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

Photon-Induced Photo-Acoustic Streaming vs. Shock Wave-Enhanced Emission Photo-Acoustic Streaming-The Effect of Three Final Irrigation Protocols on the Bond Strength of an Individually Formed Fiber Post

(1) Background: This study aimed to evaluate how laser-activated irrigation (LAI) influences the retention of a fiber post when used before an endodontic filling, as well as after post space preparation. (2) Materials and Methods: Sixty freshly extracted human incisors were selected. The teeth were randomly assigned to three groups-CONVENTIONAL (CONV), PIPS or SWEEPS-and treated endodontically. Each group received irrigation with 1 × 5 mL EDTA (17%) and 3 × 5 mL NaOCl (5.25%). In the first group, the irrigants were not activated, while in the second and third group, LAI was adopted using PIPS and SWEEPS protocols (Lightwalker from Fotona, Ljubliana, Slovenia). After post space preparation, each group received the same irrigation protocol initially established. Sticky posts (everStick Post, GC AUSTRIA GmbH Swiss) were individually adapted to the corresponding post spaces and cemented using dual cure resin cement (Gradia Core, GC Austria GmbH Swiss). All specimens were vertically embedded into self-curing acrylate (Duracryl plus, Spofa Dent, Europe), and each was sectioned into three segments of type A and type B samples for debonding through push-out and pull-out tests. The results were statistically analyzed. (3) Results: The pull-out test showed the superiority of the SWEEPS group, with a mean fracture force of 133.0 ± 50.7 N, followed by the PIPS group, with 102 N, with a lower standard deviation of ± 34.5 N. The CONV group registered the lowest fracture force. Concerning the push-out test, the SWEEPS group showed superior shear stress in comparison to the other two groups (13.45 ± 4.29 MPa); the CONV group was inferior, with shear tension values of 8.31 ± 4.67 MPa. (4) Conclusions: It can be stated that the SWEEPS and PIPS protocols resulted in considerably higher fiber post retention than the conventional method, whereas the SWEEPS protocol was superior to the PIPS protocol.

Efficacy of curcumin-mediated photodynamic therapy for root canal therapy procedures: A systematic review

BACKGROUND

This systematic review aimed to investigate the effectiveness of CUR-mediated PDT (Curcumin mediated PDT) as an adjunct to conventional chemo-mechanical debridement and/or standard PDT of the RC system with endodontic infections.

METHODS

The focused research question was: "Whether the application Curcumin mediated PDT as an adjunct is more effective than the traditional chemo-mechanical debridement and/or standard PDT of the RC system alone for improving antibacterial and/or mechanical features among subjects undergoing RCT?". An electronic literature search was performed in Scopus, PubMed, and Web of Science. In vitro reports utilizing Curcumin mediated PDT as an adjunct to conventional chemo-mechanical debridement considering permanent dentition assessing the antibacterial and/or mechanical effect were included.

RESULTS

Eighteen articles were included in the review, out of which 13 studies assessed the antibacterial activity, while 5 evaluated the mechanical properties. Most of the studies concluded that Curcumin mediated PDT had a significant antibacterial activity than the conventional chemo-mechanical debridement and/or standard PDT. Four of the five studies suggested that Curcumin mediated PDT had no impact on the push-out bond strength of root dentin. Furthermore, the significant heterogeneity in the data from the included studies did not permit the author to carry out a meta-analysis.

CONCLUSION

There is potential for application of Curcumin mediated PDT as an adjunct to the conventional chemo-mechanical debridement and/or standard PDT in reducing the bacterial load, however, Curcumin mediated PDT has minimal effect on enhancing the pushout bond strength of fiber posts to radicular dentin. Moreover, clinical studies are required to provide a more conclusive opinion on the efficacy of Curcumin mediated PDT for RCT procedures.

Photodynamic therapy and gaseous ozone versus conventional post space treatment methods on the push-out bond strength of fiber posts luting with different resin cements

BACKGROUND

The aim of this study was to compare the push-out bond strength of fiber posts by using two different resin cement after the treatments of post space with photodynamic therapy, gaseous ozone and conventional disinfection solution.

