An in vitro evaluation of setting grade, dimensional alteration, solubility and penetration in the root dentin of primary teeth sealing materials

• Grant number: 10/20474-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2011
• End date: December 31, 2011
• Field of knowledge: Health Sciences - Dentistry - Pediatric Dentistry
• Principal Investigator: Andiara de Rossi
• Grantee: Eduardo Mariano Pioltine
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Although different materials are being proposed for root canal filling of primary teeth, there is still no consensus in the literature regarding the ideal filling material that meet certain physical-chemical, microbial and biological requisites. This research project aims to evaluate in vitro the setting grade, the dimensional alteration, the solubility and penetration in the root dentin of an calcium hydroxide paste-based (Calen®) combined with zinc oxide in different proportions (1:0,5, 1:0,65, 1:0,8, 1:1), zinc oxide and eugenol (ZOE) and two endodontic sealers, one calcium hydroxide based (Sealapex®) and one methacrylate based (EndoREZ®). To determine the degree of hardening, molds (10 x 2 mm) will be filled with materials and, after 150 sec, will be tested with type needle Gillmore (100 g) every 60 seconds until the reduction of surface markings. To test the dimensional changes cylindrical specimens (3.58 x 3.0 mm), whose length will be measured by means of digital parking meter before and after immersion in 2.24 mL of distilled water and deionized water for 30 days. In the solubility test, proof-of-body (1.5 x 7.75 mm) will be weighed before and after immersion in 7.5 mL of distilled water, determining the percentage loss of weight after 7, 14 and 21 days. For the analysis of root canal penetration single-rooted extracted deciduous teeth with intact roots or with up to one third of the root resorption, submitted to conventional endodontic treatment will be used. To enable the measurement of penetration of the root dentin, a violet dye will be added to the filling materials. The teeth will be maintained in a humid environment at 37 ° C and after 14 days will be cut lengthwise (0.4 mm thick) in vestibulo-lingual direction and the measuration of the penetration of the folders in dentin will be achieved using a profilometer. Potential findings could provide physicochemical basis for better manipulation of pastes commonly used for the sealing of primary teeth root canal, generate materials with potential clinic applicability, such as endodontic sealers, which are being used for root canals filling of permanent teeth, as well to establish research parameters to the development of newer materials. (AU)