Adhesive bond integrity of dentin conditioned by photobiomodulation and bonded to bioactive restorative material

Modified Hybrid Hydroxyapatite-Silver Nanoparticles Activated via a Blue Light Source in Various Concentrations in Two-Step Self-Etch Adhesive to Caries-Affected Primary Dentin

Aims: To evaluate hydroxyapatite-silver (HA-Ag) hybrid nanoparticles (NPs), as an antibacterial agent when integrated in self-etch (SE) adhesive. Blue light activated HA-Ag hybrid NP incorporation on mechanical properties, degree of conversion (DC), and microtensile bond strength (μTBS). Method: Eighty primary molar teeth have carious lesions reaching the dentin but not involving the pulp. The infected dentin was removed and carious-affected dentin (CAD) was preserved. Forty samples were inoculated with Streptococcus mutans. All primary teeth (n = 80) were allocated into four groups based on the incorporation of HA-Ag hybrid NPs in different concentrations (0%, 1%, 5%, and 10%). Group 1: 0% HA-Ag hybrid NPs + Clearfil SE bond primer, group 2: 1% HA-Ag hybrid NPs + Clearfil SE bond primer, group 3: 5 wt% HA-Ag NPs + Clearfil SE bond primer, and group 4: 10 wt% HA-Ag NPs + Clearfil SE bond primer. The survival rate assessment of S. mutans was conducted on 40 inoculated samples. On the remaining primary teeth (n = 40), Clearfil SE bonding agent was applied uniformly via a blue light source. The composite buildup was performed on the samples and μTBS and failure analysis assessed. Fourier transform infrared spectroscopy was performed to assess DC. Survival rates of S. mutans and μTBS among the tested groups were compared using ANOVA and Tukey post hoc analysis. Results: 10 wt % HA-Ag NPs + Clearfil SE bond primer exhibited the highest level of antibacterial efficacy (0.14 ± 0.02 CFU/mL) against S. mutans. The highest μTBS (18.38 ± 0.78 MPa) at the composite/CAD interface was in group 2 (1 wt % HA-Ag NPs + Clearfil SE bond primer + Clearfil SE bonding agent + activation with a blue light source). The highest DC was observed in the control group with Clearfil SE bond primer + Clearfil SE bonding agent + activation with a blue light source. Conclusion: 1 wt% HA-Ag hybrid NPs showed enhanced antibacterial effectiveness, DC, and bond strength of the SE adhesive to the primary CAD.

Pretreatment of enamel with Riboflavin activated photodynamic therapy and Er, Cr: YSGG laser for bonding of orthodontic bracket with adhesive modified with cerium oxide nanoparticles

AIM

To assess the degree of conversion (DC) and shear bond strength (SBS) of experimental adhesive (EA) infused with and without 1 % Cerium oxide (CeO₂)-NPs on metallic bracket bonded to enamel conditioned with three different pretreatment regimes PDT-activated (Riboflavin) RF, ECY (Er, Cr: YSGG), and Phosphoric acid (PA).

MATERIAL AND METHOD

EA and EA modified with 1 % CeO₂-NPs were prepared. Characterization of CeO2NPs was assessed using a scanning electron microscope (SEM). Seventy-two premolars extracted due to periodontal or orthodontic reasons were disinfected. Samples were mounted and allocated into three groups according to enamel surface treatment before bracket bonding. Samples in Group 1 were pretreated with Traditional 37 % PA-gel; Specimens in Group 2 surface treated with RF-activated PDT, and samples in Group 3 were conditioned using ECY. Brackets were placed on conditioned surfaces and samples were aged and underwent SBS testing using UTM. ARI index was used to assess bond failure. DC was evaluated for both adhesives using FTIR. ANOVA and Tukey post hoc test were used to compare the means and standard deviation (SD) of SBS and DC in different experimental groups.

RESULTS

Enamel conditioned with PA and RF activated by PDT demonstrated comparable bond values with 1 % CeO2 infused in EA and EA (p>0.05).ARI analysis shows that enamel conditioned with PA and RF activated by PDT showed the majority of failure types between 1 and 2 irrespective of the type of adhesive. DC value in EA (73.28±8.37) was the highest and comparable to 1 % CeO2 infused in EA (66.48±6.81) CONCLUSION: RF-activated PDT can be used alternatively to 37 % PA for enamel conditioning when bonding metallic brackets. Infiltration of 1 % CeO2 NPs in EA improves SBS irrespective of the type of enamel conditioning. Infusion of 1 % CeO2 NPs in EA demonstrates no significant difference in DC compared to EA.

Microhardness and elemental analysis of ion-releasing restoration/ dentin interface following enzymatic chemomechanical caries excavation

BACKGROUND

This study was conducted to compare chemical, elemental and surface properties of sound and carious dentin after application of two restorative materials resin-modified glassionomer claimed to be bioactive and glass hybrid restorative material after enzymatic chemomechanical caries removal (CMCR) agent.

METHODS

Forty carious and twenty non-carious human permanent molars were used. Molars were randomly distributed into three main groups: Group 1 (negative control) - sound molars, Group 2 (positive control) - molars were left without caries removal and Group 3 (Test Group) caries excavated with enzymatic based CMCR agent. After caries excavation and restoration application, all specimens were prepared Vickers microhardness test (VHN), for elemental analysis using Energy Dispersive Xray (EDX) mapping and finally chemical analysis using Micro-Raman microscopy.

RESULTS

Vickers microhardness values of dentin with the claimed bioactive GIC specimens was statistically higher than with glass hybrid GIC specimens. EDX analysis at the junction estimated: Calcium and Phosphorus of the glass hybrid GIC showed insignificantly higher mean valued than that of the bioactive GIC. Silica and Aluminum mean values at the junction were significantly higher with bioactive GIC specimens than glass hybrid GIC specimen. Micro-raman spectroscopy revealed that bioactive GIC specimens showed higher frequencies of v 1 PO 4, which indicated high level of remineralization.

CONCLUSIONS

It was concluded that ion-releasing bioactive resin-based restorative material had increased the microhardness and remineralization rate of carries affected and sound dentin. In addition, enzymatic caries excavation with papain-based CMCR agent has no adverse effect on dentin substrate.

Effect of Casein Phosphopeptide-Amorphous Calcium Phosphate, Proanthocyanidin, Carbon Dioxide Laser Remineralization on the Bond Integrity of Composite Restoration Bonded to Caries-Affected Dentin

Objective: Assessment of different remineralizing pretreatment casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), proanthocyanidin (PA), carbon dioxide laser (CO2), eggshell solution (ES) on the shear bond strength (SBS) of resin composite bonded to remineralized carious-affected dentin (CAD). Materials and methods: Eighty human molars were collected with occlusal caries that extended about halfway into the dentin. Using a water-cooled, low-speed cutting saw, a flat, mid-coronal dentin surface was exposed. CAD was differentiated from healthy dentin. Based on the remineralizing agent used on the CAD surface, the teeth were arbitrarily allocated into five groups (n = 10). Group 1: no remineralizing agent, Group 2: CPP-ACP, Group 3: 6.5% PA solution, Group 4: CO2 laser, and Group 5: ES solution. All samples were bonded to composite and light cured and thermocycled. SBS and failure mode analysis were performed using universal testing and stereomicroscope 40 × . Using SPSS, SBS, and failure mode data were analyzed using analysis of variance and Tukey's honesty significant difference (HSD) test Results: Group 3 (6.5% PA solution; 15.59 ± 1.44 MPa) samples established the maximum bond integrity. Nevertheless, Group 1 (No remineralizing agent; 11.19 ± 1.21 MPa) exhibited the minimum outcome of bond strength. Intergroup comparison analysis showed that Group 1 (No remineralizing agent), Group 2 (CPP-ACP), and Group 4 (CO2 laser) established comparable values of bond strength (p > 0.05). Likewise, Group 3 (6.5% PA solution) and Group 5 (EA solution) also revealed equivalent bond integrity (p > 0.05). Conclusions: PA and ES are considered potential remineralizing agents used for caries-affected dentin surfaces in improving bond integrity to composite resin. However, further studies are advocated to extrapolate the findings of this study.

