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Purpose: The use of biologic agents is emerging in bone regeneration procedures due to their ability to increase cellular events in wound healing and therefore to obtain more predictable outcomes. Hence, the aim of the present study was to critically evaluate the methodology of systematic reviews investigating biologic agents in promoting bone formation and implant site development. Materials and Methods: A literature search for systematic reviews with and without meta-analyses was performed in Medline, Embase, and the Cochrane database, as well as in journals with high impact factors in periodontics and implant dentistry. Titles, abstracts, and full-text articles were analyzed for potential inclusion. Three guidelines--AMSTAR, R-AMSTAR, and the checklist proposed by Glenny et al-were utilized to analyze their methodologic quality. Two calibrated reviewers performed all data extraction and appraisal. Cohen's kappa coefficients were calculated to appraise the interexaminer agreement. Results: A total of 12 systematic reviews, 3 with meta-analyses, were evaluated. Platelet-rich derivatives and BMP-2 were the most widely studied biologic agents and sinus augmentation was the most common procedure evaluated. The R-AMSTAR mean score was 28 (range 14-38) and none of the systematic reviews analyzed met all of the items. In the AMSTAR checklist, the mean score was 5.75 (range 2-9) and the only item met by all the systematic reviews was the a priori design. The Glenny et al checklist mean score was 8.6 (range 4-13) and two items, "focused question" and "to identify all relevant studies," were met by all systematic reviews. Conclusion: Systematic reviews on biologic agents to promote bone formation at implant site development demonstrate substantial methodologic variability. Therefore, caution must be exercised when interpreting their findings. [ABSTRACT FROM AUTHOR]

In South America, most examples of dental modification come from Ecuador; however, none have been directly radiocarbon dated and few have associated cultural materials or context. In fact, many modified teeth and crania are housed in museum collections, divorced from their cultural and temporal milieus, and because of this it is generally assumed that this limits the interpretive possibility of these individuals. We used multiple methods to investigate temporal and geographic origins of seven crania with dental modification housed in the Museo Antropológico y Arte Contemporáneo in Guayaquil, Ecuador. We identified diverse forms of dental modification, including dental inlays and appliques, incised lines, and anterior dental avulsion. Additionally, teeth from four modified individuals were sampled for radiocarbon dating and isotopic analyses (Sr, Pb, O). The dates indicate that dental modification persisted for at least 600 years (cal. A.D. 990-1646). The relatively heavy oxygen isotopes in the sampled teeth are consistent with Ecuador as a place of origin for the four individuals assayed, but strontium isotopes are quite varied, from 0.70462 to 0.70777 indicating that they did not reside in the same geographical area. Interestingly, the observed variations in strontium isotopes in the four individuals are lower than the modeled 87Sr/86Sr for the region. The values suggest the individuals resided in terrains with volcanic bedrock, which are abundant in Ecuador, yet their influence on the strontium isoscapes is not well represented by the published regional models. This analysis highlights the utility of multiple methods in bioarchaeology and biogeochemistry to investigate "orphaned" museum collections. [ABSTRACT FROM AUTHOR]

