00000ctm a22000003a 4500 UP-1685523046126335931 Buklod 20190319163239.0 m |o d | cr ||||||||||| 190319s xx d r |||| u| (iLib)UPMNL-00016419915 UPDent rda eng LG 995 2017 D45 A34 Akhoundi, Maryam Ahmad. author. The effect of a hydrophilic bonding primer on the shear bond strength of molar tubes bonded to dry and moisture contaminated porcelain surfaces Maryam Ahmad Akhoundi; thesis adviser, Lotus D. Llavore. 104 leaves color illustration 28 cm text rdacontent unmediated rdamedia volume rdacarrier Thesis (Master of Science in Dentistry)--University of the Philippines Manila. Yes General objective: The purpose of this in vitro study was to determine the effect of hydrophilic bonding primer on the shear bond strength of orthodontic molar tubes bonded to porcelain. Material and method: Assure plus a universal bonding resin was used to bond mandibular stainless steel molar tubes to lithium disilicate porcelain disks measured 7mm. X 7mm. X 3mm., with and without using hydroflouric acid etch. The samples were randomly divided into 4 groups of 12 specimens each and the primer adhesive combinations were tested under different porcelain conditions: dry and moisture contamination. The samples were thermocycled and Shear forces were applied to the samples with a universal testing machine at a crosshead speed of 1mm./min. Shear bond strenghts (SBS) were measured in megapascals. Statistical analysis was conducted by analysis of variance (ANOVA) and Turkey tests and the one sample t-test to compare the mean values between and among the groups. Stereomicroscope was used to measure the amount of adhesive remaining on the porcelain after debonding using Adhesive Remnant Index. Results: Using Turkey's HSD as post hoc test, the significant differences were noted between SBS of the contaminated and uncontaminated groups (P<0.05). The order of SBS from the highest to the lowest was as follows: a) Group 1: etched/dry/Assure plus (17.891 MPa), b) Group 2: etched/wet/Assure plus (15.073 MPa), c) Group 3: unetched/dry/Assure plus (15.309 MPa), d) Group 4: unetched/wet/Assure plus (10.371 MPa), respectively. Group 1 had SBS values significantly higher than Groups 2 and 4 (P<0.05)but did not differ significantly from Group 3 (P<0.05). Groups 2 and 3 had SBS values significantly different from Group 4 (P<0.05). No statistically significant differences in SBS (P<0.05) were found between Groups 2 and 3. However, based on the sample t-test all SBS values in the four groups, still fall well above the optimal range of of 6 to 8 MPa. Comparison of the ARI scores in all groups showed that among the four experimental groups the Assure plus unetched moisture contaminated group (Group 4), showed the greatest adhesive failure at the porcelain adhesive interface. In addition, adhesive failure at the adhesive-molar tube interface was only observed in assure plus group with etching and no contamination (Group 1). Conclusion: The Assure plus universal bonding primer resulted in statistically significant differences between the contaminated and uncontaminated porcelain groups, with a high shear bond strengths needed for all groups. Molar tubes bonding to porcelain with assure plus primer produced suitable bond strengths with low ARI scores for the contaminated groups and high ARI score for the uncontaminated groups. Orthodontics. Porcelain. Hydrophilic Bonding Primer. Llavore, Lotus D. thesis adviser. UP FI UPMNL DENT LG 995 2017 D45 A34 Thesis