Antibacterial efficacy of NanoCare, Fullerene (C60) activated by UV light, and Morinda Oleifera against S.Mutans and bond integrity of composite resin to caries affected dentin

AIM

Assessment of the impact of contemporary disinfection techniques Moringa Oleifera (M. Oleifera), NanoCare Plus Silver Gold® (Nanocare), and Fullerene (C60) on survival rates of S.Mutans and shear bond strength (SBS) of composite to the carious affected dentin (CAD) MATERIAL AND METHODS: Sixty mandibular molars having caries progression till the middle 1/3rd of the dentin were disinfected. The CAD surface of twenty samples was inoculated with S.mutans. Based on different disinfection regimens samples were arbitrarily assigned to four groups (n:15) Group 1: 2 % CHX, Group 2:NanoCare, Group 3:Fullerene (C60), and Group 4 (M. Oleifera. This was followed by calculating the survival rate of S.mutans. Ten samples from each group were then restored with composite restoration and thermocycled. Assessment of SBS and failure mode was performed using a universal testing machine and stereomicroscope at 40X magnification. Statistical significance among groups was assessed using analysis of variance (ANOVA) and Tukey's test at a significance level of p = 0.05 RESULTS: Group 2 samples treated with NanoCare exhibited the lowest survival rate (0.39 ± 0.02 CFU/ml) of S.Mutans. However, Group 1 (CHX) samples exhibited the highest survival count (0.51±0.10 CFU/ml). Furthermore, the highest composite to CAD bond was observed in Group 3 Fullerene(C60) (18.44±0.25 MPa) samples and the lowest SBS was observed in Group 1 (CHX) (12.48±1.69 MPa) CONCLUSION: Fullerene(C60) and Moringa Oleifera extract hold promise as potential substitutes for chlorhexidine (CHX) in clinical applications, offering the potential for improved S.Mutans elimination and enhanced bond strength to CAD surface.

Adhesive Bond Strength of Restorative Materials to Caries-Affected Dentin Treated with Antimicrobial Photodynamic Therapy: A Systematic Review and Meta-Analysis

Objective: This systematic review aimed to evaluate the adhesive bond strength of restorative materials to caries-affected dentin (CAD) treated with antimicrobial photodynamic therapy (aPDT) in comparison with conventional chemical disinfectants. Methods: Three databases, including the Web of Science, Scopus, and PubMed, were searched to address the focused question: "What is the effect of aPDT compared to conventional chemical disinfection techniques on the adhesive bond strength of restorative materials to CAD?." Search keywords included "dentin*" "adhes bond*" "caries-affected dentin" "photodynamic "photochemotherapy" "photosensitizing agent" "phototherapy" "photoradiation" "laser" "light activated" "photoactivated." A fixed-effects model was used in each meta-analysis and the inverse variance was used to calculate the standard mean difference (SMD). For evaluating the statistical heterogeneity, the Cochrane's Q test and the I2 statistics were used. The risk of bias was evaluated based on the Cochrane Collaboration's tool. Results: Fourteen studies were included in the qualitative as well as quantitative analysis. The results of the meta-analyses exhibited an SMD of 2.38% [95% confidence interval (CI): 2.03-2.73; p < 0.00001], indicating a statistically significant difference in the shear bond strength scores between the tested group (samples treated with aPDT) and the control group (i.e., favoring the sound dentin and/or conventional chemical disinfectants). Contrarily, an SMD of -1.46% (95% CI: -2.04 to -0.88; p < 0.00001) and -0.37% (95% CI: -0.70 to -0.03; p = 0.03) was observed, indicating a statistically significant difference in the microtensile bond strength (μTBS), as well as microleakage scores between the tested group (favoring the samples treated with aPDT) and the control group (i.e., sound dentin and/or conventional chemical disinfectants). Conclusions: Adhesive bond strength of restorative materials to CAD treated with conventional chemical disinfectants showed superior outcomes compared to photodynamic therapy (aPDT).

Canal disinfection using photo-chemically activated micro-bubble emulsion, Emblica officinalis, and Nd: YAP laser on smear layer and push-out bond strength of resin-based root canal sealer to the radicular dentin

AIMS

Evaluation of the effects of the latest root canal disinfectants i.e., Micro-bubble emulsion (MBE), Neodymium-doped yttrium aluminum perovskite (Nd: YAP), Emblica officinalis (E. officinalis) on the removal of smear layer (SL) and push out bond strength (PBS) of resin-based root canal sealer to the radicular dentin.

METHODS

The coronal portion of sixty single-rooted human mandibular premolar teeth was precisely sectioned at the cementoenamel junction. The canals were prepared to utilize ProTaper universal rotary files till F3. All the study specimens were divided into four groups based on the disinfection regime (n = 15) Group 1: 5.25% NaOCl, Group 2: MBE, Group 3: Nd: YAP laser and Group 4: E. officinalis extract. All the canals were then finally irrigated using 17% EDTA solution as a final disinfecting agent. SL removal assessment was performed on five samples from each group using a scanning electron microscope (SEM). Ten samples from each group were then filled with root canal filling material and the roots were sectioned. Push-out test and failure mode analysis were performed using the universal testing machine (UTM) and stereomicroscope respectively. The mean scores of PBS and SL removal were compared using a one-way analysis of variance (ANOVA) and Post Hoc Tukey's HSD test p = 0.05.

RESULTS

Group-2 (MBE + EDTA) coronal section (1.50 ± 0.23) exhibited the most effective eradication of SL from the canal space. The apical third of Group-1 (NaOCl+EDTA) (2.68 ± 0.82) samples demonstrated the least effective removal of SL from the radicular canal. The maximum score of PBS of AH plus sealer to the canal dentin was exhibited by the coronal section of Group-2 (MBE + EDTA) (9.55 ± 0.45 MPa) samples. However, the apical third of Group-1 (NaOCl+ EDTA) specimens (5.16 ± 0.32 MPa) demonstrated the minimum EBS.

CONCLUSION

MBE+ EDTA displayed better smear layer removal and bond integrity of AH plus sealer to the root canal dentin. Nd: YAP+ EDTA laser and E.officinalis displayed comparable outcomes to that of control NaOCl+ EDTA.

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.

Comparative evaluation of effect of chlorhexidine application on dentin bond strength with two different adhesives after ER, CR: YSGG phototherapy: an in vitro study

This study aimed to assess the efficacy of phototherapy with an Er, Cr:YSGG laser on the bond strength of dentin using two different adhesive systems after chlorhexidine (CHX) application. Twenty-four non-carious human molar teeth were separated into three main groups: negative control Group A (Group A), CHX and phototherapy with an Er, Cr:YSGG laser (Group PC), and CHX with conventional diamond bur (no phototherapy) (Group C). These groups were divided into two subgroups based on adhesives: Clearfil Universal Quick Bond and Clearfil SE Bond. To evaluate the microtensile bond strength, the occlusal enamel surfaces of the teeth were removed with a low-speed, water-cooled diamond bur to expose hard dentin tissue. The teeth within Group PC were treated with Er, Cr:YSGG phototherapy. The surfaces were then disinfected with 0.2% chlorhexidine gluconate. Subgroups were applied according to the manufacturer's instructions using the adhesive systems mentioned above. Following adhesive application, the teeth were restored with composite resin. A microtensile bond strength test was performed on the test sticks obtained from the teeth using a universal test device. Data were analyzed using variance analysis (ANOVA) at a significance level of p < 0.05. Among all groups, the highest bond strength was achieved with Clearfil SE Bond with CHX + phototherapy (45.6 ± 4.2), while the lowest was achieved with Clearfil Universal Quick Bond without phototherapy (control group) (27.0 ± 6.7) (p < 0.05). Phototherapy with Er, Cr: YSGG following chlorhexidine application enhanced the bond strength of both the bond systems (p < 0.05).

Micro Tensile bond strength and microleakage assessment of total-etch and self-etch adhesive bonded to carious affected dentin disinfected with Chlorhexidine, Curcumin, and Malachite green

AIMS AND OBJECTIVES

Assessment of micro tensile bond strength (microTBS) and micro-leakage scores of total-etch adhesive (TAE) and self-etch adhesive (SAE) bonded to carious affected dentin (CAD) sterilized using different cavity disinfectant (curcumin photosensitizer (CP) and malachite green (MG) and Chlorhexidine (CHX) in comparison to no disinfection (ND) control group.

MATERIALS AND METHODS

One hundred and twenty human molars having International Caries Detection and Assessment System (ICDAS) scores of 4 and 5 were included. Visual inspection, dental explorer hardness testing, and caries detector solution using 5% basic Fuchsin dye solution was applied to dentin to identify the CAD surface. All the specimens were divided into four groups (n = 30) according to the cavity disinfectants used. Group A: 2% CHX, Group B: CP, Group C: MG, and Group D: ND. Each group was further divided into two subgroups (n = 15) based on the adhesion protocol. Groups A1, B1, C1, and D1 were held using TEA, and groups A2, B2, C2, and D2 were adhered using SEA system. The composite material was then built in 2 mm increments and then cured with light. MicroTBS and failure mode assessment using a universal testing machine (UTM) and stereomicroscope at a 40X magnification was performed on 10 samples from each subgroup. The microleakage assessment was performed using a dye penetration test on five samples from each group. ANOVA and Tukey post-hoc tests were used to compare means and standard deviation (SD) of bond strength and microleakage (p < 0.05). RESULTS The maximum microTBS was displayed by A1= CHX and TEA (13.28± 1.01 MPa). The lowest bond scores were demonstrated by C2= MG and SEA (5.98±0.44 MPa). The highest micro-leakage was exhibited by C1= MG and TEA (58.32 ± 2.11 nm). Whereas, the lowest micro-leakage values were displayed by A2= CHX and SEA (24.34± 1.11 nm).

