Evaluation of shear bond strength of labial veneers after sandblasting/micro-abrasion of prepared teeth by aluminum oxide particles. An in-vitro study.

Objectives: To explore the feasibility and effectiveness of using sandblasting with aluminum oxide particles to improve the shear bond strength of labial veneer restorations in dentistry. Materials and Methods: A sample size of 50 extracted teeth was divided into five groups, with each group containing ten teeth (n = 10) subject to different treatment protocols. Group 1the control group, underwent conventional surface treatment for labial veneer restorations, including the application of phosphoric acid etchant and bonding protocols. Groups 2 and 3 underwent micro-abrasion using aluminum oxide particles alone for durations of 30 and 45 s, respectively. Groups 4 and 5 experienced a combined approach of micro-abrasion for 30 and 45 s, respectively, followed by conventional surface treatment. The shear bond strength test was performed on each specimen. The resulting modes of failure and surface characteristics were then examined under a digital microscope.The data was analyzed statistically using a one-way analysis of variance (ANOVA) and a post hoc test. Results: Significant differences were observed in shear bond strength among the five groups (p < 0.05). The group that underwent conventional + 45-second micro-abrasion treatment exhibited the highest mean shear bond strength (25.69 MPa), while the conventional (controlled) group had the lowest (9.01 MPa). Conclusion: Fusing sandblasting and aluminum oxide particles could improve the bond strength of labial veneer restorations. Yet, more research is needed to refine this technique for practical application. This includes a broad array of cement types, particle sizes, and clinical situations to ensure the long-term success of veneer restorations.

Effect of Fibres on Physico-Mechanical Properties of Bulk-Fill Resin Composites.

OBJECTIVE: To measure the flexural strength (FS) of bulk-fill resin composites and assess their long-term water absorption and solubility properties with and without the inclusion of short glass fibres. METHODS: One resin composite, everX Flow with fibres, and four commercially available bulk-fill composites without fibres, namely, PALFIQUE, Activa, SDR Plus, and Filtek Bulk Fill One, were tested. Six specimens (2 × 2 × 25 mm) were fabricated for each material and stored in water for 1 day and 30 days to measure the flexural strength using a three-point bending test. To evaluate water absorption and solubility, circular disks measuring 15 × 2 mm (n = 5) were immersed in water for 60 days, and their weights were recorded periodically. After 60 days, the specimens were dried for an additional 21 days to determine solubility. RESULTS: Flexural strength values ranged from 101.7 to 149.1 MPa. Significant distinctions were observed among the resin composites at the onset of the study (p < 0.05). The highest FS value was identified in everX Flow, while ACT exhibited the lowest (p < 0.05). However, the flexural strength values exhibited a significant decrease with increased storage time (p < 0.05), except for ACT, which demonstrated a noteworthy increase. Concerning water absorption and solubility, ACT displayed the highest absorption, while the range of solubility varied from -0.88 to 5.8 µg/mm3. ACT also had the highest solubility, whereas everX Flow exhibited negative solubility. SIGNIFICANCE: The addition of short fibres, along with potential differences in matrix composition, enhanced the flexural strength of everX Flow. However, the substantial reduction in flexural strength observed in everX Flow and SDR following exposure to water corroborates the manufacturers' recommendation to apply a conventional resin composite cap on these materials.

Influence of lithium disilicate pretreatment using photodynamic therapy, non-thermal plasma, and laser treatment on surface roughness and bond strength.

AIMS: To assess the shear bond strength (SBS) and surface roughness (Ra) of lithium disilicate ceramic (LDC) after using different pretreatment methods i.e., Non-Thermal Plasma (NTP), self-etching ceramic primer (SECP), curcumin photosensitizer (CP), Er and Cr: YSGG lasers (ECL) in comparison to hydrofluoric acid + Silane (HF + S). MATERIALS AND METHODS: A total of fifty LDC discs were prepared. All the discs were arbitrarily divided into five groups based on the surface conditioning used (n = 10). Group 1: PDT+S, group 2: HF+ S, group 3: NTP + S, group 4: SECP, and group 5: ECL+ S. A confocal optical microscope was used to calculate Ra for each sample. A self-adhesive resin cement was applied followed by LED light curing. A universal testing machine was used to assess SBS and a stereomicroscope was used to determine the failure mode. Two-way analysis of variance (ANOVA), and a Tukey post hoc test was used to analyze data (p = 0.05). RESULTS: The highest bond integrity of resin luting bonded to conditioned LDS ceramics were presented by group 2 (HF+ S) (21.48±1.39 MPa) and lowest by group 1 (CP+S) (13.01±1.19 MPa) respectively. Intergroup comparison analysis revealed that group 1(13.01±1.19 MPa) and group 3 (14.28±0.62 MPa) displayed comparable outcomes of bond integrity(p>0.05). Similarly, it was observed that group 2 (21.48±1.39 MPa) and group 5 (21.31±1.85 MPa) exhibited comparable values of bond strength(p>0.05). Specimens conditioned with HF+ S showed the highest Ra (1445.86±0.019 µm). However, discs treated with SECP exhibited the lowest Ra (0139.76±0.081 µm). CONCLUSION: Er, Cr: YSGG laser retains the ability to be used as an LDC surface conditioner as an alternative to HF+ S.Both the methods of pretreatment results in high surface roughness of LDC.

