Hybrid computer-aided design and computer-aided manufacturing (CAD/CAM) materials have gained prominence in restorative dentistry due to their advantageous mechanical and esthetic properties; however, their long-term performance may be adversely affected by acidic oral environments, such as those associated with gastroesophageal reflux disease (GERD). This in vitro study aimed to investigate the effects of simulated gastric acid exposure on the surface roughness, gloss, color stability, and microhardness of two hybrid CAD/CAM materials: Vita Enamic and Cerasmart. Standardized rectangular specimens (2 mm thickness) were prepared and polished using a clinically relevant intraoral protocol. Baseline measurements were obtained for surface roughness, gloss, color change (ΔE), and Vickers microhardness. All specimens were then immersed in hydrochloric acid (pH 1.2) for 24 h to simulate prolonged gastric acid exposure, after which the same properties were re-evaluated. Post-immersion analysis revealed significant increases in surface roughness and reductions in gloss and microhardness for both materials (p < 0.05), with Vita Enamic demonstrating greater susceptibility to degradation. Color changes remained below the clinically perceptible threshold, with no significant differences between materials. These findings highlight the potential vulnerability of hybrid CAD/CAM materials to acidic environments and underscore the importance of careful material selection in patients predisposed to acid-related challenges.

The repair of defective composite restorations, particularly bulk-fill composites, offers a conservative alternative to complete replacement. However, establishing durable adhesion between aged and fresh composites remains a clinical challenge due to the altered surface properties of aged materials. This in vitro study investigated the effects of different surface treatment protocols (no treatment, diamond bur roughening, and air abrasion) and adhesive systems (G-Premio Bond, Clearfil SE Bond, and Adper Single Bond 2) on the shear bond strength (µSBS), tensile bond strength (µTBS), and microleakage of repaired bulk-fill composites. Results demonstrated that both surface treatment and adhesive type significantly affected bond strength (p < 0.05). Mechanical surface treatments, particularly diamond bur roughening and air abrasion, enhanced µSBS and µTBS compared to untreated controls. The highest µSBS and µTBS values were observed with diamond bur treatment combined with Adper Single Bond 2, reaching mean values of 25.8 ± 2.1 MPa and 28.3 ± 1.8 MPa, respectively. Air abrasion with Clearfil SE Bond also significantly increased bond strengths (µSBS: 22.1 ± 2.0 MPa; µTBS: 23.5 ± 1.7 MPa) relative to no treatment (p < 0.05). Micro-computed tomography analysis revealed that Clearfil SE Bond following diamond bur roughening resulted in the lowest microleakage scores, with a mean leakage volume of 0.12 ± 0.04 µm. These findings underscore the importance of mechanical surface conditioning and appropriate adhesive selection to enhance both bond strength and sealing efficacy in composite repair procedures.

Objectives: The aim of thi s retrospective study was to determine the frequency and localization of the overhanging restorations by observing patients’ routinely taken panoramic radiographs. Materials and Methods: The panoramic radiographs of 4,960 patients who applied to a dental clinic in University between 2015 and 2016 and had one or more previous restorations were retrospectively examined. The study group included 243 patients (133 females and 110 males) with a mean age of 39.7 ± 12.5 years. Superposed interdental areas were not evaluated. Frequency distributions and percentages were calculated for the categorical data as to the surface of the maxillary-mandibular premolar and molar teeth, also the presence or absence of root canal treatment. Chi-square tests were used to compare data relating to the localization and frequency of overhanging restorations. Results: In the radiological evaluation of 243 patients, a total of 280 overhanging restorations were detected. Root canal treatment was present in 45.4% of the teeth with an overhanging restoration. The frequency of overhanging restorations in the maxilla was significantly higher (60.4%) than that of the mandible (39.6%), (p<0.05). The frequency of overhanging restorations in molar teeth (82.9%) was significantly higher than that of premolar teeth (p<0.05). Of all the overhanging restorations, 90.4% were in Class II cavities and 9.6% were in mesio-occluso-distal (MOD) cavities. More than half (57.3%) of the overhanging margins in the Class II restorations were distal; 42.7% were mesial surfaces (p<0.05). The most frequent restorations with overhanging were found in the maxillary molars (49.6%) and the least frequent were in the premolar teeth of the mandible (6.4%). Conclusions: The restorations with overhanging margins determined most often at the disto-occlusal margins of the maxillary molars. The frequency of overhanging restorations was higher in areas that are difficult to reach during treatment.

Direct and indirect composite laminate veneers have been frequently used, however the wear of composite restorative materials is still a major problem. Objective: This study aimed to investigate the surface roughness and wear of composite laminate veneers made by two different methods after toothbrushing simulation. Material and Methods: Ninety-six upper incisors and canines were divided into two groups: 1-Componeer prefabricated composite veneer (CPV), 2- Uveneer direct composite veneer (UDV). At the UDV group, restorations were made by using Uveneer template system with the same nanofilled composite material (Synergy D6, Coltène, Altstatten, Switzerland) of the prefabricated Componeers’. The initial surface roughness was measured with a profilometer, then the weight was measured. Before the simulation, samples were screened with a 3D extra-oral scanner. Toothbrush simulation was performed at 10,000 rotational strokes with 2.5 N. The measurements were repeated after toothbrushing simulation. Data were analyzed using variance analyses and t-tests (p < 0.05). Results: Before and after polishing, a significant difference was found between two groups’ surface roughness in both lateral incisors (p = 0.000, p = 0.000) and canines (p = 0.048, p = 0.001), respectively. After toothbrushing simulation, significant increases were observed in central and lateral incisors’ surface roughness with two methods. There was no significant difference between weight loss (p > 0.05). In 3D scans, wear rate was quite similar except UDV group central incisors. Conclusions: Surface roughness of the CPV restorations were less affected after toothbrushing simulation. However, the Uveneer template system, a facilitated treatment procedure compared to the manual buildup of direct restoration, has shown comparable results with CPV’s.

Aim: This study aimed to determine the effects of toothbrushing force on the surface roughness, gloss, and color change of dental enamel. Material and Methods: This study was carried out on the sound vestibular enamel surfaces of 16 human permanent incisors extracted for periodontal or orthodontic reasons. Teeth were randomly divided into 2 subgroups (n=8, per group) and embedded in acrylic blocks. The vestibular enamel's initial surface roughness, gloss, and color were measured. Three measurements per sample were performed and averaged. Six months of toothbrush simulation with 5,000 circular cycles (with a load of 1.5 and 2.5 N for groups 1 and 2, respectively) (MOD Dental, Turkey) was performed. The same measurements were repeated and the data were analyzed with independent samples and paired sample t-tests (p<0.05). Results: A significant difference was observed between the surface roughness values after the toothbrushing simulation with 1.5 and 2.5 N (p=0.022). Surface gloss values decreased significantly when 1.5 and 2.5 N forces were applied (p=0.001, p=0.002, respectively). Color change (ΔE) for brushing force of 2.5 N (3.48±0.83) was statistically significantly higher than 1.5 N (2.42±0.86), (p=0.025). Conclusion: Results of this study revealed that the surface roughness and color change values increased depending on the applied brushing force whereas gloss values decreased.