Hydrophilicity of unset impression materials underlies changes occurring during working time. Hence, the clinical application time when impression materials contact oral tissues after mixing may play a critical role in successful impressions. The aim of this study was to analyze the clinical time course of impression taking applying the single-step/ double-mix technique. Application times of 86 impressions, comprising 265 prepared teeth and 46 implants, taken by 14 different clinicians at a university dental clinic were analyzed. The mean time from loading the impression tray until its final position in the patient's mouth (total application time) was 51.2 seconds; confidence intervals were 46.9 (lower limit) and 55.5 (upper limit). The number of registered teeth and implants did not influence the duration of impression taking. Related to wettability data, several polyvinyl siloxane impression materials show decreased hydrophilicity with respect to estimated application times. The authors suggest considering clinically relevant application times for impression taking in future in vitro studies on physicochemical characteristics of impression materials. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of chlorhexidine on the presence of collagen in aged resin-dentin bonds produced on sound and caries-affected dentin. Materials and Methods: Flat dentin surfaces were obtained from 16 sound molars, from which 8 were microbiologically processed for induction of caries. Single Bond 2 was applied to both sound and caries-affected substrates. In half of the teeth assigned for 6-month storage in water, the phosphoric acid demineralized dentin was impregnated with 2% chlorhexidine before the application of the adhesive. Specimens (2 x 2 x 5 mm) were produced and stored in water for 24 h, or 6 months in either water or mineral oil. The specimens were subjected to histological processing and sections were stained with Goldner’s Trichrome. The thickness of the zone of exposed collagen was measured by optical microscopy and the data were subjected to two-way ANOVA and Tukey’s test (α = 0.05). Results: There was no statistically significant difference (p > 0.05) between sound and caries-affected dentin regardless of the storage condition. For both substrates, significantly greater collagen exposure was observed after 6 months in water. Chlorhexidine-treated groups resulted in similar collagen exposure to that of the control and 6 months in water groups (p > 0.05), while no increase of the exposed collagen zone was observed after mineral oil storage. Conclusion: Aging in water resulted in degradation of the resin-dentin bond, as demonstrated by the increase of the zone of exposed collagen. However, the degradation of the exposed collagen was decelerated in the presence of chlorhexidine. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies have shown the relationship of individual clinical variables to the survival of Dicor (Corning Glass Works) restorations. The purpose of the present investigation was to examine the effect of combinations of these variables on the intraoral survival of Dicor restorations. Materials and Methods: Dicor glass-ceramic restorations (n = 1,444) were placed in 417 adult patients. Failure was defined as a restoration that required remake because of material fracture. The survival of restorations with different combinations of variables that were each individually associated with survival was described using Kaplan-Meier survivor functions. The statistical significance of differences in survival between different combinations of specific predictor variables was examined using the proportional hazards model. Results: Kaplan-Meier survival analysis indicated that significantly worse survival rates were found for restorations that included combinations of molar teeth, a dentin core, and a glass-ionomer luting agent; molar teeth, a dentin core, and a resin luting agent; and single-rooted teeth, a dentin core, and a glass-ionomer luting agent than for any other combinations tested. The Cox proportional hazards model described a hazard ratio of 3.37 (95% confidence interval [CI]: 2.23 to 5.08) for molar teeth (versus single-rooted teeth), 2.65 (95% CI: 1.44 to 4.87) for dentin core (versus gold core), 2.35 (95% CI: 1.58 to 3.51) for men (versus women), and 1.72 (95% CI: 1.13 to 2.60) for glass-ionomer luting agent (versus resin) after adjusting for the other variables in the model. Conclusion: Factors beyond individual restoration design impact the survival of Dicor glass-ceramic. These include sex, tooth position, and restorations luted to gold core foundation bases. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the effect of an acrylic-based resilient liner (ARL) on perceived chewing ability in patients using mandibular complete dentures compared with that of patients using mandibular complete dentures with a conventional acrylic resin (CAR). Materials and Methods: This randomized controlled trial was conducted at two centers from April 2004 to July 2006. Seventy-four subjects were randomly allocated to either the ARL or CAR group using a random permuted block method after obtaining written informed consent. A valid questionnaire listing 35 foods was used to evaluate the subjects' perceived chewing ability of each item, assessed according to the following scale: 0 = cannot eat, 1 = can eat with difficulty, and 2 = can eat easily. If subjects did not eat the food because they disliked it or had not eaten it since first wearing dentures, they filled in a triangle or square, respectively. These figures were treated as a 0 during analysis. Results: No significant differences were observed between the ARL and CAR groups. The perceived chewing ability of subjects with new complete dentures was significantly higher than that of those with their old complete dentures. The duration of edentulism was positively associated with perceived chewing ability. Conclusions: An ARL applied to mandibular complete dentures has no significant impact on the perceived chewing ability of edentulous patients in comparison to a CAR. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether two-step cementation of prefabricated fiber posts leads to higher bond strengths. Materials and Methods: Forty-eight human canine teeth were divided into six groups and fiber posts were cemented with DC Core, RelyX Unicem and Panavia F2.0, according to a one-step or two-step procedure. Per root, four cross-sections were prepared. The differences in push-out strength between procedure, cement and location within the root were determined. Results: For all cements, the push-out strengths for the two-step procedure were significantly higher than for the onestep procedure (p < 0.001). Differences between the cements for both the one-step and two-step procedure were not statistically significant (p = 0.05). Conclusion: The reduction of the C-factor by means of a two-step cementation, a procedure equivalent to the layering technique of composite restorations, resulted in significantly higher bond strengths. The increase of 60% in bond strength may be beneficial to the retention of post and core restorations. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to compare the clinical performance of a polyacid modified resin composite and a nanocomposite applied with an antibacterial adhesive system over a period of 2 years in noncarious Class V lesions. Materials and Methods: Twenty-four patients with at least two noncarious cervical lesions were enrolled in the study. The teeth were restored with a polyacid modified resin composite (Dyract eXtra, Dentsply DeTrey) or a nanocomposite (Filtek Supreme, 3M/ESPE). Fifty restorations of each material were placed with no marginal bevels and no mechanical retentions using an antibacterial self-etching adhesive system (Clearfil Protect Bond, Kuraray). All lesions were evaluated at baseline, 6, 12, and 24 months periods using the USPHS criteria for color match, marginal discoloration, marginal adaptation, caries formation, anatomic form, postoperative sensitivity, surface roughness, and retention. The changes across the four time points were assessed using Friedman and Wilcoxon Signed Ranks tests. The two restorative materials were compared in the same recall period for each of the criteria using chi-square test (p = 0.05). Results: Dyract eXtra restorations exhibited a significantly better color match than Filtek Supreme restorations; however, all restorations in both groups were clinically acceptable. Filtek Supreme's retention rate (100%) was found to be significantly better than that of Dyract eXtra (96%). Two Dyract eXtra restorations were completely lost while one was partially fractured (p = 0.05). Significant differences were observed in marginal adaptation and color match of Filtek Supreme restorations and marginal discoloration of Dyract eXtra and Filtek Supreme restorations between the baseline and the 2-year scores (p = 0.05). Conclusion: Both restorative materials showed acceptable clinical performance in Class V noncarious lesions after 2 years of clinical service. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of long-term water storage on the microleakage of a fissure sealant applied with or without different bonding agents. Materials and Methods: Extracted human third molars were randomly assigned into 8 groups (n = 24/each). The occlusal surfaces were sealed with a fluoride fissure sealant material (Helioseal F) after one of the following pretreatments: 1. phosphoric acid etching only; 2. phosphoric acid etching + Single Bond; 3. phosphoric acid etching + Prime & Bond NT; 4. Clearfil SE Bond; 5. FL Bond; 6. One Up Bond F; 7. Prompt L-Pop; 8. Mac Bond II. All specimens were thermocycled (1000X), after which half of them (n = 96) were stored in distilled water for 48 h (group A), and the remaining half (n = 96) for 48 months (group B). The specimens were immersed in 0.5% basic fuchsin solution, sectioned, and digitally photographed. Microleakage was evaluated quantitatively using an open-source image analysis toolkit (ImageJ), and the data were analyzed statistically. Results: Four-year water storage significantly increased the amount of leakage in all test groups (p < 0.001). In both the absence and presence of water aging, the etch-and-rinse adhesives yielded the lowest microleakage scores (p < 0.001). In the 48-h group, the following ranking was achieved in terms microleakage values: phosphoric acid + Prime & Bond NT = phosphoric acid + Single Bond < Prompt L-Pop = phosphoric acid etching only < FL Bond < Clearfil SE Bond < Mac Bond II = One Up Bond F. In the 48-month group, the ranking changed as follows: phosphoric acid + Prime & Bond NT = phosphoric acid + Single Bond < Prompt L-Pop = FL Bond < Clearfil SE Bond = Mac Bond II = One Up Bond F < phosphoric acid etching only. Conclusion: Long-term water storage significantly increased the microleakage of Helioseal F applied alone and with a bonding agent. Regardless of the storage term, the use of etch-and-rinse adhesives resulted in significantly less microleakage compared to that achieved with self-etching adhesives or acid etching alone. The sealants placed without a prior bonding agent showed the greatest amount of leakage after four years. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the cytotoxicity of three desensitizers, one nonrinse, and one etch-and-rinse adhesive system applied on dentin specimens of different thickness. Materials and Methods: The test materials (A: Admira Protect, B: Gluma Desensitizer, C: Seal&Protect, D: Clearfil Protect Bond, E: Optibond FL) and a positive control (35% H2O2) were applied on 1.0-, 1.5-, and 2.5-mm-thick bovine dentin specimens (each subgroup n = 5) in a dentin barrier test device. The experiments were performed with perfusion (2 ml/h) of the pulpal part of the chamber. The eluates were obtained before (baseline) and 15, 30, 45, 60, and 120 min after application of the adhesives and pipetted onto L-929 fibroblasts. Cytotoxicity of the materials was determined in relation to the baseline value using the MTT assay (succinic dehydrogenase activity). Statistical analysis was performed using ANOVA and Student's t-test. Results: With regard to 1.0-mm dentin specimens, application of Clearfil Protect Bond (D) decreased enzyme activity significantly, while test materials A to C and E were not cytotoxic. However, cytotoxicity of D was limited to up to 15 min and decreased thereafter. Application of the test materials A to E on 1.5- and 2.5-mm dentin samples exhibited no significant cytotoxic effects within 120 min. Generally, ANOVA found significant interactions between the test materials and dentin thickness. However, only for Admira Protect was a significant increase of enzyme activity with increasing dentin thickness observed. Conclusion: Desensitizing agents might exhibit cytotoxic potential when applied on dentin less than 1.0 mm thick. The tested desensitizers and the adhesive systems caused similar effects, in which cytotoxicty might be influenced by the duration of perfusion and dentin thickness. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to assess the 6-year performance of the ART (atraumatic restorative treatment) approach in Class III restorations in permanent teeth. Materials and Methods: A total of 127 ART Class III restorations, using Ketac-Molar (3M ESPE) ionomer cement, was performed in 58 adult patients by one experienced operator in 1998. After a 6 years, 34 patients and 65 restorations were evaluated according to ART criteria. Two calibrated examiners carried out the evaluation. Data were analyzed by exact 95% Confidence Interval and Survival Analysis using the Jackknife method for standard error determination. Results: Among assessed restorations, 73.8% (95% CI = 61.5% to 86.2%) were in good condition and classified as successful, with a 67.6% (95% CI = 54.4% to 80.7%) cumulative survival rate. Failed restorations included 13.9% completely or partially missing restorations, 9.2% restorations that had been replaced by other treatment, 1.5% restorations with a large defect at the margin, and 1.5% restorations that presented high wear on the surface. No caries was observed even in those teeth in which restorations were absent. Conclusion: The 6-year success rate of the ART approach in anterior permanent teeth (Class III) was considered high. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of different curing modes of dual-curing luting systems and root regions on the pushout strength of fiber posts to intraradicular dentin. Materials and Methods: Forty-two extracted premolars with a single root canal were sectioned at the cementoenamel junction and the roots were endodontically treated. The roots were divided into two groups according to two dual-curing luting systems: (1) XP BOND-Dual Cure/Calibra resin cement; (2) XP BOND-Dual Cure/FluoroCore 2. For each luting system, three different curing modes were applied to the dentin adhesive and resin cement: "Self-cure and Self-cure (SC&SC)", "Self-cure and Dual-cure (SC&DC)", and "Dual-cure and Dual-cure (DC&DC)". Translucent Easy fiber posts (Dentsply Maillefer) were luted in the roots. A thin-slice push-out test was performed, and the data of push-out strength were analyzed using three-way ANOVA with luting system, curing mode, and root region (apical, middle and coronal) as factors. Tukey's test was used for post-hoc comparisons. Results: The push-out strength of XP BOND-Dual Cure/Calibra was significantly lower when Calibra resin cement was self-cured than when it was dual-cured (SC&SC: 6.04 ± 2.65 MPa; SC&DC: 10.69 ± 3.01 MPa; DC&DC: 10.72 ± 3.63 MPa; p < 0.05). The curing modes did not affect the push-out strength of XP BOND-Dual Cure/FluoroCore 2 (SC&SC: 7.90 ± 3.94 MPa; SC&DC: 8.32 ± 2.73 MPa; DC&DC: 9.27 ± 4.12 MPa; p > 0.05). The coronal push-out strength was significantly higher than the apical push-out strength (p < 0.05). Conclusion: Retention of fiber posts in root canals was affected by the curing modes of dual-curing luting system and root regions. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this in vivo study was to clarify how blistering formation occurs along intraradicular dentin bonded interfaces. Materials and Methods: Patients were selected and post space was prepared in vivo in endodontically treated teeth. Post space was etched, dried with ethanol, and bonded with one of the following adhesive systems: All Bond 2, XP-Bond, Clearfil SE Bond, Xeno III. The four adhesives were considered as representative of each bonding system class. An additional group was prepared with phosphoric acid treatment + application of Pre-Bond unfilled resin of All Bond 2, without the use of the primer agent. Etching was avoided for self-etching materials. Replicas of the post space were taken (1) after post space preparation; (2) after etching, rinsing, and drying; (3) after ethanol drying, and (4) after adhesive application. Replicas were analyzed with SEM and blisters were counted by independent observers. Statistical analysis was performed with Kruskal-Wallis ANOVA and Dunn's multiple comparison tests at p = 0.05. Results: No blister formation occurred on replicas taken prior to adhesive application, while blister formation was evident in all replicas of bonded interfaces, irrespective of the adhesive system. No statistical difference in the number of droplets was found between All Bond 2, XP-Bond, and Clearfil SE Bond. Xeno III exhibited the highest number of blisters. Specimens bonded with Pre-Bond unfilled resin of All Bond 2 without primer application showed no blister formation. Conclusion: This study revealed that blister formation occurs only if the priming agent of the adhesive system was applied, thus supporting the hypothesis that blistering occurs due to adhesive phase separation or insufficient solvent evaporation. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of different adhesives on the shear bond strength between a feldspathic machinable ceramic and a luting resin. Materials and Methods: Seven groups of 20 ceramic specimens each were machined from Vita Mark II blocs. Their surfaces were uniformly treated with 1000-grit paper. Group 1 (control) was hydrofluoric-acid etched for 60 s, group 2 abraded with CoJet, and group 3 PyrosilPen-treated and silanized. Groups 4 and 5 were hydrofluoric-acid etched for 60 s and silanized with two experimental silanes. Variolink II was used as the luting resin for groups 1 to 5. Group 6 and 7 were phosphoric-acid etched for 15 s. Then group 6 was treated with Nexus and group 7 with the Panavia F 2.0 system. All specimens were stored dry for 24 h at 37°C. Shear bond strength was measured prior to and after 5000 thermocycles (TC) between 5°C and 55°C in water. ANOVA was performed with p ≤ 0.05. Results: Shear bond strength values 24 h / TC in MPa (SD) were as follows: group 1: 11 (3.0) / 12 (5.3), group 2: 22 (3.9) / 25 (7.3), group 3: 26 (9.0) / 30 (8.0), group 4: 12 (5.9) / 8 (2.0), group 5: 8 (2.4) / 7 (3.4), group 6: 16 (6.1) / 3 (1.6) and group 7: 16 (8.6) / 16 (4.3). Cojet (24 h, p ≤ 0.0007 / TC, p ≤ 0.0001) and PyrosilPen (24 h, p ≤ 0.0001 / TC, p ≤ 0.0001) showed significantly higher bond strength than the control but did not differ significantly from each other. No significant differences between the control and groups 4, 5, 6, and 7 were found. PyrosilPen (p ≤ 0.0001) significantly performed best prior to and after TC. Bond strength of experimental silane A (p ≤ 0.0499) and Nexus (p ≤ 0.0002) significantly decreased after TC. Conclusion: Silicoating technology and tribochemistry are fast, trouble-free, and effective surface treatment methods for achieving very good bond strength between feldspathic ceramics and luting resins. Etching with H2F2 can thus be avoided. [ABSTRACT FROM AUTHOR]

