Poly-Ether Ether-Ketone Post Conditioned with Sulfuric Acid, Rose Bengal Activated by Photodynamic Therapy and Sandblasting on Pushout Bond Strength to Radicular Dentin Luted with Methyl Methacrylate and Composite-Based Cement.

Objective: Assessment of post surface conditioners [sulfuric acid (SA), Rose Bengal (RB), and sandblasting (SB)] and different luting cements [methyl methacrylate (MMA)-based cement and composite-based cement] on pushout bond strength (PBS) of poly-ether ether-ketone (PEEK) post bonded to canal dentin. Materials and methods: Endodontic treatment was performed on 120 single-rooted human premolar teeth. The preparation of the post space was performed and 4 mm of gutta-percha was retained in the apical region of the root. One hundred and twenty PEEK posts were fabricated from a PEEK blank utilizing a Computer aided design-Computer aided manufacture (CAD-CAM) system. The PEEK posts were allocated randomly into four groups based on post surface conditioning (n = 30). Group A: SA, Group B: RB, Group C: SB, and Group D: No conditioning (NC). Each group was further divided into two subgroups based on the luting cement used for bonding (n = 15). Group A1, B1, C1, and D1 specimens were cemented using composite-based resin cement. However, Group A2, B2, C2, and D2 posts were luted with MMA-based resin cement. PBS assessment using a universal testing machine was performed. Failure modes were analyzed under a stereomicroscope. The data relating to the effects of surface treatment and luting types of cement were analyzed using one-way analysis of variance (ANOVA) and Tukey's post hoc test (p = 0.05). Results: Coronal section of Group B2: RB+Super-Bond C&B [9.61 ± 0.75 megapascals (MPa)] displayed the highest bond scores of PEEK after root dentin. Whereas it was also discovered that Group D1: NC+Panavia®V5 (2.05 ± 0.72 MPa) presented the lowest PBS scores. Intergroup comparison analysis revealed that Group A2: SA+Super-Bond C&B and Group B2: RB+Super-Bond C&B displayed no significant difference in their bond scores. Conclusions: RB and SA possess the potential to be used as a PEEK post conditioner. MMA-based cement displayed better performance than composite-based cement.

Decontamination of lithium disilicate ceramics using various photosensitizers, herbal and chemical disinfectants, and the effect of surface conditioners on bond strength values.

AIM: To assess and compare the antimicrobial efficacy of disinfectants on lithium disilicate ceramic (LDC) used in dental applications and shear bond strength (SBS) of LDC after using different conditioners hydrofluoric acid (HF), self-etching ceramic primers (SECP) and Neodymium-doped yttrium orthovanadate (Nd: YVO4). MATERIALS AND METHODS: One hundred and twenty LDC discs were fabricated by auto-polymerizing acrylic resin using the lost wax technique. S. aureus, S. mutans, and C. albican were inoculated on thirty discs (n = 30 each). Each group was further divided into three subgroups based on different disinfecting agents used (n = 30) Group 1: Garlic extract, Group 2: Rose Bengal (RB) activated by PDT, and Group 3: Sodium hypochlorite (NaOCl). An assessment of the survival rate of microorganisms was performed. The remaining thirty samples were surface treated using three different LDC surface conditioners (n = 10) Group 1: HF + Silane (S), group 2: SECP, and Group 3: Nd: YVO4 laser+S. SBS and failure mode analysis were performed using a universal testing machine and stereomicroscope at 40x magnification, The statistical analysis was conducted using one-way ANOVA and Post Hoc Tukey test. RESULTS: Garlic extract, RB, and 2% NaOCl sample displayed comparable outcomes of antimicrobial potency against C. albicans, S aureus, and S. mutans (p > 0.05). Furthermore, SBS analysis showed HF+S, SECP, and Nd: YVO4+S exhibited comparable outcomes of bond strength (p > 0.05). CONCLUSION: Garlic extract and Rose bengal activated by PDT can be contemplated as alternatives to the chemical agent NaOCl used for LDC disinfection. Similarly, SECP and Nd: YVO4 possess the potential to be used for the surface conditioning of LDC to improve the bond integrity with resin cement.

