Conditioning of PEEK Implant Abutment Surfaces Using Photodynamic Therapy, Nd:YAG Laser, and Conventional Methods to Evaluate Shear Bond Strength.

Objective: This study was done to evaluate shear bond strength (SBS) and modes of failures after different surface treatment modalities on polyetheretherketone (PEEK) implant abutments. Materials and methods: Seventy-five PEEK implant abutment specimens were randomly distributed into five groups based on surface treatment methods: Group I: No treatment, Group II: methylene blue-mediated photodynamic therapy (MB-PDT), Group III: neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, Group IV: Sulfuric acid (H2SO4), and Group V: Sandblasting (Sb). The measurements for SBS and failure modes for PEEK implant abutment specimens were evaluated via Universal Testing Machine and Stereomicroscope, respectively. Two-way analysis of variance and Tukey's post-hoc test (p > 0.05) were used for the statistical analysis. Moreover, the Shapiro-Wilk normality test was also performed for normality. Results: The SBS mean values and standard deviations in megapascals (MPa) for PEEK abutment specimens with different surface pretreatment groups are shown in Table 1 and Fig. 1. The control group had the lowest SBS (9.67 ± 2.1 MPa), while the highest SBS was observed in Group II (MB-PDT; 17.21 ± 1.32 MPa). SBS values for Group IV (H2SO4; 15.83 ± 0.63 MPa) and Group III (Nd:YAG laser; 16.91 ± 2.10 MPa) were similar to Group II (MB-PDT; p > 0.05). The SBS values for the sandblasted specimens (13.90 ± 1.87 MPa) were not significantly different from the control group (p > 0.05). Conclusions: The PEEK implant abutment surfaces treated with MB-PDT and Nd:YAG laser expressed significantly improved SBS.

Decontamination of a siloxane impression material by using 5-aminolevulinic acid activated by photodynamic therapy, microwave irradiation, and hydrogen peroxide.

AIM: The present study was intended to evaluate the antimicrobial effect of PDT, H2O2, and MI on the contact angle, strain-in-compression, and tear strength of siloxane impression material formerly colonized with E. coli, S.aureus and S.mutans. MATERIAL AND METHODS: One hundred and twenty disk-shaped specimens (diameter 10 mm and thickness 2 mm) were prepared by polyvinylsiloxane impression material and inoculated by the American Type Culture Collection (ATCC) of E.coli, S.mutans, and S.aureus in an in-vitro situation. The specimens were broadly divided into six groups then exposed to the various disinfection approaches for 3 min per each group: group 1: Control (no treatment), group 2:PDT 5-ALA, group 3: H2O2, group 4: MI, group 5: H2O2 + MI, group 6: PDT + MI. After disinfection, assessment of mechanical properties (contact angle, strain-in-compression, and tear strength) of impression materials were instigated. Statistical analysis was executed for CFU/mL (log10) for exposed E. coli, S.aureus, and S.mutans, by two-way ANOVA and Tukey's honestly significant test (p>0.05). RESULTS: The highest anti-microbial values against all inspected microbial colonies were unveiled when disinfection was performed in combination i.e., H2O2 + MI and PDT + MI and the least cleansing of impression material was seen by the control group as no treatment was provided. Solo application of MI was more effective than control, H2O2 and 5-ALA activated by PDT but less active when used in combination method H2O2 with MI and PDT with MI. PDT and control group showed the least antimicrobial effectiveness against E. coli (p<0.05) CONCLUSION: Disinfection of impression materials with combination therapies including photodynamic therapy with microwave irradiation and hydrogen peroxide with microwave irradiation displayed highest antimicrobial efficacies against E. coli, S. aureus, and S. mutans with no adverse effects on mechanical properties of impression material.

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

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

Influence of silane and heated silane on the bond strength of lithium disilicate ceramics - An in vitro study.

OBJECTIVES: To evaluate the effect of silane application and silane heat treatment on lithium-disilicate ceramic when bonded to composite resin. METHODS: Twelve blocks of lithium-disilicate (LD) ceramic were fabricated and bonding surfaces were etched using 9.5% hydrofluoric acid (90 seconds). Three experimental groups resulted from the various surface treatment combinations, which included, no silane application (NS) (controls), silane application (S) and silane heat treatment (HS) (100°C for 5 minutesutes). Ceramic and composite resin blocks were bonded using an adhesive resin and light cured restorative composite as a luting agent, under standard conditions. A total of 90 specimen sticks (8 x 1mm²) were subjected to micro-tensile bond strength testing. The means of micro-tensile bond strength (µ-tbs) of the study groups were analyzed using t-test and ANOVA. The tested specimens were analyzed for mode of failure using scanning electron microscopy (SEM). RESULTS: The highest µ-tbs value (42.6 ±3.70 MPa) was achieved for LD ceramics with heat-dried silane. Both silane application and heat treatment of silane resulted in significant (p<0.05) improvements in micro-tensile bond strength of LD ceramics when bonded to resin composite. CONCLUSIONS: The application of silane and its heat treatment showed significant improvement in bond strength of lithium disilicate ceramic when bonded to composite.