Purpose: The bond strength and bond durability of two high-viscosity dual-curing resin luting agents with different surface treatments of ceramic were investigated. Materials and Methods: GN-I machinable ceramic surfaces were treated with 37% phosphoric acid for 30 s (PA), 5% hydrofluoric acid for 5 s (HF-5), 10 s (HF-10), or 30 s (HF-30), or blasting with 50-μm Al2O3 for 10 s (AB). The roughness of the ceramic surface was measured. Treated ceramic surfaces were bonded with three resin bonding systems (RBS): Ceramic Primer/LinkmaxHV (CP/LMHV), Monobond S/VariolinkIIHV (MBS/VLIIHV), or MBS/Heliobond/VLIIHV (MBS/HB/VLIIHV). A microshear test was used to measure the bond strength after 24 h (TC 0) and subsequent thermocycling (TC 10,000 at 4°C and 60°C). ANOVA was performed for statistical analysis, with significance set at p < 0.05. Results: For three RBSs, bond strength at TC 0 was not affected, regardless of ceramic surface treatment (p > 0.05). All combined groups of ceramic surface treatment and resin bonding system decreased after 10,000 thermal cycles, especially groups treated with alumina blasting and bonded with each of three RBSs (p < 0.05). MBS/HB/VLIIHV with each surface treatment did not improve the bond strength and durability compared with MBS/VLIIHV. Conclusion: CP/LMHV and MBS/VLIIHV obtained sufficient bond strength and bond durability to GN-I machinable ceramic by only cleaning with PA; the application of HB may not be necessary. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate whether the application of an enamel etchant (Etch-37 BAC) and a desensitizer (PrepEze desensitizer) which contain the antibacterial agent benzalkonium chloride (BAC) affects the bond strength of the orthodontic resin Transbond XT. Materials and Methods: Eighty-five extracted premolars were used. They were divided into four groups: 1. Transbond XT, 2. Etch-37 BAC/Transbond XT, 3. PrepEze/Transbond XT, 4. Etch-37 BAC/PrepEze/Transbond XT. Shear bond strength was measured using a universal testing machine with a crosshead speed of 1 mm/min. The adhesive remnant on the tooth after debonding was quantified using image analysis equipment. Results: No significant differences were found in shear bond strength when Transbond XT was bonded with the conventional etchant or with Etch-37 BAC (p > 0.008). PrepEze decreased the shear bond strength and the amount of adhesive remnant on the tooth after debonding significantly (p < 0.008). The amount of adhesive remnant on the tooth surface diminished significantly when the enamel was etched with Etch-37 BAC (p < 0.008). Conclusions: The bond strength values obtained with the application of Etch-37 BAC are similar to those obtained with a conventional etchant. However, the application of PrepEze significantly decreased the bond strength of Transbond XT. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effect of the composite surface conditioning on the microtensile bond strength of a resin cement to a composite used for inlay/onlay restorations. Materials and Methods: Forty-two blocks (6 x 6 x 4 mm) of a microfilled composite (Vita VMLC) were produced and divided into 3 groups (N = 14) by composite surface conditioning methods: Gr1 - etching with 37% phosphoric acid, washing, drying, silanization; Gr2 - air abrasion with 50-Ìm Al203 particles, silanization; Gr3 - chairside tribochemical silica coating (CoJet System), silanization. Single-Bond (one-step adhesive) was applied on the conditioned surfaces and the two resin blocks treated with the same method were cemented using RelyX ARC (dual-curing resin cement). The specimens were stored for 7 days in water at 37°C and then sectioned to produce nontrimmed beam samples, which were submitted to microtensile bond strength testing (µTBS). For statistical analysis (one-way ANOVA and Tukey's test, ⋅ = 0.05), the means of the beam samples from each luted specimen were calculated (n = 7). Results: µTBS values (MPa) of Gr2 (62.0 ± 3.9a) and Gr3 (60.5 ± 7.9a) were statistically similar to each other and higher than Gr1 (38.2 ± 8.9b). The analysis of the fractured surfaces revealed that all failures occurred at the adhesive zone. Conclusion: Conditioning methods with 50-Ìm Al203 or tribochemical silica coating allowed bonding between resin and composite that was statistically similar and stronger than conditioning with acid etching. [ABSTRACT FROM AUTHOR]

