Microleakage in posterior teeth with different materials and different types of cavities

Background

The purpose of this study was to investigate the behavior of a resin-based 2,2-bis (p-[2'-hydroxy-3'-methacryloxypropoxy] phenylene) propane and a composite resin modified with oxirane, regarding the ability of marginal sealing, both with direct restorations and indirect restorations.

Materials and Methods

To achieve this, mesio- and disto-occlusal cavities were made on the same tooth, totalling 100 cavities. These cavities were restored with two materials, Filtek P90 (3M ESPE) and Opallis (FGM). Then, they were divided into two groups: Fifty direct restorations, each sample restored with the two materials, following the manufacturer's protocol and fifty indirect restorations, and then cemented with a paste obtained by diluting the resin in its adhesive. The templates were thermally cycled, 30 s at 5°C and 30 s at 55°C for 500 cycles and then were immersed in methylene blue for 24 h. Afterward, they were trimmed using a plaster trimmer from occlusal toward a gingival direction. These samples were analyzed with stereomicroscope (×3) by two blinded observers. Then, a system which considers the average number of surrounding walls that have suffered infiltration on a scale of 0-3 was used.

Results

Data were subjected to statistical analysis (Mann-Whitney and Kruskal-Wallis tests) with a significance level of 5% maximum.

Conclusion

It was concluded that the indirect restorations showed the greatest number of restorations with score 0 and 1 (34) and lowest score 2 and 3 (16). This suggests that indirect restorations regardless of the material used behaved more effectively regarding the marginal sealing of restorations.

Clinical evaluation of posterior composite restorations: 6-year results

PURPOSE

To evaluate the wear resistance of resin restorations (Z100; Tetric; Charisma) in posterior teeth (Class I and II) after 6 years.

MATERIAL AND METHODS

One operator placed 103 restorations in 13 patients. Each patient had at least three restorations with three different resin-based composites. All restorations were made using rubber dam isolation and the cavity design was restricted to the elimination of carious tissue. Deeper cavities were covered with calcium hydroxide and/or glass ionomer cement and in shallow and medium cavities only an adhesive system was used. Each composite was placed according to the manufacturer's instructions. In Class II cavities the resin placement followed the Krejci et al or Opdam et al technique, according to the cavity size. One week later, the restorations were finished/polished and stone dies were immediately built from the impressions. Eleven patients attended the 6-year recall, and 90 restorations were evaluated based on new stone dies. The 6-year stone dies were compared with the baseline ones by two examiners. The evaluation was based on the modified Mahler et al. criteria and Busato et al, using six different scores. The scores were statistically analyzed.

RESULTS

A total of 87% of the restorations were analyzed after 6 years. Only 15% (6 for Tetric and 7 for Charisma) of the 90 evaluated restorations had been already replaced. No statistical difference was found in the wear rate of the composites used in this study. None of the patients complained of any symptom after the placement of the composite (baseline data) nor after 6 years.

One-year clinical evaluation of posterior packable resin composite restorations

This study evaluated the clinical performance of four packable resin composite restorative materials in posterior teeth (Class I and II) compared with one hybrid composite after one year. Eighty-four restorations were placed in 16 patients. Each patient received at least five restorations. The tested materials were: (1) Solitaire + Solid Bond; (2) ALERT + Bond-1; (3) Surefil + Prime & Bond NT (4) Filtek P60 + Single Bond and; (5) TPH Spectrum + Prime & Bond 2.1. All restorations were made using rubber dam isolation, and the cavity design was restricted to the elimination of carious tissue. Deeper cavities were covered with calcium hydroxide and/or glass ionomer cement. In shallow and medium cavities, no protection was performed except for the respective adhesive system used in each group. Each adhesive system and resin composite was placed according to the manufacturer's instructions. One week later, the restorations were finished/polished and evaluated according to the USPHS modified criteria. All patients attended the one-year recall, and the 84 restorations were evaluated at that time based on the same evaluation criteria. The scores were submitted to statistical analysis (Chi-square test, p<0.05). Solitaire and TPH showed some fractures at marginal ridges. Solitaire, ALERT and TPH showed some concerns related to color match and surface texture. Surefil and Filtek P60 showed an excellent clinical performance after one year.

Biological restorations using tooth fragments

A "biological" restoration technique using dental fragments and adhesive materials is described. These fragments were obtained from extracted human teeth which had been previously sterilized and stored in a tooth bank. The advantages are: the use of extracted teeth as restorative material, esthetics, and treatment cost. The positive sensation of having back the missing tooth was the most mentioned comment among patients. The disadvantages are: the difficulty of obtaining teeth with the needed characteristics, problems of making an indirect restoration, matching the original color, and the non-acceptance by some patients who consider it strange to have other people's teeth placed in their mouths.