Cementado de postes de fibra con cementos híbridos de ionómero vítreo: estudio de las interfases por microscopía electrónica de barrido (MEB).

Abstract

ABSTRACT. Morphological study of fiber post/hybrid glass ionomer cement/dentin interface by evaluation of two cements. Objectives: The aim of the study was to analyze the interfaces, the structure and the seal between root dentin and cemented fiber posts. The interfaces were obtained by cementing the posts with two brands of cements both used after application of polyacrilic acid (Cavity Conditioner, GC Corp). . The interfaces were evaluated by SEM observation of the continuity between the fiber posts, the cement and the root dentin. The structure of the cements were also evaluated. Method: Twenty single rooted teeth extracted for periodontal reasons were treated endodontically and then randomly separated into two groups of 10 teeth each: group 1: Fuji Plus (GC); group 2: Meron Plus (VOCO). After preparation of the root canal and application of the cavity conditioner (Cavity Conditiones GC Co) each specimen received a Macro-Lock Post (RTD), a serrated, translucent radiopaque quartz fiber post that was cemented with one of the two hybrid cements according to the manufacturer’s instructions. After storage at room temperature for 48 hours in physiological saline solution, 10 roots were sectioned transversally into 3 pieces and 10 roots longitudinally. The specimens were then prepared for SEM observation of the structure and continuity of the interfaces and EDX of various structural phases identified by SEM along the interfaces. Results: SEM revealed a perfectly sealed interface between glass ionomer and root dentin. In the other hand, the fiber post-cement interface was the fiber post-cement interfase evidence zones of no-adhesion. SEM also revealed numerous air voids with spherical bodies inside within the RMGI matrix. EDX analyses of the spherical body showed an electron dense perifery with a higher Al and Si content than the surrounding ionomer. Conclusion: Hybrid glass ionomer cements provide a perfectly sealed interface with root dentin. There’s no evidence of adhesion between fiber post and cement. Into the cement structure there are air voids with Si and Al coated spherical bodies within, finding that provides evidence for the permeation of water through the root into the hybrid glass ionomer interface.