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Background: Osseointegration is defined as the direct structural and functional connection between neo-formed bone and dental implants. Among the parameters suggested to predominantly influencing the establishment of a successful osseointegration is the quality of the implant surface, which may enhance the strength and speed of this biomechanical process. Objective: The purpose of this study was to evaluate the ability of a novel laser-treated surface, compared to sandblasted, large-grit, acid-etched (SLA) surfaces, to enhance and accelerate implant integration in delayed implant placement.Methods: Thirty patients with two missing posterior teeth were enrolled in this study. Each patient received, at a randomly allocated site, an implant with a conventional SLA surface, and at a second site, an implant with laser-textured surface. A total of 60 tissue-level implants were subsequently placed. Implant stability (ISQ) was measured using resonance frequency analysis (RFA). ISQ was assessed at baseline (T0), 8 weeks (T1), and 12 weeks (T2) following implant placement. Results: There was a statistical difference in implant stability between laser-textured and SLA group at 12 weeks postoperatively. Implant stabilization showed a successful osseointegration with both surface types. Conclusion: Both laser and SLA surface treatments had positive impacts on implant stabilization following delayed placement. Laser-treated surfaces presented higher values of osseointegration at 3 months postoperatively.
RESUMO
BACKGROUND: The aim of this study was (1) to determine and compare the shear bond strength (SBS) of a bioactive composite "Activa Bioactive Restorative" with and without bonding agent and a nanocomposite "Filtek Z350 XT/Z350" and (2) to measure and compare the amount of fluoride release from a bioactive composite "Activa Bioactive Restorative" and a glass ionomer "Equia forte". MATERIAL AND METHODS: Forty two dentin surfaces from freshly extracted human molars were prepared for shear bond strength testing. The specimens were randomly divided into three equal groups. The restorative materials were applied to all dentin surfaces according to the manufacturer's instructions, using a special jig (Ultradent) in the following manner : Group 1 (Activa Bioactive Restorative with adhesive), Group 2 (Activa Bioactive Restorative without adhesive) and Group 3 (Filtek Z350 XT/Z350). The bonded specimens were subjected to thermocycling in 5°C and 55°C water baths then tested for SBS in a universal testing machine (1 mm/minute). Kolmogorov-Smirnov and Levene tests were used to evaluate the distribution of the variable and the equality of variances respectively and a Student's T- test was applied to compare the mean strength between the groups. In the next test, thirty disc shaped specimens were fabricated using Activa BioActive restorative and Equia Forte; 15 specimens from each material. The specimens of each group were immersed separately in 5 ml of deionized water. Fluoride release was measured daily throughout 15 days using a fluoride-specific ion electrode and an ion-analyzer. Repeated measures analysis of variance with one within-subject factor (time) and one between-subject factor (Activa Bioactive / Equia Forte) was applied to compare the amount of released fluoride between groups and within time. It was followed by univariate analyses and Bonferroni multiple comparisons tests. RESULTS: The mean shear bond strength of Activa Bioactive Restorative with adhesive was found to be 17.379 (± 8.5043) MPa and 19.443(± 8.3293) MPa for the Filtek Z350 XT/Z350 group. There was no significant difference between both groups. Regarding fluoride release, the amount of Fluoride released was significantly greater in the Equia Forte group compared to the Activa Bioactive group (-p-value<0.05). The mean amount of Fluoride has significantly decreased over time with Activa Bioactive group (-p-value<0.001); it showed the highest fluoride release during the first 24 hours post-setting. Also in the Equia Forte group, the mean amount of Fluoride release showed a progressive and significant decrease over time (-p-value<0.001), although the amount of Fluoride released was significantly greater in the Equia Forte group compared to the Activa Bioactive group (-p-value<0.05). CONCLUSIONS: Activa Bioactive Restorative with adhesive and a nanocomposite showed similar bond strengths. Activa Bioactive Restorative doesn't have the self-adhesive property. The fluoride ion release profile of Activa was lower than that of the Equia Forte. Key words:Bioactive composite, nanocomposite, glass ionomer, fluoride release, shear bond strength, thermocycling.
