Basic Informations

C.V

Master Title

The influence of acidic and/or abrasive challenge on the surface roughness of microfilled and nanohybrid flowable resin restorative materials : An in vitro study

Master Abstract

This study was conducted to investigate the effect of acidic and/ or mechanical challenge on the surface roughness of flowable resin composites. Ninety six resin composite discs were prepared according to manufactures instructions. The specimens were divided into two main groups of 48 specimens each, according to the type of flowable resin composite used; nanohybrid flowable resin composite Tetric N Flow (F1), or microfilled flowable resin composite Heliomolar Flow (F2). Each group was further subdivided into four equal subgroups of 12 specimens each according to the type of challenge. First: the control group specimens were stored in artificial saliva at pH 7.4 (C0). In the second group the specimens were subjected to an acidic challenge with orange juice at pH 5 (C1). For the third group the specimens were subjected to mechanical abrasion challenge by automatic tooth brushing (C2). Finally, the specimens in forth group were subjected to an acidic challenge followed by mechanical abrasion challenge (C3). Specimens of each group were examined for surface roughness at base line R0 and after exposure to the proposed challenge R1. The change in the surface roughness values following application of different challenges were tested using USB Digital microscope with a built-in camera, using fixed magnification of 120X. Results were collected, tabulated and statistically analyzed. The collected results showed that, no statistical significant difference was found between the tested flowable resin composites or between the different applied challenges and the control group. Regarding the results of the surface roughness at the base line and after the applied challenges a statistical significant decrease in the surface roughness was detected. The nanohybrid resin composite group which received the mechanical challenge showed the lowest mean surface roughness. However, it was not statistically significant than all other groups. The Summary and conclusions 67 nanohybrid resin composite control group showed the highest mean surface roughness, which was also not statistically significant than all other groups. Within the limitations of the present investigation, it could be concluded that: 1) The surface roughness of the tested resin composites were not influenced by the type of the material as both types performed similarly under the different challenges types. 2) The acid used in this study was able to change the surface roughness of the tested materials which indicate that the patient's fruit beverage consumption habit could affect the longevity of the resin restorations. 3) The two tested resin composites presented similar surface roughness after simulated tooth brushing 4) No synergistic effect was evident after the combination between acidic and mechanical abrasion challenges. 5) Exposure to acidic and mechanical challenges altered the surface roughness of both evaluated flowable resin composite. Recommendations: • Further studies are needed to identify the weight loss of resin composite specimens after being subjected to different challenges to correlate between surface roughness and weight loss. • It could be of value to test surface roughness at different time intervals shorter /within one month period to speculate a pattern of wear of the tested materials. • Further studies could be conducted to examine the behavior of resin matrix and/or fillers to specify the effect of each applied challenge on the wear-deterioration of the tested materials.

PHD Title

RESTORING BLACK TRIANGLE WITH BIOCLEAR MATRIX AND INJECTION MOLDING TECHNIQUE VERSUS CELLULOID CONVENTIONAL MATRIX METHOD: A RANDOMIZED CLINICAL TRIAL

PHD Abstract

This study was conducted to assess the clinical performance of restored black triangle by conventional celluloid matrix technique in comparison to a restored black triangle by bioclear matrix. Participants were randomly divided into two equal groups. Follow-up assessment appointments immediate after restoration (T 0), 6 months (T 6 ), and 12 months (T 12 ) were carried out. The esthetic evaluation was a primary outcome, marginal integrity was a secondary outcome, and patient satisfaction was a tertiary outcome. Esthetic evaluation involves the esthetic anatomical form, proximal anatomical, periodontal response, and marginal staining. The secondary outcome involves clinical and radiographic marginal adaptation. The third outcome involves the patient`s view in the forms of phonetics and food impaction. All the assessment was done using the FDI criteria by two blinded examiners. Statistical analysis was done as categorical and ordinal data were presented as frequency and percentage values. Categorical data were compared using fisher’s exact test. Intergroup comparisons for ordinal data were analyzed utilizing the Mann-Whitney U test, while intragroup comparisons were analyzed using Friedman’s test followed by the Nemenyi post hoc test. The significance level was set at p=0.05 within all tests, statistical analysis was performed with R statistical analysis software version 4.1.2 for Windows1.and the results revealed that all cases of both groups were successful and there was no significant difference between both groups (p=0.166). For both groups, there was no significant difference between scores measured at different intervals (p=1) according to proximal anatomical form. All cases in both groups were successful, the difference between both groups was not statistically significant (p=0.208) and there was no significant difference between scores measured at different intervals (p=1). Related to esthetic anatomical form, no significant difference between both groups (p=1) but there was a significant difference between scores measured at different intervals. There was no significant difference between both groups when evaluating marginal staining. Radiographic marginal integrity: At all intervals, there was a significant difference between both groups. There was a significant difference at all intervals between both groups when evaluating marginal adaptation. Phonetics and food impaction for both groups, all cases were successful. Therefore, it can be concluded that the restorative management of the black triangle with both protocols meets the following objectives: superior aesthetic and good marginal adaptation; suitable biological properties; enhanced subjective and objective appearance of the treated teeth; and adequate survival time. A longer follow up is needed to formulate decisive superiority between both treatment protocols.