BACKGROUND This study aimed to compare a composite resin (Duo-Shade) shade guide with Vita ceramic shades before/after chemical and autoclave sterilization. MATERIAL AND METHODS Color values (L*a*b*) were recorded directly from shade tabs of prefabricated composite resin (Brilliant NG Universal Duo-Shade) and ceramic (Vita classic) shade guide with a calibrated spectrophotometer (Vita Easy Shade Advance 4.0). Seventy-two composite resin disk samples with 6 different shades (A1/B1, A2/B2, A3/D3, A3.5/B3, A4/C4, and C2/C3) (n=12 each) were divided into 2 groups (Gp) - Gp A (Autoclave) and Gp C (Chemical) (15 cycles) - to assess their influence on respective shades. Mean values calculated the color differences (ΔE) while differences in color values (L*a*b*) were graded on the National Bureau of Standards (NBS) 6-grade scale and assessed for Clinical Acceptance/Perceptible Threshold (CAT), (CPT). All differences were considered significant if the color difference ΔE was ≥3.3. RESULTS Only 2 out of 12 Shade tabs (C2C3, A4C4) of composite resin matched to Vita shade tab C2 and C4 (ΔE ≤3.3). Both groups showed notable color differences after respective sterilization protocols, with color differences in Gp A significantly higher than Gp C (DE ³3.3). Within groups, all shades in Gp A showed remarkably different color changes, with shade C2C3 and A1B1 being denoted as clinically unacceptable. CONCLUSIONS Manufacturer-provided shade guides do not match ceramic shades as claimed and chemical sterilization using 10% Deconex was associated with less color changes than with autoclave sterilization.

Surface etching before cementation is a vital step that determines the clinical performance of ceramic restorations. Etching alters surface topography that contributes effective bonding between ceramic restoration and resin cement. This study aimed to compare etching techniques to determine the most effective etching method contributing the highest bond strength that helps in improving dental implants. Materials and methods: sixty discs of feldspathic ceramic measuring 10 mm diameter and 4 mm thickness were prepared. The 60 samples were divided into four equal groups based on the surface treatment technique used: group A: 9.6% hydrofluoric acid; group B: coarse diamond burs; group C: CO₂ laser; and group D: no treatment. Ceramic disc specimens were examined under a Scanning Electron microscope (SEM) after surface treatment to characterize their surface morphology. Further, the specimens were luted with a resin luting agent and incubated for 24 h at a temperature of 37 °C simulating the oral environment. After 24 h, shear bond strength (SBS) and the nature of bond failure was determined for each specimen using a universal Instron testing machine. Results: significant change in surface morphology was noticed on hydrofluoric acid treatment forming larger irregular roughness (4.83 ± 1.78 µm) with multiple patterns of grooves and pores compared to other groups. Further, the highest SBS value was measured on hydrofluoric acid etching that display the highest bond strength due to the high surface roughness. In conclusion, our findings report a strong association between the surface roughness and bond strength upon hydrofluoric acid compared to other methods. Further work in this direction will enhance the utility of the etching technique on the improvement of dental implants.

Maxillofacial defects can result from several reasons, including neoplasia, congenital malformations, trauma, oral infections, etc. This kind of defects can be severely debilitating to the patients. To improve the quality of life of these patients, the options include surgical reconstruction and maxillofacial prosthesis. However, surgical approaches have many inherent disadvantages and limitations. This case report describes the prosthetic rehabilitation of a female patient who underwent partial rhinectomy secondary to basal cell carcinoma. The case was planned with a silicone prosthesis with anatomic and spectacle retention. A non-surgical method of rehabilitation was followed owing to the patient’s choice and financial constraints. The final prosthesis was aimed at enhancing the esthetics and function of the patient, thereby improving her quality of life.

INTRODUCTION. The extensive loss of coronal and radicular tooth structure, changes to dentin characteristics, and biomechanical constraints make endodontically treated teeth (ETT) more prone to fractures. Prosthodontic rehabilitation, including post-and-core systems and full-coverage crowns, is a standard approach to restore their function and structural integrity. However, a clear, stepwise comparison of the fracture resistance imparted by endodontic treatment alone versus subsequent stages of prosthodontic restoration is needed to guide clinical decision-making. MATERIALS AND METHODS. Forty extracted human maxillary premolars of similar dimensions were selected and randomly allocated into four groups (n = 10): Group I (Control) – intact sound teeth; Group II (ETT) – endodontically treated teeth with access cavities left unrestored; Group III (ETT + PC) – endodontically treated, restored with a fiber post and composite core; and Group IV (ETT + PC + C) – endodontically treated, restored with a fiber post, composite core, and a full-coverage cast metal crown. After the specimens underwent thermocycling, they were placed in acrylic resin blocks that included a periodontal ligament simulation. Until fracture occurred, a universal testing machine was used to apply a compressive force at a speed of 1 mm/min to the central fossa of each tooth, which was angled at 90 degrees to the occlusal plane. It was noted the maximum load at crack (in Newtons, N). The data was examined with the use of Tukey’s post hoc test (α = 0.05) and one-way ANOVA. RESULTS. The average fracture resistance values (± standard deviation) for the four groups were as follows: 1650.5 ± 180.2 N for Group I, 615.8 ± 95.4 N for Group II, 950.3 ± 110.7 N for Group III, and 1425.6 ± 155.1 N for Group IV. Statistical analysis using one-way ANOVA showed that there was a notable difference between the several groups ( p < 0.001). Every group except Group I (intact) was much weaker. Group IV (ETT + PC + C) showed a noticeably greater resistance to fracture compared to Group II (ETT) and Group III (ETT + PC) ( p < 0.05). In comparison to Group II, Group III was likewise much stronger ( p < 0.05). The fracture resistance of Group IV was still noticeably lower than the intact control group ( p < 0.05), nevertheless. CONCLUSIONS. For premolars, the fracture resistance is significantly reduced only by preparing the endodontic access. Placing a full-coverage crown is necessary to provide a major strengthening of the tooth structure, while adding a post-and-core gives a small improvement in strength. But, the strength of an unbroken tooth when it was first cracked is not entirely restored by modern restorative procedures.