Dorothy McComb

Retention of castings with glass ionomer cement

Abstract The retentive abilities of a glass ionomer cement, a zinc phosphate cement, and a zinc silicophosphate cement were compared using 20 cast-gold inlays. The mean retentive strength of the glass ionomer cement was the greatest and that of the zinc phosphate cement the weakest. The differences between the mean retentive strengths of all three cements were statistically significant (p = .001).

Shear bond strengths of resin luting cements to laboratory-made composite resin veneers

Retention problems have been reported with the clinical use of indirect microfilled resin veneers. This study used 24-hour shear tests to assess the bond strengths of such a resin veneer compared with other veneer types. The effect of different resin luting cements and resin veneer surface treatments were analyzed to elucidate factors by which retention could be increased. The six resin luting systems investigated showed a range of bond values. Debonding occurred primarily at the veneer/cement interface. G-Cera material produced the weakest bonds to Isosit-N resin. Surface treatment of Isosit-N veneers resulted in bond strength changes. Sandblasting reduced the force required for bond failure; Special Bond resin increased it slightly. Improving retention of prefabricated resin veneers proved difficult. Etched hybrid resin veneers delivered higher bond strengths than micro-filled resin veneers but not significantly. Etched porcelain veneers, however, provided consistently the strongest bond strengths with cohesive, as opposed to adhesive, bond failure.

Influence of NaHCO3 powder on translucency of microfilled composite resin immersed in different mouthrinses.

UNLABELLED The regular use of mouthrinses, particularly when combined with the use of air-powder polishing, could affect the appearance of tooth-colored restorations. The current study sought to evaluate the effect of NaHCO(3) powder on translucency of a microfilled composite resin immersed in different mouthrinses, at distinct evaluation periods. Eighty disk-shaped specimens of composite resin (Durafill VS, Heraeus Kulzer GmbH & Co. KG, Hanau, Germany) were prepared. The composite specimens were then randomly allocated into two groups according to the surface treatment: exposure to NaHCO3 powder (10 seconds) or nonexposure, and they were randomly assigned into four subgroups, according to the mouthrinses employed (N = 10): Periogard (Colgate/Palmolive, São Bernardo do Campo, SP, Brazil), Cepacol (Aventis Pharma, São Paulo, SP, Brazil), Plax (Colgate/Palmolive), and distilled water (control group). The samples were immersed for 2 minutes daily, 5 days per week, over a 4-month test period. Translucency was measured with a transmission densitometer at seven evaluation periods. Statistical analyses (analysis of variance and Tukeys test) revealed that: distilled water presented higher translucency values (86.72%); Periogard demonstrated the lowest translucency values (72.70%); and Plax (74.05%) and Cepacol (73.32%) showed intermediate translucency values, which were statistically similar between them (p > 0.01). NaHCO3 air-powder polishing increased the changes in translucency associated with the mouthrinses. Air-powder polishing alone had no effect on material translucency. Translucency percent was gradually decreased from 1 week of immersion up to 4 months. It may be concluded that the NaHCO3 powder and the tested mouthrinses have affected the translucency of microfilled composite resin, according to the tested time. CLINICAL SIGNIFICANCE During the last decade, the demand for composite resin restorations has grown considerably, however, controversy persists regarding the effect of surface roughness on color stability.

Operative dentistry considerations for the elderly

As the mean age of an older dentate population increases, so does the incidence of dental caries in its primary and secondary forms. Primary and secondary root decay gingival to existing restorations are significant operative problems prevalent in the elderly. Treated root decay is prone to recurrence if the etiology is ignored. Effective, customized prevention must parallel operative intervention. The dentist today has a wider selection of techniques and materials than ever before to treat the elderly patients. Use of preventive restorative materials such as conventional and hybrid glass ionomer materials for the treatment of root decay are discussed.

No reliable evidence that ozone gas stops or reverses tooth decay

Data sourcesThe Cochrane Oral Health Group’s Trials Register, Cochrane Central Register of Controlled Trials, Medline and Premedline, Embase, CINAHL (Cumulative Index to nursing and Allied Health Literature)l and the Allied and Complementary Medicine Database were searched. The journal Quintessence was searched by hand and KaVo Dental (Biberach, Germany) manufacturers of HealOzone apparatus were contacted for any additional published or unpublished trials.Study selectionInclusion was assessed independently by at least two reviewers. Trials were only included if they met the following criteria: randomisation in a controlled trial; single surface in vivo carious lesion accessible to ozone application; clear allocation concealment; ozone application to the lesions in the intervention group; no such application of ozone in the control group; and outcomes measured after at least 6 months.Data extraction and synthesisReviewers independently extracted information in duplicate. A paucity of comparable data did not allow meta-analytic pooling of the included studies.ResultsThree trials were included, with a combined total of 432 randomised lesions (137 participants). Forty-two conference papers, abstracts and posters were excluded (from an unknown number of studies). The risk of bias in all studies appeared high. The analyses of all three studies were conducted at the level of the lesion, which is not independent of the person. For this reason, pooling of data was not appropriate or attempted. Individual studies showed inconsistent effects of ozone on caries, across different measures of caries progression or regression. Few secondary outcomes were reported, but one trial reported an absence of adverse events.ConclusionsGiven the high risk of bias in the available studies and lack of consistency between different outcome measures, there is no reliable evidence that application of ozone gas to the surface of decayed teeth stops or reverses the decay process. There is a fundamental need for more evidence of appropriate rigour and quality before the use of ozone can be accepted into mainstream primary dental care or can be considered a viable alternative to current methods for the management and treatment of dental caries.