National Survey on Silver Diamine Fluoride (SDF) Awareness, Knowledge, Attitude, and Use among General Dental Practitioners in the Kingdom of Saudi Arabia-An Exploratory Survey.

Silver diamine fluoride (SDF) has been accepted as an appropriate alternative for caries management. However, knowledge and utilization of SDF among dentists vary considerably. The authors in the present study aimed to assess the awareness, knowledge, attitudes, and use of SDF among general dentists (GD) in Saudi Arabia and to correlate the differences based on the different regions and experience levels of the dentists. In this regard, a cross-sectional web-based questionnaire was conducted, and a response was received from 311 GDs from different parts of the country. Information regarding demographic data, knowledge, attitudes, use, and barriers to SDF in dentists' professional lives were elicited. The mean age of the participants (55.3%) was between 25-35 years. Most (92.45%) of the dentists were aware of the material and (61%) agreed that SDF could arrest carious lesions. More than half of the dentists agreed/strongly agreed that SDF was a good treatment alternative for restorations in children with behavioral issues (63.1%), medically fragile patients (53.7%), patients with severe anxiety (64.5%), patients who underwent radiation or chemotherapy (47.3%), and patients needing general anesthesia for dental treatment (74%). Comparative evaluation using ANOVA revealed regional differences based on knowledge, attitudes, and use. Tukey HSD further highlighted that the practitioners in the western region are more knowledgeable regarding its benefits and utilize it more frequently in their practice compared to other regions. On the other hand, the experience level of the GDs did not have any impact on their knowledge, attitudes, and use of SDF.

Evaluation of the Shear Bond Strength of Four Bioceramic Materials with Different Restorative Materials and Timings.

The objectives of this study were to evaluate the shear bond strength (SBS) of a resin composite (RC) and a resin-modified glass ionomer (RMGI) to four different bioceramic materials and to compare the effects of the immediate vs. delayed placement of restoration on the SBS. A total of 160 Teflon blocks and 40 blocks/material, were randomly filled with one of the bioceramic materials (NeoPUTTY®, NeoMTA2®, TotalFill® BC RRM™ Fast Set Putty, and ProRoot® MTA). The restoration was performed immediately or in a delayed time frame (after 7 days) using a Filtek™ Z350 XT Flowable composite (bonded to the bioceramic materials using Single bond universal 3M) or GC Fuji II LC® RMGI. The SBS test was performed at a crosshead speed of 1 mm/min, and the failure mode was evaluated under a digital microscope by one blinded examiner. One-way analysis of variance (ANOVA) with the Games-Howell post hoc test was used to compare the mean SBS between the groups. The mean SBS of the bioceramic materials to RC was significantly higher than to RMGI except for ProRoot MTA (p-value 0.65). The SBS values to RC were as follows: ProRoot MTA (7.64 MPa); NeoMTA2 (8.57 MPa) which was significantly higher than both NeoPUTTY (4.04 MPa) and TotalFill® BC RRM™ Fast Set Putty (4.38 MPa). For RMGI groups, ProRoot MTA showed the highest SBS (7.18 MPa), followed by NeoMTA2 (4.15 MPa), NeoPUTTY (1.62 MPa), and TotalFill® BC RRM™ Fast Set Putty (1.54 MPa). The delayed timing restoration showed a significantly higher SBS than the immediate, except for the immediate RMGI restoration with MTA. To conclude, the SBS of RC to the bioceramic materials was significantly higher than RMGI, except for ProRoot MTA. Both restorative materials had a significantly higher SBS to the MTA groups in comparison to premixed bioceramics. Delayed RC restoration had a higher SBS than immediate restoration. Similarly, delayed RMGI restoration had a higher SBS than immediate restoration with premixed bioceramic but not with MTA.

