Gildo Coelho Santos Júnior

Clinical evaluation of two types of ceramic inlays and onlays after 6 months

The aim of the present study was to evaluate the clinical performance of two types of ceramics: a slurry-powder ceramic (Duceram Plus, Degussa) - D and a hot-pressed leucite-based glass-ceramic (IPS Empress, Ivoclar Vivadent) - IPS. Eighty-six restorations, 44 IPS and 42 D, were made by one operator. A total of 33 onlays and 53 inlays on twenty-seven premolars and 59 molars were cemented in 35 patients of both sexes, mean age 35 years. All restorations were cemented with the dual-resin cement (Variolink, Ivoclar-Vivadent) under rubber dam and were evaluated at the baseline and after six months, using the modified U.S.P.H.S. criteria for postoperative sensitivity, secondary caries, fracture, color match, marginal discoloration, marginal integrity and surface texture. Additionally radiographs and intraoral photographs were carried out. At baseline 86 restorations were analyzed and all of them received Alfa rating, except for the following that received Bravo rating for postoperative sensitivity - IPS (2.27%); D (7.14%); for color match - IPS (2.27%); D (2.38%) and for surface texture - IPS (2.27%); D (11.90%). After 6 months 100% of the restorations were analyzed and the following received Bravo rating: color match - IPS (4.55%) and D (9.52%); surface texture - IPS (2.27%) and D (11.9%); marginal discoloration - IPS (6.82%) and D (4.76%) and marginal integrity - IPS (4.55%) and D (7.14%). The results were submitted to the Fisher and McNemar Statistical Tests. No significant differences were noticed between the two ceramics. Both ceramics demonstrated satisfactory clinical performance after six months.

Influence of light intensity and curing cycle on microleakage of Class V composite resin restorations

The aim of this study was to determine the effect of a softstart polymerization method from Quartz-Tungsten-Halogen (QTH) and Plasma Arc (PAC) curing units on microleakage of Class V composite resin restorations with dentin cavosurface margins. Seventy-five bovine incisors received standardized class V cavities in all dentin margins. Teeth were divided into 5 equal groups according to the curing cycle. The cavities were incrementally restored with a composite resin (Single Bond/Z-100, 3M). Light curing was applied as follows: Group I: PAC light continuous-cycle curing at 1600 mW/cm² for 3s; Group II: PAC light step-cycle curing (2s at 800 mW/cm² then 4s at 1600 mW/cm²); Group III: QTH light continuous-cycle curing at 400 mW/cm² for 40s; Group IV: QTH light ramp-cycle curing (from 100 to 600 mW/cm² in 15s followed by 25s at 600 mW/cm²); Group V: QTH light pulse-delay curing (200 mW/cm² for 3s followed by 3 min delay then 600 mW/cm² for 30s). Teeth were stored in distilled water at 37ºC for 30 days and then subjected to thermocycling for 500 cycles at 5 and 55ºC. Root apices were sealed and teeth coated with nail varnish before they were immersed in 0.5% fuchsine red dye solution. Teeth were then sectioned and slices were scanned with a computer scanner to determine the area of dye leakage using a computer program (Image Tools). Images of tooth slices were also visually examined under magnification and dye penetration along the tooth/restoration interface was scored. Significant differences in the degree of dye penetration and leakage were detected between groups (p<.05). Groups I and II had significantly higher values of dye penetration and leakage than groups III, IV and V. In conclusion, the use of PAC light curing in a continuous or step cycle modes resulted in increased microleakage of Class V resin composite restorations compared with medium intensity QTH light curing. Pulse, ramp and continuous-cycle curing modes with QTH light resulted in similar degrees of microleakage.