ABSTRACT
Periodontal disease is one of the most common diseases worldwide. It has a significant impact on oral health and subsequently the individual's quality of life. However, optimal regeneration of periodontal tissues, using current treatments, has yet to be achieved. Peptide self-assembly has provided a step-change in nanobiotechnology and regenerative medicine fields. Our aim was to investigate the effects of a self-assembling peptide (SAP; P11-4) on periodontal regeneration in a preclinical model. Twenty-six bilateral maxillary critical-sized periodontal defects were created surgically in 13 rats. Defects on one side of the mouth were filled with P11-4 hydrogel; the contra-lateral defect was untreated (control). Rats were sacrificed immediately post-surgery (time 0) and after 2 and 4 weeks. Retrieved maxillae were processed for histological, immunohistochemical, and histomorphometric assessments. The results of histological analysis showed greater organization of periodontal fibers in defects treated with P11-4, at both time points, when compared to untreated defects. Histomorphometry showed that treated defects had both a significant increase in functional periodontal ligament length and a reduction in epithelial down growth after 4 weeks. At 2 weeks, treated defects showed a significant increase in expression of osteocalcin and osteoprotegerin as judged by immunohistochemistry. Also, a significantly higher osteoprotegerin/RANKL ratio was shown in treated defects. In conclusion, the results demonstrated enhanced regeneration of periodontal tissues when SAP P11-4 was used to fill periodontal defects in rats. The findings of this study suggest that SAP P11-4 is a promising novel candidate for periodontal regenerative therapy. Further investigations are required for optimization before clinical use.
ABSTRACT
OBJECTIVES: Oral manifestations recorded for congenital heart disease (CHD) patients include teeth hypoplasia and high caries incidence. These observations suggested that the enamel and dentin of the teeth may be altered, increasing the risk for caries incidence. This study was designed to investigate the effect of CHD on the ultrastructure and composition of deciduous sound teeth. METHODS: Thirty sound exfoliated human deciduous incisor teeth were selected for this study. They were divided into three groups, Group I (control) from healthy children (n = 6), Group II from acyanotic CHD children (n = 12) and Group III from cyanotic CHD children (n = 12). Each tooth was longitudinally sectioned, providing enough specimens for ultrastructure and chemical analysis using ESEM/EDAX. The results of ESEM/EDAX and dentin image analysis were statistically analyzed using one-way ANOVA test followed by Tukey's test. RESULTS: Enamel of groups II and III showed increased dissolution and irregular orientation of enamel prisms. Orifices of dentinal tubules demonstrated widening and irregular outlines, also lateral branching increased markedly. Image analysis of dentin ESEM photomicrographs showed a highly significant increase in surface area of dentinal tubules. Decrease in calcium (Ca) and phosphorus (P) levels was statistically significant (P < 0.05). CONCLUSION: CHDs affect the structure and chemical composition of deciduous teeth.
