered.

Spin-Neto, Rubens; Wenzel, Ann

2014-01-01

320

Mechanochemical control of mesenchymal condensation and embryonic tooth organ formation  

Science.gov (United States)

Mesenchymal condensation is critical for organogenesis, yet little is known about how this process is controlled. Here we show that Fgf8 and Sema3f produced by early dental epithelium respectively attract and repulse mesenchymal cells, which causes them to pack tightly together during mouse tooth development. Resulting mechanical compaction-induced changes in cell shape induce odontogenic transcription factors (Pax9, Msx1) and chemical cue (BMP4), and mechanical compression of mesenchyme is sufficient to induce tooth-specific cell fate switching. The inductive effects of cell compaction are mediated by suppression of the mechanical signaling molecule RhoA, and its over-expression prevents odontogenic induction. Thus, the mesenchymal condensation that drives tooth formation is induced by antagonistic epithelial morphogens that manifest their pattern-generating actions mechanically via changes in mesenchymal cell shape and altered mechanotransduction.

Mammoto, Tadanori; Mammoto, Akiko; Torisawa, Yu-suke; Tat, Tracy; Gibbs, Ashley; Derda, Ratmir; Mannix, Robert; de Bruijn, Marlieke; Yung, Chong Wing; Huh, Dongeun; Ingber, Donald E.

2011-01-01

 
 
 
 
321

In phantom dosimetric response of tooth enamel to neutrons  

International Nuclear Information System (INIS)

Electron Paramagnetic Resonance dosimetry based on tooth enamel has one important application in dose reconstruction of nuclear plant workers, where the contribution of neutrons to individual dose is often important. Evaluation of tooth enamel response to neutrons is thus an important goal. A few experimental data at thermal and fast neutron energies are available. A first evaluation of the tooth enamel relative response to 60Co in monoenergetic neutron flux of 2.8 and of 14 MeV, published elsewhere, has provided results apparently non-consistent with the results obtained at lower and higher energies. A comparison of those results in the 2.8 and 14 MeV beams with those available in the literature for other beams is reported and possible reasons for incongruities are discussed. Dose conversion factors of enamel to the water and air are also calculated and reported. (authors)

2003-10-03

322

Sonographic 'molar tooth' sign in the diagnosis of Joubert syndrome.  

Science.gov (United States)

The characteristic imaging finding common to Joubert syndrome and related disorders is the 'molar tooth' sign. The prenatal diagnosis of Joubert syndrome using both ultrasound and fetal magnetic resonance imaging (MRI) in families with an affected child has been reported previously. We report two cases in which the molar tooth sign was identified by sonography at 26 + 4 weeks and at 20 + 6 weeks, respectively, prior to fetal MRI or genetic testing. In both cases the finding was subsequently confirmed on fetal MRI. As definitive prenatal genetic testing may not be conclusive in Joubert syndrome, the ability to identify the molar tooth sign sonographically before 24 weeks provides a valuable adjunct to prenatal diagnosis. PMID:21370303

Pugash, D; Oh, T; Godwin, K; Robinson, A J; Byrne, A; Van Allen, M I; Osiovich, H

2011-11-01

323

The potential optical coherence tomography in tooth bleaching quantitative assessment  

Science.gov (United States)

In this paper, we report the outcomes from a pilot study on using OCT functional imaging method to evaluate and quantify color alteration in the human teeth in vitro. The image formations of the dental tissues without and with treatment 35% hydrogen peroxide were obtained by an OCT system at a 1310 nm central wavelength. One parameter for the quantification of optical properties from OCT measurements is introduced in our study: attenuate coefficient (?). And the attenuate coefficient have significant decrease ( p tooth bleaching process. From the experimental results, it is found that attenuate coefficient could be useful to assess color alteration of the human tooth samples. OCT has a potential to become an effective tool for the assessment tooth bleaching. And our experiment offer a now method to evaluate color change in visible region by quantitative analysis of the infrared region information from OCT.

Ni, Y. R.; Guo, Z. Y.; Shu, S. Y.; Zeng, C. C.; Zhong, H. Q.; Chen, B. L.; Liu, Z. M.; Bao, Y.

2011-12-01

324

Asymmetric extractions in orthodontics  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

325

Asymmetric extractions in orthodontics  

Directory of Open Access Journals (Sweden)

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.

Camilo Aquino Melgaço

2012-04-01

326

Effect of Orthodontic Tooth Movement on Gingival Crevicular Fluid Infiltration; a Preliminary Investigation  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: The gingival crevicular fluid (GCF is an inflammatory exudate found in the gingival sulcus. The forces exerted during orthodontic treatment cause distortion of the periodontal ligament (PDL extra-cellular matrix, resulting in some biological features that can lead to modification of both GCF volume and its components. The present study investigated the effect of orthodontic tooth movements, specifically canine retraction, on the volume of GCF exudate.Materials and Methods: Fourteen upper and lower canines of patients with different Angle classifications were selected for the study. After extraction of the first premolars, the canines were subjected to orthodontic distal retraction. GCF was sampled from mesial anddistal gingival crevices of each canine separately at baseline, 1 hour, 7 days, 14 days, 21 days, and 28 days after the application of the orthodontic distal retraction. GCF volume was determined by means of an electronic device.Results: GCF volume at tension sites was slightly greater after 21 and 28 days compared to other observation time points. At pressure sites, GCF volume was slightly greater after 28 days compared to other observation time points. None of the observed differences,however, was statistically significant (P>0.05.Conclusion: Orthodontic tooth movement, namely canine retraction, does not significantly increase the volume of GCF exudate. The slight increase in GCF volume could be due to a slight degree of gingival inflammation.