METHODS

The root canal treatments of one hundred maxillary incisors were performed. The roots were randomly distributed into 5 groups (n = 20). NaOCl of 2.5% + EDTA of 17% in group 1, CHX of 2% in group 2, toluidine blue + diode laser as the photodynamic therapy (PDT) in group 3 and ozone in group 4 were applied to the post spaces. Group 5 was washed with distilled water as control group. Each group was divided into two subgroups according to the adhesive types and the posts were bonded by using RelyX and LinkForce. The bond strength was calculated using the push-out test method. Resin tag formations were photographed with SEM. The push-out bond strength was analyzed by ANOVA and Tukey tests (p = .05).

RESULTS

The PDT group, which showed the highest PBS among the groups bonded with LinkForce at all levels, was significantly higher than Ozone and DW groups (p<.05). NaOCl and ozone treatments provided the highest PBS among the groups bonded with RelyX for all levels and this difference was significant according to the DW group (p < .05).

CONCLUSION

Post space treatments improved the bond strength of the fiber post ​​in both types of resin cement.

Efficacy of root canal treatment in c-shaped canals with adjunctive photodynamic therapy using micro-CT

AIM

To investigate the efficacy of conventional root canal treatment (cRCT) with adjunctive photodynamic therapy (aPDT) against microbial biofilms within infected c-shaped root canals.

METHODS

In this in vitro report, the inoculation of 20 freshly extracted human mandibular molar teeth having c-shaped root canal configuration was performed with E. faecalis and P. aeruginosa to produce three-day biofilms in prepared canal system. PDT used a combination of chlorin (ce6) and polyethylenimine (PEI) as the photosensitizer (PS). A 200 μ-fiber was employed to deliver a 660 nm diode laser light into the root canal, and this was compared and conjugated with conventional endodontic treatment utilizing antiseptic irrigation and mechanical debridement.

RESULTS

The utilization of aPDT (group-2) resulted in a considerable decrease in the count of E. faecalis and P. aeruginosa from 12.84 ± 2.18 CFU/mL to 5.13 ± 0.67 CFU/mL, and from 14.06 ± 3.98 CFU/mL to 4.82 ± 1.05 CFU/mL pre-and post-treatment, respectively. A statistically significant reduction in the bacterial counts of both microbes was observed after treatment among the samples of the both study groups (p < 0.05). Specimens in group-2 (8.42 ± 1.14 MPa) demonstrated the highest mean push-out bond strength, whereas the lowest was shown by samples in group-1 (7.08 ± 1.09 MPa). ANOVA showed no statistical difference between the research groups (p = 0.676). The independent t-test revealed that the mean push-out bond strength scores of the cervical segments were higher than the apical and middle segments of roots in research groups (p < 0.05).

CONCLUSION

In c-shaped root canals, the application of photodynamic therapy as an adjuvant to conventional root canal treatment contributes to a statistically significant decrease in the microbial count of E. faecalis and P. aeruginosa along with an improved push-out bond strength of the root canal filling material with root.

Impact of photodynamic therapy on the push-out bond strength of fiber posts to root dentin: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

This systematic review documents the up-to-date evidence on the efficacy of photodynamic therapy (PDT) on the push-out bond strength of fiber posts cemented to root dentin.

MATERIALS AND METHODS

The focused PICO question was: "What impact does PDT have on the push-out bond strength of fiber posts cemented to root dentin?" This systematic review followed the guidelines and recommendations reported in the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines chart. An electronic search was performed in MEDLINE/PubMed, SCOPUS, Web of Science, and Embase from January 1980 up to and including January 2020. Heterogeneity was calculated for push-out bond strength by means of the Chi-square test and I² statistics. For meta-analyses, if the I² was higher than 50 %, a random effects model was used, otherwise a fixed effects model for I² ≤50 % was applied. A p-value <0.05 was set for significant heterogeneity. Forest plots were computed reporting standard mean differences (SMD) of outcomes and 95 % confidence intervals (CI).

