Effects of ultrasonic instrumentation on microleakage in composite restorations with glass ionomer liners

Influence of Hand Instrumentation and Ultrasonic Scaling on the Microleakage of various Cervical Restorations: An in vitro Study

INTRODUCTION

In cervical lesions, various restorative materials can be inserted, which can be affected by the application of periodontal scalers. This study evaluated and compared the marginal seal of class V glass ionomer, composite resin, and amalgam restorations after subjecting them to hand instrumentation and ultrasonic scaling.

MATERIALS AND METHODS

In this experimental study, 30 sound human first premolars were selected. In each tooth, buccal and lingual cavities (4 mm mesiodistal width, 3 mm occlusogingival height, and 2 mm depth) were made. The teeth were randomly assigned to three groups of 10 teeth: (1) Glass ionomer group, (2) composite group, and (3) amalgam group. Teeth were subjected to thermocycling procedure for 1,000 cycles between 5 and 55°C water baths and a 1-minute dwell time. Then, each group was randomly subdivided: (1) Margins of 30 restorations were exposed to hand instrumentation procedures by applying 10 working strokes, (2) margins of 30 restorations were exposed to a periodontal tip mounted on a piezoelectric ultrasonic handpiece working at 25 kHz for 10 seconds. The specimens were serially sectioned mesiodistally. Each section was examined under a stereomicroscope. The extent of microleakage was ranked using a 0 to 4 scale at both occlusal and cervical margins of the restorations. Data were analyzed initially using the Kruskal-Wallis test, followed by multiple comparisons using the Mann-Whitney and Wilcoxon test.

RESULTS

The type of restorative material had a significant influence on dye penetration, whether in the enamel margin or in the dentinal margin (p < 0.001). The microleakage of glass ionomer group was the highest. No statistical differences were found in dye penetration between scaling groups (hand instrumentation and ultrasonic scaling) (p > 0.05).

CONCLUSION

Type of restorative material had a significant influence on microleakage. No statistical differences were found in dye penetration between scaling groups.

CLINICAL SIGNIFICANCE

The microleakage of glass ionomer restoration is greater than amalgam and composite restorations after subjecting them to hand instrumentation and ultrasonic scaling.

Effects of four prophylaxis pastes on surface roughness of a composite, a hybrid ionomer, and a compomer restorative material

PURPOSE

This study was undertaken to compare the effects of three prophylaxis pastes (Nupro with coarse, medium, or fine pumice) with a new paste (Clinpro with perlite) on the surface roughness of a resin composite (Dyract AP), a hybrid ionomer (Fuji II LC), and a compomer (TPH Spectrum).

MATERIALS AND METHODS

Twenty disks (2 mm thick x 10 mm in diameter) of each material were prepared in split molds and stored for 24 hours at 37 degrees C in a 100% relative humidity humidistat. Baseline Mylar surface roughness values were determined. A single operator polished each specimen for 10 seconds with each paste. Five tracings of each specimen of surface roughness (Ra, microm) were made using a surface profilometer. Means and standard deviations were calculated, and analyzed by two-way analysis of variance (three restorative materials and four prophylaxis pastes as factors) and compared using Tukey-Kramer intervals calculated at the 0.05 level of significance.

RESULTS

Analysis of variance showed significant differences among restorative materials (after polishing) and prophylaxis polishing agents. Tukey-Kramer intervals for comparisons were 0.04 and 0.05 microm, respectively. All polishing agents produced significant increased roughness compared with baseline, yielding the following results (X + SD, microm) for the three restorative materials (Fuji II LC, TPH Spectrum, Dyract AP): perlite, 0.16 +/- 0.07, 0.28 +/- 0.26, 0.79 +/- 0.64; course pumice, 0.36 +/- 0.17, 0.48 +/- 0.25, 0.88 +/- 0.46; medium pumice, 0.26 +/- 0.10, 0.35 +/- 0.30, 0.46 +/- 0.21; and fine pumice, 0.16 +/- 0.06, 0.34 +/- 0.30, 0.42 +/- 0.24). Fine pumice and perlite produced the least roughness on the hybrid ionomer, medium and fine pumice on the resin composite, and perlite on the compomer.

CLINICAL SIGNIFICANCE

Since prophylaxis pastes have the potential to increase the surface roughness of resin composite, hybrid ionomer, and compomer restorative materials, routine polishing during prophylaxis should be avoided.

Position paper: sonic and ultrasonic scalers in periodontics. Research, Science and Therapy Committee of the American Academy of Periodontology

Ultrasonic and sonic scalers appear to attain similar results as hand instruments for removing plaque, calculus, and endotoxin. Ultrasonic scalers used at medium power seem to produce less root surface damage than hand or sonic scalers. Due to instrument width, furcations may be more accessible using ultrasonic or sonic scalers than manual scalers. It is not clear whether root surface roughness is more or less pronounced following power-driven scalers or manual scalers. It is also unclear if root surface roughness affects long-term wound healing. Periodontal scaling and root planing includes thorough calculus removal, but complete cementum removal should not be a goal of periodontal therapy. Studies have established that endotoxin is weakly adsorbed to the root surface, and can be easily removed with light, overlapping strokes with an ultrasonic scaler. A significant disadvantage of power-driven scalers is the production of contaminated aerosols. Because ultrasonics and sonics produce aerosols, additional care is required to achieve and maintain good infection control when incorporating these instrumentation techniques into dental practice. Preliminary evidence suggests that the addition of certain antimicrobials to the lavage during ultrasonic instrumentation may be of minimal clinical benefit. However, more randomized controlled clinical trials need to be conducted over longer periods of time to better understand the long-term benefits of ultrasonic and sonic debridement.