CONCLUSION

Chlorohexidiene displayed better bond strength and the lowest microleakage scores with Total-etch adhesive and Self-etch adhesives when used as a cavity disinfectant. Total-etch adhesives performed better in terms of microTBS scores whereas self-etch adhesives displayed superior seal ability within the same disinfectant group.

The effect of ascorbic acid and cranberry on the bond strength, surface roughness, and surface hardness of bleached enamel with hydrogen peroxide and zinc phthalocyanine activated by photodynamic therapy

AIM

To evaluate the effect of different bleaching methods 40% (hydrogen peroxide) HP and Zinc Phthalocyanine (ZP) activated by photodynamic therapy (PDT) with the utilization of diverse procedures of reversal (10% ascorbic acid and 6% cranberry solution) on bond values, surface microhardness and surface roughness of bleached enamel surface.

MATERIAL AND METHODS

An aggregate of 60 extracted human mandibular molars was gathered and the buccal surface of each specimen was exposed to 2 mm of enamel surface for bleaching with chemical and photoactivated agents with the use of reversal solutions. Specimens were divided into six groups (n = 10) at random- Group 1: samples bleached with 40% HP with 10% ascorbic acid (reversal agent), group 2: ZP activated by PDT with 10% ascorbic acid (reversal agent), group 3: 40% HP with 6% cranberry solution as a reversal agent, group 4: ZP activated by PDT with 6% cranberry solution, group 5: 40% HP and group 6: ZP activated by PDT with no reversal agents. Resin cement restoration was performed via etch and rinse technique and SBS was estimated by using the universal testing machine, SMH by using Vickers hardness tester, and Ra by stylus profilometer. Statistical analysis was executed using the ANOVA test and the Tukey multiple tests (p<0.05).

RESULTS

Enamel surface bleached with 40% HP reversed with 10% ascorbic acid displayed the highest SBS while 40% HP with no reversal agent use showed the least SBS. For SMH, ZP activated by PDT when applied on the enamel surface and reversed with 10% ascorbic acid showed the highest SMH while when bleached with 40% HP and reversed with 6% cranberry solution showed the least SMH value. For Ra, Group 3: samples bleached with 40% HP with 6% cranberry solution as reversal agent showed the highest Ra value while bleaching of enamel surface with ZP activated by PDT with 6% cranberry displayed the least Ra value.

CONCLUSION

Bleached enamel surface with Zinc Phthalocyanine activated by PDT with the application of 10% ascorbic acid as reversal solution has demonstrated the highest SBS and SMH with acceptable surface roughness for bonding adhesive resin to the enamel surface.

Use of final irrigants MTAD, Salvedora Perscia, Malachite green, and Ti-sapphire laser on push-out bond strength of Zirconia post

AIM

Evaluation of the push-out bond strength (PBS) of zirconia post-bonded to radicular dentin after using different final irrigants (MTAD, Malachite green (MG), Ti-sapphire laser and Salvadora persica (S.persica).

MATERIAL AND METHOD

Forty human permanent single-rooted were decoronated above the cement-enamel junction. An experienced endodontist performed all the root canal instrumentation using ProTaper universal rotary files. Canals were irrigated using 5.25% NaOCl solution followed by EDTA as a final sterilant. Obturation with gutta-percha using AH Plus sealer was performed. Post-space preparation was completed using Gates Glidden and specimens were randomly assigned to four groups based on the final disinfectant received (n=10). Group 1: 5.25% NaOCl + MTAD, group 2: 5.25% NaOCl + MG, group 3: 5.25% NaOCl +Ti-sapphire laser, and group 4: 5.25% NaOCl + S. persica. The chemically polymerized resin was used to lute zirconia posts. PBS and failure mode analysis were performed using a universal testing machine and stereomicroscope at 40X magnification. Data were compared between the two groups with 95% CI using one-way analysis of variance (ANOVA) with the Tukey post hoc test. p=0.05.

RESULTS

Group4(5.25% NaOCl+ S.persica) specimens demonstrated the maximum (8.94±0.14 MPa) bond strength. Conversely, the apical third of Group 2 (5.25% NaOCl+ MG) (2.87±0.15 MPa) samples revealed the minimum bond strength scores. Intergroup comparison exposed that Group 1 (1.3% NaOCl+ MTAD), Group 3 (5.25% NaOCl+Ti-sapphire laser), and Group 4 (5.25% NaOCl+ S. persica) at all three-thirds unveiled no significant difference in PBS (p<0.05).

CONCLUSION

Ti-sapphire laser and Salvedora Persica possess the potential to be used as a final root canal irrigant to improve the push-out bond strength of zirconia post-to-root dentin.

Thickness-Dependent Light Transmittance and Temperature Rise in Dual-Cure Bioactive and Light-Cure Bulk-Fill Composite Resins

This study aimed to assess the light transmittance (T) and temperature increase through different increments of dual-cure bioactive bulk-fill restorative material (ACTIVA), light-cure bulk-fill, and conventional composite resin materials. Cylindrical specimens with a diameter of 8 mm and heights of 1, 2, 3, and 4 mm of ACTIVA, Tetric-N-Ceram bulk-fill (TBF), Filtek One bulk-fill (FBF), and Filtek Z250 (FZ) (n = 6 per group, 96 in total) were light-cured with a visible blue low-intensity light-emitting diode (LED) (650-800 mW/cm² irradiance). T, and the temperature increase, were measured using an optical power meter and a digital thermometer during curing. The T mean values ranged between 0.012 and 0.239 (76.02 to 98.81% light attenuation), while the temperature rise mean values ranged between 9.02 and 20.80 °C. The parameters, including material type (partial eta squared (ηp²) = 0.284, p < 0.0001), thickness (ηp² = 0.284, p < 0.0001), and their interaction (ηp² = 0.185, p = 0.047), significantly affected the T values, whereas only the material type (ηp² = 0.352, p = 0.047) affected the temperature rise values. The T and temperature rise mean values were highest in ACTIVA increments of 1-mm increments, in particular, showing the highest T mean values, followed by similar increments of TBF. A significantly higher T was found in 1-mm increments compared to thicker increments for all materials (p < 0.0001), and a significant positive correlation existed between T and temperature rise values (r = 0.348, p = 0.001). These findings show that the bioactive material ACTIVA and TBF allow for better T than the other materials, with ACTIVA recording a higher temperature rise. However, the large light attenuation observed for all materials, irrespective of thickness, suggests that curing in more than one location with a low-intensity LED is necessary to optimize the curing process. Furthermore, incremental filling of bulk-fill materials using a low intensity LED could be beneficial.

Dentin disinfection and adhesive bond strength using modified photoactivated carbon nanoparticles

AIMS

The present study aimed to investigate the bond integrity and disinfection efficacy of Methylene blue(MB) alone, MB-PDT (Photodynamic therapy), MB@ carbon nanoparticles (CP)-PDT, and Cr, Cr: YSGG (ECL) against lactobacilli in Caries-affected dentin (CAD) MATERIAL AND METHODS: Methods consisted of Shear bond strength (SBS), Scanning electron microscopy (SEM), energy dispersive X-ray (EDX), methods of disinfection, and failure analysis. CAD samples were prepared and biofilm formed on the specimens randomly allocated into five groups based on disinfection. Group 1: CHX; Group 2: MB; Group 3: MB-PDT: group 4: MB@CP-PDT and group 5: ECL. After disinfection Colony forming units were measured and specimens were restored and positioned under a universal testing machine (UTM). Failure analysis was performed using a stereomicroscope. The difference in survival rate was assessed using the Kruskal-Walis test. Mean and standard deviation for bond values after different methods of disinfection was evaluated using analysis of variance (ANOVA) and Post Hoc Tukey. The significance level was p<0.05 RESULTS: Morphological analysis revealed that CPs under SEM are flat discs with edged irregular shapes. EDX analyses show a spike indicating carbon particles by more than 95%. MB@CP-PDT displayed the highest reduction in lactobacillus levels in comparison to the other disinfection methods. The highest SBS was exhibited by the CAD sample disinfected with ECL. The lowest SBS values in CAD specimens after cavity cleansing with MB alone. The predominant failure type in CAD disinfected with MB alone, ECL CHX, MB-PDT, and MB@CP-PDT was adhesive.

CONCLUSION

The use of MB@CP-PDT showed high antibacterial potency against lactobacillus but demonstrated bond values similar to CHX. Use of Er, Cr: YSGG showed considerable effectiveness against lactobacillus along with the highest bond values.

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 10mm 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.

Different cavity disinfectant efficacy against S.Mutans and shear bond strength of caries affected dentin bonded to resin restoration

AIMS

The existing study aimed to assess the survival rate of S.mutans and shear bond strength (SBS) of resin adhesive restoration bonded to carious affected dentin (CAD) after using different cavity disinfectants (Chitosan, Fotoenticine®, and CO₂ laser) in comparison to Chlorhexidine (CHX).

