Comparison of torque measurements and clinical handling of various surgical motors.

PURPOSE: Modern implant dentistry requires the application of torque during various treatment steps. This study investigated seven different surgical motors for the accuracy of the applied torque and their reliability. MATERIALS AND METHODS: The following surgical motors were evaluated: Chiropro 980 (Bienair), INTRAsurg 300 and INTRAsurg 500 (KaVo), Osseocare (Nobel Biocare), Surgic XT (NSK), Elcomed SA-200 C (W and H), and Osseo System (XO Dentalcare). The torque was measured during typical surgical and prosthetic procedures using a special load transfer mechanism for a torque gauge. For each setting, 30 measurements were made and means were calculated. RESULTS: The highest percentage shortfall was 20.5% at a set torque of 11.4 Ncm (absolute deviation of -2.4 Ncm). The highest percentage by which a torque was exceeded was 54.6% (absolute deviation of 5.5 Ncm). The lowest value for absolute shortfall was found to be -5.6 Ncm at a set torque of 45 Ncm. The highest absolute exceeded was 15 Ncm at a set torque of 40 Ncm. Potentially problematic torque values were identified in the low-torque-value setting, as the implant position may be changed if a machine driver applies excessive torque to the first-stage healing screw. In addition, in the indication of immediate loading in the high-set-torque group, torque values above the critical value of 50 Ncm may be unwittingly applied while working with a set torque of 40 Ncm. CONCLUSION: For most of the clinically relevant torque settings, precise values were measured, although a few devices delivered potentially problematic torque values for some of the indications.

Stability change of chemically modified sandblasted/acid-etched titanium palatal implants. A randomized-controlled clinical trial.

AIM: The aim of this randomized-controlled clinical study was to examine stability changes of palatal implants with chemically modified sandblasted/acid-etched (modSLA) titanium surface compared with a standard SLA surface, during the early stages of bone healing. MATERIALS AND METHODS: Forty adult volunteers were recruited and randomly assigned to the test group (modSLA surface) and to the control group (SLA surface). The test and control implants had the same microscopic and macroscopic topography, but differed in surface chemistry. To document implant stability changes resonance frequency analysis (RFA) was performed at implant insertion, at 7, 14, 21, 28, 35, 42, 49, 56, 70 and 84 days thereafter. RFA values were expressed as an implant stability quotient (ISQ). RESULTS: Immediately after implant installation, the ISQ values for both surfaces tested were not significantly different and yielded mean values of 73.8+/-5 for the control and 72.7+/-3.9 for the test surface. In the first 2 weeks after implant installation, both groups showed only small changes and thereafter a decreasing trend in the mean ISQ levels. In the test group, after 28 days a tendency towards increasing ISQ values was observed and 42 days after surgery the ISQ values corresponded to those after implant insertion. For the SLA-control group, the trend changed after 35 days and yielded ISQ values corresponding to the baseline after 63 days. After 12 weeks of observation, the test surface yielded significantly higher stability values of 77.8+/-1.9 compared with the control implants of 74.5+/-3.9, respectively. CONCLUSION: The results support the potential for chemical modification of the SLA surface to positively influence the biologic process of osseointegration and to decrease the healing time.

[Acceptance of the meridol toothbrush by dental hygienists. A questionnaire study]. / Akzeptanz der meridol-Zahnbürste bei Dentalhygienikerinnen. Eine Fragebogenstudie.

Two manual toothbrushes were tested in a questionnaire study by 171 dental hygienists in a crossover design: a new toothbrush with conical filaments (meridol toothbrush, GABA International AG) and a reference toothbrush with end-rounded filaments (ADA toothbrush, American Dental Association). Each trial subject tested the two manual toothbrushes in two consecutive periods. Not only was the immediate impression of interest but also the impression after a period of three weeks. Therefore, four questionnaires in total had to be answered. All but a few questions (e.g. "the most often used toothbrush up to date" in the first questionnaire) were identical in the four questionnaires. After a single use the overall impression of the meridol toothbrush was good and very good for 95.1% of the trial subjects (ADA: 26.4%). The feeling along the gingival margin was very positively judged after a single brushing by the meridol user: 92.7% (ADA: 35.3%). The cleaning performance of the meridol toothbrush was found to be good and very good by 85.5% of the meridol beginner group, whereas only 60.2% of the ADA beginner group judged the ADA toothbrush as good or very good. The most remarkable fact is that nearly 90% of these professional trial subjects have decided to continue to use the meridol toothbrush and more than 90% would recommend it to their patients.

Enhanced implant stability with a chemically modified SLA surface: a randomized pilot study.

PURPOSE: Chemical modification to a sandblasted, large-grit, acid-etched (SLA) implant surface has been shown to enhance the rate of osseointegration. The goal of the present study was to examine changes in stability for implants with a chemically modified SLA surface and to compare their outcomes to those of control implants. MATERIALS AND METHODS: A randomized controlled trial was conducted with 31 patients. Each patient received 2 implants with the same physical properties but with surfaces that were chemically different. The control implants had a standard SLA surface, while the test implants had a chemically modified surface. Resonance frequency analysis was assessed weekly over the first 6 weeks following implant placement. RESULTS: All implants proved clinically successful, allowing for restoration. Most implants were placed in the mandible (50 of 62). A shift in implant stability from decreasing stability to increasing stability (P < .001), occurred after 2 weeks for the test implants and after 4 weeks for the control implants. CONCLUSION: The findings from this pilot study provide clinical support for the potential for chemical modification of the SLA surface to alter biologic events during the osseointegration process and demonstrate levels of short-term clinical success similar to those observed for implants with an SLA surface.

Effect of posterior crown margin placement on gingival health.

STATEMENT OF PROBLEM: The clinical impact of posterior crown margin placement on gingival health has not been thoroughly quantified. PURPOSE: This study evaluated the effect of posterior crown margin placement with multivariate analysis. MATERIAL AND METHODS: Ten general dentists reviewed 240 patients with 480 metal-ceramic crowns in a prospective clinical trial. The alloy was randomly selected from 2 high gold, 1 low gold, and 1 palladium alloy. Variables were the alloy used, oral hygiene index score before treatment, location of crown margins at baseline, and plaque index and sulcus bleeding index scores recorded for restored and control teeth after 1 year. The effect of crown margin placement on sulcular bleeding and plaque accumulation was analyzed with regression models (P<.05). RESULTS: The probability of plaque at 1 year increased with increasing oral hygiene index score before treatment. The lingual surfaces demonstrated the highest probability of plaque. The risk of bleeding at intrasulcular posterior crown margins was approximately twice that at supragingival margins. Poor oral hygiene before treatment and plaque also were associated with sulcular bleeding. Facial sites exhibited a lower probability of sulcular bleeding than lingual surfaces. Type of alloy did not influence sulcular bleeding. CONCLUSION: In this study, placement of crown margins was one of several parameters that affected gingival health.