Cardiovascular & Hematological Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Cardiovascular & Hematological Agents) - Volume 2, Issue 1, 2020

Background: It’s shown that the clinical success of ceramic restorations much depends on the quality and durability of the bond to ceramic. For zirconia-based ceramics (Y-TZP), the surface treatment has a substantial impact on bond strength. Therefore, the bond strength evaluation of Y-TZP surface treatments is a requirement for predicting the clinical performance of such restorations.

Objective: Evaluating the resin bond strength to Y-TZP after different surface treatments.

Methods: Monolithic Y-TZP (Zenostar Zr Translucent, Wieland Dental, Rosbach vor der Höhe, Germany) blocks were bonded to resin composite blocks using a resin-based cement system after two Y-TZP surface treatments: APA- airborne particle abrasion with alumina particles; and CJ- silicatization (Cojet sand, 3M ESPE, St. Paul, MN, USA). A silane coupling agent and an adhesive system were applied to the treated Y-TZP surfaces and resin composite blocks were cemented (RelyX Ultimate, 3M ESPE, St. Paul, MN, USA) and light activated from all sides. These structures were cut to obtain bar-shaped specimens (n=30), which were stored in 37ºC distilled water for 7 days before microtensile testing. Specimens were loaded to failure under tension using a universal testing machine. Data was statistically analyzed using Students t test (α=0.05) and Weibull distribution. Failure modes were evaluated using optical (OM) and scanning electron microscopy (SEM).

Results: Mean bond strength values (CJ= 25.7±8.2 MPa; APA= 22.0±6.3 MPa) were statistically similar (p>0.05). No difference was found for the characteristic strengths (σ0) and for Weibull moduli (m) since the confidence intervals (95% CI) overlapped. The bond strength values for a 5% failure probability (σ5%) were 12.4 (CJ) and 11.5 (APA). All fractures were due to cohesive failure within the adhesive cement system.

Conclusion: Both Y-TZP surface treatments (CJ and APA) produced similar structural reliability and short-term bond strength to a resin cement system.

Objective: To compare the success rate of different obturation procedures in primary mandibular second molars clinically and also by digital radiovisiography.

Methods: A total of 40 children aged between 4-8 years with deeply carious mandibular second primary molars indicated for single session pulpectomy were selected. Canals were obturated with Metapex. The 3 study groups (Endodontic plugger, Handheld lentulospiral, Navi Tip syringe) were compared with the control group (reamer) both clinically and radiovisiographically. The data collected were statistically analyzed using Pearson’s Chi-square and Fisher’s exact test.

Results: The use of Navi tip syringe led to the least number of voids followed by Endodontic plugger and Reamer and the highest number of voids was reported with Lentulospiral. Navitip presented maximum number of optimally filled cases followed by Endodontic plugger and Lentulospiral and least number of optimally filled cases with reamer. However, there was no statistically significant difference (p>0.05) in any of the groups with clinical (pain and tenderness to percussion) and radiographic parameters (presence or absence of voids and length of obturation).

Conclusion: Within the limitations of the present study, though the clinical outcome was statistically insignificant, Navitip syringe exhibited encouraging results and is a promising option for obturation in primary teeth.

Objective: To investigate the effect of filler content and the time spent before light-curing on mechanical properties of dual-cured cement.

Methods: Experimental dual-cured resin cements were formulated with 60, 65 or 68wt% of filler. The viscosity of experimental cement was measured using a digital viscometer. Bar-shaped specimens (25 x 2 x 2 mm) were fabricated, while the light-curing was started immediately or 5 minutes after the insertion of cement into the mold (n = 7). A three-point bending test was performed and the values of flexural strength and elastic modulus were measured. The Vickers hardness of fractured specimens was measured on the surface of the cement. Data from viscosity were submitted to one-way ANOVA, while the data from mechanical properties were analyzed by two-way ANOVA. All pair-wise comparisons were performed using Tukey’s test (α = 0.05).

Results: The experimental cement with 68wt% of filler showed the highest viscosity and those with 60wt% showed the the lowest viscosity. Irrespective of the time spent before light-curing, the cement with 65wt% of filler presented the highest values of flexural strength and elastic modulus. The addition of 60wt% of filler resulted in the lowest elastic modulus, while 68wt% of filler resulted in lowest flexural strength. Regarding the hardness, the cement with 68wt% of filler showed the highest values, while there was no difference between 60 and 65wt% of filler.

Conclusion: Filler content affected the mechanical properties of the experimental cement and this effect did not depend on the waiting time before the light-curing procedure.

Objective: This study aimed to analyze the presence of lesions in the skull and face and the associated factors in pedestrian victims of traffic accidents.

Methods: A cross-sectional, descriptive-analytical study carried out through the analysis of medical records of pedestrian victims of traffic accidents in an emergency service in the city of Campina Grande, Brazil, during the year of 2016. Information was collected regarding gender, age group, day of the week, time of the accident, type of vehicle involved, presence of trauma to the skull and face, and outcomes. The Chi-square and Fisher's Exact tests were used, with a significance level of 5%.

Results: A total of 1,884 medical records were evaluated, out of which 7.1% (n = 133) involved pedestrians. Men were the most frequent victims (68.4%), and victims of age 60 years old or over (30.5%) predominated. Almost one-third of the cases were recorded during the weekends (30.5%), and the most prevalent time was at night (52.7%). Regarding the type of vehicle involved, motorcycles predominated (47.4%). Head trauma was present in 37.6% of victims, while facial injuries corresponded to 8.2%. In 12% of cases, the victims died. The variables of gender, age group, occurrence on weekends, and trauma to the face showed a statistically significant association with the occurrence of traffic accidents (Chi-square test; p<0.05).

Conclusion: Among pedestrian victims of traffic accidents, there is a predominance of men aged 65 years or over. Accidents are frequent at night, and motorcycles are the main vehicles involved. The presence of trauma to the skull and face regions is high.

Background: Different treatment protocols for teeth affected by fluorosis have been applied. Among them, microabrasion associated with tooth bleaching has presented satisfactory results in the treatment of intrinsic and/or extrinsic staining.

Case Presentation: A 22-year-old female patient attended the Dental Clinic of FOP/UNICAMP, reporting dissatisfaction with her smile due to the presence of white striations contrasting with the yellowish hue of the other teeth. Initially, the adequacy of the oral environment was performed by supragingival scraping and prophylaxis. Due to the characteristics of the staining, fluorosis TF3, the treatment plan consisted of teeth whitening with 35% hydrogen peroxide (Whiteness HP, AutoMixx 35% FGM) and microabrasion (Whiteness RM, FGM).

Conclusion: The association of tooth bleaching and microabrasion techniques provided the harmonization of the smile and resolution of the clinical case of the main complaint.