MATERIALS AND METHODS

The study included human mandibular molars assessed on International Caries Detection and Assessment System (ICDAS) score 4 and 5. The cusp part of the clinical crown was cut off until the reduction reaches the central fossa while being continuously supplied with water coolant till the tooth cementoenamel junction (CEJ). The root sections were embedded in polymethyl methacrylate acrylic resin followed by culturing S.mutans biofilm on the CAD surface. Specimens were arbitrarily allocated into four groups(n = 10) based on the type of disinfection. Group 1 (2% CHX), Group 2 (Chitosan), Group 3 (Fotoenticine), and Group 4 (CO₂ laser). S.mutans survival rate was assessed and CAD was restored with a composite restorative material. Thermoocycling of the samples was performed and a universal testing machine (UTM) and Stereomicroscope were used to identify bond integrity and type of fracture. ANOVA and Tukey multiple comparison tests were used to assess SBS. Data on the survival rate of S. mutans were compared between groups using the nonparametric Kruskal-Wallis test RESULTS: Outcomes revealed that Group 1 (CHX) displayed the highest survival rate (0.65±0.10). However, lowest survival rate was demonstrated by Group 3 (Fotoenticine) treated specimens (0.25±0.06). It was also discovered that CHX unveiled highest bond strength values (21.48±1.39 MPa). Nevertheless, Group 2 (Chitosan) showed lowest SBS (11.01±1.00 MPa). Intergroup comparison analysis presented that group 1, and group 4 (Co2 laser) (17.76±0.41 MPa) displayed no significant difference in their bond integrity achieved. (p>0.05). However, group 3 (Fotoenticine) (16.28±0.51 MPa) and group 2 demonstrated comparable outcomes of SBS. (p>0.05) CONCLUSION: The use of CHX and CO₂ lasers as disinfectants on the CAD surface resulted in a positive impact on the SBS of resin composite, according to the study's findings. However, it is worth noting that Fotoenticine exhibited better antimicrobial efficacy against S. mutans.

Adhesive bond of Bioactive and bulk fill resin to disinfected caries affected dentin (lactobacillus specie) with laser and photodynamic therapy

AIMS

To evaluate the antimicrobial effectiveness of cavity disinfectants chlorhexidine gluconate (CHX), Er, Cr, YSGG laser (ECL), and curcumin photosensitizer (CP) against Lactobacillus and shear bond strength (SBS) of Bioactive (BA) and bulk fill composite (BFC) restorative material bonded to carious affected dentin (CAD).

MATERIALS AND METHODS

Sixty human mandibular molars scored 4 and 5 on the International Caries Detection and Assessment System (ICDAS) were included. After inoculating the specimens with lactobacillus specie all the samples were arbitrarily divided into three groups based on the disinfection regime used (n=20). Groups 1 and 2: CAD disinfection using ECL, Groups 3 and 4: CAD disinfection using CP, and Groups 5 and 6: CAD disinfection using CHX. After cavity sterilization, the survival rate was estimated and each group was further divided into two sub-groups based on the restorative material used. Groups 1, 3, and 5 (n = 10) were restored using BFC restorative material, and groups 2, 4, and 6 (n = 10) were restored using a conventional bulk-fill resin material. A universal testing machine (UTM) was used to determine the SBS and debonded surfaces were examined under a stereomicroscope to determine the modes of failure. Kruskal-Walis, ANOVA, and Post Hoc Tukey were applied to investigate the survival rate and bond strength values.

RESULTS

ECL group displayed the highest survival rate (0.73±0.13) of Lactobacillus. The least survival rate (0.17±0.09) was demonstrated by CP activated by PDT. Group 1 (ECL+ BA) treated specimens exhibited the maximum value of SBS (18.31 ± 0.22 MPa). However, group 3 (CP + BA) revealed the minimum values of bond strength (14.05 ± 1.02 MPa). The intergroup comparison revealed that group 1, group 2 (ECL+BFC) (18.11 ± 0.14 MPa), group 5 (CHX+ BA) (18.14 ± 0.36 MPa), and group 6 (CHX+BFC) (18.18 ± 0.35 MPa) displayed comparable outcomes of bond integrity (p>0.05).

CONCLUSION

Caries-affected dentin disinfected with Er, Cr: YSGG, and chlorhexidine improve bond scores of bioactive and conventional bulk-fill restorative material.

Influence of contemporary ceramo-metallic crown decontamination on the surface roughness, color stability, and disinfection. An in vitro analysis

AIM

To assess the antimicrobial effects, surface roughness (Ra), and color change (ΔE) of Morinda Citrofolia, Sapindus Mukorossi, Indocyanine green photosensitizer, and 2% NaOCl on metal ceramic crown colonized with C. Albicans, S aureus, S. mutans, and E. coli.

MATERIAL AND METHODS

An aggregate of 40 (n = 10 each) Ni/Cr metal-ceramic crowns were fabricated and inoculated with the American Type Culture Collection (ATCC) of varied microbial colonies colonized by C. Albicans, S aureus, S. mutans, and E. coli. After inoculation, specimens were exposed to four different types of disinfection methods i.e. group 1: MC, group 2: SM, group 3:ICGP, and group 4 2% NaOCl respectively to evaluate antimicrobial efficacy, Ra, and color change. Later, the microbial assay was performed and expressed as CFU/ml (log 10). Ra was assessed using a surface analyzer and color change ΔE was evaluated using a spectrophotometer Statistical analysis was performed by using two-way ANOVA and Post HocTukey's test maintaining a significance level of p less than 0.05.

RESULTS

The highest antimicrobial efficacy for metallic-ceramic crown decontamination against all inspected microbial colonies was unveiled by group 1: MC, whereas the lowest disinfection efficacy was revealed by group 4 sterilized with 2% NaOCl (control). Metallic ceramic crown decontamination with MC and SM substantiated equivalent antimicrobial efficacy in plummeting CFU/mL (log10) of C.Albicans, S aureus, S.mutans, and E. coli (p>0.05). However, ICGP as a crown disinfectant validated antimicrobial efficacy significantly less compared to MC and SM (p<0.05). Ra was assessed post-disinfection with no changes observed (p>0.05) among all groups. Similarly, ΔE was significantly higher in crowns disinfected with ICGP (p<0.05) CONCLUSION: Metallic ceramic crown decontamination using herbal disinfectants Morinda Citrofolia and Sapindus Mukorossi exhibited favorable antimicrobial efficacies against microbial colonies of C. albicans, S aureus, S.mutans, and E. coli with no changes in surface roughness and color.

Efficacy of Er, Cr: YSGG laser phosphoric acid gel and Riboflavin activated by Photodynamic therapy on enamel reconditioning rebonded to metallic brackets: An Invitro study

AIM

To evaluate the shear bond strength (SBS) and failure percentage of rebonded metallic brackets after employing various enamel-reconditioning methods (37% phosphoric acid, sandblasting, Er, Cr: YSGG laser, and Riboflavin (RF).

MATERIAL AND METHODS

After sample size calculation, a sum of 40 non-carious, non-traumatically extracted and sound human premolar teeth were collected and the enamel surface was prepped by etching, washing, and drying. The enamel surface was primed with a bonding agent and light cured, later brackets were bonded via composite. After bonding, bracket debonding was begun using a Weingart plier and the enamel surface was reconditioned before rebonding. Samples were divided into four (n=10) reconditioning groups at random and subjected to SB with 90-μm alumina particles group 1, Er, Cr: YSGG laser group 2, 37% PA (control) group 3, and RF group 4 respectively. After reconditioning, brackets were rebonded to the enamel surface via an adhesive system and composite. Later, samples were exposed to the universal testing machine for SBS analysis, and bond failure analysis was performed by using an adhesive remnant index (ARI). Statistical analysis was executed by one-way ANOVA and Post Hoc Tukey multiple comparison tests at a statistically significant level of p ˂ 0.05.

RESULTS

The SBS analysis showed that the highest SBS of rebounded brackets was exhibited by 37% phosphoric acid (control) and the lowest SBS by sandblasting enamel surface with 90-μm alumina particles for enamel prior rebonding. However, Er, Cr: YSGG laser and RF activated by PDT validated comparable SBS results to control (p>0.05). Contrarily, sandblasting with 90-μm alumina particles showed a statistically significant difference from other analyzed reconditioning groups (p<0.05). Deliberating failure rate analysis by ARI index, the most eminent failures predicted among groups were scored between 0 and 1 except for sandblasting which majorly resulted in a score of 2 showing cohesive type failure.

CONCLUSION

Chromium-doped erbium, yttrium-scandium-gallium-garnet (Er, Cr: YSGG) laser, and Riboflavin activated by photodynamic therapy have the potential to be used as an alternative to 37% phosphoric acid for enamel surface reconditioning before the rebonding metallic bracket.