Objective: To assess in vitro the bond strength of a machined surface of a Au-Ti alloy to a veneering ceramic. Method and Materials: Metal strips of the alloy Au 1.7-Ti 0.1-Ir were milled from a semiproduct fabricated by continuous casting and cold forming. For comparison, the same alloy as well as a traditional Au-Pt-Pd-In alloy were used in the as-cast state. Six samples of each group were fabricated for the crack initiation test, according to ISO 9693:1999, by preparing appropriate metal strips that were veneered with ceramic using a standard firing procedure. The crack initiation test was performed in a universal testing machine. Load at fracture was recorded. Means of bond strength were calculated for each group and the results compared by use of a 1-sided Student t test (P< .05). Fracture sites were documented by means of SEM. Results: Bond strength in the 3 groups was in the same order of magnitude. Failure mode was different for both alloys. Failure of the bonding to the Au-Ti alloy predominantly occurred at the alloy-oxide interface, no matter which fabrication process was used. On the Au-Pt-Pd-In alloy, more ceramic residues were observed. Conclusion: The machined alloy Au 1.7-Ti 0.1-Ir provides sufficient bond strength to veneering ceramics, but this has to be proven by a clinical study. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the toxicity of 4 types of resin-based dental composites with different compositions and to determine the components released from them using high-performance liquid chromatography (HPLC). Method and Materials: Resin composite disks (Z100, Solitaire 2, Filtek P60, and Synergy) were prepared, and cytotoxicity was tested on Balb/C 3T3 fibroblasts. In the first part of the study, cells were exposed to the composites for 72 hours (direct method), and in the second part to ethanolic extracts of the composites for 24 hours (indirect method), both at 37°C. Cell viability was then determined by the MTT (3[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) method. Results: The dental composites and their ethanolic extracts had adverse effects on the viability of Balb/C 3T3 fibroblasts. ANOVA revealed highly significant differences in cytotoxicity between the groups (P < .001) for both the direct and indirect methods. Follow-up comparison by Tukey test (α = .05) showed that Synergy was significantly less toxic than the other resin composites and Solitaire 2 was significantly more cytotoxic when the materials were tested by the direct method. However, using the indirect method, the extract of Synergy was significantly more toxic than all the other extracts. Bis-GMA, TEGDMA, UDMA, bis-EMA, and bisphenol A were detected by HPLC analysis; however, their presence and concentrations varied from one composite to another. Conclusions: The cytotoxicity level of resin-based dental composites depends on their chemical composition, leaching medium, and the amount and type of the components that can be extracted from the materials. [ABSTRACT FROM AUTHOR]

Objectives: This study tested the hypothesis that the size of repair sites on amalgam restorations with mechanical undercuts on the repair surface would affect interfacial strength using a 3-point bending test. Method and Materials: Six groups of 12 rectangular bars each were fabricated from an admix alloy and a spherical alloy. Each specimen was cut into 2 equal-sized end sections, and 1 smaller midsection, which was discarded. A medium-coarse diamond disk was used to roughen and flatten the surface for repair. The 2 end sections were fit back into the original mold. The empty space in the middle was approximately 1, 1.5, and 2 mm, mimicking the size of repair sites to be filled with amalgam. There were 2 groups for each repair size; 1 group had rounded undercuts prepared on the surface for repair with a ½ round bur, and the other group received no additional treatment. Condensation was carried out with condensers having a dimension slightly less than the width of the repair defect. After 7-day storage, a 3-point bending test was used to determine the repair strengths of the specimens. Results: The strength values ranged from 33.9 to 75.6 MPa, which is comparable to published data. ANOVA showed that the mean strength values were higher with spherical amalgam (P < .0001), were lower with undercut (P = .0148), and increased as the width of repair site decreased (P < .0001). Conclusion: Reducing the dimension of the repair site improved repair strength, but rounded undercuts reduced the repair strength values slightly. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the speed (efficiency) and effectiveness of 3 different fiber post removal systems. Method and Materials: Fiber posts (D.T. Light-Post no. 1 [Bisco Dental] and ParaPost FiberLux no. 5 [Coltène/Whaledent]) were cemented into 60 single-rooted teeth after endodontic therapy and post space preparation were completed. Three methods of fiber post removal were evaluated-D.T. Light-Post removal kit, the Kodex twist/Tenax ParaPost fiber post removal drill kit, and a combination of diamond bur/Peeso reamer. Results: The efficiency to remove either fiber post was not significantly different, nor was efficiency of any of the 3 post removal systems significantly different. For effectiveness, no difference was observed between post types, but effectiveness was higher with the diamond bur/Peeso reamer compared with the Kodex twist/Tenax ParaPost drills, which in turn was more effective than the D.T. Light-Post removal kit. Conclusions: Fiber posts are efficiently removed by all 3 methods, but effectiveness of removal is higher using the diamond bur/Peeso reamer. [ABSTRACT FROM AUTHOR]

Purpose: Chemical modification to a sandblasted, large-grit, acid-etched (SLA) implant surface has been shown to enhance the rate of osseointegration. The goal of the present study was to examine changes in stability for implants with a chemically modified SLA surface and to compare their outcomes to those of control implants. Materials and Methods: A randomized controlled trial was conducted with 31 patients. Each patient received 2 implants with the same physical properties but with surfaces that were chemically different. The control implants had a standard SLA surface, while the test implants had a chemically modified surface. Resonance frequency analysis was assessed weekly over the first 6 weeks following implant placement. Results: All implants proved clinically successful, allowing for restoration. Most implants were placed in the mandible (50 of 62). A shift in implant stability from decreasing stability to increasing stability (P < .001), occurred after 2 weeks for the test implants and after 4 weeks for the control implants. Conclusion: The findings from this pilot study provide clinical support for the potential for chemical modification of the SLA surface to alter biologic events during the osseointegration process and demonstrate levels of short-term clinical success similar to those observed for implants with an SLA surface. [ABSTRACT FROM AUTHOR]

Objectives: This study investigated the microleakage, etching ability, and dentin-restorative interface of 2 different single-step self-etching bonding agents with compomers as restoratives. Method and Materials: Fifteen extracted noncarious human premolars were used for each dental material system. The bonding agent Xeno III was used with their compomer Dyract AP (Dentsply) and Adper Prompt L-Pop with their compomer Z2000 (3M Espe). Cylindrical cavities were prepared in enamel and dentin on the buccal surface at the cementoenamel junction and restored. The specimens were thermocycled and cut into slices, and the depth of dye penetration scored. The dentine-restorative interface was examined through a confocal scanning laser microscope. Results: Microleakages between the enamel and dentin sides differed significantly for Xeno (Wilcoxon rank sum test; P = .0058) as well as for Prompt (P = .0106), while the microleakages between the dentin sides of Xeno and Prompt did not differ significantly. However, between the enamel sides, a significant difference was found (P = .000), with the highest value for Prompt. The confocal laser studies showed tag formation, penetration of the bonding agents deep into the tubules, and hybrid layer formation for both bonding agents. Conclusions: It can be concluded that both adhesives gave microleakage values for dentin that are on the lower side. However, careful inspection of the enamel side indicated that both cannot be recommended for enamel sealing. [ABSTRACT FROM AUTHOR]

Objective: Monochromatic ceramic blocks used for computer-generated posterior restorations require color modification to achieve acceptable shade matches. However, it is not known whether manipulative variables affect the final color of these restorations. This study aimed to determine the effects of ceramic type, thickness, extrinsic colorants, glazing, and luting agent on the final color of monochromatic computer-generated ceramics. Method and Materials: One hundred forty-five ceramic specimens (12 mm × 10 mm) with different thicknesses were machined from monochromatic ProGAD ceramics (shades 100, 200, and 300; Ivoclar Vivadent) and Vita ceramics (shades A3.5 and 3M2; Vita). The influence of thickness on color was determined on ProCAD and Vita specimens with thicknesses of 1.0, 1.2, 1.5, 2.0, and 10.0 mm, and the influence of extrinsic colorants, glazing, and luting agent was determined on ProCAD and Vita ceramics of 1.5-mm thickness. Panavia F TG (Kuraray) was used to create a luting-agent backing of 100-μm thickness. GIELAB color coordinates (L*a*b*) were measured using a spectrophotometer, and color differences (ΔE) between the specimens were calculated. The criterion for color difference was considered to be 1.5 ΔE units. The data were statistically evaluated with ANOVA and the 2-tailed t test with a level of significance of 5%. Results: All 5 variables demonstrated significant differences for both ProCAD and Vita ceramics (P = .000). The ΔE values were larger than 1.5 units. Conclusion: Thickness and type of ceramic as well as extrinsic colorants, glazing, and a luting agent affect the color coordinates of monochromatic industrial ceramic. [ABSTRACT FROM AUTHOR]

