Valoración de la microdureza y la estructura química de la dentina en endodoncia regenerativa

Laburpena

Introduction: Pulp necrosis in young permanent teeth with open apices is one of the greatest challenges that the dentist has to achieve treatment success. Tipically, the tratment of choice is the apexification with the induction of an apical barrier with calcium hydroxide or alternatively with MTA. However, this treatment increase the long term risk of fracture. Against this background, revascularization or regenertive endodontic therapy is proposed like an alternative treatment. It is based on the introduction of an intracanal dressing that will be applied in different periods of time. Among the proposed medications is tri-antibiotic paste (3-ATB) and calcium hydroxide. Several studies have described that the application of these agents and their solvents can affect the chemical structure and microhardness of the tooth over time. Objective: To investigate the effects of tri-antibiotic paste (ciprofloxacine, metronidazole, cllindamycin) and calcium hydroxide, used with distilled water and propylene glycol as solvents, in the microhardness and chemical structure of the dentin in the time periods of one and two months. Matherial and methods: It is an in vitro study with 100 singled-rooted teeth extracted from orthodontic, periodontal or another reasons that impede their conservation. There will be divided into differents study groups: negative control (intact tooth), positive control (instrumented tooth) calcium hydroxide and distilled water, calcium hydroxide and propylene glycol, tri-antibiotic paste and distilled water, tri-antibiotic paste and propylene glycol. The medicament gropus will be instrumented and irrigated with sodium hypochlorite (NaOCl) 5,25% and filled with medicament and the solvent corresponding to the group concerned. Microhardness test will be done in one month and two months in each group using a Vickers microhardness tester as well as the evaluation of the chemical structure by means of Raman spectroscopy. Results: Both in the microhardness tests and in the Raman spectroscopy test, it is observed that there are significant differences (p <0.005) between the treatment groups (calcium hydroxide and tri-antibiotic paste) and there are no significant differences (p> 0.005) between the times (1 month and 2 months). The group that generally has lower values in microhardness and spectroscopy tests is the tri-antibiotic paste combined with propylene glycol. Conclussion: The application of tri-antibiotic paste and the use of propylene glycol as a solvent affect to a greater degree the microhardness and chemical structure of dentin, compared with calcium hydroxide and distilled water.