Bleached enamel reversal using grape seed extract, green tea, curcumin-activated photodynamic therapy, and Er: YAG on microleakage and bond integrity of composite material bonded to the enamel surface.

AIMS: Bleached enamel reversal using antioxidants sodium ascorbate (SA), Green tea extract (GTE), grape seed extract (GSE), Curcumin photosensitizer (CP) and Er: YAG laser on the adhesive strength and marginal leakage of composite material bonded to the bleached enamel surface. MATERIALS AND METHODS: Enamel surface of hundred and twenty sound human first premolar teeth was cleansed using pumice and bleached with 35 % hydrogen peroxide. The samples were randomly divided into 5 groups based on the antioxidants used. n = 20 Group 1 (Control): No antioxidant agent, Group 2: 10 % SA solution, Group 3: 6.5 % GSE, Group 4: 5 % GTE, Group 5: Er: YAG laser and Group 6: CP. Following reversal, the composite was built and cured for 40 s. All the specimens were stored in distilled water at room temperature for 1 day. Microleakage, SBS, and failure mode were analyzed. Kolmogorov-Smirnov test, one-way analysis of variance, and Tukey's multiple post hoc test were used to analyze the data statistically. RESULTS: Group 2 (SA) (20.11 ± 5.79 nm) exhibited minimum value of microleakage and highest SBS (10.22 ± 1.62 MPa). Whereas, Group 1 (No antioxidant agent) displayed maximum scores of marginal leakage (28.11±8.89 nm) and lowest SBS (7.02 ± 1.22 MPa). CONCLUSION: CP, GTE and GSE can be used as a potential alternative to the commonly used SA solution to reverse the negative impact of bleaching on the enamel surface. The use of reversal agents CP, GTE and GSE improves bond values with a decrease in microleakage scores However, future studies are still warranted to conclude the outcomes of the existing study.

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.

Influence of Surface Conditioning on the Repair Strength of Bioactive Restorative Material.

OBJECTIVE: To evaluate the effects of surface treatment and repair material on the repair shear bond strength (SBS) of the bioactive restorative material. METHODS: A total of 240 Activa BioActive Restorative (Activa) discs were prepared, aged, and polished, and divided randomly into eight groups (n = 30). Groups 1-4 discs were repaired with bulk-fill flowable resin-based composite (Bulk-RBC), and Groups 5-8 discs with Activa. Surface treatment used for each repair material type were air abrasion with silica-coated 30-m Al2O3 particles (air abrasion) (Groups 2 & 6), Air abrasion with universal primer (Groups 3 & 7), and Air abrasion with universal adhesive (Groups 4 & 8). Groups 1 and 5 were controls without surface treatment. SBS test was performed, and the failure mode and surface topography were assessed. RESULTS: Surface treatment with air abrasion significantly improved the SBS for repair using both Activa and Bulk-RBC. Repair SBS using Activa was significantly higher compared with Bulk-RBC. Cohesive failure in substrate and mixed failures were most common in the surface-treated groups (2-4, 6-8). Air abrasion produced prominent surface topography changes compared with polishing. CONCLUSION: Air abrasion enhances the repair SBS of aged bioactive restorative material. The use of the same material (Activa) for repair affords a higher bond strength compared with the use bulk-RBC.

Treatment of caries affected dentin with different photosensitizers and its effect on adhesive bond integrity to resin composite.

OBJECTIVE: The aim of the present study was to evaluate the effect of different photosensitizers activated by photodynamic therapy (PDT) on shear bond strength (SBS) of composite resin on caries affected dentin compared to conventional cavity disinfectants. MATERIALS AND METHODS: Forty 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 arbitrarily allocated in to four groups (n = 10). Group 1, affected dentin disinfected with methylene blue (MB) [100 mg/L]; Group 2, caries affected dentin disinfected using curcumin photosensitizer (CP) [500 mg/L]; Group 3, affected dentin disinfected with indocyanin green photosensitizer (ICGP) [0.5 mL] Group 4, affected dentin treated with 3 % H2O2. Two-step self-etch adhesives was smeared on all specimens for 15 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. RESULT: In group 2 dentin disinfection using CP, displayed the highest SBS value (18.21 ± 1.39 MPa). Whereas, group 4 (3% H2O2 as cavity disinfectant) presented the lowest SBS values (13.39 ± 1.26 MPa). SBS in Group 3 (ICGP) (17.42 ± 0.55 MPa) specimens was comparable to group 2 (p > 0.05) samples. In group 1, samples disinfected with MB (15.18 ± 0.39 MPa) was found to be significantly lower compared to group 2 and group 3 (p < 0.05) respectively. CONCLUSION: Curcumin and Indocyanin green (ICGP) PS have the potential to be used as cavity disinfectant as it improves SBS of caries affected dentin to resin composite. Photodynamic therapy for disinfection of caries affected dentin will augment its bond strength, however its long-term effect on bond integrity still needs to be investigated.