Objective: Commercial quick-heating phosphate-bonded investments are frequently used to reduce the operating time during the dental casting process. The aim of this study was to evaluate the characteristics of commercial quick-heating phosphate-bonded investments. Method and Materials: Characterization of the 2 investments (Maruvest-Speed [Megadental] and Z4 C&B [Neirynck and Vogt]) focused on the setting expansion, compressive strength, thermal expansion, and surface roughness. Two different heating methods-the quick-heating method (OHM) and conventional heating method (CHM)-were used with the investments. The dimensional accuracy and surface roughness of the nick-el-chromium alloy castings obtained from the investments were also examined. Results: The Maruvest-Speed investment had a significantly greater setting expansion (2.2%) than the Z4 investment (1.1%) after a 30-minute setting time. The fired strength of both investments was greater with OHM (21.2 to 27.7 MPa) than with CHM (13.8 to 17.9 MPa). The thermal expansion of the Maruvest-Speed investment and Z4 with OHM was 1.7% and 1.4%, respectively. There was no significant difference in surface roughness of the castings between samples treated with OHM and CHM. The dimensional accuracy of the castings was larger in length and slightly deformed in bend. Conclusion: The characteristics of the 2 commercial quick-heating phosphate-bonded investments for the accelerated casting technique may be acceptable. [ABSTRACT FROM AUTHOR]

Purpose:The aim of this prospective randomized controlled trial was to evaluate the influence of clinical baseline characteristics on the survival of 2 post systems. Materials and Methods:One hundred patients needing a post were included. Half the patients received a glass fiber--reinforced post (FRP), and the other half received metal screw posts (MSP). The posts were assigned randomly. In addition to demographic data, the following parameters were recorded: type of tooth (incisor/canine versus molar/premolar), length of the post in relation to root length (percentage), extent of coronal tooth destruction (percentage), ferrule height (in millimeters), type of restoration (fixed or removable partial denture), and presence of antagonistic contacts (yes/no). After at least 1 year (mean: 13.84 months), the patients were recalled. Statistical analysis was performed using the log-rank test and Cox regression analysis. Results:The survival rate of FRPs was 93.5%. In the MSP group, the survival rate was significantly lower (75.6%; log-rank test, P = .049). Additionally, the metal posts were associated with more unfavorable complications, for example, root fracture. The type of the tooth and the degree of coronal tooth destruction influenced the survival of MSPs, whereas no influence of these variables could be seen for FRPs. Conclusion: FRPs are superior to MSPs with respect to short-term clinical performance. Especially for MSPs, clinical survival depends on several variables. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to investigate the effect of laser welding parameters (current [A], spot diameter [mm], and pulse duration [ms]) on the weld penetration depth by Nd:YAG laser into cast titanium and Ag-based and Au-based alloys. Method and Materials: Two cast blocks of each metal were laser welded with various parameters at their interface. The blocks were then separated, and the penetration depth into each metal was measured on the separated surface using a computer program. The data were statistically analyzed. Results: Increasing the current and decreasing the spot diameter increased the penetration depth into each alloy. No statistical differences in penetration depth were found for each metal among the pulse durations. Conclusion: The results suggested that, regardless of the pulse duration, the current and the spot diameter in relation to the power density (W/cm2) of the laser affected the weld penetration depth into each metal. Cast titanium produced more penetration depth compared to gold alloys because of its low thermal conductivity value and high rate of laser beam absorption. [ABSTRACT FROM AUTHOR]

Accurate bracket placement is the key for the successful treatment of an orthodontic case. With indirect bonding, not only is the bracket placement more accurate but this technique also significantly reduces chairtime. In this article, the author explains use of thermal glue in an indirect bonding technique. In cases of constricted arches, a modified rapid maxillary expander can be used along with indirect bonding to reduce overall treatment time. [ABSTRACT FROM AUTHOR]

Purpose: This pilot clinical trial evaluated the clinical behavior of 3-unit inlay fixed partial dentures (IFPDs) made of the glass-fiber composite system SR Adoro/Vectris and luted with 2 different bonding systems over an observation period of 2 years. Materials and Methods: Thirty-nine glass-fiber--reinforced composite IFPDs were made to replace 1 missing maxillary or mandibular tooth. Nineteen IFPDs were randomly assigned to group A and luted with a 2-step bonding system (Excite DSC), while the other 20 IFPDs of group B were cemented with a 3-step adhesive (Syntac). Events such as partial or total debonding of the IFPDs, fracture of the framework, or veneer and fiber exposures were considered failures. Color match, marginal discoloration, secondary caries, marginal adaptation, postoperative sensitivity, and surface texture were evaluated according to the United States Public Health Service modified criteria. Results: Two debondings and 2 fiber exposures occurred during the observation period. All failures occurred in group A. Some fatigue microcracks in the pontic area of the 2 detached IFPDs were observed under scanning electron microscopy. The postoperative sensitivity of group A was much higher than that of group B, and the abutments luted with Excite DCS showed postoperative sensitivity during the first month in 42.2% of cases. The sensitivity disappeared completely after 6 months. Statistical analysis indicated significant differences in postoperative sensitivity (P < .05) between the 2 groups. Conclusion: The IFPDs bonded with a 3-step adhesive demonstrated good clinical service in the short observation period. The microfractures of the layering material observed on the debonded IFPDs may suggest excessive flexibility of the fiber structures, which occurs if the framework is fabricated without observing the recommended dimensions. Int J Prosthodont 2006;19:577-585. [ABSTRACT FROM AUTHOR]

Purpose: This study compared the speed and strength of osseointegration and osteoconductivity between an oxidized experimental magnesium (Mg) implant, an oxidized commercially available TiUnite implant, and a dual acid-etched surface Osseotite implant. The aim was to investigate which surface properties enhance bone response to implants, and thereby to test a biochemical bonding theory. Materials and Methods: A total of 60 screw implants (20 of each design) were inserted through 1 cortex into the tibiae of 10 rabbits. Surface chemistry, oxide thickness, morphology, crystal structure, and surface roughness were evaluated. After healing times of 3 and 6 weeks, all bone implants were unscrewed with removal torque (RTQ) devices, and the bone specimens were subjected to histomorphometry. Results: RTQ values for Mg, TiUnite, and Osseotite implants were 27.1, 21.3, and 15.4 Ncm, with new bone formation values of 29%, 18%, and 15%, respectively, at 3 weeks. At 6 weeks the RTQ values were 37.5, 36.4, and 21.5 Ncm, with new bone formation values of 39%, 31%, and 26%, respectively. Discussion: Mg implants demonstrated significantly greater RTQ values (P= .008 and P = .0001) and more new bone formation (P= .031 and P= .030) than Osseotite at 3 and 6 weeks, respectively. Mg implants also showed higher RTQ values at 3 weeks and new bone formation at 6 weeks than TiUnite, but neither were significant ( P> .05). TiUnite showed significantly higher RTQ values than Osseotite at 6 weeks (P = .001), but was not significant at 3 weeks (P >.05). Osseointegration rate (ΔRTQ/Δweeks) was significantly faster for Mg (P= .011) and TiUnite (P= .001) implants between 3 and 6 weeks of healing time, but was not significant for Osseotite. Conclusions: The results indicate that surface chemistry facilitated more rapid and stronger osseointegration of the Mg implants despite their minimal roughness compared to the moderately roughened TiUnite. This suggests potential advantages of Mg implants for reducing high implant failure rates in the early postimplantation stage and in compromised bone, making it possible to shorten bone healing time from surgery to functional loading, and enhancing the possibility of immediate/early loading. [ABSTRACT FROM AUTHOR]

