Effect of white mineral trioxide aggregate compared with biomimetic carbonated apatite on dentine bridge formation and inflammatory response in a dental pulp model.

AIM: To evaluate the effects of apatite precipitation on the biocompatibility and hard tissue induction properties of white mineral trioxide aggregate (WMTA) in a dental pulp model. METHODOLOGY: Pulp exposures were created on the axial walls of 32 sound canine teeth of eight dogs. Four additional sound teeth served as controls. The pulps were capped either with WMTA or apatite derivatives [biomimetic carbonated apatite (BCAp)] in the interaction of WMTA with a synthetic tissue fluid and restored with zinc oxide-eugenol cement. After 7 and 70 days, the animals were killed, and the histological specimens taken from the teeth were stained with haematoxylin and eosin for histomorphological evaluation. The Brown and Brenn technique was employed to stain bacteria. The data were subjected to nonparametric Kruskall-Wallis analysis and Mann-Whitney U_tests. RESULTS: Biomimetic carbonated apatite did not induce hard tissue bridge formation. WMTA performed significantly better than BCAp in this respect at both periods (P < 0.05). BCAp was associated with a significantly greater inflammatory response as compared with WMTA after 7 days (P < 0.05). Both materials were associated with similar reactions after 70 days (P >0.05). CONCLUSIONS: White mineral trioxide aggregate induced hard tissue formation via a mechanism other than that postulated via apatite formation.

Prevalence of oral leukoplakia and lichen planus in 1167 Iranian textile workers.

OBJECTIVE: To evaluate the prevalence of oral precancerous lesions in textile workers. MATERIALS AND METHODS: A cross-sectional study was undertaken to assess a total of 1167 textile factory workers randomly selected from a total of 6947. An overall 97 women and 1070 men aged 18-69 years (mean=31.8 years) were studied. Regular smoking during the past 6 months was considered as the smoker group. Leukoplakia lesions were classified in accordance to Axell criteria [Axell T, Pindborg JJ, Smith CJ and Van-der-waal I (1996). J Oral Pathol Med 25: 49]. RESULTS: The results showed that 115 workers (9.9%) had red and white lesions. Among these 43 positive detections (3.7%) had leukoplakia and six cases (0.5%) had lichen planus. The smoking habits of the workers were limited to cigarette smoking. There was a statistically significant positive correlation between tobacco smoking and oral leukoplakia (P<0.001). CONCLUSION: There was a statistically significant positive correlation between tobacco smoking and leukoplakia in this relatively young cohort with generally mild tobacco use. The prevalence of leukoplakia had an inverse relationship with the level of education.