Surface conditioning of PEEK post using Nd: YVO4 laser, photodynamic therapy, and sulfuric acid on the pushout bond strength to canal dentin.

AIM: To assess the push-out bond strength (PBS) of polyetheretherketone (PEEK) post-to-root dentin using post-surface conditioners i.e., Neodymium-doped yttrium orthovanadate (Nd: YVO4) and Riboflavin (RF) and Rose Bengal (RB) mediated photodynamic therapy (PDT) compared to sulfuric acid (SA). MATERIALS AND METHODS: Decoronation of forty human single-rooted premolar teeth was performed. Followed by chamber opening, working length (WL) was established at 15 mm. Root canal preparation was completed using ProTaper Ni-Ti rotary system till F3 finishing file along with root canal disinfection. The canals were dried with paper cones followed by obturation using gutta-percha (GP) and AH sealer. Post space was prepared by drilling out 11 mm of GP using a Gates Glidden drill #3. PEEK posts were fabricated using the CAD-CAM system and then randomly allocated into 4 groups based on the post-surface conditioning (n = 10). Group 1: SA, group 2: PDT RF, group 3: PDT RB, and group 4: Nd: YVO4 laser. The PEEK post was then cemented in their respective canal. PBS and failure mode assessment were performed using a universal testing machine and stereomicroscope at 40x magnification. The SBS data set was subjected to a one-way analysis of variance (ANOVA) and Tukey's Post Hoc test at a significance level of 0.05. RESULTS: The samples in group 4 (Nd: YVO4 laser) coronal third (7.99±0.24 MPa) demonstrated the highest PBS. The apical third of samples in group 1 PEEK post surface conditioned with SA (5.15± 0.52 MPa) exhibited the minimum values of PBS. Intergroup comparison analysis showed that samples in group 1 (SA), group 2 (RF activated by PDT), group 3 (RB activated by PDT), and group 4 (Nd: YVO4 laser) demonstrated comparable outcomes of bond scores (p>0.05) CONCLUSION: Neodymium-doped yttrium orthovanadate (Nd: YVO4) and riboflavin and Rose bengal activated by photodynamic therapy (PDT) have been investigated as potential alternatives for the surface conditioning of PEEK (polyetheretherketone) posts.

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.

Impact of riboflavin and curcumin mediated photodynamic therapy and Er,Cr:YSGG on microleakage of class V resin glass ionomer restorations in permanent molar teeth.

PURPOSE: The present study aimed to evaluate the impact of PDT using curcumin and riboflavin as photosensitizers and Er,Cr:YSGG on microleakage in class V RMGIC restorations in permanent teeth. MATERIALS AND METHODS: Eighty permanent molars were investigated and randomly divided into 4 groups: control group: resin-modified glass ionomer restoration with no treatment, R-PDT: PDT with riboflavin, Cu-PDT: PDT with curcumin (Cu) and, Er,Cr:YSGG: laser application. All the teeth in each group were restored with the help of RMGIC. The samples were dipped for 24 h in 0.5 % Fuchsine solution, and subsequently fixed in acrylic resin-based molds. Microleakage scores were estimated considering both cervical and occlusal boundaries. Intergroup comparisons were made at each margin, and intragroup comparisons made at the cervical and occlusal margins. The Shapiro Wilk test was used to check the normality of the values. Whereas, the analysis of data was conducted using SPSS version 25 via the Kruskal-Wallis and Wilcoxon tests. P < 0.05 was contemplated to be statistically important. RESULTS: A high frequency (95%) of the enamel walls were not penetrated when subjected to treatment with R-PDT, followed by Cu-PDT and Er,Cr:YSGG. The highest amount of microleakage was observed (55%) Cu-PDT at the site of the cavity near the cementum. The least amount of microleakage was observed in the control group. A statistically significant difference in microleakage was noted at the cervical wall (p=0.015), while no significant difference was seen at the occlusal wall (p=0.789) between the groups. A significant difference was noted at the cervical wall between the control and R-PDT group (p=0.021) and Cu-PDT group (p=0.005), respectively. A significant difference in microleakage was observed when occlusal was compared with cervical walls within each group (p<0.05). CONCLUSION: Photosensitizers using riboflavin and curcumin may reduce the microleakage within the enamel surface restored with RMGIC in class V lesions that may not interfere with bonding. However, extreme caution should be taken while considering riboflavin and curcumin for class V RMGIC restorations extending to cementum surface.