Effectiveness of antimicrobial photodynamic therapy as an adjunct to mechanical instrumentation in reducing counts of Enterococcus faecalis and Candida albicans from C-shaped root canals.

BACKGROUND/PURPOSE: The aim was to assess the effectiveness of antimicrobial photodynamic therapy (aPDT) as an adjunct to mechanical instrumentation (MI) in reducing Enterococcus faecalis (E faecalis) and Candida albicans (C albicans) counts from C-shaped root-canals. METHODS: Teeth with C-shaped canals as identified on cone beam computed tomographic images were included. Following incubation with E faecalis and C albicans, samples were divided into 4 groups a four follows: Group-1: MI with adjunct aPDT; Group-2: aPDT alone; Group-3: MI alone; and Group-4: no treatment. The pulp chambers of these teeth were exposed and coronal pulp was mechanically derided using sterile endodontic excavators. Using flexible files, all canals were debrided up to size #30 K-files with intermittent irrigation with 2.5% sodium hypochlorite irrigation. In Groups 1 and 3, methylene-blue was injected in all canals and aPDT was performed using a 600 nm diode laser. Sample-size estimation was done on data from a pilot investigation and group-comparisons were done using one way analysis of variance and Bonferroni post-hoc adjustment tests. P < .05 was considered statistically significant. RESULTS: Sixty periodontally hopeless mandibular second molars with C-shaped canals were included. There was a statistically significant reduction CFU/mL of E faecalis (P < .001) and C albicans (P < .001). At post-operative microbial assessments in Group-1. There was no difference CFU/mL of E faecalis and C albicans at post-operative microbial assessments in Groups 2-4. CONCLUSION: MI with adjunct aPDT is more effective in reducing count of E faecalis and C albicans from C-shaped root canals.

Effects of CAD/CAM ceramics and thicknesses on translucency and color masking of substrates.

OBJECTIVE: To compare the translucency and masking of zirconia-reinforced lithium silicate with lithium disilicate glass-ceramic and hybrid composite. MATERIALS AND METHODS: One hundred and twenty disc-shaped specimens were fabricated using Enamic, Celtra Duo, IPS E.max CAD, and Suprinity. Twelve groups were prepared according to material type and thickness (0.5, 1.0, and 1.5 mm). The specimens were tested over five substrates: composite resin-A3.5 shade (A3.5 control group), zirconia-A1 shade (ZR), nickel-chromium alloy (NC), black (B), and white (W). A spectrophotometer operating at wavelengths from 360 to 750 nm and a view-area size of 9.53 mm was used for color measurement. RESULTS: Mean color difference values (ΔΕ) were found to be lowest in Suprinity and highest in IPS E.max. CAD. Color difference values were significantly related to substrate shade. The A3.5 substrate revealed the significantly lowest ΔΕ values of all the substrates (P = 0.05). Regarding the translucency parameters for ceramics of different thicknesses, a significant difference was observed among all groups except in Suprinity. CONCLUSIONS: Different ceramic types with different thicknesses and substrate strongly affect translucency and masking. CLINICAL SIGNIFICANCE: Fabricating durable aesthetic restorations that also meets patients' expectations is among the most significant challenges in dentistry. With high demand for more natural restorations, ceramics based on computer-aided design (CAD) and computer-aided manufacture (CAM) became popular and exhibited excellent results. However, various factors such as abutment shade, luting cement color, and ceramic type, thickness, and translucency may affect the prosthesis shade. The objective of this study was to evaluate the effects of these factors on the final shades of CAD/CAM-based ceramic restorations.

Anatomical Shaping for Zirconia Custom Implant Abutment to Enhance Anterior Esthetic: A Clinical Technique.

Abutments are used in dentistry to attach dental crowns to dental implant. Currently, zirconia custom abutment is the one which is mostly used in restorations, since it offers several advantages, especially better esthetics and prevention from infection. Several innovations are done in the implant designs and procedures to achieve better esthetics. Computer-aided design & computer-aided manufacturing (CAD/CAM) system is widely used innovative technology in dentistry. This technology offers custom implants that help to achieve better esthetics and good internal fit. This procedure used a novel technique of anatomical modification of the final abutment incisal edge from straight anatomical edge to irregular one with a mamelon-incisal effect to enhance esthetic, shade matching, and anatomical replication of incisal structure that resembles the natural incisor. Usually, dental technicians will perform facial and incisal cut-back and apply porcelain layers to the crown in order to reproduce the translucency and the other optical effects that most closely match that of natural dentin and enamel, especially at the incisal edge. These optical effects will make the prosthetic crown look more natural and esthetically pleasant. By this presented technique will help the dental technician to achieve highly esthetic crown with completely digital workflow without the need for porcelain layering. The procedure was also followed up to 3, 6, and 12 months after the surgery and found no complications or complaints from the patient and esthetically satisfied.