In this article, the author analyzes the problems that can occur with the traditional technique of indirect bonding with the complete arch transfer tray, and describes step-by-step the technique of a double tray bonding technique and its advantages. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to test the hypothesis that remineralized dentin lesions induced by glass ionomer are less vulnerable to subsequent acid challenge. Method and Materials: Baseline demineralized (BDe) lesions were created in 50 bovine dentin slices immersed for 3 weeks in acid solution. A resin-modified glass ionomer (RMGI) was applied to the specimens before immersion in salivalike solution to allow remineralization (Re) for 2 weeks (V2W) or 6 weeks (V6W). Resin-modifed glass ionomer was coated to block further ion release before a 3-week immersion in acid solution as a second demineralization (SDe). Control groups (C2W and C6W) were done simultaneously without RMGI. In another group, RMGI was left undisturbed (V2W+) to allow continuous ion release during SDe. Mineral content was converted from microradiographs, after BDe, Re, and SDe steps. Changes in mineral content were calculated and compared between groups. Results: The remineralized surface zone was maintained after SDe, but the lesion body became deeper. Percentage of mineral loss from SDe was not significantly different between V2W and C2W (t test, P > .05). When remineralization was extended to 6 weeks, V6W showed significantly less mineral loss than C6W. Mineral loss was lowest when RMGI was not blocked (V2W+). Conclusion: Dentin lesions remineralized in the presence of RMGI maintained the highly mineralized surface zone when subjected to second demineralization. However, the remineralized surface zone could not prevent advance of the lesion body. The subsequent demineralization was markedly reduced by extending the remineralization period or by leaving the RMGI undisturbed to resume ion release. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the effects of different light-curing techniques on the microtensile bond strength of hybrid and packable resin composite to dentin. The null hypotheses were that different light-curing techniques do not affect the adhesion of resin composites to tooth structure and that different resin composites do not have a similar bond to dentin. Materials and Methods: One hundred four box-shaped buccal preparations were made and dentin/enamel adhesive was applied according to the manufacturer's instructions (Single Bond 3M ESPE). A hybrid resin composite (Filtek Z250, A2, 3M ESPE) or a packable resin composite (Solitaire 2, A2, Heraeus Kulzer) were inserted in bulk and polymerized using one of these techniques (n = 13): (a) Soft-start (SS) using a halogen lamp (QTH); (b) LED low intensity; (c) Plasma arc (PAC) curing for 6 s for packable resin composite and 3 s for the hybrid resin composite; (d) Conventional (C) QTH curing for 40 s. Afterwards, specimens were thermocycled 1,000 times between 5°C and 55°C in tap water, and were sectioned into beams with a rectangular cross-sectional area of approximately 1 mm². Microtensile bond strength testing was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. Results: Bond strength means ± (SD) in MPa were: Filtek Z250: SSQTH = 17.9 (5.4); LED = 17.9 (6.4); PAC = 16.8 (6.8); CQTH = 16.1 (4.6). Solitaire 2: SSQTH = 12.4 (6.4); LED = 15.5 (4.3); PAC = 16.2 (4.4); CQTH = 13.8 (5.7). The data were structured in a split-plot design and analyzed by a two-way ANOVA and Tukey's tests ( α= 0.05). Conclusion: The light-curing method did not significantly affect bond strengths. However, the bond strengths of the packable resin composite were significantly lower than those of the hybrid resin composite for all polymerization techniques, suggesting that the restorative material itself might be a more critical factor in adhesion than the curing method. [ABSTRACT FROM AUTHOR]

Purpose: This two-centre study evaluated the clinical performance of Class I and Class II restorations of the giomer material Beautifil, placed using Fluorobond, a self-etching adhesive system, to determine the suitability of the test system as an alternative for the restoration of posterior teeth. Materials and Methods: A total of 108 restorations, comprising 72 Class II and 36 Class I restorations, was placed predominantly in molars (82%). Evaulations using modified USPHS/Ryge criteria were conducted at baseline and thereafter at 6 months and 1, 2, and 3 years. Die stone replicas of the restored teeth were examined retrospectively. Results: A total of 5 restorations was found to fail during the study -- 3 in the first year and 2 during the third year of the study. Occlusal marginal adaptation was less than ideal at baseline in 11% of cases, primarily as a consequence of overcontouring, as observed in the die stone replicas. The combined percentage Alpha ratings at 3 years were: colour match, 98%; marginal adaptation (occlusal), 78%; marginal adaptation (proximal), 97%; anatomic form (occlusal), 99%; anatomic form (proximal), 95%; surface roughness (occlusal), 100%; surface roughness (proximal), 100%; marginal staining (occlusal), 90%; marginal staining (proximal) 81%; interfacial staining (occlusal), 99%; interfacial staining (proximal), 100%; contacts (occlusal), 95%; contacts (proximal), 93%; sensitivity, 100%; secondary caries, 100%; lustre of restoration, 100%. Conclusion: It is concluded that the 3-year performance of Fluorobond-bonded Beautifil for Class I and II restorations demonstrated some marginal changes, but most of the direct evaluation ratings were > 90% Alpha, with the performance observed being similar in the two centres. [ABSTRACT FROM AUTHOR]

Purpose: Matrices of adhesive restorative materials and repair procedures may both influence bond strength of repaired adhesive materials. This study examined the bond strength of adhesive filling materials to mature adhesive materials after pretreatment with Co-Jet, Monobond S, and Silibond. Materials and Methods: A hybrid composite (Tetric Ceram), a polyacid-modified composite resin (Dyract), and an ormocer (Definite) and their corresponding bonding agents were tested in combination with the repair systems. Restorative materials were placed in molds and polymerized. In group A (control), homologous materials were applied on the polymerized surface directly. In group B, homologous filling materials were placed onto the respective material with the corresponding bonding agent. In group C, adhesive repair filling material was applied after solely pretreating with the repair systems. In group D, the restorative material was applied after pretreatment with the repair systems and application of the corresponding bonding agent. Each subgroup consisted of 20 specimens. The shear bond strength of the samples was measured in a universal testing machine according to the test procedure ISO 10477. Results: The significantly best bond strength of repair filling material on Tetric was achieved by pretreating with Co-Jet followed by application of the corresponding bonding agent (25.5 ± 5.4 MPa, p<0.05). A single application of the bonding agent or use of Monobond with bonding agent also yielded bond strengths of 20 MPa or more on Tetric. For Dyract or Definite, bond strengths of 15.5 ± 5.3 MPa or less were achieved with the different repair procedures. Conclusion: Successful pretreatment of hybrid composites for repair can be achieved by application of Co-Jet followed by the corresponding bonding material, whereas sufficient repair of ormocers and polyacid-modified resin composites is limited. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare the bond strengths of two new self-etching one-step (Prompt L-Pop 2 and Adper Prompt L-pop) to a total-etch three-step dentin bonding system (Scotchbond Multipurpose Plus). Materials and Methods: One hundred twenty human molars were randomly divided into 3 groups of 40 specimens each. Dentin surfaces of each group were bonded with either Scotchbond Multipurpose Plus (SMP), a three-step system, Prompt L-Pop 2 (PLP), or Adper Prompt L-Pop (APLP), two one-step bonding systems -- according to manufacturers' recommendations. After adhesive application, a composite resin cylinder was incrementally built in a Teflon mold (5 mm high and 5 mm in diameter). The samples of each group were randomly divided into 2 subgroups of 20 samples each and were tested in a shear bond or in a tensile bond strength mode (crosshead speed 5 mm/min). Statistical analyses were performed with one-way ANOVA and Student's t-test. Results: The significantly lowest shear and tensile bond strength values were obtained with APLP. PLP revealed higher shear bond strengths than APLP and SMP. There were no differences in tensile bond strengths between PLP and SMP (p < 0.05). Conclusion: The results of this in vitro study showed that the chemical modifications (adjunction of monomers and copolymers) of the self-etching all-in-one system APLP did not improve its mechanical properties. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the effect of different acid etching times with 9.6% hydrofluoric acid gel and two adhesive systems on shear bond strengths of resin composite to porcelain. Materials and Methods: Ninety-eight 7 x 7 x 2 mm feldspathic porcelain blocks (VMK 95, Vita) were prepared. The specimens were divided into 7 groups: 1 control (no surface treatment) and 6 groups acid etched with 9.6% hydrofluoric acid gel for different etching times, including 30 s, 30+30 s, 60 s, 60+60 s, 120 s, and 180 s. Each of the etching time groups was divided into two bonding agent (Single Bond, AdheSE) subgroups (n = 7). Microhybrid composite (Filtek Z250) was condensed using a teflon mold and light polymerized for 20 s on the porcelain specimens. The prepared specimens were then stored in distilled water at 37°C for 24 h before mechanical testing. Shear testing of all groups was performed on a universal testing machine (Lloyd LRX) at a crosshead speed of 0.5 mm/min. The bond strength data were analyzed with two-way ANOVA. The means were compared using the Tukey HSD test ( α = 0.05). Results: Acid etching time and bonding agent statistically significantly influenced bond strength (p < 0.05). In the Single Bond group, the bond strengths between group 0 (10.48 MPa) and Group 30 (11.17 MPa) did not differ significantly, with these groups exhibiting the lowest bond strength values. The highest bond strength in Single Bond group was observed in group 120 (15.07 MPa) and group 60+60 (15.42 MPa), which did not differ significantly from each other. In the AdheSE group, the bond strengths of group 0 (9.33 MPa) and group 30 (9.49 MPa) did not differ significantly, and these groups exhibited the lowest bond strength values. The highest bond strengths in the AdheSE subgroup were observed in group 120 (14.84 MPa) and group 60+60 (14.96 MPa), which were not significantly different. Comparing the two different adhesive systems, Single Bond exhibited higher bond strength values than did the self-etching adhesive AdheSE. Conclusions: Acid etching of porcelain with 9.6% hydrofluoric acid gel for 120 s provided adequate bond strength for composite repair with a microhybrid composite. When a porcelain restoration is repaired with composite, Single Bond adhesive should be preferred to the AdheSE self-etching adhesive system. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the four-year performance of a highly filled resin composite in Class II and Class I cavities. Materials and Methods: Each of 63 participants received at least one pair of restorations of the same size: one resin composite (Tetric Ceram) and one calcium aluminate cement. Seventy-one pairs were placed. The restorations were evaluated clinically according to slightly modified USPHS criteria at baseline, after 6 months, 1, 2, 3, and 4 years. At 3 years, the calcium aluminate cement material showed an inacceptable clinical cumulative failure frequency of 57% and its evaluation was discontinued. Results: Postoperative sensitivity was reported for 5 restorations (2 resin composite, 3 calcium aluminate cement). At 4 years, a cumulative failure frequency of 7.5% was observed for the resin composite material. Reasons for failure were partial material fracture (2), cusp fracture (2) and endodontic treatment (1). Conclusion: An annual failure rate of 1.9% for the resin composite material provided a good clinical performance during the 4-year period, which fulfills the ADA criteria for posterior resin composite materials. [ABSTRACT FROM AUTHOR]

