Journal of Adhesive Dentistry最新文献

Purpose: To determine and compare the effects of tribochemical silica coating and alumina-particle air abrasion on 3 mol% and 5 mol% yttria-stabilized tetragonal zirconia polycrystals (Y-TZP).

Materials and methods: Two different 3Y-TZP samples (Lava Plus, 3M Oral Care; Ceramill Zolid, Amann Girrbach) and one 5Y-TZP sample (Katana Zirconia UTML, Kuraray Noritake) were prepared and treated with alumina-particle air abrasion and a 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)-containing self-adhesive composite cement or with tribochemical silica coating followed by silanization (n = 30). Resin columns were cemented onto the treated ceramic surfaces to form specimens. After 24-h water storage or aging with 10,000 thermocycles plus 60-day water storage, shear bond strength (SBS) testing was conducted. Surface roughness, surface Vickers hardness, and crystallographic phase analyses were also performed.

Results: The SBS of tribochemically silica-coated 5Y-TZP before and after aging were 13.8 ± 1.4 and 13.2 ± 1.5 MPa, resp., for Lava Plus (3Y-TZP) 14.4 ± 1.4 and 13.9 ± 1.6 MPa, respectively, and for Ceramill Zolid (3Y-TZP) 14.8 ± 1.1 and 13.9 ± 1.5 MPa, respectively. There was no statistical difference between tribochemical silica coating and alumina air abrasion treatments (p = 0.21) on the bonding performance (SBS) of the 3Y-TZPs and 5Y-TZP (p = 0.25) before and after aging (p = 0.50). After alumina air abrasion, 5Y-TZP showed higher surface roughness (Ra = 1.7 ± 0.1) than did the 3Y-TZPs (Ra = 1.2 ± 0.1 for Lava Plus; Ra = 1.2 ± 0.1 for Ceramill Zolid), while the Vickers hardness was similar among the three materials (p = 0.70). Monoclinic zirconia was not detected in 5Y-TZP irrespective of treatment, with the zirconia being mainly cubic phase. However, the 3Y-TZPs were mainly tetragonal phase with some monoclinic zirconia; the latter increased after being alumina-particle air abraded.

Conclusion: The bond strength to 5Y-TZP is similar to those of the 3Y-TZPs under the same bonding strategies. Durable bonding can be achieved both by alumina air abrasion combined with a 10-MDP-containing self-adhesive composite cement and by tribochemical silica coating followed by silanization for both the 3Y-TZPs and 5Y-TZP.

Purpose: This sub-analysis of our multicenter trial was to assess the long-term periodontal health (PH) of teeth, esthetically reshaped by means of direct composite buildups.

Materials and methods: 198 patients who received 667 direct composite buildups on 585 treated teeth (TT) between 01/2001 and 12/2013 were included. PH was assessed for each TT and for an untreated control tooth (CT) by recording the pocket probing depths (PPD), clinical attachment level (CAL), sulcus bleeding index (SBI), and Turesky's modification of the Quigley Hein plaque index (PI). Statistical analysis was performed using the two-sample Student's t-test and Mann-Whitney U-test. Regression models were performed to check for associations between PH and patients' age, gender, age of the buildups, enlargement range, jaw, and tooth type. The level of significance was set at α = 0.05.

Results: PI scores were significantly (p < 0.001) higher in TT (1.60 ± 0.81) than in CT (1.41 ± 0.81). Differences between TT and CT regarding PPD (TT: 2.14 ± 0.56/CT: 2.18 ± 0.56), CAL (TT: 2.34 ± 1.05/CT: 2.33 ± 0.92), and SBI (TT: 0.41 ± 0.60/CT: 0.41 ± 0.65) were not statistically significant (p > 0.05). The enlargement range of the TT and the tooth type were not associated with PH. Male patients had significantly higher PPDs, CAL, and SBI values than did female patients. CAL and SBI values increased over time for both the TT and CT. CAL, SBI, and PI values were significantly higher in the mandible and the PPD values in the maxilla.

Conclusion: Direct composite buildups made for reshaping, change of color or position of teeth did not impair PH in the long term.

Purpose: To evaluate the biocompatibility in rat subcutaneous tissue of conventional orthodontic cements, Riva (R) and Meron (M), modified by the addition of ethanolic extract of red propolis (EERP), at different concentrations and time intervals.

Materials and methods: One hundred eight male adult Wistar rats were used, distributed in nine groups of cements with added EERP at the concentrations used (C-control, MC, M10, M25, M50, RC, R10, R25, and R50). The rats were sacrificed after 3 time intervals (7, 15, and 30 days). Histological and immunohistochemical analyses were performed. The findings were statistically analyzed using the Kruskal-Wallis test followed by Dunn's test (p < 0.05).