Effect of photodynamic therapy and ErCrYSGG laser irradiation on the push-out bond strength between fiber post and root dentin.

BACKGROUND: To evaluate the push out bond strength and modes of failure of fiber post by using photodynamic therapy (PDT), Er,Cr:YSGG laser and conventional cleaning and shaping (CCS). METHODS: Sixty maxillary anterior teeth were sectioned horizontaly 2 mm incisal to the cemento-enamel junction, and root canal were prepared for post space. Tapered fiber posts were placed inside the root canal after post space was made. The fiber posts were subjected to PDT, Er,Cr:YSGG laser and CSS with 20 specimens in each group. The specimens obtained were sectioned in cervical and apical sections. A universal testing machine was used to perform the push out test and the push out bond strength was formulated by σ = C/A, expressed in mega-pascals (MPa). RESULTS: The highest mean push out bond strength was achieved by PDT group (8.08 ±â€¯2.73 MPa) and the lowest was shown by specimens in CCS group (7.45 ±â€¯1.04 MPa). ANOVA showed no statistical difference among the experimental groups (p = 0.481). In the cervical segments, the mean push-out bond strength was found to be slightly higher for all three groups compared to apical segments (P < 0.05). The independent t-tests results showed that the mean push-out bond strength values of the cervical segments were slightly higher than the apical segments in PDT, Er,Cr:YSGG and CSS groups (P < 0.05). Significant differences were observed when mean push-out bond strengths were compared for both cervical (p = 0.037) and apical (p = 0.019) segments between all the groups. Twenty-one failures were found at the interface between the adhesive and the dentin surface, 6 failures were observed at the interface between the adhesive and post, whereas 5 failures were mixed. CONCLUSION: Push-out bond strength to root canal dentin were not affected by Er,Cr:YSGG compared with conventional cleaning and shaping. However, PDT produced the smallest number of failure modes and slightly higher push-out bond strength to root dentin.

Effect of Er,Cr:YSGG on bond strength and microleakage of dentin bonded to resin composite with different distance and irradiation time.

BACKGROUND: To explore the surface modification of dentin using Er,Cr:YSGG phototherapy and bonding system on the shear bond strength and microleakage scores at two different distances and times of laser irradiation. MATERIALS AND METHODS: Ninety disease-free third molars were collected for the experiment. The four laser groups were divided on the basis of non-contact mode distance and time of irradiation: Group-I: Distance of 1 mm with duration of 60 s; Group-II: Distance of 1 mm with duration of 120 s; Group-III: Distance of 2 mm with duration of 60 s and; Group-IV: Distance of 2 mm with duration of 120 s. The surface for control group (Group-EB: Etch & bond group) was treated with etch and rinse bonding regime. Specimens from all the groups were assessed for shear bond strength and microleakage scores. Samples from all groups were immersed in 2% methylene blue for 24 h and assessed under a digital microscope for microleakage. RESULTS: The lowest bond strength and microleakage was observed in the control group EB. The maximum bond strength score was observed in Group-IV with mean scores 23.41 ± 1.83, while the maximum microleakage scores were observed in Group-II and Group-IV with mean scores 1.0 ± 0.36 and 1.0 ± 0.11, respectively. The lowest bond strength and microleakage among laser groups was observed in Group-II and Group-III, respectively. However, specimens in laser groups showed comparable bond strength and microleakge scores (p > 0.05). For bond strength and microleakage values, analysis of variance showed significant difference among the study groups (p < 0.001). Using Tukey post hoc test, bond strength and microleakage of laser groups showed statistically significant values than EB group. CONCLUSION: Use of phototherapy using Er,Cr:YSGG for dentin surface treatment has the potential for clinical application in comparison to conventional conditioning technique. Increasing the distance of laser application and time of irradiation has significant effect on the shear bond strength and microleakage scores of dentin bonded to resin composite. However, further in-vitro analysis should be undertaken in order to prove such findings.

