Gregor J. Petersilka

Working parameters of a sonic scaler influencing root substance removal in vitro

Abstract This study assessed defect depth and volume resulting from root instrumentation using a KaVo Sonicflex Lux 2000 L sonic scaler with a slim scaling tip (Perio-Tip no. 8) in vitro. Combinations of the following working parameters were analyzed: lateral forces of 0.5 N, 1 N, and 2 N; tip angulations of 0°, 45°, and 90°; and instrumentation time of 10 s, 20 s, 40 s, and 80 s. Defects were quantified using a three-dimensional optical laser scanner. Instrumentation time had an almost linear impact on defect depth and volume. Although lateral force (β-weight 0.55±0.062) had a greater influence on defect volume than tip angulation (β-weight 0.29±0.062), their effects on defect depth were similar (β-weight 0.43±0.052 and 0.50±0.052, respectively). The combination of force and angulation showed synergistic effects resulting in a wide range of defect depths (21.9±0.96 µm to 174±28.8 µm, at 40 s) and volumes (0.056±0.019 mm3 to 0.68±0.10 mm3 at 40 s). Severe root damage (>50 µm/40 s) did not occur at any combination of 0.5 N lateral force and/or 0° tip angulation. By adjusting lateral force and tip angulation, the efficacy of the assessed sonic scaler may be adapted to various clinical needs.

Subgingival air-polishing in the treatment of periodontal biofilm infections.

Periodontitis is a chronic bacterial infectious disease. Its treatment necessitates thorough removal of the bacterial biofilm during the initial therapy and the periodontal maintenance phase (62, 88, 100). However, debridement using hand instruments or oscillating scalers is both technically demanding and time consuming, and may lead to severe root damage over time (29–31, 52, 98, 101). Even if instrumentation during periodontal maintenance therapy is performed by well-trained and experienced therapists, many patients find debridement uncomfortable, which may have a negative effect on patient compliance (6, 20). Also, safety, as well as ease of biofilm removal, are of major importance because the demand for periodontal therapy is increasing and the number of welltrained dental personnel is limited (12, 42, 68). For optimal treatment of periodontal disease, instrumentation techniques should be employed that can be safely used by the dentist, hygienist or auxiliary dental staff. The use of commercially available injection abrasive water jets, also known as air-polishing devices, allows highly efficient and convenient biofilm removal. With the goal of establishing an efficient and safe technique for subgingival biofilm removal, a low-abrasive air-polishing powder (Clinpro Prophypowder; 3M ESPE, Seefeld, Germany) was developed for use in commercially available air-polishing devices (26, 27, 77). This novel approach to biofilm removal substantially facilitates periodontal debridement. The purpose of this article was to review the safety and efficacy of the application of glycine powder air-polishing in the treatment of oral biofilm infections. Air-polishing devices: basic function principles

Impact of the Daily Use of a Microcrystal Hydroxyapatite Dentifrice on De Novo Plaque Formation and Clinical/Microbiological Parameters of Periodontal Health. A Randomized Trial

Aim This 12-week prospective, randomized, double-blind, two-center trial evaluated the impact of a microcrystalline zinc hydroxyapatite (mHA) dentifrice on plaque formation rate (PFR) in chronic periodontitis patients. We hypothesized that mHA precipitates cause delayed plaque development when compared to a fluoridated control (AmF/SnF2), and therefore would improve periodontal health. Material & Methods At baseline and after 4 and 12 weeks, PFR and other clinical and microbiological parameters were recorded. Seventy periodontitis patients received a mHA or AmF/SnF2 dentifrice as daily oral care without hygiene instructions. Four weeks after baseline, participants received full mouth debridement and continued using the dentifrices for another 8 weeks. Results Primary outcome PFR did not change statistically significantly from baseline to weeks 4 and 12, neither in mHA (n = 33; 51.7±17.2% vs. 48.5±16.65% vs. 48.4±19.9%) nor in AmF/SnF2-group (n = 34; 52.3±17.5% vs. 52.5±21.3% vs. 46.1±21.8%). Secondary clinical parameters such as plaque control record, gingival index, bleeding on probing, and pocket probing depth improved, but between-group differences were not statistically significant. Microbiological analyses showed similar slight decreases in colony-forming units in both groups. Conclusion In patients with mild-to-moderate periodontitis, periodontal therapy and use of a mHA-or AmF/SnF2 dentifrice without instructions induced comparable improvements in periodontal health but did not significantly reduce the PFR. Trial Registration ClincalTrials.gov NCT02697539