Purpose: To compare the antibacterial activities of two dentin bonding systems (DBS), Clearfil Protect Bond and Xeno III, by agar well, paper and dentin disks, and a cavity tooth model. Materials and Methods: For the well technique, the test materials were filled in the agar wells inoculated with Streptococcus mutans (ATCC 25175). The paper disks were embedded in adhesives and placed on the seeded agar plates for the second technique. The adhesives were applied on the dentin disks and placed in holes in the plates for the third technique. After 48 h, the zones of inhibition were measured. In the cavity tooth model test, 3 cavities were prepared in the flat occlusal dentin of extracted human molars. The teeth were left in S. mutans for 72 h to allow bacterial invasion. The DBS were applied in the same manner as in clinical application on each of the two infected cavities and the third was left unapplied for control. The teeth were kept in saline for 72 h. Standard amounts of dentin chips were obtained from the cavity walls and the number of bacteria recovered was counted. Results: The results were analyzed by factorial ANOVA and Dunnett C test. Clearfil Protect Bond primer exhibited the greatest inhibition zones followed by Consepsis and unpolymerized Xeno III in all the techniques tested (p ≤ 0.05). Clearfil Protect Bond resulted in significantly less bacterial recovery than Xeno III by the tooth cavity method (p ≤ 0.05). Conclusion: Clearfil Protect Bond was found to be the most antibacterial material with all the techniques used. Furthermore, Clearfil Protect Bond was able to inactivate the bacteria in the cavity more effectively than Xeno III. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of different insertion techniques and adhesive systems on microleakage of Class V composite resin restorations. Materials and Methods: Forty-eight human molars were randomly assigned to four groups (n = 12). Standardized mixed Class V cavities (enamel and dentin margins) were prepared at the CEJ. A total-etch (Adper Scotchbond MultiPurpose) and a self-etching (iBond) adhesive system were evaluated using either an incremental or single-step (bulk) insertion technique. The preparations were restored with Esthet•X micromatrix hybrid composite. The teeth were thermocycled 1000 cycles, immersed in 1% methylene blue dye for 24 h, and invested in acrylic resin. The specimen blocks were then sectioned longitudinally, with dye penetration (microleakage) examined with a 20X binocular microscope. Enamel and dentin margins were scored separately for microleakage using an ordinal ranking system. Results were analyzed using non-parametric tests at a p < 0.05 level of significance. Results: Significance was exhibited between the groups (adhesive material/insertion technique) at the coronal and apical margins. At the coronal margin, the total-etch adhesive/incremental insertion group exhibited significantly less leakage than the other groups, while at the apical margin, the total-etch adhesive/incremental insertion group showed significantly less leakage than the self-etching adhesive/bulk insertion group. Significantly less leakage was found at the coronal margins compared to the apical margins of the material/technique groups. Conclusion: The use of a total-etch adhesive system and incremental insertion of composite significantly reduced microleakage at the coronal and apical margins of Class V composite restorations. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the immediate microtensile bond strengths achieved with representative adhesive systems from each of the four current bonding approaches. Materials and Methods: Resin composite was bonded incrementally to flat, midcoronal dentin from 33 human molars, using the adhesives (Adper Scotchbond MP; Adper Scotchbond 1; Optibond Solo Plus; Clearfil SE Bond; AdheSE; Tyrian SPE + One Step Plus; Optibond Solo Plus self-etching; One-Up Bond F; iBond; Adper Prompt L-Pop; Xeno III) according to the respective manufacturer's instructions. The bonded specimens were immediately sectioned into sticks and underwent microtensile bond testing either immediately or after 24 h. Data were analyzed with two-way ANOVA and LSD tests. Results: No significant differences were found between immediate and 24-h bond strengths (p > 0.05). However, significant differences were observed among adhesives (p = 0.001). The all-in-one adhesive iBond showed statistically lower values when compared to all the other adhesives. Adper Prompt L-Pop, Xeno III, Tyrian SPE + One Step Plus and One-Up Bond F, all self-etching adhesives, were significantly weaker than AdheSE, Optibond Solo Plus, Adper Scotchbond 1, Optibond Solo Plus self-etching, Clearfil SE Bond, and Adper Scotchbond MP, which did not differ statistically from each other. Conclusion: Microtensile bond strengths of representative adhesive systems from the four categories of bonding agents were not equivalent, with the lowest values recorded for the one-step self-etching adhesives. There were no differences in the bond strengths when measured immediately and after 24 h. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the effect of age of dentin and enamel on the microtensile bond strengths of a glass-ionomer based, all-in-one, single-step, self-etching adhesive system (Reactmer Bond, RB) and an antibacterial, two-step self-etching primer system (ABF Bond, ABF). Materials and Methods: Extracted molars from 3 age groups (20 to 25, 35 to 40, and 50 to 55 years) were used. Enamel was removed from the occlusal surfaces of the teeth, and the entire flat surfaces were covered with composite resin (4 mm in height) following application of bonding agents. The bonded specimens were thinly sectioned parallel to the long axis of the tooth into 0.87 ± 0.03 mm² rectangular sections, resulting in 6 to 7 enamel specimens and 10 to 15 dentin specimens per tooth. The specimens were subjected to the microtensile test at a crosshead speed of 1 mm/min. The data were analyzed by Univariate ANOVA, Tukey HSD, and regression analysis. Results: The bond strength of ABF to both enamel and dentin was higher than the bond strength of RB. Bond strengths of ABF to dentin were significantly higher than the bond strengths to enamel (p < 0.05). The 35- to 40-year age group of ABF showed the highest bond strength of all. In RB dentin groups, 34% of specimens showed cohesive failure in composite resin material. Conclusion: Bond strength values to enamel were not affected by age of teeth in either bonding system. Dentinal bond strength using ABF changed according to age of the teeth. Age did not affect bond strength values of RB to dental hard tissues. However, the high number of cohesive failures in Reactmer paste indicated low tensile strength of the material. [ABSTRACT FROM AUTHOR]

