Esthetic compomer restorations in posterior teeth using a new all-in-one adhesive: case presentation

Amalgam safety and dentists' attitude: a survey among a Subpopulation of Nigerian dentists

OBJECTIVE

To investigate Nigerian dentists' perception of amalgam safety and to highlight the dentists' attitude toward amalgam.

METHODS

A cross-sectional survey of all dentists in Southeastern Nigeria was done using a self-administered, structured questionnaire.

RESULTS

The report recorded a 90.9% response rate. More specialists (95.7%) than general dentists (74.5%) agreed to the safety of amalgam. Furthermore, more patients seen by the general dentists (85.1%) than by specialists (34.88%) agreed with amalgam safety. Undergraduates' education (82.9%) was the highest source of awareness of the amalgam controversy, followed by inquires (64.3%), colleagues (47.1%), TV/radio (41.4%), conferences (27.1%) and continuing dental education (15.7%). About 37% of respondents knew all the signs and symptoms of amalgam toxicity, while 47.1% of respondents knew that the lung is the fastest route for mercury absorption. About 81.0% of dentists do not support an amalgam ban and 84.3% would not even recommend an alternative to amalgam. Amalgam is well accepted by both dentists and patients in the studied population.

Use of a self-etching primer in combination with a resin-modified glass ionomer: effect of water and saliva contamination on shear bond strength

The purpose of this study was to evaluate the effects of 3 different enamel conditioners (10% polyacrylic acid, 37% phosphoric acid, and self-etching primer) on the shear bond strength and site of bond failure of a resin-modified glass ionomer (Fuji Ortho LC, GC Europe, Leuven, Belgium) bonded onto dry, water-moistened, and saliva-moistened enamel. One hundred eighty bovine permanent mandibular incisors were randomly divided into 12 groups; each group consisted of 15 specimens. Three different enamel surface conditions were studied: dry, soaked with water, soaked with saliva. One hundred eighty stainless steel brackets were bonded with the resin-modified glass ionomer. After bonding, all samples were stored in distilled water for 24 hours and then tested in a shear mode on a testing machine. After self-etching primer application, Fuji Ortho LC produced the highest shear bond strengths under all the different enamel surface conditions; these values were significantly higher than those achieved in the remaining groups, except when Fuji Ortho LC was used in combination with 37% phosphoric acid on dry enamel. Fuji Ortho LC bonded without enamel conditioning produced the lowest shear bond strengths. The bond strength of the groups conditioned with 10% polyacrylic acid was significantly lower than that of the groups etched with 37% phosphoric acid, except when both conditioners were used on enamel soaked with water.

Effect of water and saliva contamination on shear bond strength of brackets bonded with conventional, hydrophilic, and self-etching primers

This study assessed the effect of water and saliva contamination on the shear bond strength and bond failure site of 3 different orthodontic primers (Transbond XT, Transbond Moisture Insensitive Primer, and Transbond Plus Self Etching Primer; 3M Unitek, Monrovia, Calif) used with a light-cured composite resin (Transbond XT). Bovine permanent mandibular incisors (315) were randomly divided into 21 groups (15 in each group). Each primer-adhesive combination was tested under 7 different enamel surface conditions: (1) dry, (2) water application before priming, (3) water application after priming, (4) water application before and after priming, (5) saliva application before priming, (6) saliva application after priming, and (7) saliva application before and after priming. Stainless steel brackets were bonded in each test group with composite resin. After bonding, all samples were stored in distilled water at room temperature for 24 hours and then tested for shear bond strength. Noncontaminated enamel surfaces had the highest bond strengths for conventional, hydrophilic, and self-etching primers, which produced the same strength values. In most contaminated conditions, the self-etching primer had higher strength values than either the hydrophilic or conventional primers. The self-etching primer was the least influenced by water and saliva contamination, except when moistening occurred after the recommended 3-second air burst. No significant differences in debond locations were found among the groups bonded with the self-etching primer under the various enamel conditions.

Direct restorative material use of selected practitioners in the United Kingdom

PURPOSE OF THE INVESTIGATION

To investigate, by questionnaire, the direct restorative materials used by a sample of practitioners from the United Kingdom.

BASIC PROCEDURES

A postal questionnaire was distributed to a group of self-selected practitioners, who volunteered to participate in the study. In all 110 practitioners participated in the study.

MAIN FINDINGS

The most used material for the restoration of occlusal (Class I) and approximal (Class II) lesions was amalgam with 61% and 73% of practitioners indicating that they used amalgam in this situation. Adhesive tooth-coloured materials, specifically composites and compomers, were preferred by the majority of practitioners for anterior approximal (Class III) and incisal (Class IV) restorations with compomer preferred for Class V restorations including non-carious cervical lesions and for the restoration of primary teeth.