Assessment of Caries-Affected Dentin Adhesive Interface Treated with Contemporary Conditioning Techniques

Objective: The aim of this study was to assess shear bond strength (SBS) and failure analysis of adhesion of composite resin (CR) to caries-affected dentin (CAD) pretreated with the Er,Cr:YSGG (ECY) laser, photodynamic therapy (PDT), and etch and rinse (ER) used for cavity disinfection. Materials and methods: Methods used in this study included scanning electron microscopy (SEM), SBS analysis, failure analysis, and digital microscopy. The methods were adopted to assess bond integrity, CAD interface, smear layer, and hybridization. Thirty human third molars assessed clinically and having scores of 4 and 5 based on International Caries Detection and Assessment System (ICDAS) criteria were inspected. Infected dentin was removed. Dentin that was hard and stained pink was categorized as CAD. Ten samples were used in each group for pretreatment of CAD. Ten samples of healthy dentin [sound dentin (SD)] were collected separately and taken as controls. Samples were divided into the following groups: group 1: SD+ER; group 2: CAD+ER; group 3: CAD+ECY; and group 4: CAD+PDT after the pretreatment bonding agent was applied and the restorative procedure was performed using CR. Results: CAD conditioned with PDT before bonding to CR demonstrated the lowest SBS values (11.22 ± 0.77 MPa), whereas the highest SBS values were observed in the SD surface treated with ER (18.25 ± 1.22 MPa). In CAD and SD pretreated with ER, majority of failure modes were cohesive failure and admixed failure, whereas in CAD pretreated with PDT and the ECY laser, the adhesive failure mode was pertinent. Conclusions: The use of the ECY laser and PDT on CAD for cavity disinfection does not have potential for application in clinical settings as it decreases bond integrity of CR. Moreover, the ER pretreatment method for CAD and SD remains the gold standard.

Disinfection of caries-affected dentin using activated vitamin B2 and diode laser with total-etch technique. An assessment of adhesive bond

AIM

The present study aims to evaluate the bond integrity of composite restoration bonded to CAD after disinfection using pineapple peel extract (PPE) Diode laser (DL) and riboflavin (RF) activated by photodynamic therapy (PDT).

MATERIAL AND METHODS

Forty human permanent mandibular molars were collected, disinfected, and mounted in poly-vinyl pipes. Carious infected dentin was removed and CAD was disinfected. Samples were divided into 4 groups based on disinfection. Group 1: CAD disinfected with CHX; group 2: CAD disinfected with diode laser; CAD disinfected with PPE and CAD sterilized with riboflavin. Following disinfection, CAD surfaces were applied with the etch-and-rinse adhesive system and bonding agent and restored with a composite restoration. Samples were placed in a thermocycler to simulate oral aging and then mounted on the universal testing machine (UTM) for shear bond strength (SBS) testing. Failure mode was assessed using a steriomicroscoscope at 40X magnification. One-way analysis of variance (ANOVA) compared the mean SBS and failure type obtained to identify intergroup differences. Similarly, for multiple group comparison, the Tukey HSD test was used keeping the level of significance at 0.05 RESULTS: : CAD disinfected with chlorhexidine (CHX) established the highest bond integrity of the restoration. However, group 2 CAD disinfected with DL displayed the lowest bond values. It was also observed that dentin disinfected using CHX demonstrated comparable SBS values to CAD disinfected with PPE and CAD disinfected with RF.

CONCLUSION

RF and PPE displayed comparable outcomes of SBS of composite restoration bonded to CAD to that of CHX. DL displayed lower bond integrity than the other investigated groups. Further studies are recommended to deduce the findings of the existing study.

Noncarious cervical lesion pretreated using antimicrobial photodynamic therapy and diode laser in reducing dentin hypersensitivity bonded to different restorative material: Valuation of bond values and invitro dye leakage

AIM

The present study aimed to appraise the effect of Diode laser (DL), riboflavin, and curcumin on the bond strength of adhesive restorative material and the effects of pretreatment on microleakage scores.

MATERIAL AND METHODS

Ninety caries-free human permanent premolars were obtained and disinfected. All specimens were mounted till CEJ. To provide standardization, a 2 × 2 mm flat non-carious cervical lesion (NCCL) dentin surface was exposed. This was followed by dentin surface roughening/cervical groove preparation with a round bur. After tooth surface preparation, ninety specimens were divided arbitrarily into three groups. Group 1: NCCL exposed to DL; group 2: NCCL pretreated with riboflavin photosensitizer (RFP) and group 3 pretreated with curcumin photosensitizer (CP). All the three groups were further divided into two subgroups A1, A2, B1, B2, C1, and C2 based on the restorative material used (n=15). Subgroup A1, B1, and C1 were restored with composite resin (CR). Subgroup A2, B2, and C2 were restored with RMGIC. Ten samples from each subgroup were evaluated for shear bond strength (SBS) testing under a universal testing machine (UTM). Five from each subgroup were evaluated for microleakage assessment. Bond strength and microleakage analysis were performed using analysis of variance (ANOVA) with a Post-hoc test (Tukey's post hoc test) at a significance level (p=0.05).

RESULTS

The group A1, DL-CR shows the highest SBS (16.41± 0.4 MPa). However, CP-RMGIC groups demonstrated the lowest bond integrity. RFP-CR and the DL-CR group displayed comparable outcomes of SBS (p>0.05). The highest microleakage was observed with CP-RMGIC. The least microleakage was displayed by DL-CR.

CONCLUSION

Noncarious cervical lesions pretreated with diode laser and riboflavin photosensitizer showed better shear bond strength and reduced microleakage when bonded to composite resin than non-carious cervical lesions pretreated with curcumin.

Influence of methylene blue, Riboflavin, and indocyanine green on the bond strength of caries affected dentin when bonded to resin-modified glass ionomer cement

AIM

The present study aimed to assess the influence of methylene blue (MBP), Riboflavin, and indocyanine green (ICG) on the bond strength of caries affected dentin (CAD) when bonded to resin-modified glass ionomer cement (RMGIC).

MATERIALS AND METHODS

Human third molars with caries lesions were isolated and collected scrutinized based on ICDAS criteria. The teeth were cleaned using a periodontal scaler and disinfected. All samples were positioned in polyvinyl up to the cementoenamel junction. The samples were randomly distributed into five groups based on the pretreatment regime. Samples in group 1, were pretreated with MBP; group 2, polyacrylic acid (PAA) group 3, ICG, group 4, Riboflavin photosensitizer, and group 5, 37% phosphoric acid (PA). All samples were bonded with RMGIC. 10 samples were subjected to the universal testing machine for shear bond strength (SBS) testing. Five samples from each group were placed in fuchsine dye for the microleakage assessment. Comparison of means and standard deviations (SD) of SBS and microleakage in investigated groups was performed using analysis of variance (ANOVA) and Tukey's post hoc test at a significance level (p=0.05) RESULTS: : The highest micro shear bond values were observed in group 2 (CAD conditioned with PAA) (14.26±1.67 MPa). Whereas, the lowest bond values were found in group 1 (treated with MBP) (8.82±1.08 MPa). CAD conditioned with different photosensitizers i.e., MBP, ICG, and Riboflavin before bonding to RMGIC displayed comparable bond values (8.82±1.08 MPa), (9.47±0.21 MPa), and (11.23±0.47 MPa) respectively (p>0.05). Samples conditioned with 37% PA showed significantly higher microleakage scores compared to other surface-treated groups (p<0.05).

CONCLUSION

Caries-affected dentin conditioned with polyacrylic acid demonstrated low microleakage and high bond strength.

Interaction of zirconium oxide nanoparticle infiltrated resin adhesive with dentin conditioned by phosphoric acid and Er, Cr: YSGG laser

The aim was to prepare experimental adhesive (EA) with ZrO₂ nanoparticles (ZEA) and without it; and its interaction with dentin conditioned with photodynamic therapy (PDT), etch and rinse, and Er, Cr: YSGG laser (ECL). Methods consisted of the scanning electron microscope (SEM), energy dispersive X-ray (EDX), shear bond strength (SBS) failure mode, and rheological property analysis. The methods were employed to assess bond integrity; the shape of ZrO₂ NPs and interfacial dentin and adhesive interaction. Ninety premolar teeth were collected and pre-bonding, conditioning of dentin was performed utilizing phosphoric acid (H3PO4), photodynamic therapy (PDT), and ER-CR-YSGG laser (ECL). The teeth were set to form bonded specimens using two adhesives EA and ZEA. The microscopic imagery of ZrO₂ revealed irregular-shaped, non-edged particles. EDX analysis revealed Zr to be 75.7% whereas, O2 by weight was 25.3%. The highest SBS was demonstrated in dentin conditioned with etch and rinse and ZEA (19.05 ± 0.13 MPa). Whereas, the lowest SBS was observed in dentin surface treated with PDT and EA (12.25 ± 0.14 MPa). Most of the reported failure modes were adhesive. Rheological analysis revealed that with increasing frequencies the viscosities of adhesives were reduced. The presence of 10% ZrO by weight in adhesive improves SBS of restoration and this improvement in bond values is statistically significant compared to EA. Bond values may be influenced by surface treatment of dentin.

