Advocacy training in US advanced pediatric dentistry training programs

PURPOSE: This study: (1) assessed pediatric dentistry residency program directors' attitudes toward and involvement in advocacy training; and (2) identified types and extent of advocacy training in U.S. pediatric dentistry programs. METHODS: Between October 2005 and February 2006, all 66 pediatric dentistry residency program directors were invited to complete a 62-item online questionnaire. The survey investigated: (1) directors' attitudes toward advocacy training; (2) nature of advocacy training offered during residency; (3) extent of resident involvement in different settings; and (4) directors' involvement in advocacy. RESULTS: Forty-two program directors responded (64%). Overall, respondents agreed that advocacy by pediatric dentists for children beyond the dental office was important and that residency programs should provide advocacy training. Most programs did not routinely offer advocacy opportunities in nonclinical settings. Over half of programs required community outreach clinic rotations for all residents. One third offered didactic curriculum in the legislative process. Over 50% of program directors reported personal involvement in legislative oral health lobbying within 3 years, but fewer than a third were involved with professional political action committees (PACs). CONCLUSIONS: Advocacy is seen as on important in pediatric dentistry but variation in attitudes of program directors and program offerings exists in US training programs.     

Determination of bactericidal activity of antibacterial monomer MDPB by a viability staining method

In this study, the bactericidal activity of antibacterial monomer MDPB (12-methacryloyloxydodecylpyridinium bromide) against Streptococcus mutans was tested by a rapid method for monitoring viability. To S. mutans culture containing fluorescence staining solution that distinguishes live from dead cells, MDPB was added at a concentration of 250, 100, 50, or 10 microg/ml. Bacterial cells were observed by fluorescence microscopy and the percentage of dead cells was calculated. After 10, 20, or 30 minutes' contact with MDPB, the live/dead ratio was measured by fluorometry and viable counts (CFU) determined by the conventional plating method. Viability staining revealed that MDPB exhibited significant bactericidal effects at 50 microg/ml or greater (ANOVA, Fisher's PLSD test), and complete killing of the cells at 250 microg/ml of MDPB was demonstrated in conjunction with a plating method. The staining method thus provided a sensitive means to determine loss of viability, and indicated the strong killing effects of MDPB on S. mutans.     

Natural history of Candida species and yeasts in the oral cavities of infants

A longitudinal study was made of the presence of Candida species and yeasts in infants from the day of birth until 1-yr-old, diagnosed by the culture of oral swab samples. The isolation rate of Candida rose from 5.7 per cent neonatally to 14.2 per cent on discharge from hospital at 7 days. The prevalence increased sharply when the infants returned home, reaching 82 per cent at 4 weeks of age, but then slowly declined to 50 per cent at 1 yr. At 4 weeks, yeasts were isolated from an additional 14 per cent of infants. The predominant species was C. albicans with relatively few isolates of C. tropicalis, C. parapsilosis and C. pseudotropicalis. Estimates of neonatal serum antibody to C. albicans showed no correlation with initial or subsequent oral colonization by this organism.     

The effect of casting procedures on rotational misfit in castable abutments

PURPOSE: Misfit of implant components has been linked to restorative complications such as screw loosening. Although previous studies have shown a correlation between rotational misfit and screw loosening, the impact of casting procedures on rotational misfit is lacking. The aim of this in vitro study was to evaluate the effect of casting procedures on rotational misfit of cast abutments when compared to machined titanium abutments. MATERIALS AND METHODS: Forty-eight external hexagonal implants and 48 abutments were placed in 4 groups of 12 samples each: (1) machined titanium abutments, (2) premachined palladium abutments cast-on with palladium, (3) plastic burnout abutments cast with nickel chromium, and (4) plastic burnout abutments cast with cobalt chromium. Rotational misfit between the external hexagon of the implant and the internal hexagon of the abutment was measured using standardized techniques and recorded in degrees. Mean values for each group were analyzed with analysis of variance and Tukey test. RESULTS: The mean rotational misfit was 1.21 +/- 0.57 degrees for machined titanium abutments, 1.77 +/- 130 degrees for cast-on abutments, 1.98 +/- 0.72 degrees for cast NiCr abutments, and 2.79 +/- 1.13 degrees for cast CoCr abutments. Significantly greater rotational misfit was recorded with cast CoCr abutments when compared to machined titanium abutments (P < .05). CONCLUSION: Rotational misfit was less than 2 degrees for all groups except for cast CoCr abutments, which demonstrated a significantly greater rotational misfit.     

The osteoinductive potential of demineralized freeze-dried bone allograft in human non-orthotopic sites: a pilot study

