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There have been many developments in operative dentistry in recent years, including a progressive shift to the use of resin composites, rather than dental amalgam, in the restoration of posterior teeth. This shift allows the adoption of minimal intervention approaches, thereby helping to conserve and preserve remaining tooth tissues and structures. This paper presents the position of the Academy of Operative Dentistry European Section (AODES) in relation to posterior resin composites. The AODES considers adhesively bonded resin composites of suitable composition and properties to be the "material of choice" for use in direct minimal intervention approaches to the restoration of posterior teeth. In so doing, the AODES emphasises the importance of the practice of evidence-based minimal intervention dentistry, including the use of refurbishment and repair techniques to extend the longevity of restorations. Guidance, based on best available evidence, has been made in relation to certain aspects of resin composite placement techniques in posterior teeth. © 2014 Elsevier Ltd. All rights reserved.

A 3-year follow-up clinical trial of two experimental Bayer total-etch adhesive systems and two commercial total-etch systems. Clearfil Liner Bond System and Scotchbond Multi-Purpose, was conducted to evaluate their clinical effectiveness in Class V cervical lesions. Four hundred twenty abrasion-erosion lesions were restored randomly using the four adhesive systems. There were two experimental cavity designs, in which the adjacent enamel margins either were or were not beveled and acid etched. Clearfil Liner Bond System and Scotchbond Multi-Purpose demonstrated high retention rates in both types of cavity design at 3 years. The two experimental Bayer systems scored much lower retention rates in both cavity designs at 3 years. None of the systems guaranteed margins free of microleakage for a long time. At 3 years, superficial, localized marginal discolorations were observed, the least for Clearfil Liner Bond System, followed by Scotchbond Multi-Purpose and the two experimental systems. Small marginal defects were recorded at the cervical dentin and the incisal enamel margin. Retention of Clearfil Liner Bond and Scotchbond Multi-Purpose appears to be clearly improved over earlier systems, but marginal sealing remains problematic. The two Bayer systems were found to be clinically unreliable.

Recently, several new resin-modified glassionomers have been introduced on the dental market. At the moment a real confusion exists over the right terminology of the products and its limits in use. Therefore, an in vitro and in vivo study with simultaneously a comparison with conventional glassionomers and composite resins was really necessary. This study revealed that resin-modified glassionomers have physico-mechanical properties that are situated between those of conventional glassionomers and composite resins. The manufacturers have a different approach concerning the particle size distribution. The new materials give a rough surface. They are not indicated for posterior restorations, because their surface hardness is too low compared to that of enamel, and their fatigue resistance is insufficient. The elasticity decreases during setting and maturation. Consequently, they are mainly indicated in situations that require a moderate strength and esthetics, for patients with a high caries activity and when ease in use is requested.

To investigate the interaction of six experimental and commercial bonding systems with dentin in vivo.One-Step, Clearfil Liner Bond 2, OptiBond, Permagen with 10% phosphoric acid, Permagen with 35% phosphoric acid, and PrimeBond were applied in standard Class I occlusal cavities in premolars scheduled for extraction for orthodontic reasons, combined either with a self-cured or with a light-cured resin composite. The teeth were carefully extracted 5 minutes after resin polymerization and fixed in 2.5% glutaraldehyde. After fixation, the specimens were dehydrated, sectioned, and processed for field-emission SEM.Although some systems produced gap-free intact interfaces in specific specimens, all of them showed detachment at the transition between the resin-dentin interdiffusion zone and the fluid resin placed over it. It was apparent that the presence of air-bubbles and/or thick layers of polymerized-filled fluid resin resulted in less frequent separation areas at the resin-dentin interface, providing support for the concept of the elastic cavity wall. It was also confirmed that some dentin adhesive systems do not form a thick layer over the dentin, otherwise the resin composite would not have penetrated the dentin tubules.

Objectives: The marginal quality of four tooth-coloured inlay systems was clinically investigated and subjected to computer-aided semiquantitative marginal analysis under scanning electron microscopy (SEM) after 3 years of clinical service. Methods: Three of the restoration types were made using the Cerec CAD-CAM apparatus: one was milled from preformed glass ceramic blocks, and the two other inlay types were milled from preformed porcelain blocks. The fourth system was based on an experimental indirect resin composite inlay system. Each inlay type was luted with a different luting resin composite. The clinical evaluation was performed with a mirror and explorer by two clinicians separately, and the marginal analysis was conducted microscopically on replicas (SEM X 200). Results: After 3 years in situ, all the restorations were clinically acceptable. No recurrent caries was observed. Marginal analysis under SEM detected a high percentage of submargination for all four systems, which suggests that their respective resin composite luting agents were all subject to wear. The percentage of marginal fractures on the enamel side as well as on the inlay side did not increase dramatically compared to the 6-month results. Conclusion: The first recall after 6 months of clinical service indicated how tooth-coloured inlays behave at their margins. The 3-year results confirmed the early findings, indicating that wear of resin composite lutes is important and present in all systems. The two ceramic materials showed a similar behaviour at the margins. The resin composite inlay performed better at the inlay site than at the enamel site.

Thirteen dual cure luting composites were compared in function of film thickness, consistency, and working time by using the American National Standard/American Dental Association (ANS/ADA) specifications for zinc phosphate cement and direct filling resins. The effect of temperature and setting reaction on the film thickness was also evaluated for some representative products. All three clinically related properties varied widely among the products investigated. A strong linear correlation was found between film thickness and consistency. This relation is supported by the temperature dependence of film thickness of dual cure luting composites. Cooling of the material increased the consistency, resulting in a larger film thickness, while heating reduced the film thickness because of the lower consistency. However, one product with a rather short working time at room temperature occasionally exhibited a dramatically enlarged film thickness after heating, probably caused by accelerated chemical polymerization. No correlation emerged between film thickness and maximum filler size or between consistency and filler weight content. Maximum filler size and filler weight content had been measured previously in Part I of this study. Scanning electron microscope (SEM) analysis of the cured film thickness samples revealed that the largest filler particles had been crushed under the heavy load pressure during film thickness measurement. The lack of correlation between consistency and filler weight content can be explained by the multifactorial determination of the consistency. It is concluded that the great diversity in the currently available luting composites makes clear specifications with regard to the optimum composition of luting composites urgently needed. Furthermore, more adequate methods for testing the film thickness of luting composites are also required.

Although an efficient bond of resin composites to enamel can be realized since quite a long time, reliable dentine bonding is nowadays still a clinical problem. After the failure of the dentine-etch technique, followed by the misfortunes of the chemical dentine adhesion technique, modern dentine adhesive systems are believed to function by a micromechanical attachment mechanism. Based on a morphological study of the resin-dentine interface, a broad selection of dentine adhesive systems was classified following their adhesion-strategy. In a second part, eight dentine adhesive systems were clinically tested in terms of retention.

Fourteen dual-cure luting composites were analyzed for their filler particle shape, predominant and maximum filler size, and filler weight in function of their clinical use. Polished surfaces were etched with an argon ion beam and studied by means of scanning electron microscopy. The type of filler particles, either inorganic or prepolymerized, could clearly be recognized. Their shapes were angular, rounded or spherical, depending on the product. The maximum filler size varied extremely from less than 1 mum to 250 mum. A particle-size distribution analyser disclosed a bell-shaped filler-size distribution. The predominant filler size for all the products was much smaller than the maximum filler size. The filler weight varied from 36 to 77%. After ion etching, some products showed small areas with a low degree of filler loading. A classification of the luting composites based on the maximum filler size is proposed. Since the particle size varies widely within the group of products analyzed, a standard specification for luting composites is urgently needed.