Polymer-Based Bioactive Luting Agents for Cementation of All-Ceramic Crowns: An SEM, EDX, Microleakage, Fracture Strength, and Color Stability Study

The aim of the study was to compare microleakage and fracture loads of all ceramic crowns luted with conventional polymer resins and polymeric bioactive cements and to assess the color stability of polymeric bioactive cements. Seventy-five extracted premolar teeth were tested for fracture loads and microleakage in all-ceramic crowns cemented with two types of polymeric bioactive cements and resin cements. In addition, the degree of color change for each cement with coffee was assessed. Thirty maxillary premolar teeth for fracture loads and thirty mandibular premolar teeth for microleakage were prepared; standardized teeth preparations were performed by a single experienced operator. All prepared specimens were randomly distributed to three groups (n = 20) based on the type of cement, Group 1: resin cement (Multilink N); Group 2: polymeric bioactive cement (ACTIVA); Group 3: polymeric bioactive cement (Ceramir). The cementation procedures for all cements (Multilink, ACTIVA, and Ceramir) were performed according to the manufacturers' instructions. All specimens were aged using thermocycling for 30,000 cycles (5-55 °C, dwell time 30 s). These specimens were tested using the universal testing machine for fracture strength and with a micro-CT for microleakage. For the color stability evaluation, the cement specimens were immersed in coffee and evaluated with a spectrometer. Results: The highest and lowest means for fracture loads were observed in resin cements (49.5 ± 8.85) and Ceramir (39.8 ± 9.16), respectively. Ceramir (2.563 ± 0.71) showed the highest microleakage compared to resin (0.70 ± 0.75) and ACTIVA (0.61 ± 0.56). ACTIVA cements showed comparable fracture loads, microleakage, and stain resistance compared to resin cements.

Caries effected dentin disinfection using Ozone, methylthioninium chloride and turmeric activated by photodynamic therapy on bond integrity of resin-modified glass ionomer cement

AIM

To evaluate the shear bond strength (SBS) of caries effected dentin (CAD) bonded to resin-modified glass ionomer cement (RMGIC) after being disinfected with different methods their effect on microleakage scores.

MATERIAL AND METHODS

Based on criteria of ICDAS seventy-five teeth were selected and disinfected. All samples were grounded and a cavity prepared followed by random allocation of samples into different disinfection groups i.e., methylene blue photosensitizer (MBP), Silver diamine fluoride (SDF), Ozone (O₃); curcumin photosensitizer (CP) and chlorhexidine (CHX) (n = 15). All samples were restored with resin modified glass ionomer (RMGIC) incrementally. Ten specimens from each group were placed in universal testing machine (UTM) to calculate bond failure and failure type. Five samples from each group were evaluated for microleakage scores. SBS and microleakage scores was examined using analysis of variance (ANOVA) with a Post-hoc test. For all tests p-value, less than 0.5 was considered statistically significant.

RESULTS

The highest SBS was observed in CAD disinfected with CP bonded to RMGIC (16.42 ± 1.10 MPa). Similarly, the lowest bond values were demonstrated by CAD disinfected with MBP (9.21 ± 0.22 MPa) bonded to RMGIC respectively. CAD disinfected with CHX (Control) bonded to RMGIC demonstrated the lowest microleakage scores and showed a significant difference compared to other experimental groups (p< 0.05).

CONCLUSION

Curcumin along with O₃ has the potential to be used as a disinfectant in CAD as it improves SBS to RMGIC. CHX demonstrates low microleakage scores with decrease of bond integrity.

Influence of ER-CR-YSGG Laser and Photodynamic Therapy on the Dentin Bond Integrity of Nano-Hydroxyapatite Containing Resin Dentin Adhesive: SEM-EDX, Micro-Raman, Micro-Tensile, and FTIR Evaluation

The study aimed to analyze the effect of the addition of nano-hydroxyapatite (nano-HA) particles on the mechanical properties of experimental adhesive (EA). Furthermore, dentin interaction of EA (without nano-HA) and EA with nano-HA (hereon referred to as HA-10%) were also investigated and equated. Methods consisting of scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDX), micro-Raman spectroscopy, micro-tensile bond strength (µTBS) test, and Fourier transform infrared (FTIR) spectroscopy were employed to study nano-HA particles shape, dentin bond strength, degree of conversion (DC), and adhesive-dentin interaction. Ninety teeth (N = 90) were collected, and pre-bonding, conditioning of dentin was performed utilizing phosphoric acid (H₃PO₄) etching, photodynamic therapy (PDT), and ER-CR-YSGG (ECY) laser. The teeth were set to form bonded specimens using two adhesives. Nano-HA particles were spherical-shaped, and EDX confirmed the presence of oxygen, calcium, and phosphorus. Micro-Raman spectroscopy revealed distinct phosphate and carbonate peaks for nano-HA. The µTBS test demonstrated highest values for HA-10% group on the H₃PO₄ conditioned dentin. The greatest DC was observed for the EA group. The addition of nano-HA-10 wt.% particles in dentin adhesive resulted in improved bond strength. The incorporation also demonstrated acceptable DC (although lower than EA group), suitable dentin interaction, and resin tag formation.

Bond Integrity of Titanium Surface to Resin Cement After Conditioning with Different Photobiomodulataion Therapy (PBT)

The aim of the present study was to evaluate the efficacy of interfacial bonding between resin cement and titanium alloy conditioned with different Photobiomodulataion Therapy (PBT) in comparison with conventional regimes. Seventy-five samples of titanium bar were segmented polished; and based on conditioning regime divided into five groups (15 each specimens). Group 1: No treatment (control), Group 2: Sand blasting with 120 µm Al2O3, Group 3: Er,Cr:YSGG (ECL), Group 4: Er:YAG laser (EYL), Group 5: Nd:YAG laser (NYL). After different conditioning regimes, resin cement was mixed and applied. All specimens were thermocycled for 500 cycles and positioned on universal testing machine for shear bond strength testing. Modes of failure was assessed by a single examiner using stereomicroscope at 40× magnification. Three pairs of specimens in each group were sputter coated and scanning electron microscope (SEM) images were taken at 1000× magnification using 20 Kv. The highest SBS values were observed in group 2 (14.25±2.29 MPa) and the lowest bond values were displayed in group 1 (6.98 ±0.59 MPa). Titanium alloy abutments conditioned with different laser prototypes ECL (11.22±1.40 MPa), EYL (9.29±1.22 MPa) and NYL (9.12 ±1.84 MPa) exhibited comparable SBS (p > 0.05). Adhesive failures were primarily dominant among all experimental groups. Photo-biomodulation in the form of ECL lasers has the potential to be used as a supplement to sandblasting procedure in conditioning of cement retained titanium alloy implant abutments.

Bonding of an ion-releasing restorative material to caries-affected dentin disinfected with photodynamic therapy, Er,Cr:YSGG laser, and chemical disinfectants

AIM

The study aimed to evaluate the microtensile bond strength (μTBS) of giomer, an ion-releasing restorative material, to caries-affected dentin (CAD) when different cavity disinfectant protocols were applied before the restoration.

MATERIAL AND METHODS

Thirty extracted non-carious human third molars were embedded in acrylic resin. The occlusal portions of the samples were excised using an IsoMet saw. After creating artificial caries, samples were divided into six groups (n = 12): sound dentin with no disinfection (Group SD), CAD with no disinfection (Group CAD), CAD disinfected with 2% chlorhexidine gluconate (Group CHX), CAD disinfected with 6% NaOCl (Group NaOCl), CAD disinfected with photodynamic therapy with methylene blue photosensitizer (Group PDT), and CAD disinfected with Er,Cr:YSGG (Group ECYL). Following disinfection protocols, the universal adhesive was applied, and all samples were restored using giomer. Subsequently, μTBS analyses were performed, and data were analyzed statistically.

RESULTS

The highest μTBS values were obtained from the SD and CAD groups, which exhibited no statistical differences (p > 0.05). The PDT and ECYL groups had higher μTBS values compared with the CHX and NaOCl groups (p < 0.05), and all disinfection protocols decreased the bond strength to CAD (p < 0.05).

CONCLUSION

The microtensile bond strength of disinfected CAD was greater with Er,Cr:YSGG laser and photodynamic therapy treatment than with chemical disinfectants. Giomer may enhance the bond strength to CAD, which has a weaker bonding potential than sound dentin due to structural differences. However, disinfection protocols adversely affect adhesion between the restorative material and CAD.

Influence of photodynamic therapy and different conventional methods on conditioning of lithium di silicate ceramics bonded to metallic brackets: An assessment of bond strength

AIM

The aim of the current study was to assess the effect of different conditioning methods on Lithium di silicate (LDC) employing conventional and contemporary regimes bonded to metallic brackets.

