Purpose: Numerous laboratory and clinical studies have proven that certain power toothbrush technologies are more effective in removal of dental plaque and reduction of gingivitis than regular manual toothbrushes. Regardless of this evidence, there is still a large group of individuals who prefer the experience of a manual-like toothbrush. Recently a novel multi-directional power brush has been developed as an alternative for those people who favor the traditional size and shape of a manual toothbrush and prefer the manual brushing technique, but would benefit from the greater cleaning efficiency of the power brush. Methods: This unique multi-directional power toothbrush with triplezone cleaning technology has been tested in multiple clinical trials. This special issue introduces the technical features of the brush and presents four clinical investigations conducted with this power toothbrush versus manual and sonic controls. Results: The studies described in this issue demonstrate the superior efficacy of the multi-directional brush in plaque and gingivitis reduction relative to control brushes, even in the hard-to-reach interdental spaces and marginal areas. (Am J Dent 2012;25 Sp Is A:3A-9A). CLINICAL SIGNIFICANCE: Dental professionals should consider this novel multi-directional power brush for patients who prefer a manual toothbrush experience but need improved plaque control and gingival health. : Dr. Malgorzata Klukowska, Procter & Gamble Health Care Research Center, 8700 Mason-Montgomery Road, Mason 45040, OH, USA. E: klukowska.m@pg.com

Purpose: To provide a brief overview of the diagnosis, epidemiology, etiology and clinical management of dentin hypersensitivity, to discuss technical approaches to relieve sensitivity, with special emphasis on dentin tubule occlusion and the clinical evidence for efficacy of desensitizing toothpastes based upon this approach, and to summarize the science behind a new dentifrice technology, based upon arginine and calcium carbonate, and the clinical evidence which proves that it delivers both instant and lasting relief of dentin hypersensitivity. Results: Clinical studies have shown that a new toothpaste, containing arginine and calcium carbonate (known as Pro-Argin technology) with 1450 ppm fluoride, offers clinically proven instant and lasting relief of dentin hypersensitivity. Three 8-week clinical studies have shown that this new toothpaste provides statistically significantly superior efficacy in reducing sensitivity to market leading desensitizing toothpastes containing 2% potassium ion. Importantly, three further clinical studies have shown that a single direct topical application of toothpaste to sensitive teeth, using a fingertip or cotton swab followed by 1 minute of massage, resulted in instant relief of dentin hypersensitivity and that the relief was maintained with subsequent twice-daily brushing. Mechanism of action studies have shown that this technology physically seals dentin tubules with a plug that contains arginine, calcium carbonate and phosphate. This plug, which is resistant to normal pulpal pressures and to acid challenge, effectively reduces dentin fluid flow and thereby relieves sensitivity. A new whitening variant of this desensitizing toothpaste, containing the Pro-Argin technology, fluoride and a high cleaning calcium carbonate system, has now been clinically and scientifically validated. This toothpaste works by the same mechanism of action as its non-whitening counterpart and is clinically proven to provide both instant and lasting relief of sensitivity, while providing proven efficacy in removal of extrinsic stains. No difference in desensitizing efficacy was observed between the whitening and nonwhitening versions. (Am J Dent 2010;23 Sp Is A:3A-13A). CLINICAL SIGNIFICANCE: The results of a series of clinical studies support the conclusion that a new toothpaste containing 8.0% arginine, a high cleaning calcium carbonate system, and 1450 ppm fluoride provides statistically significant relief of dentin hypersensitivity immediately after direct topical application and during regular twice daily brushing, as well as statistically significant removal of extrinsic stains. : Dr. Diane Cummins, Colgate-Palmolive Technology Center, 909 River Road, Piscataway, NJ 08855-1343, USA; E: diane_cummins@colpal.com

Tooth whitening has been the subject of extensive clinical trials research since the introduction of the first hydrogen-peroxide whitening strips in 2000. Availability of digital image analysis, an unambiguous and reproducible method for assessing color change, has contributed to global clinical research and product development on whitening strips. The research has included a series of global randomized controlled trials in distinct sites and cultures, involving 6-6.5% hydrogen peroxide whitening strips used for 7-21 days. These studies, conducted at research hospitals, dental schools, and private dental practice, demonstrated significant color improvement with whitening strips relative to baseline and/or various controls without serious adverse events. This integrated clinical trials research provides important evidence of long-term safety and effectiveness of tooth whitening with 6-6.5% hydrogen peroxide whitening strips. (Am J Dent 2007;20:3A-6A). CLINICAL SIGNIFICANCE: Randomized controlled trials, conducted in diverse populations worldwide, provide evidence of initial tooth color improvement, post-treatment color stability, and extended safety for peroxide-containing whitening strips. : Dr. Robert W. Gerlach, The Procter & Gamble Company, 8700 Mason-Montgomery Road, Mason, OH 45040-8006 USA. E: gerlach.rw@pg.com

The purpose of this study was to quantify the cuspal deflection produced by polymerization shrinkage, comparing 3 different techniques in the placement and polymerization of Class II posterior composite resin restorations in vivo. Thirty primary second molars in need of a Class II restoration were identified. An index, with a size o carbide round bur, was placed on the buccal and lingual cusp tips of the tooth that was to receive the restoration. A standardized conventional Class II preparation was completed, then each tooth was restored with posterior composite resin, using 3 different application techniques (Technique I--placement and polymerization as one complete unit; Technique II--placement and polymerization in gingivo-occlusal increments; Technique IIIplacement and polymerization in buccolingual increments). Preoperative and postoperative impressions were made, then poured with an epoxy resin die material. Photomicrographs were projected on a digitizing pad and measured by 3 independent investigators. Results demonstrated the mean cuspal deflection to be 19.7 ~m for Technique I, 14.7 #m for Technique II, and 5.2 #m for Technique IlL

This in vitro study investigated strain produced in the placement and polymerization of Class II posterior composite resin restorations in primary teeth. Mesio-occlusodistal preparations were placed in primary teeth, followed by posterior composite resin restoration placement, using 3 different application techniques (technique I--placement and polymerization in 1 complete unit; technique II--placement and polymerization in gingivo-occlusal increments; and technique III--placement and polymerization in buccolingual increments). A precision strain gage was attached to the buccal surface of each tooth, balanced at O, and after each increment was polymerized, the strain appearing on the strain gage indicator was recorded. Each tooth was restored using all 3 techniques. Results demonstrated the mean microstrain units to be 60.3 for technique I, 46.5 for technique II, and 38.5 for technique III. Scheffe’s test indicated that the buccolingual incremental polymerization produced a statistically significant lower amount of strain on the tooth than polymerizing the restoration as 1 complete unit (P < 0.05).