Results: The highest concentrations led to a higher level of inflammation at the initial times (p < 0.05), but without differences after 30 days. In terms of collagen, there was less collagenization at the initial times in comparison with the control group C. However, over time, the addition of propolis resulted in healing compatible with that of group C. The level of CD68 immunostaining was statistically significantly higher in the groups with the highest concentrations (R50 and M50) (p = 0.001).

Conclusion: Orthodontic cements with the addition of EERP were found to be biocompatible in rat subcutaneous tissue. Riva cement with the addition of 50% EERP showed the highest tissue inflammation, but with satisfactory tissue repair.

This literature-based OPINION PAPER reflects in an introductory historical perspective on the rapid advancement of dental adhesive technology. Past and current techniques to bond to tooth tissue, in particular to dentin as the most challenging bonding substrate, are critically appraised. Including the historical perspective in (1), this paper focuses on fourteen items thought to be of primary importance with regard to the current status of dental adhesive technology. In (2) the primary mechanisms involved in adhesion to enamel and especially dentin are dealt with having (3) also revisited the previously introduced adhesion-decalcification concept (AD concept) as basis of biomaterial-hard tissue interaction; the worldwide accepted classification of today's adhesives into etch&rinse (E&R) and self-etch (SE) adhesives are presented in (4), along with presentation of their respective PLUS-MINUS balances in (5) and (6); nomination of the GOLD-STANDARD E&R (7) and SE (8) adhesives is based on evidence of successful laboratory and long-term clinical performance, resulting in a recommended 3-step full E&R bonding route in (9) and the preferred 3-step combined selective enamel E&R with 2-SE bonding route in (10); (11) description of the main bond-degradation pathways and eight strategies to preserve bond stability; (12) coverage of the PROS and CONS of the newest generation of UNIVERSAL adhesives. Looking into the future, some expected future developments in dental adhesive technology have been suggested in (13), along with (14) a first status determination of the latest research-and-development towards self-adhesive restorative materials that no longer require any pre-treatment.

Purpose: The development of a novel material requires a comprehensive pre-clinical assessment of clinical longevity before any market release. This study aimed to investigate the mechanical performance of a novel self-adhesive restorative material (ASAR MP4).

Materials and methods: Fracture strength (FS), flexural fatigue strength (FFS) and fracture toughness (KIc) were measured for the experimental material ASAR MP4 in self-cure (SC) and light-cure (LC) mode. ASAR MP4 was processed in capsules. Three direct resin composites (CeramX mono+, DentsplySirona; Heliomolar, IvoclarVivadent; Filtek Supreme XTE, 3M) and two glass-ionomer-cement (GIC) based materials (Equia Forte, GC; Fuji II LC, GC) were selected for comparison with ASAR MP4. FS specimens (n = 15) were tested in a 4-point bending configuration according to ISO 4049 and 9917. FFS specimens (n = 25) were additionally stressed for 104 loading cycles using the staircase approach. The single-edge-notch beam (SENB) configuration was selected for determining KIc according to ISO 13586. All specimens were stored for 14 days at 37°C. Data were analyzed using Weibull statistics (FS), ANOVA (FS, KIc), and the non-parametric Mann-Whitney U-test (FFS).

Results: The FS, FFS and KIc data of the ASAR MP4 material reveal a mechanical performance in the range of the successful permanent direct resin composites CeramX mono+ and Heliomolar. The results for ASAR MP4 in SC mode were superior to the LC mode. A fine-grained and pore-free microstructure was observed.

Conclusion: Within the limitations of this study we conclude that the novel self-adhesive restorative material ASAR MP4 exhibits mechanical performance close to that of the resin composites Heliomolar and CeramX mono+, both indicated for permanent use in the load-bearing posterior region. Processing the material in either self-cure or light-cure mode led to superior performance over glass-ionomer cements.

Purpose: To evaluate the clinical performance of direct posterior composite restorations with and without short glass-fiber (SGF) reinforced composite in endodontically treated teeth.

Materials and methods: Twenty-four patients (mean age 32.5 years) were included in the study and two molars of each patient received endodontic treatment. After endodontic treatment, one tooth was restored with G-aenial Bond/fiber-reinforced composite (everX Posterior GC) using a microhybrid composite (G-aenial Posterior), and the other tooth was restored with G-aenial Bond/microhybrid composite (G-aenial Posterior). The modified USPHS criteria were used to evaluate the restorations at baseline, 1-, 2-, and 3-year follow-ups.

Results: The success rate of the everX Posterior and G-aenial Posterior restorations after 3 years was 78.3% and 91.3%, respectively. Five everX Posterior restorations and two G-aenial Posterior restorations failed. Based on the criteria used in this study, no significant differences between the two restorations were found at any evaluation time.