A. Dannan

2009-09-01

327

A technique to measure the absorbed dose in human tooth enamel using EPR method  

International Nuclear Information System (INIS)

The EPR spectrum of irradiated tooth enamel contains a multitude of signals that are divided into two categories of radiation-induced and radiation insensitive (native) signals. At lower doses the broad native signal obscures the radiation-induced signal. In this work attempt has been made to find a method to measure the radiation-induced signal other than peak-to-peak signal amplitude measurement. For this reason software was programmed to extract the data from EPR system. The average amplitude of the radiation-induced EPR signal which is defined between the known g-values can also be calculated using the software. The result of this calculations were considered as the EPR response for the tooth enamel samples irradiated from 100 to 500 mGy and was drawn as the calibration curve. The resulted data as compared to the peak-to-peak amplitude measurement method seems to be more reproducible and shows a better variation against the dose values

2008-08-01

328

Risk indicators for tooth loss in adult workers  

Directory of Open Access Journals (Sweden)

Full Text Available Tooth loss continues to be a prevalent condition in Brazilian adults and elderly individuals. The aim of this cross-sectional study, conducted among workers in a wholesale grocery chain in the State of São Paulo, was to identify risk indicators for tooth loss in adults. The presence of caries and periodontal status were examined in 387 adults aged 20-64 years, according to World Health Organization criteria. Two outcomes were analyzed: loss of one or more teeth, and loss of four or more teeth. Independent variables analyzed were demographic and socioeconomic factors, clinical conditions, use of dental services, and self-perceived oral health. Poisson regression models were used for multivariate statistical analysis. Participants were missing a mean of 5.38 teeth, and 76.9% (n = 297 had lost at least one tooth; the most frequently lost teeth were permanent molars. Older age and the presence of visible dental biofilm were associated significantly with the two tooth loss outcomes (p < 0.05. Individuals who had visited the dentist 3 or more years previously showed a lower prevalence of tooth loss (prevalence ratio = 0.79; 95% confidence interval, 0.68-0.91. Those with lower household incomes were significantly more likely to have lost four or more teeth (prevalence ratio = 1.35; 95% confidence interval, 1.07-1.70. Study results indicated that age and dental biofilm were risk indicators for tooth loss, independently of socioeconomic factors. These risk indicators should be considered when planning oral health programs for adults.

Marília Jesus Batista

2012-10-01

329

Root canal treatment of mandibular second premolar tooth with taurodontism  

Directory of Open Access Journals (Sweden)

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.

Vujaškovi? Mirjana

2008-01-01

330

Morphological and Functional Parameters in Patients with Tooth Wear before and after Treatment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Advanced tooth wear often results in lost vertical dimension and impacts facial aesthetics. Complex restorative treatment can replace the lost tooth structure and improve functional occlusal and facial skeleton parameters.

Sierpinska, Teresa; Kuc, Joanna; Golebiewska, Maria

2013-01-01

331

Tooth breakage in patients injected with "2"2"4Ra  

International Nuclear Information System (INIS)

Tooth breakage has been common among the"2"2"4Ra patients, especially those injected as teenagers. The fracture of 1 or more teeth was reported by 26% (8/31) of boys and 23% (7/30) of girls injected with "2"2"4Ra at 16-20 years of age. Combining results from all age groups, the incidence of tooth fractures increased significantly with dose (P=0.01). Unlike the normal loss of permanent teeth by periodontal disease, in which the entire tooth is lost, the tooth loss following "2"2"4Ra injection was primarily from tooth resorption near the gum line causing the tooth crowns to break off easily. Eventually the tooth roots may either become incorporated into the jawbone or are resorbed and replaced with bone. These tooth fractures resembled those observed in the U.S. radium dial painters and in dogs injected with bone-seeking ?-emitters. (orig.)

1984-10-29

332

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

DEFF Research Database (Denmark)

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.

Nascimento, Marcelle M; Gordan, Valeria V

2011-01-01

333

Palmoplantar keratoderma and Charcot-Marie-Tooth disease.  

Science.gov (United States)

A close association was noted between palmoplantar keratoderma (PPK) and Charcot-Marie-Tooth disease (CMT) in nine members of a family in five generations. Clinical, genealogic, electroneurophysiologic, chromosome, urinary amino acid, and histopathologic studies were performed to define the two entities. Charco-Marie-Tooth disease occurred with advancing age in all of the members with PPK, but in none without PPK. Palmoplantar keratoderma and CMT appear to be genetically associated and transmitted as an autosomal dominant trait. This is the first report, to our knowledge, of an association between PPK and CMT. PMID:6446889

Rabbiosi, G; Borroni, G; Pinelli, P; Cosi, V

1980-07-01

334

Spatial distribution of radiation defects in tooth enamel  

International Nuclear Information System (INIS)

Spatial distribution of radiation defects in tooth enamel is studied through the method of the EPR-tomography. The enamel plates, irradiated by ? rays and electrons with energy of 1.2 and 3.8 MeV, are studied. Decrease in the radiation defects concentration is determined along the direction of radiation action. Distribution of defects in the ?-irradiated plates was uniform. It is shown that the tooth enamel study through the EPR-tomography may be used for determination of the type and energy characteristics of ionizing radiation, effecting living body

1999-07-01

335

Temporary tooth separation in the treatment of approximal carious lesions.  

Science.gov (United States)

The tunnel preparation is among the techniques proposed for restoration of approximal carious lesions. The preparations minimizes the sacrifice of sound tooth structure. The diagnostic and management problems associated with the restricted access to the approximal area, however, have limited use of this treatment modality. The difficulty of ascertaining the possible loss of enamel surface integrity is overcome by temporary tooth separation, which permits direct visual and tactile examination of approximal sites. Additionally, the increased access facilitates both preparation of the cavity and placement of the restorative material. PMID:8941842

Bjarnason, S

1996-04-01

336

Gear sound levels with various tooth contact ratios and forms  

Science.gov (United States)

The real noise reduction benefits which may be obtained through the use of one gear tooth form as compared to another is an important design parameter for any geared system, especially for helicopters in which both weight and reliability are very important factors. The design and testing of nine sets of gears which are as identical as possible except for their basic tooth geometry are described. Noise measurements were made at various combinations of load and speed for each gear set so that direct comparisons could be made. The resultant data was analyzed so that valid conclusions could be drawn and interpreted for design use.

Lenski, Joseph W., Jr.; Spencer, Robert H.; Drago, Raymond J.; Valco, Mark J.; Oswald, Fred B.