Effect of Zirconia Core Thickness and Veneer Firing Cycle on the Biaxial Flexural Strength of Veneering Ceramic.

PURPOSE: To evaluate the influence of various Y-TZP thicknesses and veneer firing cycles on the strength of two ceramic veneers. MATERIALS AND METHODS: 180 Y-TZP cores of 0.5, 1.0, and 5.0 mm thickness were prepared followed by sintering in a high temperature furnace; 180 presintered veneering ceramic discs (Vita VM9 porcelain and e.max Ceram) were also prepared using a mold. The discs were placed on zirconia plates (zirconia cores) of different thickness (0.5, 1.0, and 5.0 mm) and exposed to different firing cycles (Vita VM9 porcelain-910, 930, and 950°C; e.max Ceram-750, 770, and 790°C). Ball-on-three-balls flexural strength test was performed (universal testing machine) at a crosshead speed of 0.5 mm/min. Scanning electron microscopy of fractured specimens was performed. Means and standard deviations of flexural strength were analyzed using Tukey-Kramer HSD test for multiple comparisons. RESULTS: Specimens within material groups showed no significant difference (p > 0.05) for flexural strength with respect to Y-TZP core thickness (0.5, 1.0, and 5.0 mm) (VM9 [117.30 ± 14.328, 117.75 ± 13.66, 113.75 ± 20.10], e.max Ceram [94.79 ± 17.5, 100.02 ± 14.7, 95.23 ± 15.4]). Flexural strength within material groups with respect to different firing cycles ([VM9-910, 930, 950°C], e.max Ceram [750, 770, 790°C]), for VM9 (111.49 ± 15.7, 120.86 ± 13.2, 116.46 ± 18.4), and e.max Ceram (94.64 ± 15.2, 101.6 ± 16.69, 93.8 ± 15.20) showed no significant difference (p > 0.05). CONCLUSIONS: Different zirconia thicknesses (0.5, 1.0, and 5.0 mm) and veneer firing cycles for Vita VM9 and e.max ceramics failed to show any significant influence on their biaxial flexural strengths.

Clinical peri-implant parameters and inflammatory cytokine profile among smokers of cigarette, e-cigarette, and waterpipe.

BACKGROUND: To date, there has been no study identified that assessed peri-implant parameters and local levels of proinflammatory cytokines between waterpipe smokers (WS) and electronic cigarette users (VS). To evaluate the true effect of the risk indicator (WS and VS), a positive control (cigarette smokers [CS]) was added in the study design. PURPOSE: To compare clinical and radiographic peri-implant parameters and proinflammatory cytokine profile in the peri-implant sulcular fluid (PISF) among CS, WS, VS, and nonsmokers (NS). MATERIALS AND METHODS: Forty CS, WS, VS, and NS were included. Details regarding demographics, duration of implants, and habits were recorded. Clinical examination for periodontal and peri-implant plaque index (PI), bleeding on probing (BOP), and probing depth (PD ≥ 4 mm) were assessed. Radiographic bone loss (RBL) was assessed using digital periapical radiographs and viewed on a calibrated computer screen using an image analyzer. Levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and IL-1ß in PISF were evaluated using enzyme-linked immunosorbent assay. RESULTS: Mean peri-implant PI (P < .05), PD ≥ 4 mm (P < .05), and total RBL (P < .01) was significantly higher among CS, WS, and VS compared with NS. Statistical differences in BOP were observed in NS (P < .01) compared to CS, WS, and VS. CS and WS showed significantly higher PD ≥ 4 mm and RBL compared with VS (P < .05). Levels of TNF-α, IL-6, and IL-1ß were significantly higher in CS, WS, and VS compared to NS. There were no statistical differences in the mean levels of all proinflammatory cytokines among individuals in CS and WS. CONCLUSION: Tobacco smoking is associated with poor peri-implant health. The effect of waterpipe smoking was of largely the same extent as that of cigarette smoking. Higher levels of inflammatory cytokines in tobacco smokers may propose increased peri-implant inflammatory process which could play a principal role in the progression of peri-implant tissue damage.