Influence of chlorhexidine application on longitudinal adhesive bond strength in deciduous teeth

The aim of this study was to evaluate the influence of applying 2 percent chlorhexidine for 30 seconds after phosphoric acid conditioning of dentin on the immediate and long-term bond strengths in deciduous teeth. The occlusal enamel was removed from 40 human sound deciduous molars, which were exfoliated by natural means, and the dentin was conditioned with 37 percent phosphoric acid for 15 seconds and washed with running water. The specimens were divided into two groups of 20 teeth. The test group received an application of 2 percent chlorhexidine for 30 seconds prior to a three-step etch-and-rinse adhesive system, whereas the control group received only the adhesive system. Three cylindrical restorations were made with a composite resin for each tooth. Ten teeth in each group were submitted to a microshear bond strength test after 24 hours, while the remaining teeth were stored in distilled water at 37 °C for 6 months before testing the microshear bond strength. The test group had a higher bond strength than did the control group after 6 months of storage. No statistical differences were found when groups with the same dentin treatment were compared at different times. Short applications of chlorhexidine at low concentrations prevent hybrid layer degradation and positively affect bond strength over time.

Cimentos usados em prótese fixa: uma pesquisa com especialistas em prótese de Porto Alegre / Cements used for fixed prosthodontics: a survey with Porto Alegre specialists

Actually, many dental cements are available to cement fixed prosthesis at dental clinical practice. The aim of this study was to evaluate the cements used to fixed prosthesis by specialists who work at city of Porto Alegre with a questionnaire. A questionnaire with 22 questions was elaborated and applied to professionals registered at Regional Dentistry Council (CRO). From the 225 electable subjects, 39 were excluded. The sample of 186 specialists, 72 weren´t interviewed. The 114 interviewed subjects represented a 61.29% of response rate. The graduate year of 52% of subjects was between 1981 and 2000, and 63% finished the post graduate course after 1991. To final cementation of fixed metal ceramic prosthesis, 65% used zinc phosphate cement. However, to cements metal free fixed prosthesis, 57% used resinous cement. With technological advances at rehabilitation materials, new materials and techniques were developed. However, the zinc phosphate cement is still the first choice to cement metal ceramic prosthesis to Porto Alegre specialists.

Atualmente, diversos cimentos são utilizados para cimentação de próteses fixas na prática clínica odontológica. Sendo assim, o objetivo do presente estudo foi avaliar o uso de cimentos para prótese fixa por especialistas em prótese dentária que atuam no município de Porto Alegre. Para isso, um questionário com 22 perguntas foi elaborado e aplicado a tais profissionais registrados no Conselho Regional de Odontologia. Dentre os 225 indivíduos elegíveis, 39 foram excluídos. Da amostra de 186 especialistas, 72 não foram entrevistados. Os 114 indivíduos entrevistados representaram uma taxa de resposta de 61,29%. O ano de graduação de 52% dos respondentes foi entre 1981 e 2000 e 63% concluíram o curso de pós-graduação após 1991. Para cimentação final de próteses fixas métalo-cerâmicas, 65% dos dentistas usavam cimento de fosfato de zinco. Entretanto, para prótese fixas livres de metal, 57% utilizavam cimento resinoso. Com o avanço da tecnologia em materiais reabilitadores, novos materiais e técnicas foram criados, no entanto, o cimento de fosfato de zinco segue como primeira escolha entre os especialistas para cimentação final de próteses métalo-cerâmicas.