Fiber post bonding with beta-tricalcium phosphate incorporated root dentin adhesive. SEM, EDX, FTIR, rheometric and bond strength study.

The aim was to formulate an experimental adhesive (EA) and added nanoparticles (NPs) of beta-tricalcium phosphate (ß-TCP) to see the impact on pushout bond strength (PBS) and other mechanical properties. Three adhesives were prepared, including EA (control, without ß-TCP NPs), 2.5%-ß-TCP NPs containing adhesive (2.5%-NPA), and 5% ß-TCP NPs containing adhesive (5%-NPA). For the characterization of the NPs, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy was accomplished. For the adhesive's characterization, rheological assessment, and degree of conversion (DC) analysis were performed. PBS of these adhesives against resin fiber post to root dentin, interfacial failure categories, and resin dentin interface analysis were also assessed. The ß-TCP NPs were seen as agglomerated asymmetrical particles on SEM. These NPs were composed primarily of calcium (Ca), and phosphorus (P). Rheological evaluation of the adhesive's showed a drop in the viscosity of all adhesives at greater angular frequencies. The greatest DC was detected for the EA group (67.54 ± 7.9) followed by 2.5%-NPA group (45.32 ± 5.1), whereas the lowest DC values were seen for the 5%-NPA group (38.97 ± 6.5). Concerning PBS, the 2.5%-NPA revealed the highest values at the coronal (12.81 ± 3.0) and middle (8.50 ± 2.3) sections, whereas, for the apical section, the highest PBS values were seen for the 5%-NPA (4.9 ± 1.6). Most of the failures for all adhesive groups were seen at the adhesive-dentin interface (cohesive type failures) for all root segments (coronal, middle, and apical). The resin-dentin interface analysis verified hybrid layer and resin tag formation for all adhesives, but the presence of dispersed ß-TCP NPs was only seen in the two NP-reinforced adhesives. The adding of ß-TCP NPs in the adhesive could be beneficial as it could improve its PBS. Suitable rheological properties and dentin interaction were also observed for NP-reinforced adhesives. A reduced DC was seen for both ß-TCP NP-containing adhesives as compared to the EA. RESEARCH HIGHLIGHTS: Experimental adhesives were reinforced with beta-tricalcium phosphate (ß-TCP) nanocrystals. The ß-TCP NPs were seen as agglomerated asymmetrical particles on SEM. These NPs were composed primarily of calcium (Ca), and phosphorus (P). ß-TCP adhesives demonstrated superior pushout bond strength and a drop in the adhesive viscosity at greater angular frequencies compared to control adhesive. The greatest DC was detected for the EA group followed by 2.5%- ß-TCP group, whereas the lowest DC values were for the 5%- ß-TCP group.

Use of final irrigant potassium titanyl phosphate laser; Sapindus Mukorossi and Fotoenticine on the bond values of zirconia post-to-canal dentin.

AIMS: Assessment of the efficacy of final root canal irrigants Sapindus mukorossi (SM), Potassium titanyl phosphate laser (KTPL), and Fotoenticine (FTC) on the push-out bond strength (PBS) of zirconia post. MATERIALS AND METHODS: The root canal procedure was initiated using the 10 K file and the working length was determined on single-rooted human premolar teeth after decoration. The canals were then enlarged using ProTaper universal system and filled using single cone gutta-percha (GP) and AH Plus resin sealer. Post space was prepared by removing 10 mm of GP from the canal. All the teeth were then allocated into four groups based on the final irrigating regime used (n = 10) Group 1: 5.25% NaOCl+17% EDTA, Group 2: 5.25% NaOCl + KTPL, Group 3: 5.25% NaOCl + FTC and Group 4: 5.25% NaOCl+ SM. Zirconia posts were cemented in the canal space. The specimens were sectioned and implanted in auto-polymerizing acrylic resin. A universal testing machine and stereomicroscope at 40x magnification were used for PBS and failure mode analysis. ANOVA and Tukey post hoc test were used to make group comparisons(p = 0.05). RESULTS: Group 4 (5.25% NaOCl+ SM) coronal section displayed the highest PBS (9.29±0.24 MPa). However, group 3 (5.25% NaOCl+ FTC) apical third (4.08±0.14 MPa) showed the lowest bond values. Group 2 (5.25% NaOCl+ KTP laser) and Group 3 at all three-thirds unveiled no significant difference in PBS(p>0.05). However, Group 1 (5.25% NaOCl+17%EDTA) and Group 4 displayed comparable outcomes of bond strength(p>0.05) CONCLUSION: Sapindus mukorossi has the ability to be used as a final root canal irrigant alternative to EDTA. However, future studies are still required to conclude the outcomes of existing research.