1993-01-01

337

Anomalies of tooth formation in hypohidrotic ectodermal dysplasia  

DEFF Research Database (Denmark)

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.

Lexner, Michala Oron; Bardow, Allan

2007-01-01

338

Genome-Wide Association Study Reveals Multiple Loci Associated with Primary Tooth Development during Infancy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tooth development is a highly heritable process which relates to other growth and developmental processes, and which interacts with the development of the entire craniofacial complex. Abnormalities of tooth development are common, with tooth agenesis being the most common developmental anomaly in humans. We performed a genome-wide association study of time to first tooth eruption and number of teeth at one year in 4,564 individuals from the 1966 Northern Finland Birth Cohort (NFBC1966) and 1,...

2010-01-01

339

Exogenous FGF8 rescues development of mouse diastemal vestigial tooth ex vivo  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Regression of vestigial tooth buds results in the formation of the toothless diastema, a unique feature of the mouse dentition. Revitalization of the diastemal vestigial tooth bud provides an excellent model for studying tooth regeneration and replacement. It was shown previously that suppression of FGF signaling in the diastema is a causative of vestigial tooth bud regression. In this study, we report that application of exogenous FGF8 to the mouse embryonic diastemal region rescues diastema...

Li, Lu; Yuan, Guohua; Liu, Chao; Zhang, Lu; Zhang, Yanding; Chen, Yiping; Chen, Zhi

2011-01-01

340

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

International Nuclear Information System (INIS)

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

2008-05-01

 
 
 
 
341

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

Directory of Open Access Journals (Sweden)

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.

S. Muttagi

2011-09-01

342

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Soghra Yassaei

2013-01-01

343

A case of large dentigerous cyst containing canine tooth in the maxillary antrum  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A ease of large dentigeram cyst containing a canine tooth in the maxillary antrum is presented. This case is of interest because of its extension up to the skull base and presence of canine tooth in the cyst. Excision of cyst containing the eclopic tooth was made.

Sharma, Yojana; Kaushik, Sundeep; Singh, P. P.

2003-01-01

344

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 0Gy< D<1,2Gy, are well fitted (R"2 =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

2000-11-22

345

Peripheral neuropathies: Molecular diagnosis of Charcot-Marie-Tooth disease.  

Science.gov (United States)

Charcot–Marie–Tooth disease (CMT) is a hereditary neuropathy attributed to mutations in more than 30 different genes. A recent study identified the causative mutation in 67% of 787 screened patients with CMT, and the findings raise important issues concerning genetic testing for CMT. PMID:21587243

Berciano, José

2011-06-01

346

INTERESTING CASE RECORD OF A TOOTH INSIDE NASAL CAVITY  

Directory of Open Access Journals (Sweden)

Full Text Available I am presenting an interesting case report of an ectopic eruption of teeth into left nasal cavity. Discussion is focused on clinical, radiological presentation, probable etiology, diagnosis, management and complications.Tooth inside nasal cavity is a rare form of supernumerary teeth which can be identified by performing CTscan.

Balasubramanian Thiagarajan

2011-09-01

347

Fetal age estimation using MSCT scans of deciduous tooth germs.  

Science.gov (United States)

Evaluation of fetal age is an essential element in many fields such as anthropology, odontology, paleopathology, and forensic sciences. This study examines the correlation between fetal age, femoral diaphyseal length (considered as the gold standard), and deciduous tooth germs of fetuses aged 22 to 40 weeks amenorrhea (WA) based on computed tomography (MSCT) reconstructions. Qualitative and quantitative studies of femoral and deciduous tooth germ lengths were performed on 81 fetuses (39 females and 42 males). R software was used for statistical analyses. Intra-observer and inter-observer variabilities and the interclass correlation coefficient (ICC) were calculated. Correlation coefficients (R (2)) and linear regression equations were calculated. Intra- and inter-observer variabilities were very satisfactory (intra-observer ICC???0.96, inter-observer ICC???0.95). Femoral length was significantly correlated with age (R (2)?=?0.9). The correlation coefficient between age and height, width, and dental volume was R (2)???0.73. Tooth germs were good indicators of fetal age. Our method appears to be reliable and reproducible, and the results of this study agreed with those of the literature. The dental formula provided a precise estimation of fetal age between 25 and 32 WA. Tooth germs were reliable indicators of fetal age, and multislice computed tomography was shown to be an innovative and reliable technology for this purpose. PMID:23828625

Minier, Marie; Maret, Delphine; Dedouit, Fabrice; Vergnault, Marion; Mokrane, Fathima-Zohra; Rousseau, Hervé; Adalian, Pascal; Telmon, Norbert; Rougé, Daniel

2014-01-01

348

Risk indicators for tooth loss in adult workers  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Tooth loss continues to be a prevalent condition in Brazilian adults and elderly individuals. The aim of this cross-sectional study, conducted among workers in a wholesale grocery chain in the State of São Paulo, was to identify risk indicators for tooth loss in adults. The presence of caries and pe [...] riodontal status were examined in 387 adults aged 20-64 years, according to World Health Organization criteria. Two outcomes were analyzed: loss of one or more teeth, and loss of four or more teeth. Independent variables analyzed were demographic and socioeconomic factors, clinical conditions, use of dental services, and self-perceived oral health. Poisson regression models were used for multivariate statistical analysis. Participants were missing a mean of 5.38 teeth, and 76.9% (n = 297) had lost at least one tooth; the most frequently lost teeth were permanent molars. Older age and the presence of visible dental biofilm were associated significantly with the two tooth loss outcomes (p

Marília Jesus, Batista; Lílian Berta, Rihs; Maria da Luz Rosário de, Sousa.

349

Dentigerous cyst associated with an impacted anterior maxillary supernumerary tooth.  

Science.gov (United States)

Most typical dentigerous cysts are commonly seen in association with third molars and maxillary canines. Only 5-6% of dentigerous cysts are associated with supernumerary teeth. We report a rare case of dentigerous cyst associated with an impacted anterior maxillary supernumerary tooth. The patient was treated surgically by enucleation of the cyst. PMID:23376673

Shah, Kaushal Mahendra; Karagir, Amol; Adaki, Shridevi; Pattanshetti, Channaveer

2013-01-01

350

Protection and Reinforcement of Tooth Structures by Dental Coating Materials  

Directory of Open Access Journals (Sweden)

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.