MATERIAL AND METHODS

70 discs of LDC were prepared and polished to attain smooth surface. Samples were allocated into seven groups according to ceramic surface conditioning. Group 1 surface treated with Er-YAG laser and saline (S), Group 2 PDT using MBP + S, Group 3 H F + S (control), Group 3 HF (Hydrofluoric acid) + saline, Group 4 HF (Hydrofluoric acid) + ultrasonic bath (UB) + S, Group 5 sand blasting the glass ceramic surface with 120 um Al₂O₃, Group 6 LDC surface conditioned with SECP(Etch and Prime) and Group 7 ECL(Laser) + S on was irradiated on LDC. Both chemical and mechanical surface treatments of LDC were followed by placement of metallic brackets. Samples were arranged in universal testing machine for shear bond strength (SBS) testing. Bond failure of brackets were assessed using ARI. To assess and compare the mean and standard deviations (SD) among experimental groups analysis of variance (ANOVA) was employed. All treatment combination means were compared using the post hoc Tukey's multiple comparison test at a significance level of (p ≤ 0.05).

RESULTS

SBS values of Group 2 H F acid + S displayed highest bond durability (22.28 ± 1.09 MPa). Whereas, specimens in Group 4 surface treated with 120 μm Al₂O₃ displayed lowest SBS scores (11.81 ± 0.55 MPa) and these bond scores were comparable to PDT using MBP + S (12.54 ± 1.09 MPa) (p > 0.05). LDC surface treated by ECL + S (21.11 ± 3.85 MPa), HF + UB + S (19.28 ± 0.52 MPa) exhibited results comparable to HF acid + S (p > 0.05).

CONCLUSION

LDC conditioned with HFS still remains as gold standard. Use of PDT for surface treatment of LDC and bonded to metallic bracket is not recommended as it results in decreased bond durability. Use of ECL-S and HF + UB + S has a potential to be used alternatively to HFS for LDC conditioning.

Influence of Propolis, Ozone and Photodynamic therapy in root canal disinfection on resin bond strength to radicular dentin

AIM

The aim of the present study was to assess post space disinfection using different irrigants and their effect on radicular dentin bond to SERC.

MATERIALS AND METHODS

Forty single rooted mandibular 2nd premolars were collected and disinfected. All samples were decoronated maintaining root length of 12 mm and embedded vertically in acrylic resin. Shaping of the canal was performed using reciprocating system. Canals were dried using paper points and obturated with gutta percha via lateral condensation. Peso-reamers were used to create post space up to 10 mm. The post space was irrigated with 1% NaOCl before being randomly allocated into four groups (n = 10) according to different methods of canal disinfection. Samples in group 1 were subjected to photoactivated disinfection (PAD), group 2 irrigated with ethanol based propolis group 3 disinfected using ozone and group 4 irrigated with 2.25 % NaOCl with 17 % EDTA and ECL. GFP was fitted using SERC. Each sample was cut into 1 mm from coronal, middle and apical and subjected to pushout bond strength (PBS) via universal testing machine. Fracture analysis were confirmed by stereomicroscope at 40x magnification. For comparison of means, Analysis of variance (ANOVA) and Tukey multiple comparison test was used maintaining the level of significance at p <  0.05.

RESULTS

The highest PBS at all three levels were found in group 4, canal disinfected with 2.5 % NaOCl with 17 % EDTA and ECYL. Whereas, the lowest PBS was observed in group 1. Inter group comparison, prosthetic space disinfected with propolis extract showed no significant difference to group 4 canal disinfected with 2.5 % NaOCl with 17 % EDTA and ECYL at all three levels (p > 0.05). Intra group comparison in all experimental groups showed no significant difference was noted in coronal and middle thirds of group 1, group 2 and group 3 respectively (p > 0.05).

CONCLUSION

2.5 % NaOCl with EDTA and ECL treatment (group 4) remains the gold standard when used as a final canal irrigant. Propolis can be used as potential irrigant for canal disinfectant provided if the composition becomes standardized.

Repair strength and surface topography of lithium disilicate and hybrid resin ceramics with LLLT and photodynamic therapy in comparison to hydrofluoric acid

AIM

The aim was to compare the repair bond strength and surface topography of lithium disilicate ceramics (LDC) and hybrid resin ceramics (HRC) using different surface conditioning treatments [low level laser therapy (LLLT), photodynamic therapy (PDT), hydrofluoric acid (HF) with silane and air abrasion (AA) and silane].

MATERIAL AND METHOD

Sixty specimens each of LDC and HRC were used. Discs were prepared for each group (6 × 2 mm), conditioned using different regimes. Specimens in group 1 and 5 were laser irradiated using Er,Cr:YSGG (ECYL), group 2 and 6 were conditioned using methylene blue photosensitizer (PDT), group 3 and 7 surface was treated with hydrofluoric acid and silane (HFA-S), group 4 and 8 conditioned with Al₂O₃ air abrasion and silane (AA-S). A Porcelain Repair Kit was used according to manufacturer recommendation in all samples. Peak universal bond adhesive was rubbed on ceramic surface and then bonded with composite resin. For shear bond strength testing the specimens were placed in a universal testing machine. A stereomicroscope at 40x magnification was used to analyse failure pattern. Five specimens in each group after surface treatment were evaluated for surface changes and topography using scanning electron microscopy. The mean repair bond strength was calculated using ANOVA and Tukey's post hoc test at a significance level of (p < 0.05).

RESULT

The highest repair bond strength was observed in group 3 (LDC) (20.57 ± 3.58 MPa) (HFA-S), whereas, the lowest score was displayed in Group 2 (LDC) using methylene blue photosensitizer (MBPS) (12.18 ± 1.08 MPa). Similarly, in HRC the highest repair SBS was presented in group 8 (AA-S) (20.52 ± 2.51 MPa) and the lowest SBS values were exhibited by PDT treated group 6 (13.22 ± 0.62 MPa).

CONCLUSION

A combination of mechanical and chemical surface treatments should be used in order to achieve adequate repair bond strength between resin composites and ceramic interface of LDC and HRC.

Surface treatment of RMGIC to composite resin using different photosensitizers and lasers: A bond assessment of closed Sandwich restoration

AIM

The aim of present study was to assess and compare different conditioning methods (laser, PDT and conventional) on shear bond strength (SBS) of resin modified glass ionomer cement (RMGIC) bonded to composite (sandwich technique).

MATERIAL AND METHODS

Fifty specimens were prepared from RMGIC and were packed in a teflon mould placed on glass slab. Through each of the glass slab the cement was light cured for 20 s. Now samples were randomly allocated into five groups (n = 10) according to pre-treatment protocols. In group 1 RMGIC were conditioned with MBP using PDT, Samples in group 2 treated with Er,Cr:YSGG (ECYL), group 3 pre-treated with Nd:YAG laser (NYL), samples in group 4 surface conditioned with air abrasion (AA) and group 5 conditioned with 37 % phosphoric acid (PA). Specimens after conditioning were rinsed with distilled water. Adhesive Adper Single Bond 2 was applied on treated surface of RMGIC and cured. Teflon mold was utilized to hold the composite Filtek Z250 in an incremental technique. For SBS testing all specimens were placed under shear knife edge at 1 K N at a speed of 0.5mm2 until bond failure. Optical microscope was used to evaluate failure pattern at 10x magnification. The data of SBS in Megapascal were subjected to statistical test. Analysis of variance was followed by Post hoc test with level of significance at 5 %.

RESULT

The maximum SBS was found in group 5 RMGIC conditioned with 37 % PA (16.45 ± 0.32 MPa). Whereas, group 1 (MBP, PDT) demonstrated significantly lower bond integrity (9.82 ± 1.08 MPa) compared to all experimental groups. Bond integrity of RMGIC surface treated with MBP, PDT (9.82 ± 1.08 MPa), group 3 lased with NYL (11.47 ± 0.53 MPa) and samples in group 4 conditioned with AA (11.23 ± 0.47 MPa) were comparable (p > 0.05).

CONCLUSION

ECYL has a potential to be used for conditioning of RMGIC prior to composite restoration (sandwich technique). MBP at 100 mg/L deteriorates SBS of composite to RMGIC.