Effect on martens hardness and pushout bond strength of fiber post to canal dentin final irrigated with fotoenticine, chitosan, and ozone.

AIMS: To estimate the effect of contemporary final root canal irrigants (Ozonated water (OW), Chitosan, and Fotoenticine (FTC) on the bond scores of glass fiber post (GFP) and Martens hardness (MH) of root dentin. MATERIALS AND METHODS: Sixty extracted human premolars having a single straight canal that ends in a closed apex were included. Specimens were de-crowned till the cementoenamel junction preserving 12 mm of root length and were mounted vertically. Canal therapy was performed using a crown-down approach. Obturation was performed followed by post-space preparation. Samples were allocated into 4 groups based on chemical irrigations and photosensitizers used(n = 15). Group 1 (5.25% NaOCl + 17% EDTA), group 2 (5.25% NaOCl + FTC), group 3 (5.25% NaOCl + Chitosan), group 4 (5.25% NaOCl + OW). The ultra microhardness tester was put under a load of 5 mN at a speed of 1.5 mN/s for 1 s to assess the MH. The fiber post was luted with dual-cure cement and slices of 1 mm were prepared from each third of the tooth. PBS and failure mode analysis were performed using a universal testing machine (UTM) and stereomicroscope respectively. ANOVA and Tukey multiple comparisons t-tests for assessment of PBS and MH p > 0.05 RESULTS: Group 1 (5.25% NaOCl + 17% EDTA) exhibited the highest MH (0.19 ± 0.04 GPa). Whereas, group 2 (5.25% NaOCl + FTC) displayed the lowest MH (0.011 ± 0.14 GPa). The highest PBS was exhibited by the coronal third of group 1 (5.25% NaOCl + 17% EDTA) (7.11 ± 0.81 MPa). The apical section of group 3 specimens (5.25% NaOCl + Chitosan) (2.33 ± 0.26 MPa) unveiled the lowest PBS. Intergroup comparison analysis revealed that group 2 and group 3 displayed comparable outcomes of PBS. Group 1 and Group 4 also demonstrated no significant difference in the bond scores in all three sections. CONCLUSION: OW as a final irrigant can be used as an alternative to EDTA as it improves the bond strength with minimum impact on marten hardness.

Self-Perception of Dental Esthetics among Dental Students at King Saud University and Their Desired Treatment.

OBJECTIVE: Dental esthetic procedures are popular worldwide, and dentists are responsible for recommending several treatment options to their patients. To do this competently, dentists must have an educated opinion of their features. Therefore, we aimed to evaluate the self-perception of dental esthetics among male and female dental students and assess its effect on their desired treatment. Methodology. We conducted a questionnaire-based cross-sectional study involving 450 male and female dental students from five academic years with different grade point averages (GPAs) and monthly household incomes. The questionnaire comprised four sections. The subjects selected their teeth-color preferences using a commercial shade guide. The outcomes were presented using descriptive statistics and were compared with Pearson's chi-square test. The level of statistical significance was set at a p-value of 0.05. RESULTS: Female students (52%) showed a significantly higher preference for changing their tooth color (shade B1 was desired most often), whereas male students reported a higher need for orthodontic treatment and ceramic veneers (p < 0.0001 and p=0.002). Fifth-year students were more satisfied with their teeth color as compared with 1st-year students (p=0.047). High-GPA students showed significantly lower confidence regarding their smiles (p=0.030). A high percentage of students (39.1%) with household incomes of less than 10,000 SR preferred tooth-colored restorations. CONCLUSION: We concluded that the majority of dental students were confident about their smiles. Senior students were more satisfied with their teeth color, while younger students desired whiter teeth. Bleaching and orthodontics were the most desired treatment options.