Toru Nikaido

2012-10-01

351

Non-detection of the Tooth Fairy at Optical Wavelengths  

CERN Multimedia

We report a non-detection, to a limiting magnitude of V = 18.4 (9), of the elusive entity commonly described as the Tooth Fairy. We review various physical models and conclude that follow-up observations must precede an interpretation of our result.

Armstrong, Eve

2012-01-01

352

A study on measurements of tooth length in orthopantomogram  

International Nuclear Information System (INIS)

This study was performed to evaluate the accuracy of orthopantomogram by measuring the actual and radiographic tooth length and by analyzing the vertical magnification rate. For this study, total 90 teeth of the maxilla and mandible teeth and a dry skull were used. This experiment was attached with metal balls of 1 ± 0.02 mm at the root and the crown cusp tips of central, 2nd premolar, 1st molar of the maxilla and mandible and the teeth were embedded in dry skull, and then orthopantomogram was taken. The obtained results were as follows: 1. The average of tooth length in orthopantomogram was longer that of actual tooth length. 2. The average of vertical magnification rate in orthopantomogram to actual tooth length was 17-26%. 3. Vertical magnification rate of the maxilla teeth was 18-26% and that of mandibular teeth was 17-23%, and the magnification of maxillary teeth was larger than that of mandible teeth (p<0.01). 4. Vertical magnification rate of posterior was 22-26% and that of anterior area was 17-18%, and the magnification of anterior area was less than that of posterior area (p<0.01).

1994-02-01

353

Formation of tooth-bone interface in reptiles.  

Czech Academy of Sciences Publication Activity Database

. Martin : Slovenská anatomická spole?nost, 2013. s. 21-21.[International Congress of the Slovak Anatomical Society /43./ and Lojda Symposium on Histochemistry /50./. 04.06.2013-06.06.2013, Martin]Institucionální podpora: RVO:67985904Klí?ová slova: tooth-boneKód oboru RIV: GJ - Choroby a šk?dci zví?at, veterinární medicína

Dosed?lová, Hana; Glocová, K.; Moravcová Balková, Simona; Knotek, Z.; Tichý, F.; Buchtová, Marcela

354

Fas mediated apoptotic cell death in tooth embryonic development.  

Czech Academy of Sciences Publication Activity Database

. ?eská republika : Plze?, 2003. s. 33.[Fyziologické dny/79./. 27.05.2003, Plze?]Grant CEP: GA ?R GP204/02/P112Výzkumný zám?r: CEZ:AV0Z5045916Klí?ová slova: tooth developmentKód oboru RIV: ED - Fyziologie

Matalová, Eva; Chovancová, Eva; Míšek, Ivan

355

Pinion tooth surface generation strategy of spiral bevel gears  

Science.gov (United States)

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.

Liu, Guanglei; Fan, Hongwei

2012-07-01

356

Functional convergence in bat and toothed whale biosonars  

DEFF Research Database (Denmark)

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.

Madsen, P T; Surlykke, A

2013-01-01

357

Effectiveness of LANAP over time as measured by tooth loss.  

Science.gov (United States)

This study examines the effectiveness of the laser-assisted new attachment procedure (LANAP) as measured by tooth loss, comparing data to published studies using conventional surgical treatment modalities for the primary treatment of Types III and IV periodontitis. Retrospective data from 107 patients presenting with Types III and IV periodontitis were gathered and evaluated. All patients received LANAP periodontal therapy as their primary surgical treatment according to the FDA-cleared LANAP protocol. The patients averaged 6.2 years post-treatment. The data were compared to several published studies for outcome classification and tooth loss over time. The effectiveness of LANAP as a primary treatment method for Types III and IV periodontitis compares very favorably with conventional surgical treatment modalities concerning tooth loss and stability over time, need for surgical retreatment, and outcome classification. Dentistry continues to develop less invasive means of providing patient care without sacrificing results. Less invasive treatment of periodontitis, with reduced postoperative morbidity yet equal results in tooth retention over time is an important goal. LANAP treatment for moderate and advanced periodontitis provides a less invasive treatment alternative for the dentist and patient to consider as a part of informed consent. PMID:22414508

Tilt, Lloyd V

2012-01-01

358

About Kids' Teeth: Baby Tooth Decay is Real  

Medline Plus

Full Text Available ... you need to take good care of them. Learn about Baby Tooth Decay 3 – 6 Years ... a fluoride toothpaste for kids 2 and older. Learn about Thumb Sucking and Pacifiers 6 – 12 ...

359

Classification of severe tooth discolorations and treatment options  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Tran, Huy Quoc; Jenssen, Lotte

2011-01-01

360

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Vadeboncoeur, Christian; Trahan, Luc

1983-01-01

 
 
 
 
361

Tooth engineering: searching for dental mesenchymal cells sources.  

Directory of Open Access Journals (Sweden)

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.

HervéLesot

2011-03-01

362

A design of speed reducer with trapezoidal tooth profile for robot manipulator  

International Nuclear Information System (INIS)

Robots are increasingly performing human work as manufacturing is automated. Accordingly, the use of precision speed reducers has become essential for achieving precise control of the robot arm position. Curved tooth profiles, such as cycloid or involute tooth profiles, are generally used in precision speed reducers. Speed reducers with cycloid tooth profiles, which enable high precision control, are widely used to manipulate robot systems. This study proposes a speed reducer that has a trapezoidal tooth profile with straight lines. In this work, we mechanically analyzed trapezoidal tooth profiles, and then measured performance was by various tests using a prototype manufactured specifically for this study

2011-01-01

363

A design of speed reducer with trapezoidal tooth profile for robot manipulator  

Energy Technology Data Exchange (ETDEWEB)

Robots are increasingly performing human work as manufacturing is automated. Accordingly, the use of precision speed reducers has become essential for achieving precise control of the robot arm position. Curved tooth profiles, such as cycloid or involute tooth profiles, are generally used in precision speed reducers. Speed reducers with cycloid tooth profiles, which enable high precision control, are widely used to manipulate robot systems. This study proposes a speed reducer that has a trapezoidal tooth profile with straight lines. In this work, we mechanically analyzed trapezoidal tooth profiles, and then measured performance was by various tests using a prototype manufactured specifically for this study.

