Peripheral calcifying epithelial odontogenic tumor

Most of the calcifying epithelial odontogenic tumors (CEOT) are central lesions of the jaws, but the CEOT occurs infrequently on the gingiva. A cases of peripheral CEOT arising in the right upper molar gingiva of a 31-year-old Japanese woman is presented. A direct communication between the overlying gingival epithelium and the tumor was found by examination of serial sections. As a result, it was thought that one of the sources of peripheral CEOT might be gingival epithelium with potential proliferative activity.     

Resorbable poly-L-lactide plates and screws for the treatment of mandibular condylar process fractures: a clinical and radiologic follow-up study.

PURPOSE: The purpose of this study was to determine whether a resorbable poly-l-lactide (PLLA) miniplate system could be used to treat mandibular condylar process fracture. PATIENTS AND METHODS: Fourteen patients (12 males, 2 females, aged 23.1 +/- 5.7 years) who had mandibular condylar process fractures treated with PLLA implants were recalled for follow-up clinical and radiologic examinations at 3 years. RESULTS: Mouth opening recovered to more than 35 mm and occlusion was stable in all patients. There was no facial asymmetry 3 months postoperatively. Two patients had mild chronic postoperative tenderness at the implantation site; however, there was no wound infection. All fractured mandibular condyles showed anatomic good reduction and long-term stability with the use of resorbable miniplates and screws. Bone healing was satisfactory in all patients, and there was no evidence of abnormal resorption of the condylar process. The screw holes remained evident after 3 years. Screw holes in 2 patients showed enlargement on radiographic examination. CONCLUSION: The PLLA miniplate system provides reliable stability when used for the fixation of mandibular condylar process fractures.     

Effects of smoking and drinking habits on the incidence of periodontal disease and tooth loss among Japanese males: a 4-yr longitudinal study

OBJECTIVE: We investigated the risk of periodontal disease and tooth loss, associated with habits of smoking and alcohol consumption, in a longitudinal study. SUBJECTS AND METHODS: The subjects were 1332 Japanese males, 30-59 yr of age, who were free from periodontal disease at the baseline check-up, and who underwent a second check-up 4 yr later. Periodontal disease was diagnosed using the community periodontal index score, based on the clinical probing of pocket depth (> or = 4 mm). Smoking and alcohol consumption patterns were evaluated using a self-administered questionnaire. RESULTS: A dose-response relationship was observed between the amount of smoking and the incidence of periodontal disease in each age group. The overall odds ratios (95% confidence intervals), adjusted for age and alcohol, were 1.51 (0.95-2.22), 1.58 (1.13-2.22) and 2.81 (1.96-4.03), among smokers consuming 1-19, 20 or 21 or more cigarettes per day, respectively, with a significant linear trend (p < 0.0001). A similar association was found between smoking and tooth loss, except for the 50-59-yr-old age group. The adjusted odds ratios were 1.26 (0.60-2.64), 2.01 (1.21-2.32) and 2.06 (1.23-3.48), respectively. A significant linear trend between smoking and tooth loss was also observed (p = 0.01). Ex-smokers showed no significant difference compared with nonsmokers. We also found a significant linear trend between alcohol consumption and tooth loss among 30-39-yr-old subjects, while no relationship was observed between alcohol consumption and periodontal disease. CONCLUSION: Cigarette smoking was found to be an independent risk factor for periodontal disease and tooth loss. Alcohol consumption was a limited risk factor for tooth loss in the younger age group, but was unrelated to periodontal disease. To prevent periodontal disease and tooth loss, health practitioners need to encourage people to stop smoking or not to start.     

Influence of novel resin monomer on viability of L-929 mouse fibroblasts in vitro

We have previously synthesized a novel acrylic resin monomer, methacryloyloxyethyl methyl succinate (TA). The aim of this in vitro study, therefore, was to examine its influence on cell viability using L-929 mouse fibroblasts and then compare the results with MMA, EMA, and LMA. Medium containing each monomer was changed every 15 minutes as some monomers were volatile. After one hour of exposure, these mediums were replaced with a normal medium and cells were further incubated for 72 hours. IC50 value for each monomer was determined, and chronological cell viability and cytomorphologic observation were evaluated. Viability was impaired in a dose-dependent manner. All monomers, except TA, tended to correlate between molecular weight and cell viability. On the other hand, TA showed excellent viability and did not impair growth abruptly. These results thus demonstrated that cellular damage by TA was much lower than that by other monomers.     

Blood test values and Community Periodontal Index scores in medical checkup recipients

BACKGROUND: We examined the blood test values of people who received general medical checkups and their Community Periodontal Index (CPI) score. METHODS: A total of 7,452 persons (5,742 males and 1,710 females), who had general medical and dental checkups, were the subjects of the study. Many were people who worked for companies in and around Nagoya and their family members, ranging in age from 16 to 80 years. The blood test in our study consisted of 37 items used in general blood tests. Partial-mouth recordings were used to measure CPI scores. The highest CPI score for each subject was used for analysis. Odds ratios and confidence interval values were obtained using the Mantel-Haenszel method to analyze the results. RESULTS: CPI scores of 3 and 4 were related to the test values of high-density-lipoprotein cholesterol, serum iron, white blood cell count, fasting blood sugar, glycosylated hemoglobin A1, glycosylated hemoglobin A1c, and C-reactive protein. CONCLUSION: Blood test values tended to show correlations with CPI scores, more clearly seen in males than in females.     

Relationship between large tubules and dentin caries in human deciduous tooth

The purpose of this study was to elucidate the relationship between large tubules and dentin caries by using human deciduous incisors that showed various levels of attrition but no macroscopical lesions resulting from caries. The teeth were cut longitudinally in the mesio-distal direction and the exposed surfaces observed with a high-resolution field emission scanning electron microscope. The inside of each large tubule showed dense collagen fibers running parallel to its long axis and small spherical bodies of aggregated crystals, but no marked attrition. In teeth where attrition had exposed dentin at the incisal edge, oral bacteria had infiltrated the large tubules. Furthermore, in teeth with advanced attrition, it was difficult to distinguish between the large tubules and the surrounding dentin matrix, and numerous bacteria were observed in both areas. These findings support the hypothesis that large tubules play a role in the pathway of caries formation in coronal dentin when incisal dentin is exposed by attrition. This suggests that early treatment of exposed dentin surfaces might be effective in preventing dental caries.     

Influence of mechanical properties of two resin cements on durability of bond strength to dentin after cyclic loading

The purpose of this study was to evaluate how the different mechanical properties of two luting agents (acrylic resin cement and resin composite cement) influenced their bond strength to dentin, after cyclic loading that simulated chewing. Stainless steel rods were bonded to the flattened dentin surfaces with each luting agent. After immersion in water for 24 hours, half the specimens of each group were tested for tensile bond strength and the remaining half were subjected to a vertical load (75.6 N, 1.2 Hz) using an acrylic stylus--which upon contact with the specimen would rotate counterclockwise and then counter-rotate. Bond strength of the resin composite cement with self-etching was found to be significantly lower than the other adhesive systems. After 100,000 cycles, the bond strength of resin composite cement was significantly decreased while acrylic resin cement showed no decrease in bond strength.