A Comparison of the Outcomes of Two Existing Routine Clinical Therapies for Dental Prophylaxis

According to the literature search, there was no preceding study, which compared the efficacy of conventional routine of rubber cup or air powder polishing with or without prior plaque disclosure. Therefore, this study was designed to test the hypotheses that (1) disclosing plaque prior to dental polishing was more effective than dental polishing alone, (2) air polishing was more efficient than rubber cup polishing, and (3) operators and patients prefer air polishing to rubber cup polishing.

In order to evaluate the hypotheses raised, a single blind, randomised controlled clinical trial with a split mouth design was conducted. The control groups had conventional dental prophylaxis regime of mechanical plaque removal with either fine air powder polishing or rubber cup polishing using fine grit prophylaxis paste. The test groups had plaque disclosure prior to mechanical plaque removal as described for the control groups. In total, there were 4 study groups: (1) rubber cup polishing without prior plaque disclosure (RC-NPD) (negative control), (2) rubber cup polishing with prior plaque disclosure (RC-PD) (positive control), (3) air polishing without prior plaque disclosure (AF-NPD) (negative test), and (4) air polishing with prior plaque disclosure (AF-PD) (positive test).

The quadrant that was assigned to receive RC-NPD was treated first followed by the quadrant assigned to receive AF-NPD. Plaque was disclosed in all 4 quadrants and the assigned calibrated examiner proceeded to chart the FMPS. Next, the quadrant assigned to receive RC-PD was treated, followed by the quadrant assigned to receive AF-PD; subsequently FMPS was charted. Any aberrant findings in occlusion, tooth alignment, extra/missing teeth were also noted. A digital stopwatch was used to time the treatment duration for each quadrant. Both participant and clinician completed a post prophylaxis satisfaction questionnaire. The treatment workflow used in this study was illustrated in figure 1. The primary outcome measure was the post treatment FMPS and the secondary outcomes measures were the treatment duration.

Descriptive statistics (mean and standard deviations) was used to summarize the plaque score and treatment duration for each study group. Two-way repeated measure ANOVA test was employed to examine the study hypotheses that air polishing was more effective in removing plaque compared to rubber cup polishing and disclosing plaque prior to prophylaxis increased the thoroughness of the prophylaxis. Two-way repeated measure ANOVA test was also performed to study the treatment duration between the 2 polishing methods and treatment regimens of with or without plaque disclosure prior to prophylaxis. In a secondary analysis, interactions were tested to study if there were differences among the 4 operators. Paired T-test and Pearson's Chi-Square tests were used to study the participant's and operator's preference for each treatment modality based on various yardsticks and overall, respectively. The level of significance was set at p-value<0.05. All statistical analyses were carried out using a statistical package.