Nam, Won Ki; Oh, Se Hoon [Chung-Ang University, Seoul (Korea, Republic of)

2011-01-15

364

Dynamic tooth loads and stressing for high contact ratio spur gears  

Science.gov (United States)

An analysis and computer program were developed for calculating the dynamic gear tooth loading and root stressing for high contact ratio gearing (HCRG) as well as LCRG. The analysis includes the effects of the variable tooth stiffness during the mesh, tooth profile modification, and gear errors. The calculation of the tooth root stressing caused by the dynamic gear tooth loads is based on a modified Heywood gear tooth stress analysis, which appears more universally applicable to both LCRG and HCRG. The computer program is presently being expanded to calculate the tooth contact stressing and PV values. Sample application of the gear program to equivalent LCRG (1.566 contact ratio) and HCRG (2.40 contact ratio) revealed the following: (1) the operating conditions and dynamic characteristics of the gear system an affect the gear tooth loading and root stressing, and therefore, life significantly; (2) the length of the profile modification affect the tooth loading and root stressing significantly, the amount depending on the applied load, speed, and contact ratio; and (3) the effect of variable tooth stiffness is small, shifting and increasing the response peaks slightly from those for constant tooth stiffness.

Cornell, R. W.; Westervelt, W. W.

1983-01-01

365

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

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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...

Subramanya, J. K.; Muttagi, S.

2011-01-01

366

Multiple tooth resorption in an Italian Greyhound  

International Nuclear Information System (INIS)

An Italian greyhound was presented three times during a two-year period for dental prophylaxis due to periodontal disease. Clinical examination revealed lesions on several teeth. Radiographs revealed extensive resorptive root lesions. On histological examination, the presence of odontoclasts and signs of boney remodeling of the roots confirmed the resorptive nature of the lesions. Given the extent of the lesions, and poor prognosis with conservative treatment alone, teeth affected by the most severe resorption were extracted at each visit using a flap technique combined with alveolar vestibular osteotomy. Dental resorptive lesions are rarely detected in the dog but may be more frequent than previously thought. The routine use of dental radiographs can be used to reveal these lesions in the dog

2011-06-01

367

Effect of the Simulated Disinfection by Microwave Energy on the Impact Strength of the Tooth/Acrylic Resin Adhesion  

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The objective of this study was to determine the effect of simulated microwave disinfection on the tooth/acrylic resin impact strength. Acrylic molar teeth with a wax stick attached to the ridge lap were included in brass flasks. Specimens were made with Classico thermopolymerized acrylic resin, according to the groups: 1 and 5 - tooth with no treatment (control); 2 and 6 – tooth bur abrasion; 3 and 7 – tooth bur retention; and 4 and 8 – tooth monomer etch. Eighty specimens (n=10) were ...

Consani, Rafael L. X.; Mesquita, Marcelo F.; Zampieri, Marinaldo H.; Mendes, Wilson B.; Consani, Simonides

2008-01-01

368

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

Directory of Open Access Journals (Sweden)

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.

F - Shirani

2006-01-01

369

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

Science.gov (United States)

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

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

2012-01-01

370

Regulated fracture in tooth enamel: A nanotechnological strategy from nature.  

Science.gov (United States)

Tooth enamel is a very brittle material; however it has the ability to sustain cracks without suffering catastrophic failure throughout the lifetime of mechanical function. We propose that the nanostructure of enamel can play a significant role in defining its unique mechanical properties. Accordingly we analyzed the nanostructure and chemical composition of a group of teeth, and correlated it with the crack resistance of the same teeth. Here we show how the dimensions of apatite nanocrystals in enamel can affect its resistance to crack propagation. We conclude that the aspect ratio of apatite nanocrystals in enamel determines its resistance to crack propagation. According to this finding, we proposed a new model based on the Hall-Petch theory that accurately predicts crack propagation in enamel. Our new biomechanical model of enamel is the first model that can successfully explain the observed variations in the behavior of crack propagation of tooth enamel among different humans. PMID:24813507

Ghadimi, Elnaz; Eimar, Hazem; Song, Jun; Marelli, Benedetto; Ciobanu, Ovidiu; Abdallah, Mohamed-Nur; Stähli, Christoph; Nazhat, Showan N; Vali, Hojatollah; Tamimi, Faleh

2014-07-18

371

An unusual case of talon cusp on a geminated tooth  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Cúspide em garra (talon cusp) é uma anomalia de desenvolvimento que occore na face lingual de dentes anteriores. Geminação é uma anomalia causada quando um germe dental tenta se dividir durante a fase de desnvolvimento. Estas anomalias de desenvolvimento podem causar problemas clínicos tais como com [...] prometimento estético, dor, cárie e apinhamento dental. Este artigo relata um caso incomum de geminação acompanhado de cúspide em garra (talon cusp) na dentição permemente. Os achados clínicos e radiográficos são descritos. Abstract in english Talon cusp is a developmental anomaly seen on the lingual surface of anterior teeth. Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development. These developmental anomalies may cause clinical problems including esthetic impairment, pain, caries and tooth [...] crowding. This paper presents an unusual case of gemination accompanied by talon cusp in permanent dentition. The clinical and radiographic findings are described.

Kaan, Gündüz; Aydan, Açikgõz.

372

The randomized shortened dental arch study: tooth loss.  

