Objective This study aims to investigate the microtensile bond strength (µTBS), microleakage, and antibacterial effect of bulk fill resin composite with alkaline fillers (alkasite) (alkaline fillers such as barium aluminum silicate glass and ytterbium trifluoride) in comparison to incremental nanohybrid resin composite. Materials and Methods µTBS was evaluated by using 30 human mandibular molars. Teeth were randomly divided into three groups (C): nanohybrid resin composite (C0), self-cured alkasite (C1), and dual-cured alkasite (C2). Each group was subdivided into two subgroups according to the bulk thickness: 4 mm (T1) and 6 mm (T2). The occlusal enamel of teeth was removed and the resin composite was applied to a flat dentin surface. Then, teeth were sectioned into beams to be tested under tension. For microleakage testing, mesio-occlusal class II cavities were prepared in 15 molars and divided into three groups as mentioned before. Then, cavities were restored, thermocycled, immersed in a dye, sectioned mesiodistally, and then dye penetration was assessed. The antibacterial effect of both tested materials was evaluated using agar disc diffusion and broth dilution methods against chlorhexidine as a control positive group. Results There was no significant difference in µTBS between all tested groups. Bulk fill self-cured alkasite showed the lowest microleakage value followed by bulk fill dual-cured alkasite and incremental nanohybrid resin composite, respectively. Also, cervical microleakage showed significantly higher mean value than the occlusal one. The antibacterial effect of alkasite was less than chlorhexidine. Alkasite showed maximum broth clarity at lowest tested bacterial concentration. Conclusion Resin composite with alkaline fillers was characterized by good µTBS and marginal integrity with weak antibacterial effect.

Objective This study aimed to investigate the efficacy of the Galla chinensis extract (GCE) on early dentin lesion remineralization. Materials and Methods Seventy-two dentin specimens were divided into three groups according to the treatment solution. In group S1, specimens were treated with GCE; in group S2, the specimens were treated with sodium fluoride (NaF); meanwhile, specimens of group S3 were treated with distilled water (DW). Each group was further subdivided into two subgroups according to the treatment time (1 minute and 5 minutes). An in vitro pH-cycling model for 12 days was done. Subsequently, surface microhardness (SMH) of the specimens, elemental analysis, and their micromorphological appearance were evaluated. Statistical Analysis Data were statistically analyzed. One-way analysis of variance was used to compare numerical (parametric) data between more than two separate groups followed by post hoc Tukey. Results There was no significant difference between the mean SMH of dentin between NaF and GCE groups. Regarding the time, the 5-minute treatment with NaF and DW groups recorded higher mean SMH value of dentin than the 1-minute treatment group. Meanwhile, for GCE groups, the 1-minute immersion recorded higher mean SMH value than the 5-minute immersion without any significant difference between them. The microhardness results were confirmed by environmental scanning electron microscope and energy dispersive X-ray analysis results. Conclusion GCE could be used as an effective alternative for dentin remineralization.

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BACKGROUND: Finding a restorative material that can survive and be quite resistant in high caries risk patients is very challenging, that’s why three different glass hybrid restorations were tested for their clinical performance for one year in high caries risk patients. AIM: This study was conducted to evaluate the clinical performance of three glass hybrid restorations; nano-ionomer restoration (Ketac Nano), bioactive ionomer glass fillers (Activa bioactive), and alkasite restorative material (Cention N) in Class I cavity in high caries risk patients after 1 year according to the FDI criteria for the assessment of dental restorations. METHODS AND MATERIALS: Fifteen cooperative patients, males or females with high caries risk who were approving to participate in the trial of age range 18–50 years, were selected in the present study. Every patient should have three or more posterior teeth having occlusal pits and fissure carious lesions. Three Class I cavities were performed for every patient and restored randomly with Ketac Nano™, Activa Bioactive™, and Cention N™. All three restorations were applied, according to the manufacturers’ instructions. Restorations were evaluated at baseline (immediately), after 3 months, 6 months, and 1 year by two blinded assessors using FDI criteria for the assessment of dental restorations measuring functional properties. STATISTICAL ANALYSIS USED: Evaluation of functional properties was checked by Kruskal–Wallis non-parametric test statistics at 0.05 level. Collected data were analyzed for descriptive statistics both graphically and mathematically in terms of frequency, percent, median, interquartile range, and mean and standard deviations. Differences in evaluations between materials (M1, M2, and M3) were carried out by Chi-squared test at 0.05 level. However, differences between follow-up times (T0, T1, T2, and T3) were carried out by Friedman’s test for related samples for non-parametric data. Variations caused by the three materials and follow-up times in addition to interaction between them were assessed by repeated measures ANOVA for ranked data at significance levels of 0.05. Data analysis was carried out using computer software Statistical Package for the Social Sciences SPSS (IBM-SPSSver.23.0 for MacOS). RESULTS: Results of functional properties of the three restorative materials revealed that at baseline (T0) and 3 months (T1), all cases (100%) of the three materials were clinically successful, with no significant difference between them. However, after 6 months, 58 cases (97%) of M1, 56 cases (93%) of M2, and 54 cases (90%) of M3 were clinically successful, with non-significant difference between them. Moreover, after 12 months, 55 cases (91.6%) of M1, 56 cases (93%) of M2, and 53 cases (88%) of M3 were clinically successful, with non-significant difference between them. CONCLUSION: In the purpose of restoring posterior permanent teeth in high caries risk patients, all three restorative materials demonstrated acceptable clinical performance in Class I cavities with the same success rate.

AIM: Investigation of the aging effect on the microtensile bond strength (μTBS) of bulk-fill resin composite (RC) versus a conventionally incrementally applied one. MATERIALS AND METHODS: A total number of 45 sound human impacted third molars extracted molars have been selected to prepare specimens for the μTBS test. Teeth were randomly divided into three groups (C) according to type of RC material which used for restoring the teeth. Where nanohybrid RC (Grandio®SO) was used as the control Group (C1), packable bulk-fill RC (X-tra fil®) was used for restoring teeth in C2 group and flowable bulk-fill RC (X-tra base®) was used for restoring teeth in C3 group. Each group was further subdivided into 3 subgroups (n = 5) according to the water storage time, where in subgroup 1; teeth were stored for 24 h, subgroup 2; teeth were stored for 3 months while for subgroup 3; and teeth were stored for 6 months. After water storage, teeth were sectioned for preparation of μTBS testing beams. Maximum tensile stresses were recorded in megapascal (MPa). RESULTS: After 24 h of water storage, the X-tra base® showed a higher statistically significant μTBS to dentin (33.82 ± 9.84 MPa) than did the other two types of RCs. After 3 months, the X-tra fil® showed the lowest mean value of μTBS (10.90 ± 5.66 MPa), meanwhile, after 6 months of water storage Grandio®SO showed the highest mean value of μTBS (15.85 ± 6.76 MPa). Regardless of the time the X-tra fil® showed the lowest mean of μTBS (15.07 ± 11.73 MPa), while there is no significant difference between the X-tra base® and Grandio®SO. Furthermore, the water aging adversely affects μTBS values which deceased gradually by time. CONCLUSION: The packable bulk-fill RC characterized by lower μTBS to dentin in comparison to the flowable bulk fill and the incrementally applied nanohybrid RCs. Furthermore, the μTBS of the three tested materials decreased gradually by aging.