Influence of resin cements and root canal disinfection techniques on the adhesive bond strength of fibre reinforced composite post to radicular dentin

AIM

To determine the push out bond strength (PBS) of fibre reinforced composite post (FRCP) bonded to radicular dentin using different cement types total etch resin cement (TERC) and Self-adhesive resin cement (SARC) conditioned with (PDT, 5.25 % NaOCl with EDTA and 1% NaOCl) MATERIALS AND METHODS: Sixty freshly extracted (orthodontic purpose) human single rooted mandibular premolars were collected. Teeth were disinfected and coronal part of all samples were removed. Cleaning shaping and finishing of canal space was performed and filled with gutta percha via lateral condensation. Post space was prepared and disinfected with three irrigating solutions. Samples in group 1 and 2 disinfected 5.25 % NaOCl with EDTA, group 3 and 4 steriled with 1% NaOCl and group 5 and 6 disinfected with Methylene Blue photodynamic therapy (PDT). Based on the resin cement, FRCP was luted with TERC in group 2, 4 and 5; and with SARC in group 1,3 and 6 respectively. All specimens were subjected to aging and push-out bond strength (PBS) on universal testing machine after sectioning of each sample in three segments (coronal, middle and apical). Following push out bond strength (PBS), debonded surface were observed under stereomicroscope at 40x magnification. PBS were equated by means of analysis of variance (ANOVA) and Tukey's post hoc test maintaining level of significance (p < 0.05) RESULTS: Group 1 (SARC) and 2 (TERC) disinfected with 5.25 % NaOCl with 17 % EDTA, TERC (group 2) showed higher extrusion bond strength at all three levels coronal (9.25 ± 0.21 MPa) middle (8.81 ± 0.94 MPa) and apical (8.21 ± 0.93 MPa). Whereas, canal space sterilized with 1% NaOCl [group 3 (SARC) and group 4 (TERC)], posts cemented with TERC exhibited the higher PBS at all three levels of root canal (10.22 ± 0.36 MPa), (9.68 ± 0.51 MPa), (6.33 ± 0.08 MPa). Similarly, among PDT disinfected fiber post [group 5 (TERC) and group 6 (SARC)], TERC exhibited the greater PBS values at coronal, middle and apical levels (6.25 ± 0.39 MPa) (5.17 ± 0.22 MPa) (4.32 ± 0.69 MPa) compared to SARC specimens CONCLUSION: Irrespective of canal irrigant, fiber post bonded with TERC showed higher PBS at coronal and middle third. Fiber post bonded with SARC when irrigated with 5.25 % NaOCl with EDTA, 1% NaOCl displayed higher PBS at apical third. Canal disinfected using PDT showed lower PBS for FRCP compared to 5.25 % NaOCl with EDTA and 1% NaOCl.

Efficacy of chlorhexidine, Er Cr YSGG laser and photodynamic therapy on the adhesive bond integrity of caries affected dentin. An in-vitro study

AIM

To evaluate the adhesive bond integrity (shear bond strength-SBS) of composite resin bonded to carious dentin using chlorhexidine gluconate (CHX), Er,Cr:YSGG laser (ECYL) and photodynamic therapy (PDT).

MATERIAL AND METHODS

Thirty carious and ten non-carious mandibular teeth were collected through non-traumatic extraction. All samples were embedded in polyvinyl cross-sections to the cemento-enamel junction. The preparation of caries-affected dentin was performed by grinding the specimens using silicon carbide discs. All specimens were randomly allocated in to four groups (n = 10). Group 1, non-affected dentin with no disinfection; Group 2, caries affected dentin treated with 2% CHX; Group 3, affected dentin disinfected with PDT [100 mg/L methylene blue solution (MBS) and Diode laser]; Group 4, affected dentin treated with ECYL. Self-etch adhesive was smeared on all specimens for 10 s and photopolymerized for 10 s. All specimens were placed in an incubator with humid environment for 24 h at 37 °C followed by positioning in universal testing machine for SBS testing. Failure mode examination of debonded samples was performed by a stereomicroscope. Analysis of variance (ANOVA) was used for inter group comparison through mean and standard deviation of each group. For multiple group comparison Tukey HSD was employed. Level of significance was established at p < 0.05.

RESULTS

The highest SBS value was observed in group 1 (24.98 ± 1.59 MPa). Whereas, the lowest bond strength was displayed by group 3 (14.22 ± 1.40 MPa) specimens. Lased dentin in group 4 (15.89 ± 3.22 MPa) exhibited SBS values comparable to group 3 (14.22 ± 1.40 MPa). Group 2 (CHX-18.25 ± 1.29 MPa) exhibited statistically significant difference compared to all experimental groups (p < 0.05).

CONCLUSIONS

Adhesive bond strength of disinfected carious dentin was higher with CHX treatment as compared to Photodynamic therapy and Er,Cr: YSGG laser treatment. Carious dentin showed lower bond strength to composite resin as compared to non-carious dentin.

Influence of fractional carbon-dioxide laser in comparison to ErCr-YSGG on the dentin bond integrity of bioactive materials

Objective:

The aim was to assess the influence of Er, Cr: YSGG laser (ECL) and fractional carbon dioxide laser (FCL) on the shear bond strength (SBS) and microleakage of bioactive restorative material to dentin.

Methods:

The study was performed in King Saud university in the month of June-July 2019. One hundred and twenty permanent teeth were vertically placed in acrylic resin. Based on the type of surface treatment regime (n=40), samples were divided into three groups. Group-I samples were surface conditioned with total etch and rinse (TE); Group-2 samples were surface treated with Er, Cr: YSGG laser (ECL) and Group-3 specimens were conditioned with fractional carbon dioxide laser (FCL). Surface treatment of dentin was followed by type of bulk fill resin (BFR) application. Tetric-N-Ceram was bonded to dentin conditioned with TE (n=20), FCL (n=20) and ECL (n=20). Similarly, bioactive material (BAM) was also bonded to conditioned surface (n=60). Samples (n=10) among each group were placed in a Universal testing machine. For microleakage testing 5 pairs of samples from each group (n=10) were placed in solution of 2% methylene blue for 24h Fracture analysis was performed using stereomicroscope at 40x magnification. Descriptive statistics i.e., means and standard for SBS and microleakage were compared using analysis of variance (ANOVA) and Tukey’s post hoc test at a significance level of (p < 0.05)

Results:

The highest SBS scores were displayed by TE-BFR (Bulk filled resin) (19.21 ± 0.925 Mpa) and the lowest shear bond scores were presented by FCL-BFR (11.06±1.611 Mpa). The lowest microleakage scores were exhibited by group ECL-BFR (24.11±13.01nm). Similarly, the highest microleakage score was displayed in group FCL-BAM (42.18±16.32 nm). Admixed failure was pertinent in groups conditioned by ECL. Moreover, groups conditioned with FCL adhesive type of failure was found in abundance.

Conclusions:

ECL has a potential to be used as an alternate to total etch and rinse for conditioning of dentin when bonded to bioactive materials.

Photodynamic activation of irrigation (using different laser prototypes) on push out bond strength of fiber posts

BACKGROUND

To evaluate the influence of photodynamic therapy (PDT) and light activated irrigation (LAI) using different laser prototypes Er,Cr:YSGG (ECYL), Er:Yag (EYL), Nd-Yag (NYL) on pushout bond strength of Pre-fabricated fiber reinforced composite (PFRC) post to radicular dentin.

MATERIAL AND METHOD

Fifty maxillary and mandibular teeth were collected, cleaned and decoronated. Canals were instrumented using crown-down technique. Flaring of canals was performed using protaper S1, SX files. F1, F2 and F3 files were utilized for finishing of canal preparations. Prepared root canals were dried and obturated with gutta percha. Teeth were placed vertically within the section of polyvinyl pipes using acrylic resin. Post space preparation was completed using peso-reamers. Based on the PDT and laser activated irrigation (LAI) with different laser prototypes, samples were divided into five groups of 10 specimens each. Group 1- PDT, group 2-5.25 % NaOCl (sodium hypochlorite) and 17 % EDTA (ethylene diamine tetra acetic acid), group 3-5.25 % NaOCl with 17 % EDTA and NYL, group 4-5.25 % NaOCl with 17 % EDTA and EYL ; and group 5-5.25 % NaOCl +17 % EDTA and ECYL. Fiber post were luted in root canals with self-etch dual cure cement and teeth were sectioned at three levels (apical, middle and coronal). Push-out test was performed by placing the specimens in universal testing machine. Failure analysis of debonded surfaces was evaluated using stereomicroscope at 40× magnification. Means and standard deviations of push out bond strength were assessed by one-way analysis of variance (ANOVA). Comparison between means of push out bond strength was evaluated using Tukey multiple comparison tests (p = 0.05).

RESULT

The highest push out bond strength was observed in group 5 at all three levels, coronal (10.08 ± 0.74 MPa), middle (8.95 ± 0.94 MPa) and apical (6.00 ± 0.88 MPa). The lowest push out bond strength was demonstrated by group 2 at all levels, coronal (6.15 ± 1.22 MPa), middle (5.65 ± 0.95 MPa) and apical (2.25 ± 0.55 MPa). Intra-group comparison showed decrease in push out bond strength in the coronal to apical direction among all investigated groups. Inter-group comparison exhibited comparable push out bond strength at all three levels of root for group 1 and group 2 specimens (p > 0.05).

CONCLUSION

LAI with different laser prototypes improved push out bond values of PFRC post to root dentin as an adjunct to NaOCl and EDTA treatment. PDT improved push out strength compared to conventional canal cleaning regime.