Science.gov (United States)

The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA concept. First tooth loss after treatment was the primary outcome measure. This event occurred in 13 patients in the RDP group and nine patients in the SDA group. The respective Kaplan-Meier survival rates at 38 months were 0.83 (95% CI: 0.74-0.91) in the RDP group and 0.86 (95% CI: 0.78-0.95) in the SDA group, the difference being non-significant. PMID:20400723

Walter, M H; Weber, A; Marré, B; Gitt, I; Gerss, J; Hannak, W; Hartmann, S; Heydecke, G; Huppertz, J; Jahn, F; Ludwig, A; Mundt, T; Kern, M; Klein, V; Pospiech, P; Stumbaum, M; Wolfart, S; Wöstmann, B; Busche, E; Böning, K; Luthardt, R G

2010-08-01

373

Assessment of performance parameters for EPR dosimetry with tooth enamel  

International Nuclear Information System (INIS)

In the framework of a comparison between three laboratories, electron paramagnetic resonance (EPR) signal-to-dose response curves were measured for sets of 30 tooth enamel samples and the variance of EPR measurements in dependence on absorbed dose was evaluated, in nine combinations of laboratory of sample preparation and EPR evaluation, respectively. As a test for benchmarking of EPR evaluation, the parameters 'critical dose' and 'limit of detection' were proposed as performance parameters following definitions from chemical-metrology, and a model function was suggested for analytical formulation of the dependence of the variance of EPR measurement on absorbed dose. First estimates of limits of detection by weighted and unweighted fitting resulted in the range 101-552 and 67-561 mGy, respectively, and were generally larger with weighted than with unweighted fitting. Indication was found for the influence of methodology of sample preparation and applied EPR measurement parameters on performance of EPR dosimetry with tooth enamel

2008-02-01

374

The gap-tooth scheme for homogenization problems  

CERN Multimedia

An important class of problems exhibits smooth behaviour in space and time on a macroscopic scale, while only a microscopic evolution law is known. For such time-dependent multi-scale problems, an ``equation-free framework'' has been proposed, of which the gap-tooth scheme is an essential component. The gap-tooth scheme is designed to approximate a time-stepper for an unavailable macroscopic equation in a macroscopic domain; it uses appropriately initialized simulations of the available microscopic model in a number of small boxes, which cover only a fraction of the domain. We analyze the convergence of this scheme for a parabolic homogenization problem with non-linear reaction. In this case, the microscopic model is a partial differential equation with rapidly oscillating coefficients, while the unknown macroscopic model is approximated by the homogenized equation. We show that our method approximates a finite difference scheme of arbitrary (even) order for the homogenized equation when we appropriately cons...

Samaey, G; Kevrekidis, Yu G; Samaey, Giovanni; Roose, Dirk; Kevrekidis, Ioannis G.

2003-01-01

375

Smile enhancement the conservative way: Tooth whitening procedures  

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Full Text Available This article presents clinical cases in which different bleaching modalities have been used to successfully treat unsightly teeth. Depending upon the type and severity of discoloration, in-office vital and nonvital bleaching procedures were carried out. Discoloration of a single tooth has been managed using nonvital bleaching alone or with a combination of other minimally invasive modalities for an acceptable esthetic outcome. The case selection was done by considering the patient?s needs and expectations, the type and cause of discoloration and patient economics. Moreover, prime importance was given to the conservation of the existing tooth structure and acquiring a complete change in the shade of teeth, which was comparable to that of the adjacent teeth. The desire to have a bright smile has become an important esthetic need of patients. The article explores various forms of bleaching and their successful usage in day-to-day clinical practice.

Thosre Deepika

2009-01-01

376

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)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

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

377

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)

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.

Charles Peter Tilbery

1972-06-01

378

Charcot-Marie-Tooth disease: Emerging mechanisms and therapies  

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Charcot-Marie-Tooth disease is the most common inherited disorder of the peripheral nervous system. The disease is characterized by a progressive muscle weakness and atrophy, sensory loss, foot (and hand) deformities and steppage gait. While many of the genes associated with axonal CMT have been identified, to date it is unknown which mechanism(s) causes the disease. However, genetic findings indicate that the underlying mechanisms mainly converge to the axonal cytoskeleton. In this review, w...

D Apos Ydewalle, Constantin; Benoy, Veronick; Den Bosch, Ludo

2012-01-01

379

Hand weakness in Charcot-Marie-Tooth disease 1X.  

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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 no...

Arthur-farraj, P. J.; Murphy, S. M.; Laura, M.; Lunn, M. P.; Manji, H.; Blake, J.; Ramdharry, G.; Fox, Z.; Reilly, M. M.

2012-01-01

380

Dynamin 2 in Charcot-Marie-Tooth Disease  

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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 exp...

Tanabe, Kenji; Takei, Kohji

2012-01-01

 
 
 
 
381

Mitochondrial disease mimicking Charcot–Marie Tooth disease  

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Charcot–Marie tooth disease (CMT) is a heterogenous group of peripheral neuropathies caused by various genetic defects. Three cases of mitochondrial myopathy, neuropathy and gastrointestinal encephalopathy (MNGIE) which initially presented with a peripheral neuropathy resembling CMT are described here. The diagnosis in all three cases was made after they developed eye signs and abdominal complaints. Young patients with mutation negative CMT should be followed up to monitor for signs of MNGIE.

Needham, M.; Duley, J.; Hammond, S.; Herkes, G. K.; Hirano, M.; Sue, C. M.

2009-01-01

382

Biomimetic Hybrid Scaffolds for Engineering Human Tooth-Ligament Interfaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A major clinical challenge in the reconstruction of large oral and craniofacial defects is the neogenesis of osseous and ligamentous interfacial structures. Currently, oral regenerative medicine strategies are unpredictable for repair of tooth-supporting tissues destroyed as a consequence of trauma, chronic infection or surgical resection. Here, we demonstrate multi-scale computational design and fabrication of composite hybrid polymeric scaffolds for targeted cell transplantation of genetica...

Park, Chan Ho; Rios, Hector F.; Jin, Qiming; Bland, Megan E.; Flanagan, Colleen L.; Hollister, Scott J.; Giannobile, William V.

2010-01-01

383

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

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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...

Go?tz, Thomas; Verfuß, Ursula Katharina; Schnitzler, Hans-ulrich

2006-01-01

384

Endodontic therapy of pathological resorptions of tooth root  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pathological resorptions of a tooth root very often represent both a diagnostic and therapeutical problem. The goal of this study was, based on clinical research on a number of pathological resorptions of various types and localization in relation to time, to analyze and evaluate applied endodontic therapy. Clinical research covered 30 patients (40 root canals in total). 18 teeth (22 canal) with external and 12 (18 canal) with internal root resorptions received endodontic therapy. After stand...

