Fluid flow after resin-composite restoration in extracted carious teeth

The aim of this study was to investigate fluid flow in dentin after restoration of carious teeth with resin composite bonded with a total-etching adhesive, with or without glass-ionomer cement lining. The roots of extracted third molars were removed and the crowns were connected to a fluid flow-measuring device. Each carious lesion was stained with caries detector dye and caries was removed using slow-speed burs and spoon excavators. Caries-excavated teeth were divided into two groups for restoration with resin composite bonded with a total-etch adhesive: (i) without lining; and (ii) lined with glass-ionomer cement before bonding. In non-carious teeth, cavities of similar dimensions were prepared, divided into two groups, and restored in the same manner. Fluid flow was recorded, after restoration, for up to 1 month. Caries-affected dentin was examined by scanning electron microscopy (SEM), and the bonded interfaces were observed using a confocal laser scanning microscope. No significant difference in fluid flow was observed between the two restorative procedures or between the carious and non-carious groups. The SEM images showed that the dentinal tubules of acid-etched, caries-affected dentin were usually still occluded, while some were patent. Limited penetration of fluorescent dye into dentin and into the bonded interfaces of restored carious teeth was observed.     

Posterior resin composite restorations with or without resin‐modified,glass‐ionomer cement lining: a 1‐year randomized,clinical trial

Aim: To investigate the effect of resin‐modified, glass‐ionomer cement lining on the quality of posterior resin composite restorations, bonded with a two‐step, total‐etch or self‐etching adhesive, at 1 year. Methods: Patients with 1–4 moderate‐to‐deep, primary occlusal caries in molars were informed and recruited. A total of 110 composite restorations were placed in 75 participants, with one of four restorative procedures: (a) bonded with a total‐etch adhesive (Single Bond 2); (b) lined with glass‐ionomer cement (Fuji Lining LC), and then bonded with total‐etch adhesive; (c) bonded with a self‐etching adhesive (Clearfil SE Bond); and (d) lined with glass‐ionomer cement, and then bonded with self‐etching adhesive. Results: At 1 year, 57 patients (86 restorations) attended the recall. Each of the restorations was evaluated and scored from 1 (clinically excellent) to 5 (clinically poor) using the following criteria: (a) patient satisfaction; (b) fracture and retention; (c) marginal adaptation; (d) recurrent caries; and (e) post‐operative sensitivity. At 1 year, the qualities of the restorations were not significantly affected by the placement of glass‐ionomer cement lining, regardless of the adhesive used (P > 0.05). Most of the restorations were scored 1 for all criteria. Conclusions: The benefit of placing a glass‐ionomer cement liner in resin composite restoration is questionable.     

Sealing ability of occlusal resin composite restoration using four restorative procedures

The purpose of this work was to investigate fluid flow after restoration using four restorative procedures. Micro‐gap, internal dye leakage, and micropermeability of bonded interfaces were also investigated. Each tooth was mounted, connected to a fluid flow‐measuring device, and an occlusal cavity was prepared. Fluid flow after cavity preparation was recorded as the baseline measurement, and the cavity was restored using one of four restorative procedures: bonding with total‐etch (Single Bond 2) or self‐etch (Clearfil SE Bond) adhesives without lining; or lining with resin‐modified glass‐ionomer cement (GIC) (Fuji Lining LC) or conventional GIC (Fuji IX) and then bonding with the total‐etch adhesive. Fluid flow was recorded after restoration and at specific time‐points up to 6 months thereafter and recorded as a percentage. Micro‐gap formation was analyzed using resin replicas and scanning electron microscopy. Internal leakage of 2% methylene blue dye was observed under a light microscope. In micro‐permeability testing, fluorescent‐dye penetration was investigated using confocal laser microscopy. None of the restorative procedures provided a perfectly sealed restoration. Glass‐ionomer lining did not reduce fluid flow after restoration, and micro‐gaps were frequently detected. The self‐etch adhesive failed to provide a better seal than the total‐etch adhesive, and even initial gap formation was rarely observed for the former. Penetration of methylene blue and fluorescent dyes was detected in most restorations.     

Survival Rates from Fracture of Endodontically Treated Premolars Restored with Full-coverage Crowns or Direct Resin Composite Restorations: A Retrospective Study

Introduction

The aim of the present study was to compare the survival rates against fracture of premolar endodontically treated teeth (ETT) restored with resin composite or crowns and to identify risk factors associated with the fracture.

Root Reinforcement after Obturation with Calcium Silicate–based Sealer and Modified Gutta-percha Cone

Introduction

A root canal obturated with a calcium silicate–based sealer (bioceramic sealer [BCS]) and a modified gutta-percha cone (bioceramic cone [BCC]) might improve the fracture resistance of the root. The objective of this study was to evaluate root reinforcement of a bioceramic cone/sealer (TotalFill; FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) by investigating the fracture resistance, push-out bond strength, sealer penetration, and modulus of elasticity (MOE) in comparison with gutta-percha/AH Plus (Dentsply Maillefer, Tulsa, OK) (GP/AH).