Table of Contents

Implants
Restorative

Inside Dentistry

April 2008, Volume 4, Issue 4
Published by AEGIS Communications

Effects Of Sonic And Ultrasonic Scaling On The Surface Roughness Of Tooth-Colored Restorative Materials For Cervical Lesions.

Lai YL, Lin YC, Change CS, Lee SY. Oper Dent. 2007;32:273-78.

Abstract
This study investigated the effects of sonic and ultrasonic scaling on the surface roughness of five commonly used tooth-colored restorative materials for Class V cavities, including a flowable resin composite (Tetric Flow), a compomer (Compoglass F), a glass ionomer (Fuji II), a resin-modified glass ionomer (Fuji II LC Imp) and a resin composite (Z100). Twenty rectangular block specimens (16 x 6 x 1.5 mm) of each material were cured against matrix strips, then stored in artificial saliva for two months before performing the periodontal instrumentation. Each specimen was divided into two experimental zones, and both scaling treatments were performed on each sample. The surface roughness (Ra) of these materials was determined before and after the different instrumentations, and differences were evaluated with the use of a profilometer. Data were statistically analyzed using repeated measures of ANOVA with Tukey’s multiple comparisons and paired t-tests at a significance level of 0.05. Significant increases in surface roughness of all test materials were recorded from both scaling treatments. With the exception of Tetric Flow, ultrasonic scaling had more adverse effects on the surface roughness of all test materials compared to sonic scaling. For the test materials Z100 and Tetric Flow, resin composites showed the least surface changes in both scaling treatments, while Fuji II glass ionomer demonstrated the greatest roughness after instrumentation. More importantly, the mean surface roughness values of several materials after instrumentation were above the critical threshold roughness of 0.2 micron.

COMMENTARY
Our patients expect that their teeth will be examined and cleaned during a routine recall appointment. A routine dental cleaning includes removing any calcified deposits, calculus, with both hand and mechanical scalers (usually sonic and ultrasonic). Are restoration margins and the body of our restorations at risk when teeth are cleaned with sonic and ultrasonic instruments? While this topic has been investigated for years, with the increase in esthetic restorative dentistry, the question comes up at dental meetings from both dentists and dental hygienists, “how should I clean teeth with veneers or bondings?” This study provides answers to that question. The researchers of this study investigated the effects of sonic scaling inserts (vibration ranges of 3,000 to 8,000 cycles per second) and ultrasonic scaling inserts (vibration ranges of 18,000 to 45,000 cycles per second) with restorative materials typically used to restore Class V lesions—a flowable composite resin, compomer, conventional and resin-modified glass-ionomer, and hybrid composite resin. The removal of plaque and calculus from teeth and restorations is an important part of periodontal therapy. The results of this study demonstrated that the use of sonic and ultrasonic scaling may have unintended consequences. In all cases after sonic and ultrasonic scaling, there was loss of restorative material leading to increased surface roughness. Also, except for the flowable composite resin, ultrasonic scaling was much more damaging to the restoration surfaces than sonic scaling. Based on this study and others, routine periodontal cleaning of tooth and restoration surfaces with sonic and ultrasonic scaling should be done with caution. After cleaning, the surfaces of tooth-colored restorations should be evaluated for either polishing or, in some cases, replacement.

About the Author

Howard E. Strassler, DMD
Professor and Director of Operative Dentistry
Department of Endodontics, Prosthodontics and Operative Dentistry
University of Maryland Dental School, Baltimore, Maryland