heliosit and Dental-Caries

The purpose of this study was to assess the shear bond strength (SBS) of metal brackets when placed with a caries protective adhesive patch.. Forty stainless steel brackets (Ormco) were bonded to 40 bovine enamel samples according to the following conditioning/bonding procedures using a resin-based orthodontic luting material (Heliosit Orthodontic, N=10 per group): (A) 35% phosphoric acid (30s), rinse and dry; (B) as in A but additional placement of a prototype adhesive patch (Ivoclar Vivadent) using a bonding agent (Heliobond); (C) application of a two-step self-etch adhesive (AdheSE); (D) as in C but additional patch placement. Samples were stored at 37 degrees C for 24h. SBS was measured with a universal testing machine with a crosshead speed of 0.5mm/min and the adhesive remnant index (ARI) was determined under a stereomicroscope (16x).. Mean SBS (standard deviation) values were as follows: (A) 16.6 (6.4)MPa; (B) 12.2 (5.8); (C) 12.9 (5.0); and (D) 10.5 (4.7). Analysis of variance followed by Bonferroni correction revealed no statistically significant differences. In 2 (B) and 4 (D) specimens, complete retention of the adhesive patch was observed.. All treatment groups showed adequate bond strength values. The adhesive patch could therefore be applied in combination with orthodontic brackets and seal the enamel adjacent to the bracket.

Topics: Acid Etching, Dental; Acrylates; Acrylic Resins; Animals; Cariostatic Agents; Cattle; Dental Alloys; Dental Bonding; Dental Caries; Dental Enamel; Materials Testing; Orthodontic Brackets; Phosphoric Acids; Resin Cements; Shear Strength; Stainless Steel; Stress, Mechanical; Surface Properties; Temperature; Time Factors

This study investigates the effects of fluoride-releasing bonding composites on the development of artificially created white spot lesions ex vivo. The severity of the lesions was estimated visually using the von der Fehr Caries Index. The integrated mineral loss of the lesions (delta z) was measured using microradiography/microdensitometry. The results of the visual assessment indicated that teeth bonded with Reliance exhibited more Grade 2 lesions than expected. Teeth bonded with Mirage Dual Cure, however, showed a high prevalence of teeth with no lesions (Grade 0) and few with Grade 2. Microdensitometric analysis found 17 subsurface lesions; 14 of these were in the non-fluoridated groups (Right-On and Heliosit), and 3 and 1 in the fluoridated groups (Reliance and Mirage Dual Cure), respectively. Lesion mineral content ranged from 64.93 to 20.43 per cent for Right-On, from 32.53 to 26.72 per cent for Heliosit, from 19.52 to 19.58 per cent for Reliance, and 23.58 per cent for Mirage Dual Cure. The results of this study suggest that fluoride-releasing composites may have a caries preventive effect around orthodontic brackets.

Topics: Chi-Square Distribution; Composite Resins; Delayed-Action Preparations; Densitometry; Dental Bonding; Dental Caries; Dental Cements; Dentin-Bonding Agents; Fluorides; Humans; Observer Variation; Orthodontic Brackets; Reproducibility of Results; Resin Cements

Composite restorations are prone to develop secondary caries if a gap exists between tissue and restoration. The aim of this article was to quantify the effects of a fluoridating and non-F composite on secondary dentine caries in vitro as a function of time. The mineral loss in dentine was assessed in an artificial gap of 200 microns width at the composite/dentine interface; the samples were demineralised in a carboxymethylcellulose gel (pH = 5, 37 degrees C) for 8 weeks. Once a week the mineral content of the samples was determined using non-destructive wavelength-independent microradiography (WIM). After 8 weeks transversal microradiography (TMR) was done on the samples to investigate the mineral distribution of the dentine lesions. The WIM results show that the fluoride-releasing composite decreased the dentine demineralisation statistically significantly with respect of the non-F control by approximately 45%. The mineral loss values are found to be strictly proportional to time; the demineralisation reduction is expected to continue over extended periods of clinical relevance. The TMR results show that the fluoridating composite reduced the mineral loss values significantly with respect to the non-F control by approximately 55%, but had a negligible effect on the lesion depth values. This study indicates that WIM is an accurate and reliable technique to measure in vitro secondary dentine caries next to a composite restoration as a function of time.

Topics: Animals; Cattle; Composite Resins; Dental Caries; Dental Restoration, Permanent; Dentin; Dentin-Bonding Agents; Fluorides; Microradiography; Minerals; Recurrence; Resin Cements; Tooth Demineralization

A light-curing, fluoride-releasing adhesive (VP 862, Vivadent, Liechtenstein) for bonding of brackets has been produced for inhibition of white spot lesions during orthodontic treatment. The tensile bond strength after 24 hours and 6 months was investigated and compared with two other light-curing adhesives (Transbond, 3M Corp., Monrovia, Calif., and Heliosit-Orthodontic, Vivadent, Liechtenstein) and two chemical-curing adhesives (Concise, 3M, Monrovia Calif., and Saga Bond, Saga Orthodontics, Kongsvinger, Norway). All adhesives produced adequate strength to be recommended for clinical use. The light-curing adhesives produced slightly lower bond strengths after 24 hours and 6 months, except Transbond, which showed an increase in bond strength in this period approaching the two chemical adhesives.

Topics: Adhesives; Bisphenol A-Glycidyl Methacrylate; Cariostatic Agents; Composite Resins; Dental Bonding; Dental Caries; Dental Cements; Dental Stress Analysis; Fluorides, Topical; Humans; Materials Testing; Organic Chemicals; Orthodontic Brackets; Polymethacrylic Acids; Resin Cements; Tensile Strength

In the literature, secondary caries around composite restorations is reported often. Fluoridated composites are therefore interesting materials because they might reduce or inhibit secondary caries. In this article an in situ model investigation is presented in which the effect of F-releasing composites on enamel demineralisation around an artificial gap of 200 microns width was quantified after 1 month. The fluoride content of the composites varied between 0 and 26 vol%. The beneficial effect of the fluoride released was larger in the gap than at the outer enamel surface. In the gap, all fluoridated composites reduced the enamel demineralisation statistically significantly with respect to the non-fluoridated control. Microradiography showed a reduction of lesion depth values of 27-45%, and a reduction of mineral loss values of 25-56%. At the outer enamel surface next to the artificial gap, a beneficial fluoridation effect was measurable only near the most fluoridated composite. The results indicate that fluoridated composites may play a role in the future prevention of secondary caries.

Topics: Acrylic Resins; Adult; Composite Resins; Delayed-Action Preparations; Dental Caries; Dental Cavity Preparation; Dental Enamel; Dental Restoration, Permanent; Diffusion; Female; Fluorides; Humans; Male; Middle Aged; Minerals; Polyurethanes; Recurrence; Resin Cements; Surface Properties; Tooth Demineralization