Dentin caries treatment and microbial profile analyses associeted

Author(s)

Maria Paula Maciel Rando Meirelles

• Document type: Doctoral Thesis
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2010-02-24

Examining board members

Maria da Luz Rosário de Sousa; Marcelo Henrique Napimoga; Cristiane Duque; Daniel Saito; Elaine Pereira da Silva Tagliaferro

• Advisor: Reginaldo Bruno Gonçalves; Maria da Luz Rosário de Sousa

Abstract

The most important factor to development of caries lesion is the metabolic activity of biofilm on the dental tissues. By this definition and of the development of new restorative materials, a more conservative approach about dentin caries lesion treatment has been researched. Chapter 1. Objective: To compare the clinical and radiographic outcomes of permanent molar teeth, with deep lesions treated by complete or partial removal of carious dentin after follow-up over a 24-month period. Methodology: 18 permanent molars of 11 adolescents, aged 12 to 17 years, were assigned to interventions by using random allocation. In the experimental group nine teeth were submitted to partial removal of carious dentin, protected with glass ionomer cement and restored with resin composite. In the control group, nine teeth were submitted to complete removal of carious dentin, protected with calcium hydroxide and glass ionomer cement and restored with resin composite. Radiographic examination and pulp vitality tests were performed 12-24 months after cavity sealing and the teeth were not re-entered. Results: No volunteer felt pain without stimulus and no teeth presented an image suggesting periapical lesion. Conclusion: The results suggest that partial removal of carious dentin can be indicated to maintain the pulp vitality and that there is no need to reopen after cavity sealing. Chapter 2. Objective: To compare the microbial profile of non-clinically (NCD) and clinically detected dentin-related caries lesions (CD) by Polymerase Chain Reaction based-Denaturing Gradient Gel Eletrophoresis. Methodology: 8 dentin caries sample of non-clinically detected lesions (NCD) and 8 clinically detected (CD), previously collected to operative procedure (Chapter 1), were assessed by PCRDGGE. Dentin caries lesions underlying sound enamel were considered nonclinically detected lesions. The total microbial genomic DNA of the sample was isolated. PCR was performed with a set of universal bacterial 16S rDNA primers. The PCR-amplified 16S rDNA fragments were separated by DGGE. The groups were assessed by comparing the PCR-DGGE fingerprinting profile using Bionumerics and Primer5 programs. Results: The profile heterogeneity demonstrated the evident separation of the groups with low similarity between them (45% R>0,5). There was no statistical difference between the means of amplicons (bands) of the NCD and CD lesions (p=0,40). Conclusion: These findings suggest that there are clearly differentiated species between the groups; however, with some overlap between them, and that CD lesions had a microbiota as complex as those of NCD lesions. (AU)