RESULTS

In total, ten studies were included, all of wich demonstrated medium risk of bias. All studies tested the push-out bond strength by means of a universal testing machine with applying a load ranging between 0.5 and 1 mm/min speed. Of the 10 studies, nine (90 %) indicated that PDT had no effect on push-out bond strength of fiber posts to root dentin. Only one study indicated that PDT significantly improved the bond strength when compared with other control groups. The overall mean difference for push out bond strength showed no statistically significant difference between PDT and the control group (SMD = -1.11 [-3.25, 1.02], Z=-1.02, p = 0.305).

CONCLUSION

This systematic review concludes that PDT has no effect on improving the push-out bond strength of fiber posts to root dentin.

Bonding integrity and compressive strength of re-bonded, surface conditioned and Er Cr YSGG laser treated lithium disilicate ceramics

AIM

The aim of the study was to investigate the shear bond strength (SBS) and compressive strength (CS) of Er Cr YSGG laser (ECL) treated, re-bonded lithium disilicate (LD) ceramic in comparison to standard conventional conditioning (hydrofluoric acid (HFA) and silane).

METHODS

One hundred LD ceramic disks were divided equally for SBS and CS testing. Eighty samples were conventionally surface treated and bonded to resin cement followed by de-bonding of the cement build-up. All de-bonded specimens were divided into four groups based on re-bonding surface treatments (HFA, primer, adhesive, and ECL). Resin cement build-ups were performed in 40 specimens for SBS testing (universal testing machine); however, the remaining 40 specimens were tested for CS. Ten specimens each were used as controls (surface treatment was performed once and no primary resin cement bonding) for SBS and CS assessment. Surface topography was assessed using a scanning electron microscope.

RESULTS

The maximum and minimum SBS values were shown by groups: control (33.42 ± 3.28 megapascals (MPa)); and ECL (17.50 ± 2.22 MPa) respectively. The maximum and minimum CSs were displayed by specimens in the ECL group (439.45 ± 70.68 MPa) and the control group (237.28 ± 19.96 MPa), respectively. For ECL specimens, SBS was significantly lower and CS was significantly higher as compared to control specimens.

CONCLUSIONS

Application of the Er Cr YSGG laser significantly improved the CS of de-bonded ceramic specimens. However, it did not show a positive influence on the bond integrity of re-bonded ceramics in comparison to conventional surface treatment regimes.

Bond assessment of resin modified glass ionomer cement to dentin conditioned with photosensitizers, laser and conventional regimes

AIM

To assess different conditioning regimes on shear bond strength (SBS) of resin modified glass ionomer cement (RMGIC) bonded to dentin MATERIAL AND METHODS: Fifty non carious intact maxillary molars were cleaned, isolated and randomly divided into five groups (n = 10). Before randomization, dentin surface was exposed and finished. Samples in group 1 were conditioned with methylene blue photosensitizer (MBP) 50 mg/l and activated by photodynamic therapy (PDT), Group 2: surface treated with Er,Cr:YSGG (ECL), Group 3: surface conditioned with polyacrylic acid (PAA) (control), Group 4: surface conditioned with 17 % Ethylenediaminetetraacetic acid (EDTA), Group 5: surface conditioned with total etch (Optibond solo Plus). For SBS testing the samples were placed in universal testing machine. Fracture analysis of debonded surfaces were evaluated using stereomicroscope at 40x magnification. Means and standard deviations were calculated using analysis of variance (ANOVA) and Tukey's post hoc test at a significance level of (p < 0.05).

RESULTS

The maximum bond strength was found in group 5 conditioned with Optibond solo plus total etch (23.15 ± 3.21 MPa). Whereas, the lowest bond values were observed in group 1 treated with MBP (15.25 ± 1.54 MPa). Moreover, samples in group 2, group 3 and group 4 resulted in comparable bond strength (p > 0.05).

CONCLUSION

MBP at 50 mg/l is not recommended to condition dentin prior to RMGIC application. Moreover, ECL has a potential to be suggested for dentin conditioning compared to PAA.

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.