PRINCIPAL CONCLUSIONS

It is concluded that the general practitioners surveyed in this study tend to use amalgam for the restoration of Class I and II lesions as opposed to resin composite. The majority of practitioners in this study used compomers, a relatively new group of restorative materials, with little evidence of traditional glass-ionomer cements being used routinely.

Direct posterior restorations: clinical results and new developments

The longevity of dental restorations is dependent on many different factors, including those related to materials, the dentist, and the patient. The main reasons for restoration failure are secondary caries, fracture of the bulk of the restoration or of the tooth, and marginal deficiencies and wear. The importance of direct-placement, aesthetic, tooth-colored restorative materials is still increasing. Amalgam restorations are being replaced because of alleged adverse health effects and inferior aesthetic appearance. All alternative restorative materials and procedures, however, have certain limitations. Direct composite restorations require a time-consuming and more costly treatment procedure and are actually only indicated for patients with excellent oral hygiene. Glass ionomers can be considered only as long-term provisional restorations in stress-bearing posterior cavities. Future treatment regimens that are made possible by the development of sophisticated preparation techniques, improved dentin bonding agents, and resin-based restorative materials will result in the therapy of more small-sized lesions rather than large restorations. The importance of indirect inlay techniques will shift more and more toward the direct restoratives. As the cavities become smaller, it is to be expected that the use of improved direct restorative materials will provide excellent longevity even in stress-bearing situations.

Marginal quality and microleakage of adhesive class V restorations

OBJECTIVES

The aim of this in vitro study was to determine the marginal quality and microleakage of composite resin class V restorations.

METHODS

Standardized mixed class V cavities (diameter: 4mm, depth: 2mm) with half of the finish lines limited within dentin were cut in 90 freshly extracted human molars and randomly assigned to nine groups (n=10). After etching enamel and dentin, the cavities were restored with nine different restorative systems (Syntac Sprint/Tetric Ceram=SS, Syntac Single-Component/Tetric Ceram=SC, Onestep/Aeliteflo=OS, Aquaprep+Onestep/Aeliteflo=OA, Prime & Bond 2.1/TPH=PB, Optibond Solo/Prodigy=OP, Singlebond/Z100=SB, Tenure Quik/Marathon=TQ, Solobond M/Arabesk=SM) using a wet-bonding procedure. After finishing and polishing, the teeth were stored for 24h in distilled water at 37 degrees C before they were subjected to thermocycling (5/55 degrees C, 1000x). Epoxy replicas were made for margin analysis in the SEM. Specimens were stained in methylene blue, sectioned, and evaluated for microleakage. Dye penetration was scored on a 0-3 ordinal scale.

RESULTS

Statistical analysis (Kruskal-Wallis H-test, Mann-Whitney U-test) revealed significant differences (P<0.05) among the groups at dentin and enamel margins for the microleakage scores as well as for the results of the quantitative SEM margin analysis. SC revealed a significantly higher percentage of perfect margins in the SEM than OS and SM in enamel and dentin, respectively. OA exhibited significantly more leakage in enamel than all other groups.

CONCLUSIONS

None of the tested restorative systems achieved a perfect seal in dentin and enamel of mixed class V cavities. Marginal quality and sealing ability of adhesive systems to dentin, using a wet-bonding procedure, is still inferior compared with enamel margins.

Three-year clinical evaluation of direct and indirect composite restorations in posterior teeth

STATEMENT OF THE PROBLEM

Objective long-term clinical data are necessary to assess the performance of modern posterior composites as direct and indirect restorations.

PURPOSE

This prospective, long-term clinical trial evaluated direct and indirect composite restorations for clinical acceptability as posterior restoratives in single or multisurface cavities and provided a survey on the 3-year results.

MATERIAL AND METHODS

Under the supervision of an experienced dentist, 9 dental students placed 88 composite restorations (Tetric, blend-a-lux, Pertac-Hybrid Unifil), 43 direct composite restorations, and 45 indirect inlays. Clinical evaluation was performed at baseline and in yearly intervals after placement by 2 other experienced dentists, using modified USPHS criteria. A third follow-up of 60 restorations took place within 33 to 36 months after placement.

RESULTS

A total of 93% of indirect and 87% of direct restorations were assessed to be clinically excellent or acceptable. During the third year, 1 direct restoration in a molar failed because of margin opening. Indirect inlays exhibited a significantly better anatomic form of the surface than direct composite restorations. Premolars revealed a significantly better marginal integrity and anatomic form of the surface than molars. Restorations in molars exhibited a significantly higher failure rate compared with premolars.

CONCLUSION

Posterior composite restorations provided a satisfactory clinical performance over a 3-year period, even if placed by relatively inexperienced but supervised students.