Opa?i?-Gali? Vanja; Živkovi? Slavoljub

2004-01-01

385

ON THE R-CURVE BEHAVIOR OF HUMAN TOOTH ENAMEL  

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In this study the crack growth resistance behavior and fracture toughness of human tooth enamel were quantified using incremental crack growth measures and conventional fracture mechanics. Results showed that enamel undergoes an increase in crack growth resistance (i.e. rising R-curve) with crack extension from the outer to the inner enamel, and that the rise in toughness is function of distance from the Dentin Enamel Junction (DEJ). The outer enamel exhibited the lowest apparent toughness (0...

Bajaj, Devendra; Arola, Dwayne

2009-01-01

386

Cytotoxic Chemotherapy Tooth Ache Following Chemotherapy: a Rare Case Report  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Currently, localized pulpalgia is listed as a rare manifestation of chemotherapy treatments in patients with malignant tumors. The neuropathy originated from neurotoxicity of anticancer drugs is usually described as a diffuse jaw pain or numbness in orofacial structures. This article reports localized tooth pain as a possible outcome of administrating high dosage chemotherapy drugs particularly in the last cycles of application.

Maryam Kuzekanani

2012-07-01

387

The Randomized Shortened Dental Arch Study: Tooth Loss.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or no...

Walter, M. H.; Weber, A.; Marre?, B.; Gitt, I.; Gerß, J.; Hannak, W.; Hartmann, S.; Heydecke, G.; Huppertz, J.; Jahn, F.; Ludwig, A.; Mundt, T.; Kern, M.; Klein, V.; Pospiech, P.

2010-01-01

388

Dental enamel growth, perikymata and hypoplasia in ancient tooth crowns.  

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This paper describes the hypoplastic defects commonly seen on the surface of ancient human tooth crowns, excavated from archaeological sites, and presents a new method for estimating the ages at which these defects were initiated during life. The method is based upon examination of microscopic incremental structures on the enamel surface and it is possible also to apply it to reconstruction of the sequence and timing of dental crown development. The method of examination is non-destructive an...

1992-01-01

389

Supernumerary tooth in lower incisor region: A case report  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Supernumerary teeth are defined as any supplementary tooth in addition to usual configuration of twenty deciduous and thirty-two permanent teeth. They are most commonly found in the anterior maxilla and mandibular bicuspid region. Although supernumerary teeth have been reported in the incisor region of the mandible, they are very rare. It has been confirmed that approximately 25% of permanent supernumerary teeth appear in the mouth, the rest remains unerupted. The aim of this study was ...

Grga ?urica; Dželetovi? Bojan

2010-01-01

390

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

2008-02-01

391

Storage ring free electron lasers and saw-tooth instability  

CERN Multimedia

We show that Free Electron Lasers (FEL) operating with storage rings may counteract beam instabilities of the Saw Tooth (STI) type. We use a model based on a set of equations that couple those describing the FEL evolution to those accounting for the STI dynamics. The analysis provides a clear picture of the FEL-STI mutual feedback and clarifies the mechanisms of the instability inhibition. The reliability of the results is supported by a comparison with fully numerical codes.

Dattoli, Giuseppe; Migliorati, M; Palumbo, L; Renieri, A

1999-01-01

392

Save-a-tooth: Conservative surgical management of dentigerous cyst  

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Dentigerous cysts are the most common bony lesions of the jaws in children. It is one of the most prevalent types of odontogenic cysts associated with an erupted or developing tooth, particularly the mandibular third molars; the other teeth that are commonly affected are, in order of frequency, the maxillary canines, the maxillary third molars, and rarely the central incisors. Radiographically, the cyst appears as ovoid well-demarcated unilocular radiolucency with a sclerotic border. Careful ...

Shivaprakash P; Rizwanulla T; Baweja D; Noorani H

2009-01-01

393

METHODS TO VALIDATE TOOTH-SUPPORTING REGENERATIVE THERAPIES  

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In humans, microbially-induced inflammatory periodontal diseases are the primary initiators that disrupt the functional and structural integrity of the periodontium (i.e., the alveolar bone, the periodontal ligament, and the cementum). The re-establishment of its original structure, properties and function constitutes a significant challenge in the development of new therapies to regenerate tooth-supporting defects. Preclinical models represent an important in vivo tool to critically evaluate...

Padial-molina, Miguel; Marchesan, Julie T.; Taut, Andrei D.; Jin, Qiming; Giannobile, William V.; Rios, Hector F.

2012-01-01

394

Comparative evaluation of soft tissue characteristics around implant and tooth  

Directory of Open Access Journals (Sweden)

Full Text Available "nBackground and Aim: Soft tissue condition around dental implant is an essential part for long term healthy and esthetic outcome. The aim of this study was to compare soft tissue dimensions between implant supported single  tooth replacement and the contra-lateral natural tooth. "nMaterials and Methods: This retrospective study was performed on dentate patients treated with anterior single  tooth implant at least 1 year ago. Of twenty eight, fourteen patients had been treated with one stasge method and others with two stage method. Biologic width (BW, papilla index (PI, and mucosal thickness (MT were evaluated around implants and contra-lateral teeth clinically and compared with each other. The Wilcoxon test, Mann-Whitney test, and Student pair t-test were used to assess the differences between one stasge and two stage implants, and implant and tooth groups. "nResults: The mean BW around one stasge implants, two stage implants, and contra-lateral teeth were 1.42±0.48 mm, 1.67±0.48 mm, and 1.47±0.60 mm, respectively. The mean PI adjacent to one stasge implants, Two stage implants, and contra-lateral teeth were 2.50±0.52, 2.53±0.55, and 2.72±0.47, correspondingly. The mean MT around one stasge implants, two stage implants, and contra-lateral teeth were 3.10±0.48, 3.09±0.75, and 2.57±0.88, respectively. There was no statistically significant difference among one stasge implants, two stage implants, and contra-lateral teeth with regard to measured variables. "nConclusion: Based on the results of this investigation, in standard condition, it seems that there is no noticeable difference in indicators of; biologic width, papilla index, and mucosal thickness around one stasge implants, two stage implants, and contra-lateral teeth.