Conclusion: All restorations showed acceptable clinical performance regarding all evaluation criteria, apart from the failed restorations. The main cause of restoration failure was restoration fracture. The failure rate of everX Posterior restorations was higher than G-aenial Posterior restorations.

Purpose: To evaluate the influence of new air-abrasion powders with different silica concentrations (silica-coated aluminum oxide) and aging on the bond strength between composite cement and Y-TZP ceramic.

Materials and methods: Ceramic slices (7 x 6.3 x 2 mm3) were randomly allocated into 8 groups (n = 20) considering different surface treatments (SiC: silica-coated aluminum oxide particles; AlOx: aluminum oxide particles; 7% Si and 20% Si: experimental powders consisting of 7% and 20% silica-coated of AlOx respectively) and aging (baseline: 24 h at 37°C in water; aged: 90 days at 37°C in water + 12,000 thermal cycles). A blinded researcher performed the air-abrasion procedure for 10 s (identical parameters for all groups). Composite resin cylinders (Ø = 3 mm) were cemented onto the silanized ceramic surfaces, light cured, and subjected to shear bond-strength testing (wire loop Ø = 0.5 mm). The topography of the powders and air-abraded surfaces was analyzed using SEM and atomic force microscopy (AFM). The elemental composition of the powders and air-abraded surfaces was analyzed with energy dispersive spectroscopy (EDS), and surface wetting of the air-abraded surfaces was also determined by contact-angle measurements.

Results: Under baseline conditions, all groups presented similar bond strengths, but only SiC and 7% Si yielded unaltered bond strength after aging. SiC and 7% Si presented lower contact angles. All groups presented similar surface topographies. The silica content was also similar among groups, except for AlOx.

Conclusion: 7% Si and SiC presented similar bond strength and better bonding performance after aging than AlOx and 20% Si. A higher silica concentration was not able to promote stable adhesion of composite cement after aging.

Purpose: To investigate the effect of application of a primer resembling a universal adhesive with or without light irradiation followed by a hydrophobic bonding agent on bonding effectiveness, based on shear bond strength (SBS) and shear fatigue strength (SFS) tests. Materials and Methods: An experimental two-step self-etch adhesive (BZF) that comprises a primer resembling a universal adhesive (BZP) and a hydrophobic bonding agent (BZB) were used. The two-step self-etch adhesive, Clearfil SE Bond 2 (SE), served as a comparison. Three experiments were conducted. Experiment 1: (1) BZP alone without light irradiation (BZP w/o); (2) BZP alone with light irradiation (BZP w/); (3) BZP without light irradiation followed by BZB (BZPB w/o); (4) BZP with light irradiation followed by BZB (BZPB w/). Experiment 2: (1) BZPB w/o, (2) SE primer + BZ bonding agent (SEP + BZB), and (3) SE primer + SE bonding agent (SEPB). The bonded specimens of experiment 1 and 2 were subjected to SBS tests. Experiment 3: Bonded specimens following the same experimental protocol as experiment 2 were subjected to SFS tests. Results: BZPB showed significantly higher mean enamel and dentin SBS than did BZP. BZPB showed significantly higher SBS without light irradiation than with light irradiation to both substrates. The group of BZPB without light irradiation showed significantly higher SBS than the group of BZPB with light irradiation to both substrates. For experiments 2 and 3, although no significant differences were found in SBS among groups for enamel, SEP + BZB showed a significantly lower SBS and SFS than other groups for dentin. Conclusions: BZF showed bonding performance equivalent to that of the gold standard Clearfil SE Bond 2.

Purpose: To investigate whether dental adhesives modified with polyacrylic acid copper iodide particles could inhibit esterase activity in vitro and the copper release rate from resin matrices, as well as the correlation between the two variables.

Materials and methods: Different concentrations of copper iodide (0.1, 0.5 and 1.0 mg/ml) were incorporated into three commercially available adhesives representative of each type. Disk specimens (n = 3) were fabricated and incubated in cholesterol esterase and pseudo-cholinesterase solutions for 16 days (37°C, pH 7.0). The enzymatic activity and rate of copper release from resin matrices were evaluated at different 4, 8, 12, and 16 days with a UV/visible-light spectrophotometer.

Results: Increased copper release and reduced enzymatic activity were observed with higher concentrations of copper iodide (p < 0.001). Greater copper release with reduced enzymatic activity was also demonstrated at the earlier time periods with this relationship reversing over time (p < 0.001). A moderate negative correlation between the variables was evident (-0.441; p = 0.01).

Conclusions: Adhesives containing copper iodide can inhibit esterase activity in a dose- and time-dependent manner. The correlation between the variables suggests that enzymatic activity may depend on the availability of copper.