MATERIALS AND METHODS: Sixty maxillary central incisors were divided into Group I, II, and III with 20 samples each based on luting cement used. They were OF, self-adhesive (SA) cement, and total etch (TE) cement. These groups were subdivided into "a" and "b" of ten each based on the type of veneering materials used. Veneer discs were fabricated using Ormocer restorative (O) and pressable ceramic (C). Specimens were thermocycled and loaded under universal testing machine for SBS. The statistical analysis was done using one-way ANOVA post hoc Tukey honest significant difference method.
RESULTS: A significant difference was observed between the Groups I and II (P < 0.05). The highest mean bond strength when using ormocer veneer was obtained with the Group Ia (19.11 ± 1.92 Mpa) and lowest by Group IIa (8.1 ± 1.04 Mpa), whereas the highest mean bond strength while using ceramic veneer was of similar range for Group Ib (18.04 ± 4.08 Mpa) and Group IIIb (18.07 ± 1.40 Mpa). SEM analysis revealed OF and TE presented mixed type of failure when compared with SA where failure mode was totally adhesive.
CONCLUSION: OF was found equally efficient like TE. Bond strength of ormocer as a veneer was not inferior to ceramic making it one of the promising additions in the field of dentistry.
METHODS: Six makes, three each monocrystalline (M) and polycrystalline (P) were used; PureSapphire (M), SPA Aesthetic (M), Ghost (M), Mist (P), Reflections (P), and Dual Ceramic (P). The Ortholux™ Light Curing Unit (LCU) was used to cure the orthodontic adhesive Transbond™XT. The LCU's tip irradiance was measured and TLE transmitted through the ceramic bracket was obtained, then adhesive added to the bracket, and transmitted TLE measured through bracket-plus-adhesive samples. The LCU was set at five seconds as recommended for curing adhesive through ceramic brackets.
RESULTS: Mean tip irradiance was 1859.2±16.2mW/cm2. The TLE transmitted through brackets alone ranged 1.7 to 3.9J/cm2, in the descending order: Ghost>Pure Sapphire>Reflections>Mist>SPA Aesthetics>Dual Ceramic. The TLE transmitted through bracket-plus-adhesive samples ranged 1.6 to 3.7J/cm2, in the descending order: Ghost>Mist>Reflections>Pure Sapphire>SPA Aesthetics>Dual Ceramic. TLE was reduced with the addition of adhesive (range -0.1 to -0.7J/cm2). There was a significant difference for Pure Sapphire, Reflections, and Mist (P<0.05), but not for SPA Aesthetics, Ghost, and Dual Ceramic. There was no overall significant difference between the monocrystalline and polycrystalline makes. The two best makes were of the monocrystalline type, concerning TLE transmission, but with the exception of polycrystalline Dual Ceramic; the next worst make was a monocrystalline bracket, SPA Aesthetics.
CONCLUSION: Light energy attenuation through ceramic orthodontic brackets is make-dependent, with no overall difference between monocrystalline and polycrystalline brackets. Light energy is further attenuated with the addition of resin-based orthodontic adhesive.
Materials and Methods: One hundred and sixty endodontically treated maxillary central incisors embedded in acrylic resin with decoronated root portion were taken for the study. The postspaces were prepared according to standard protocol. The samples were divided into two groups according to the post material: glass-fiber post and Quartz fiber post. These groups were further subdivided on the basis of coronal extension of 4 and 6 mm for glass fiber and Quartz fiber posts, respectively. The posts were then luted with dual-polymerizing resin cement followed by core buildup. Samples were subjected to increasing compressive oblique load until fracture occurred in a universal testing machine. Data were analyzed with one-way ANOVA and independent Student's t-test. Analysis was done using SPSS version 15 (SPSS Inc., Chicago, IL, USA) Windows software program.
Results: Glass fiber post with coronal extension of 4 mm (182.8 N) showed better results than with 6-mm length (124.1 N). Similarly, in quartz fiber posts group, 4-mm postlength (314 N) was better when compared with 6 mm (160 N). The 4-mm coronal extension of quartz fiber post displayed superior fracture resistance.
Conclusions: Glass fiber posts showed better fracture resistance than Quartz fiber posts. 4-mm coronal length showed more fracture resistance than 6 mm.
METHODS: Sixty-five cylindrical block of Fuji IX Fast were prepared using split moulds. The demineralizing solution was an acetate buffered demineralizing solution at pH 403. The remineralizing solution was a buffered solution containing 1.5 mM Ca, 0.9 mM P and 10 ppm F at pH 7. The blocks of Fuji IX Fast were subjected either to two-day alternating cycles of remineralization and demineralization for up to 24 days (test); 6 two-day cycles of demineralizing or remineralizing solution separately, or deionized distilled water alone (controls) or were left untreated (base line control). Mineral profiles of Ca, P, Sr and F within 100 microm of the material surface were assessed following 8, 16 and 24 days of treatment (test); 4, 8 or 12 days (controls) or for baseline control samples, using electron probe microanalysis (EPMA).
RESULTS: There were significant changes in mineral profile in the test specimens in terms of Sr and Ca concentrations. A molecule for molecule exchange of these elements resulted between GIC and eluant solutions. Fluoride loss from the GIC occurredto the level comparable with uptake levels recorded in eluant solutions from previous studies. The ionic exchanges appeared to be the result of dissolution followed by an equilibrium-driven diffusion. These exchanges were superficial though substantial.
CONCLUSIONS: Simulated exposure of Fuji IX to the oral environment resulted in an exchange of Ca from the bathing solutions into Fuji IX to replace any Sr which was lost to the GIC. Fluorine loss from the GIC followed previously described patterns. The possible clinical significance of this exchange was discussed.
MATERIALS AND METHODS: A questionnaire consisting of 35 questions was distributed by mail or an online survey to 425 registered dentists selected according to place of work by stratified random sampling.
RESULTS: One hundred fifty-three dentists responded to the survey. A positive attitude towards FS and PRR was noted among most Malaysian dentists. About half of the respondents used FS/PRR occasionally (48.4%), while few (13.7%) applied them routinely. The majority of the dentists agreed that minimally invasive dentistry is important and FS are effective in caries prevention, using them on high caries-risk individuals. Most of the dentists used pumice or paste to clean teeth before placing FS/PRR. A significant number of dentists used a bonding agent prior to placing FS. Although only 57.5% dentists were aware of guidelines for FS use, most dentists agreed that guidelines are important.
CONCLUSION: Although there was a positive attitude towards FS/PRR, few dentists applied them routinely. Some of the steps undertaken for placement of FS and PRR were outdated. Updating local guidelines for dentists to ensure uniform practice of FS and PRR is justified.