Stability of Bonded Resin Composite Restorations to Enamel after Bleaching with 20% Carbamide Peroxide.

AIM: This study aimed to examine the effect of postoperative home bleaching using 20% carbamide peroxide on the shear bond strengths of different adhesives to enamel and to verify the failure mode for each test specimen. MATERIALS AND METHODS: One hundred sound human molars were used in this study. Bonding procedures were performed on the flattened buccal enamel surfaces according to the manufacturer's instructions. OptiBond Solo Plus adhesive (Kerr), Single Bond Universal adhesive (3M ESPE) applied with both the total-etch and self-etch techniques, and Tetric N-Bond Universal adhesive (Ivoclar Vivadent) applied with both the total-etch and self-etch techniques were used, followed by resin composite post fabrication (Filtek Z350 XT; 3M ESPE). All specimens were thermo-cycled for 5000 cycles and then divided into the control (non-bleach) and postoperative bleaching groups (20% carbamide peroxide). The shear bond strength values were measured and compared between the two groups. Data were analyzed using one-way analysis of variance with Tukey's test (p = 0.05). The failure modes of debonded specimens were evaluated using a digital microscope (50×). The bonding interfaces of the resin composite posts to different enamel conditions (control and postoperative bleaching) were observed by a scanning electron microscope (SEM) before the shear bond test. RESULTS: The shear bond strength values of all tested adhesives were lower in the postoperative bleaching group than they were in the control (non-bleach) group, particularly the bond strength values of self-etch adhesives. CONCLUSION: The stability of bonded resin composite restorations to enamel, using different dental adhesives, could be compromised after the bleaching procedure at varying sensitivity levels. CLINICAL SIGNIFICANCE: Replacement of bonded resin composite restorations to enamel might be considered after bleaching procedures, especially if these restorations were previously bonded with self-etch adhesives.

Assessment of Bonding Effectiveness of Adhesive Materials to Tooth Structure using Bond Strength Test Methods: A Review of Literature.

BACKGROUND: The rapid developments in the field of adhesive dental materials have led to improvements in many aspects of clinical dentistry. Adhesive bond strength plays an important role in determining the clinical performance and longevity of dental restorations. Nevertheless, bond strength tests have never been well-standardized, although a number of important recommendations have been made. OBJECTIVE: The aim of this paper is to critically review the validity of different bond strength testing methods for assessment of bonding effectiveness of adhesive materials to tooth structure and discuss factors that may affect bond strength measurement. DATA COLLECTION: Relevant literature published between 1983 and 2018 was collected and reviewed from the PubMed database and Google scholar resources. REVIEW RESULTS: Results of the current bond testing methods should be used to compare materials tested under the same laboratory settings, but they shouldn't be used to make direct inferences on their clinical behaviour. Shear and micro-shear tests, result in non-uniform stress distribution, stress concentration at the substrate area, and predominantly tensile stresses rather than shear stresses. Micro-tensile bond tests provide many advantages over the shear tests, although these methods are technique sensitive and labour intensive. CONCLUSION: Bond strength testing methods should be well-standardized, but there are many factors that cannot be fully controlled which leads to variation and misinterpretation of the data about the bonding abilities of adhesives. CLINICAL SIGNIFICANCE: New adhesive materials should be subjected to a combination of testing protocols to properly assess their bonding effectiveness.

Aesthetic Rehabilitation of a Severe Dental Fluorosis Case with Ceramic Veneers: A Step-by-Step Guide.

The selection of an appropriate treatment plan for cases of dental fluorosis depends on the severity of the condition. Ceramic veneers are considered the treatment of choice for moderate to severe cases of fluorosis given the optimum aesthetics, wear resistance, biocompatibility, and long-term results of these veneers. This case report describes a step-by-step rehabilitation of fluorosed teeth, using ceramic veneers in a 26-year-old Yemeni male. The patient presented at the restorative dentistry clinics at King Saud University complaining of an unpleasant smile and generalized tooth discoloration.