Influence of Er: Cr: YSGG laser on adhesive strength and microleakage of dentin bonded to resin composite. In-vitro study.

BACKGROUND: The aim of this study was to evaluate the surface treatment of dentin with phototherapy (ER-CR-YSGG laser) in the presence of different bonding systems on their shear bond strength and microleakage. MATERIALS AND METHODS: Eighty intact human third molars were divided into two groups. Forty teeth were treated with conventional flat wheel diamond bur and the remaining forty were treated with Er Cr YSGG laser (phototherapy). The two groups i.e. treated with laser (l) and group treated with abrasive bur (NL) were further divided into two subgroups of twenty samples each. Subgroup 1 was surface treated with etch and rinse (ER) and other 20 remaining samples were treated with self- etch (SE) bonding regime. Specimens from all the groups were assessed for shear bond strength and microleakage scores. Ten samples from all groups were immersed in 2% methylene blue for 24 h and assessed under a digital microscope for microleakage. Data was assessed using analysis of variance and tukey multiple comparisons test. RESULTS: The lowest bond strength was achieved in laser prepared phototherapy group bonded with self-etch (LSE-11.87 ± 1.21). The maximum bond strength score was observed in non-laser-etch and rinse group (NLER-23.66 ± 2.56). The highest mean microleakage was observed among laser bonded with self-etch (LSE) specimens (1.0 ± 0.13). The lowest microleakage scores were seen in group treated with non-phototherapy etch and rinse (NLER-0.4 ± 0.11) regime. CONCLUSION: Use of etch and rinse dentin bonding regime in combination with ER-CR-YSGG phototherapy dentin treatment has the potential for clinical application in comparison to conventional conditioning technique.

Efficacy of photodynamic therapy or low level laser therapy against steroid therapy in the treatment of erosive-atrophic oral lichen planus.

BACKGROUND: The efficacy of photodynamic therapy (PDT) or low level laser therapy (LLLT) in the treatment of oral lichen planus (OLP) is debatable. The aim of this study was to compare the effects of PDT, LLLT or topical corticosteroid application in the treatment of erosive-atrophic OLP. MATERIALS AND METHODS: Forty-five adult patients with erosive-atrophic biopsy-proven OLP on the tongue or buccal mucosa (size ≤3 cm) were randomly divided into three groups. Group-1: patients receiving PDT topical application of 50 µl toluidine blue (1 mg/ml) with micropipette and after 10 min treated by laser irradiation using GaAlAs laser (630 nm, 10 mW/cm2, continuous wave, spot size: 1 cm2); Group-2: patients receiving LLLT using diode laser (630 nm, 10 mW, continuous wave, spot size: 1 cm2); and Group-3: patients receiving topical corticosteroid applications consisting of dexamethasone (0.5 mg in 5 ml water) mouthwash for 5 min. Demographic data, type, and severity of the lesions and pain were recorded before and after treatment and then at the 1 year follow-up. RESULTS: There was a significant difference in sign score changes before and after the treatment in the PDT group (p = 0.03), LLLT group (p = 0.04) and in the control group (p = 0.02). There was a statistically significant difference between group-1 (p = 0.001) and group-2 (p = 0.001) against group-3 before and after treatment. Mean amount of improvement in pain was significantly greater in the control group in comparison with the PDT and LLLT groups (p < 0.001). The efficacy index of the PDT group improved significantly more than the LLLT (p = 0.001) and corticosteroid groups (p = 0.001). CONCLUSION: Within the limits of the present RCT, it is indicated that PDT and LLLT are effective in the treatment of erosive-atrophic forms of OLP in adult patients. However, further comparative clinical trials are needed to obtain strong conclusions in this regard.