Push out bond strength of glass fiber post to radicular dentin irrigated with Nisin and MTAD compared to methylene blue photodynamic therapy.

AIM: Present lab-based study intended to appraise the effect of nisin, Mixture of Tetracycline, Acid and Detergent (MTAD), and photodynamic therapy (PDT) when used as a canal disinfectant on push-out bond strength (PBS) of fiber post to radicular dentin MATERIALS AND METHODS: Forty uni-radicular premolar teeth were extracted and disinfected in 0.5 % thymol solution. All specimens were decoronated to achieve standardize root length of 14 mm. Cleaning and shaping of the canal were done using protaper NiTi system. The canal space was dried and obturated. Post space was prepared using peso reamers up to 10 mm length and samples were randomly divided into 4 groups (n = 10). Group 1 irrigated with 10 % Nisin with MTAD, group 2: 1.3 % NaOCl and MTAD, Group 3 irrigated with 2.5 % NaOCl and 17 % EDTA and post space of samples in group 4 with PDT with MTAD. Fiber-reinforced composite post (FRCP) was fitted in canal space using self-etch resin cement. Each sample was cut into 1 mm from coronal, middle, and apical and subjected to PBS via a universal testing machine. For comparison of means, Analysis of variance (ANOVA) and Tukey multiple comparison test was used maintaining the level of significance at p < 0.05. RESULT: Samples in group 3 post space irrigated with 2.5 % NaOCl and 17 % EDTA demonstrated the highest PBS at all root levels (cervical: 8.83 ± 0.14 MPa, middle: 7.63 ± 0.82 MPa and apical: 5.82 ± 0.32 MPa) in comparison to other tested groups. Whereas, group 1 in which Nisin 10 % with MTAD was used as a canal disinfectant displayed the lowest PBS at all levels (cervical: 6.91 ± 0.54 MPa, middle: 6.15 ± 0.31 MPa, and apical: 3.62 ± 0.68 MPa). CONCLUSION: Post space irrigated with 1.3 % NaOCl and MTAD shows PBS similar to control group 2.5 % NaOCl and 17 % EDTA. Both types of irrigation methods have potential and can be recommended in clinical scenarios. Whereas, 10 % Nisin and PDT with MTAD as chelator needs further inquiry.

Bond Integrity of Resin-modified Glass Ionomer to Dentin Conditioned Using Photodynamic Therapy and Low-level Laser Therapy: An In Vitro Study.

AIM: The aim of the study was to assess the conditioning efficacy of photodynamic therapy (PDT) and Er,Cr:YSGG laser (ECYL) to dentin compared with conventional regime bonded to resin-modified glass ionomer (RMGIC). MATERIALS AND METHODS: Forty mandibular teeth were cleaned, disinfected, and mounted vertically within the segments of polyvinyl pipes up to cementoenamel junction. The occlusal surfaces were flattened, and samples were divided into four groups according to conditioning protocols. Samples in groups I and II underwent PDT, samples in group III were conditioned with low-level laser therapy (LLLT) using Er,Cr:YSGG laser (ECYL), and samples in group IV were conditioned using polyacrylic acid (PAA). Fuji II LC was applied incrementally and light cured for 20 seconds. All samples were placed in universal testing machine for shear bond strength (SBS) testing. The fracture surface was analyzed using stereomicroscope at 50× magnification to determine mode of failure. Among different investigational groups Tukey test was used as post hoc along with analysis of variance (ANOVA). Significance level was established at p <0.05. RESULTS: Maximum SBS values were observed in group IV dentin conditioned with PAA (19.55 ± 1.84 MPa), whereas minimum SBS values were shown by group I (methylene blue photosensitizer, MBP) activated by PDT (13.52 ± 1.22 MPa). In group III, dentin conditioned with ECYL (18.22 ± 2.07 MPa) and group IV (19.55 ± 1.84 MPa) surface treated with PAA exhibited comparable SBS values (p > 0.05). Fracture analysis revealed that in PDT group adhesive failure type was in majority. However, admixed failure type was commonly presented in groups III and IV. CONCLUSION: PDT of dentin using photosensitizers MBP and CP deteriorates bond values when bonded to RMGIC. The use of LLLT to condition dentin has the potential to improve SBS. CLINICAL SIGNIFICANCE: Dentin conditioning with LLLT using ECYL may improve, is of utmost importance for better treatment outcome, predictable prognosis, and improved bond integrity to RMGIC.