Development of Chlorhexidine Digluconate and Lippia sidoides Essential Oil Loaded in Microemulsion for Disinfection of Dental Root Canals: Substantivity Profile and Antimicrobial Activity.

The dental intracanal disinfection is crucial to achieve the success of endodontic treatment, avoiding the maintenance of endodontic infections. Chlorhexidine digluconate can act as an irrigating agent for it. However, it can cause tissue irritation in high concentrations. Therefore, combinations with other antimicrobial agents and more efficient therapeutic alternatives are studied, which make it possible to administer drugs more safely and with minimal adverse effects. Thus, the objective of this study was the development of a microemulsion containing chlorhexidine digluconate and essential oil of Lippia sidoides to be used for disinfection of dental root canals and to evaluate its profile of substantivity and antimicrobial activity. The microemulsions were obtained through phase diagrams, using the spontaneous formation method. We completed a physical-chemical characterization and evaluate the stability of the microemulsions, in addition to the substantivity profile in a bovine root dentin model, and in vitro antibacterial effect on Enterococcus faecalis. A method for quantifying chlorhexidine was developed using UV-Vis spectroscopy. The microemulsions showed acid pH, conductivity above 1.3 µScm-1, and dispersion index similar to water. The microemulsions showed antimicrobial inhibition halos similar to the commercial gel conventionally used, but with four times more substantivity to dentinal tissues. Microemulsions were obtained as a therapeutic alternative to formulations available on the market, presenting themselves as a system with great potential for the administration of drugs for disinfection of root canals.

Enamel of Premolars whose Predecessors Presented Rupture of the Follicle Bone Crypt from Periapical Infections.

OBJECTIVE: To observe if dental alterations in premolars are associated with the rupture of the follicle bone crypt caused by a periapical lesion in the predecessor molars. STUDY DESIGN: This is a cross-sectional study. Data collection consisted of the analysis of medical records, a socioeconomic questionnaire, and dental clinical examination. Records from patients with a history of a radiographically visible periapical lesion in lower primary molars submitted to pulp therapy or extraction from a university dental clinic were selected. Successor premolars were clinically evaluated for the presence of enamel development defects, shape alterations, and eruption deviations. The descriptive analysis of data was performed, and Fisher's exact tests, linear trend chi-square, and the Student's t-test were applied. RESULTS: Forty-eight permanent teeth were from 36 patients were evaluated in this study, and 20 (41.7%) of the 48 examined premolars showed a radiographic image suggestive of the rupture of the bone crypt. Rupture of the follicle bone crypt was not associated with the occurrence of enamel alterations in premolars (p = 0.418). An association between dental alterations and age over six years at the time of intervention was observed (p = 0.043). CONCLUSION: The presence of enamel alterations of premolars was not associated with the rupture of the follicle bone crypt caused by a periapical lesion in predecessor molars.