Endosseous cylinder implants in severely atrophic mandibles.

A retrospective study was completed to assess the success rate of endosseous cylinder implants placed in mandibles that were 10 mm or less in maximum anterior height as measured from lateral cephalometric radiographs. Only implants that were located anteriorly between the mental foramina and loaded prosthetically for a minimum of 1 year were studied. Twenty-eight patients with a total of 130 Nobelpharma implants (forty-six 7 mm and eighty-four 10 mm) were included. The fixtures were evaluated following standard clinical criteria for success established for implants of this type. A total of 8 (two 7 mm and six 10 mm) of 130 implants failed, yielding an overall success rate of 94%. Major complications encountered included a complete mandibular fracture, a partial mandibular fracture, and a temporary bilateral mental nerve hypoesthesia.     

A comparative investigation on autologous mandibular and iliac crest bone grafts. An experimental study in sheep

Nine Friesian sheep (age 1.5-2 years) were used to evaluate the quality of bone repair in artificial cleft-like maxillary defects repaired with autologous bone grafts of embryologically different origin. After bilateral extraction of the upper first deciduous molar the tooth socket was enlarged resulting in an open connection between the oral and nasal cavities. In the same session a graft, obtained from the iliac crest, was implanted in one of the two bilateral maxillary defects and on the opposite side a graft, obtained from the mandible, was inserted. During the experiment, serial radiographs were taken. After six months the sheep were sacrificed and the bone of the grafted areas was submitted to histological and histomorphometric investigation. Comparing both areas, it appeared that the quality of bone remodelling and alveolar reconstruction was independent of the origin of the grafts.     

The Validity of Self-reported Oral Health Status in the Elderly

The validity of self-reported number of teeth was assessed in a random sample of 50 individuals aged 70+ by comparing self-reports in a telephone interview with results of a subsequent in-home examination by a dentist. There were no significant differences between self-report and examination data, nor was there any systematic under- or over-counting of teeth as the actual number of teeth increased. These data support the validity of self-reported dentition.     

Differential scanning calorimetric studies of nickel titanium rotary endodontic instruments

Differential scanning calorimetric (DSC) analyses were performed between -130 degrees and 100 degrees C on specimens prepared from nickel-titanium (NiTi) rotary endodontic instruments: ProFile (n = 5), Lightspeed (n = 4), and Quantec (n = 3). The ProFile and Lightspeed instruments were in the as-received condition, whereas the Quantec instruments were randomly selected from a dental clinic and had unknown history. The DSC plots showed that the ProFile and Lightspeed instruments analyzed had the superelastic NiTi property, with an austenite-finish (Af) temperature of approximately 25 degrees C. Differences in DSC plots for the ProFile instruments and the starting wire blanks (n = 2) were attributed to the manufacturing process. The phase transformation behavior when the specimens were heated and cooled between -130 degrees and 100 degrees C, the temperature ranges for the phase transformations, and the resulting enthalpy changes were similar to those previously reported for nickel-titanium orthodontic wires having superelastic characteristics or shape memory behavior in the oral environment. The experiments demonstrated that DSC is a powerful tool for materials characterization of these rotary instruments, providing direct information not readily available from other analytical techniques about the NiTi phases present, which are fundamentally responsible for their clinical behavior.     

The CICERO system for CAD/CAM fabrication of full-ceramic crowns

The CICERO method of crown fabrication consists of optically digitizing a gypsum die, designing the crown layer buildup, and subsequently pressing, sintering, and milling consecutive layers of a shaded high-strength alumina-based core material, a layer of dentin porcelain, and a final layer of incisal porcelain. Final finishing is performed in the dental laboratory. The CICERO method allows efficient production of all-ceramic restorations without compromising esthetics or function. This article reviews the process involved in the fabrication of a CICERO crown.     