Paknejad M.

2008-12-01

395

Contemporary management of tooth replacement in the traumatized dentition  

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Dental trauma can result in tooth loss despite best efforts at retaining and maintaining compromised teeth (Dent Traumatol, 24, 2008, 379). Upper anterior teeth are more likely to suffer from trauma, and their loss can result in significant aesthetic and functional problems that can be difficult to manage (Endod Dent Traumatol, 9, 1993, 61; Int Dent J 59, 2009, 127). Indeed, teeth of poor prognosis may not only present with compromised structure but trauma may also result in damage to the sup...

Alani, Aws; Austin, Rupert; Djemal, Serpil

2012-01-01

396

Reattachment of complicated tooth fracture: An alternative approach  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Trauma to the anterior teeth is relatively a common occurrence. There are several treatment modalities for such condition, one of which is reattachment of fractured fragment itself. Reattachment of fractured fragment provides immediate treatment with better esthetics, restoration of function, and is a faster and less complicated procedure. Reattachment of tooth fragment should be the first choice and is a viable alternative to conventional approaches because of simplicity, natural esthetics, ...

Kumari, Nujella B. P. Surya; Sujana, V.; Sunil, C. H. Ram; Reddy, P. Satyanarayana

2012-01-01

397

Classification of severe tooth discolorations and treatment options  

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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 is v...

Tran, Huy Quoc; Jenssen, Lotte

2011-01-01

398

Smile enhancement the conservative way: Tooth whitening procedures  

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This article presents clinical cases in which different bleaching modalities have been used to successfully treat unsightly teeth. Depending upon the type and severity of discoloration, in-office vital and nonvital bleaching procedures were carried out. Discoloration of a single tooth has been managed using nonvital bleaching alone or with a combination of other minimally invasive modalities for an acceptable esthetic outcome. The case selection was done by considering the patient's needs and...

Thosre, Deepika; Mulay, Sanjyot

2009-01-01

399

Smile enhancement the conservative way: Tooth whitening procedures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This article presents clinical cases in which different bleaching modalities have been used to successfully treat unsightly teeth. Depending upon the type and severity of discoloration, in-office vital and nonvital bleaching procedures were carried out. Discoloration of a single tooth has been managed using nonvital bleaching alone or with a combination of other minimally invasive modalities for an acceptable esthetic outcome. The case selection was done by considering the patient?s ne...

Thosre Deepika; Mulay Sanjyot

2009-01-01

400

Primary cilia integrate hedgehog and Wnt signaling during tooth development.  

Science.gov (United States)

Many ciliopathies have clinical features that include tooth malformations but how these defects come about is not clear. Here we show that genetic deletion of the motor protein Kif3a in dental mesenchyme results in an arrest in odontogenesis. Incisors are completely missing, and molars are enlarged in Wnt1(Cre+)Kif3a(fl/fl) embryos. Although amelogenesis and dentinogenesis initiate in the molar tooth bud, both processes terminate prematurely. We demonstrate that loss of Kif3a in dental mesenchyme results in loss of Hedgehog signaling and gain of Wnt signaling in this same tissue. The defective dental mesenchyme then aberrantly signals to the dental epithelia, which prompts an up-regulation in the Hedgehog and Wnt responses in the epithelia and leads to multiple attempts at invagination and an expanded enamel organ. Thus, the primary cilium integrates Hedgehog and Wnt signaling between dental epithelia and mesenchyme, and this cilia-dependent integration is required for proper tooth development. PMID:24659776

Liu, B; Chen, S; Cheng, D; Jing, W; Helms, J A

2014-05-01

 
 
 
 
401

Neuropsychological studies in children with elevated tooth-lead concentrations  

Energy Technology Data Exchange (ETDEWEB)

Results from neuropsychological tests, collected under doubleblind-precautions, were evaluated for 115 schoolage children (mean age: 9.4 years) living in a lead smelter area. Tooth-lead concentrations (PbT) from shed incisor teeth as measures of longtime lead-exposure were available for these children (anti x=6.16 ppm; range: 1.9-38.5 ppm), and for 83 of them blood-lead concentrations (PbB) were available as well (anti x=14.3 ..mu..g/dl; range: 6.8-33.8 ..mu..g/dl). The following functional capacities were tested: intelligence perceptual-motor integration, reaction performance, finger-wrist tapping-speed, and repetitive cancellation-performance. In addition standardized behavior ratings were obtained by the examiners, the mothers, and the teachers. Multiple stepwise regressionanalysis (forced solution) was calculated for outcome-variables and Pb-tooth, including age, sex, duration of labor, and socio-hereditary background as covariates. Significant (P<0.05) or near-significant (P<0.1) association was established between Pb-tooth and GFT-performance (errors), reaction-performance (false reactions), and four behavioral dimensions as rated by the mothers, namely distractability, restlessness, lack of information, and wasting of time; the proportion of explained variance never exceeded 6%, however.

Winneke, G.; Kraemer, U.; Brockhaus, A.; Ewers, U.; Kujanek, G.; Lechner, H.; Janke, W.

1983-03-01

402

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.

1994-02-01

403

A radiological study on the tooth shape anomaly  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1994-02-15

404

Pattern of tooth loss in a selected population in Greece.  

Science.gov (United States)

The pattern of tooth loss with age for individual teeth was examined in a selected population. The survey covered patients attending the Dental School of Athens University. Tooth loss increased steadily with age and was higher for the periodontitis than the gingivitis group. Mortality of individual teeth was analyzed for each type of tooth within the maxillary pair and within the mandibular pair and no statistical significance was found. The statistically highly significant differences in loss rates within most groups of four teeth were clearly attributable to differences between the maxilla and mandible. For the permanent second molars differences in loss were close to the significance level while for the first molars the difference was statistically highly significant. A statistically significant difference was found between losses of the four second premolars while highly significantly differences were noticed between first premolars. Mortality for canines was low, but differences in losses were highly statistically significant. The two mandibular inci