BACKGROUND: The use of demineralized freeze-dried bone allograft (DFDBA) in periodontal therapy is widely accepted. In addition to histologic studies demonstrating its role in regenerating the attachment apparatus, its recognized ability to exhibit osteoinduction in small laboratory mammals has prompted many clinicians to regard it as osteoinductive when utilized in periodontal therapy. Despite such a theoretical deduction, evaluating and establishing the osteoinductive potential of DFDBA in humans has been problematic. The purpose of this study was to investigate, through the use of a novel implantation/recovery model, the potential of DFDBA to induce new bone formation at sites not normally considered capable of de novo osteogenic activity. METHODS: Seven patients scheduled to undergo periodontal therapy utilizing non-absorbable membranes agreed to have sterile polypropylene mesh capsules placed adjacent to the primary surgical site for the purpose of this investigation. One capsule was left empty while the second capsule contained DFDBA. At the appropriate time interval for removal of the therapeutic membrane, the capsules were removed and submitted for histologic analysis. Five of the subjects had procedures directed at regenerating bone within molar furcations (guided tissue regeneration) and had the membranes and associated capsules removed between 6 and 8 weeks. The 2 remaining patients had procedures directed toward ridge augmentation (guided bone regeneration) and had the membranes removed either at 8 or 9 months, respectively. In addition, one of the 2 long-term membrane patients had liberal cortical penetration performed directly beneath the implanted capsule. RESULTS: Histologic analysis of all recovered capsules by 2 independent oral and maxillofacial pathologists could not confirm the presence of either osteoblastic or osteoclastic activity associated with the DFDBA particles, although the 2 longer-term specimens clearly exhibited trace amounts of vital bone non-contiguous with the implanted material. CONCLUSIONS: The results of this pilot study do not support the osteoinductive potential of DFDBA when utilized in quantities normally associated with periodontal bone grafting, although they do support the use of this implantation/recovery model to study other preparations and mechanisms of bone formation.     

In-use peroxide kinetics of 10% hydrogen peroxide whitening strips

OBJECTIVE: Clinical research was conducted to establish the peroxide degradation profile of a very thin 10% hydrogen peroxide bleaching gel delivered on a flexible polyethylene strip. METHODS: Sixteen subjects participated in this study of Crest Whitestrips Premium, a thin layer of 10% hydrogen peroxide gel. Application was supervised, and strips were removed after five, 10, 30, and 60 minutes. Samples were collected from the strips, teeth, gingiva, and saliva, and peroxide levels were derived using a colorimetric peroxide assay. RESULTS: At five minutes, median peroxide concentrations were 7.3%, 6.4%, and 0.7% for strips, teeth, and gingiva, respectively, declining to 4.6%, 2.9%, and 0.1% at 30 minutes. Salivary samples never exceeded a median concentration of 0.014% at any time point. Samples differed significantly (p < 0.01) with respect to the 30- and 60-minute area-under-the-curve calculations, with the highest concentrations on the strip and teeth, and the lowest on the gingiva and in saliva. Median peroxide concentrations on strips and teeth remained above 2% over 60 minutes. At all post-treatment time points, the gingival peroxide concentration was an order of magnitude lower than the teeth samples. CONCLUSION: Use of 10% hydrogen peroxide whitening strips yielded appreciable peroxide on teeth over a 60-minute period, with rapid peroxide degradation on the gingiva, and exceedingly low accumulation in saliva anytime during use.     

Randomized controlled trial of 10% hydrogen peroxide whitening strips

OBJECTIVE: This research compared the clinical response of two different peroxide-containing gel formulations delivered using self-applied whitening strips. METHODOLOGY: A randomized, double-blind clinical trial was conducted to compare a one-week 10% hydrogen peroxide thin (0.13 mm) bleaching gel (Crest Whitestrips Premium) to a marketed two-week 6% hydrogen peroxide strip (0.20 mm) control (Crest Whitestrips). The maxillary arch was treated twice daily for 30 minutes. Efficacy (L*a*b* color change) was measured objectively by digital image analysis after one and two weeks. RESULTS: A total of 40 adults ranging from 19-48 years of age participated in the study. Both treatments were effective in whitening teeth, as evidenced by a statistically significant improvement from baseline (p < 0.001) beginning at one week. At that time, the adjusted mean deltab* (SE) (yellowness reduction) for the 10% strip was -2.42 (0.147) compared to -1.91 (0.143) for the 6% strip, with the treatments differing significantly (p = 0.02). At two weeks, the adjusted mean deltab* (SE) for the 10% strip was -3.31 (0.182) compared to -2.49 (0.167) for the control. After two weeks, treatments differed significantly (p < 0.02) for deltab* and deltaL* (lightness improvement). Comparing results from two weeks of the 6% control strip to one week of the 10% strip, the mean deltab* treatment difference was -0.07 (90% confidence interval from -0.44 to +0.31). Both treatments were generally well tolerated, with mild and transient tooth sensitivity or oral irritation representing the most common adverse events. CONCLUSION: Vital bleaching with 10% hydrogen peroxide strips at one week was as effective as 6% hydrogen peroxide strips used for two weeks.     

Effect of different application and polymerization techniques on the microleakage of proximal resin composite restorations in vitro

This in vitro study investigated cervical microleakage of proximal resin composite restorations placed with three application and polymerization techniques. Uniform mesio-occlusal-distal (MOD) preparations featuring cervical margins above (mesial) and below (distal) the CEJ suitable for restoration with resin composite were copy milled into 33 recently extracted permanent molars. The teeth were divided randomly into three groups of 11 teeth and restored using a conventional incremental technique (Group A) and two novel curing devices (Groups B and C). After 24 hours, a dye penetration test was used to assess microleakage. Conventional placement in preparations with cervical margins in enamel had significantly lower interfacial leakage scores than those recorded for placement in preparations with margins in cementum regardless of the technique used to place the restorative material. Use of the two novel curing devices conferred no advantage in reducing microleakage irrespective of where preparation margins were placed.