Prognosis of caries increment with past caries experience variables

This study aimed to select past caries experience variables as caries predictors and to compare their prognostic accuracy with the variables used in a method of caries prognosis developed in a Swiss child population. The data used for the analyses originated from an 8-year longitudinal study starting in 1980 on caries of 7.5-year-old Dutch children. Stepwise logistic regression analyses provided predictor variables. The newly introduced variables D23fi, D(123)i and D23pifi were interchangeable and the most powerful caries predictors. For the sake of uniformity and ease of application, D23fi (number of fissures of the permanent first molar with non-cavitated or cavitated caries lesions) was chosen as the first variable in the logistic regression equations. The gain in accuracy of the second and third predictor variables (number of sound primary molars and the number of buccal and lingual smooth surfaces of the permanent first molar with non-cavitated or cavitated caries) in the regression equations was limited. The D1 condition of surfaces could be omitted from the prediction models. The present forced three-predictor-regression equations for 7.5-, 9.5- and 11.5-year-old children were evaluated to assess their prognostic performance by using the area under the ROC curve as a measure of prognostic quality. For the present regression equations, the area under the ROC curve was 81-87%, which was higher compared to the Swiss regression equations for caries prognosis.     

Psychological disorder, conditioning experiences, and the onset of dental anxiety in early adulthood

Most studies examining the origins of dental fear and anxiety have relied on cross-sectional data. These are subject to several problems, such as recall and uncertainty concerning temporal relationships. This paper uses longitudinal data from the Dunedin Multidisciplinary Health and Development Study to assess risk factors for the development of dental anxiety in persons between the ages of 18 and 26 years. It was hypothesized that psychological factors would be as important as conditioning experiences in the genesis of dental anxiety over this period. The eight-year incidence of dental anxiety was 16.5%. Five variables entered models predicting onset: multiple fears, symptoms of substance dependence, previous experience of invasive dental treatment, dental visiting pattern, and the extraction of one or more teeth. Separate analyses for those avoiding and those using dental services resulted in different explanatory models. These results indicated that both psychological and conditioning variables contributed to the development of dental anxiety in this population of young adults.     

Effect of occlusal trauma on healing of periapical pathoses: report of two cases

AIM: To present two clinical cases and demonstrate that occlusal trauma may affect healing of periapical pathoses. SUMMARY: Two teeth with periradicular disease did not respond successfully to conventional root canal treatment or endodontic surgery. Occlusal adjustment was finally performed on both cases. After occlusal adjustment, uncomplicated healing and periapical repair occurred in both cases. The findings in these two cases suggest that occlusal trauma may play a role in the healing of periapical pathoses. KEY LEARNING POINTS: Occlusal trauma is positively correlated with changes in periodontal tissues. Although experiments in animals have shown that application of forces to teeth will not induce further periodontal destruction, we believe that some failures of root canal treatment may be due to the presence of occlusal trauma modulating the responses of inflamed periapical tissues or apical pathoses with persistent infection.     

Infant ectopic cervical thymus in submandibular region

Sporadic cases have been reported of ectopic thymic tissue formed along the path of embryologic descent from the mandibular region to the mediastinum, usually manifesting as an asymptomatic mass. Here is reported the case of an 8-month-old boy with a tender palpable mass in the right upper lateral neck. Preoperative posteroanterior chest radiograph revealed normal structures in the mediastinum superior including the thymus. Magnetic resonance imaging showed a 4-cm x 4-cm soft-tissue mass in the left submandibular region. Surgical resection was performed and histopathologic examination showed that the mass was composed of thymic lymphoid tissue and epithelial cells. Immunohistochemical features included positive expression of LCA, CKpan, EMA, CD20 and CD43 antibodies. The clinical 14-month follow up was negative and the child was growing normally after operation. Ectopic thymus in the submandibular region is uncommon; surgical treatment is the definitive means of pathological diagnosis. Prior to surgery, the presence of a mediastinal thymus should be confirmed to prevent the risk of a total thymectomy.