Purpose: This study tested an in vitro model of dentin hypermineralization, aiming to simulate naturally hypermineralized dentin for bond strength studies. The effect on bond strength of a double-etching treatment on the artificially hypermineralized substrate was also evaluated. Materials and Methods: Extracted human third molars were selected and 2 groups were formed: a group of 3 teeth, called N (normal dentin) and a group of 6 teeth, called H (hypermineralized dentin). Occlusal surfaces were ground flat to expose midcoronal dentin. Group H was subjected to artificial hypermineralization and subdivided into 2 subgroups: Ht and Hd. The exposed dentinal surfaces of group N and subgroup Ht were etched with 37% phosphoric acid for 15 s prior to bonding with Single Bond adhesive. Dentin of the subgroup Hd was etched twice (double etching) prior to bonding with Single Bond. A 4-mm-high Z100 composite buildup was created on each tooth and, after 24 h water storage, bond strengths were evaluated by the microtensile method. The data between group N and subgroup Ht and between subgroups Ht and Hd were compared using the Student's t test (α =0.05). Results: No significant difference was observed between bond strengths of group N and subgroup Ht (p = 0.108). Subgroup Hd was statistically different from Ht (p < 0.0001). Conclusions: Bond strengths of Single Bond to artificially hypermineralized dentin did not differ statistically from those to normal dentin substrate. The double etching approach significantly reduced bond strengths of artificially hypermineralized dentin. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the influence of substrate moisture on the clinical behavior of two dentin adhesives after 18 months. The null hypothesis tested was that drying dentin with air upon rinsing off the acid would not influence the clinical performance of two dentin adhesives as compared to leaving the preparation visibly moist. Materials and Methods: Thirty-five patients were enrolled in this study. One hundred twenty-eight restorations divided into 4 groups were inserted and evaluated at baseline: (1) NT/Moist -- Prime & Bond NT, an acetone-based adhesive, applied on moist dentin; (2) NT/Dried -- Prime & Bond NT applied on dentin dried with air for 3 to 4 s; (3) SB/Moist -- Single Bond, an ethanol- and water-based adhesive, applied on moist dentin; (4) SB/Dried -- Single Bond applied on dentin dried with air for 3 to 4 s. A microfilled composite resin was used for all restorations. Patients were recalled at 6 and 18 months. Results: At 18 months after initial placement, 110 restorations (86% recall rate) were re-evaluated. Retention rates at 18 months were 92% for NT/Moist, 93% for NT/Dried, 100% for SB/Moist, and 89% for SB/Dried. No statistically significant differences were found among groups for retention rate. Both NT/Moist and SB/Moist resulted in a significant decrease in sensitivity to air from baseline to 18 months. When data were pooled for the variable "substrate moisture", SB resulted in an overall retention rate of 95%, while NT resulted in a retention rate of 92% (statistically similar). The marginal adaptation with SB was significantly worse at 18 months than at baseline. Conclusion: The moisture level of the dentin substrate in noncarious cervical lesions does not influence retention of composite restorations, but moist conditions caused less sensitivity to air. When applied as per manufacturers' instructions (moist dentin), both adhesives resulted in Class V retention rates exceeding the ADA 18-month full acceptance guidelines. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this in vitro study was to compare the dentin bond strength of directly and indirectly inserted composite restorations. Materials and Methods: Twenty extracted human mandibular molars were prepared to form a flat occlusal dentin surface using an Isomet saw under water. Five-mm-thick composite restorations (Filtek Z 250 and Clearfil AP-X) were placed on the dentin surfaces by direct or indirect techniques. The direct restorations were bonded with Single Bond and Clearfil SE Bond bonding agents. Indirect restorations were cemented with two composite luting cements (3M Opal Luting Cement and Panavia F). All restorative procedures were applied under simulated pulpal pressure (15 cm H2O). Each tooth was then vertically sectioned with an Isomet saw through the composite buildups and the dentin. Thus, for microtensile testing, 0.65 x 0.65 mm specimens were obtained from pulpal and remote dentin regions. The results were analyzed according to the regional dentinal surfaces (pulpal and remote dentin). For statistical analyses, two-way ANOVA and Duncan post-hoc tests were used (p < 0.05). Results: Direct application of Clearfil AP-X showed that tensile bond strengths were higher than those obtained for directly and indirectly applied Filtek Z 250 and indirectly applied Clearfil AP-X. No significant difference in tensile bond strengths was demonstrated between pulpal and remote dentin (p > 0.05). Conclusion: It is concluded that the bond strengths of resin luting cements to dentin need further improvement. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of postextraction substrate aging on the microtensile bond strength (µTBS) of an adhesive system (Excite). Materials and Methods: Sixty sound human third molars were extracted for orthodontic purposes and prepared after the following storage periods in distilled water at 37°C (n = 10): G1 - 1 h; G2 - 24 h; G3 - 7 days; G4 -30 days; G5 - 1 year; G6 - 2 years. The occlusal surfaces were removed using diamond disks to expose middle dentin and a standardized smear layer was created by polishing with wet 600-grit sandpaper. The adhesive system was applied according to the manufacturer's instructions, and a resin composite block (5 mm in height, Tetric Ceram shade A2/Ivoclar Vivadent) was built in 1-mm increments, each one being light cured for 40 s (600 mW/cm²). After storage in distilled water at 37°C for 24 h, teeth were sectioned to obtain stick-shaped specimens with a cross-sectional area of approximately 0.7 ± 0.2 mm². Specimens were submitted to µTBS test in a Kratos universal testing machine at a crosshead speed of 0.5 mm/min. Data were statistically analyzed using one-way ANOVA at a significance level of 5% (p < 0.05) Results: The mean µTBS in MPa ± SD were: G1 = 47 ± 3.1; G2 = 42 ± 5.1; G3 = 41 ± 6.4; G4 = 43 ± 9.8; G5 = 40 ± 7.0; G6 = 52 ± 5.7. No statistically significant difference was found among experimental groups. Conclusion: Human teeth stored for long periods of time can be used to determine the in vitro µTBS of one-bottle adhesive systems. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the retention of restorations placed in non-undercut, noncarious cervical lesions using One-Up Bond F and Palfique Estelite resin composite. Materials and Methods: Fifty-one non-undercut, noncarious cervical lesions were restored with One-Up Bond F and Palfique Estelite in 15 patients (mean age 57.7 years). Teeth were cleaned with pumice and water and restored following the manufacturer's instructions. Restorations were evaluated at 6 months, 1 and 2 years for presence or absence, and for the degree of marginal staining using standardized colour photographs for comparison. Results: At 1 year, 42 restorations were evaluated, and all were intact. Slight marginal staining was observed in three restorations. At 2 years, 37 restorations were evaluated from 11 patients, and all were intact. Marginal staining was observed around nine restorations. ANOVA for marginal staining showed a significant increase of staining at both the enamel and cervical margins over the 2 years of the study. No caries was detected in association with any restoration. Conclusion: Although a number of restorations could not be evaluated, the retention of 100% at 2 years showed very good promise for the treatment of noncarious cervical lesions. The marginal staining was limited to a small number of patients. [ABSTRACT FROM AUTHOR]

Purpose: To test the hypothesis that simpler-to-use dentin adhesives (7th-generation adhesives) perform better when used by inexperienced operators than do the more complex 4th-generation adhesives. Materials and Methods: Six operators with no previous experience regarding dental adhesives, three residents in pediatric dentistry, and three experienced dentists used one 4th-generation dentin adhesive (MA) and two 7th-generation adhesives (MB and MC). With each adhesive, each operator performed 6 bondings to enamel and 6 bondings to dentin. After 24 h of storage in water at 37°C, the shear bond strength was determined. Results: The pooled results showed that the bond strength to dentin was higher (p < 0.05) than that to enamel (dentin mean value = 14.0 MPa, SD = 9.1 MPa; enamel mean value = 11.9 MPa, SD = 7.1 MPa), and that adhesive MA performed better (p < 0.05) than adhesives MB and MC (inexperienced operators = 16.2 ± 10.9 MPa, residents in pedodontics = 12.0 ± 6.8 MPa, and experienced operators = 10.7 ± 4.8 MPa). Of the two 7th-generation adhesives, one performed better on enamel than on dentin, while the other 7th-generation adhesive performed better on dentin than on enamel. Regarding operators, there were large individual variations. The inexperienced bonders performed as well as the residents (p > 0.05), while the experienced operators performed best (p < 0.05). Conclusion: In general, the tested 4th-generation adhesive performed better than the 7th-generation adhesives. Even inexperienced operators performed better with the more difficult-to-use 4th-generation adhesives than with the 7th-generation adhesives. Dentin adhesion was stronger than enamel adhesion. [ABSTRACT FROM AUTHOR]

Purpose: This in vitro study evaluated the wall-to-wall adaptation of a new self-adhesive resin-based cement (RelyX Unicem) in comparison with that of other cements when luting gold and porcelain inlays in standardized Class II cavities in extracted teeth. Materials and Methods: In each experimental group (n = 10), a different combination of inlay and luting material was tested. Group 1: Porcelain Empress II (EII) and RelyX Unicem (U); group 2: EII and resin-based cement Variolink II in combination with primer and bonding Excite DSC; group 3: gold inlays (G) and U; group 4: G and Harvard zinc-oxy-phosphate cement; group 4: G and glass-ionomer cement Fuji Cem. After storage and thermocycling, microleakage testing was carried out and dye penetration was examined at the occlusal and cervical margins of each inlay. The differences in microleakage score were tested for statistical significance first comparing all groups, then pooling the groups for inlay material (Kruskal-Wallis nonparametric ANOVA and Mann-Whitney U test, p < 0.05). SEM observations of the tooth/cement/restoration interfaces were also made in each group. Results: Harvard cement had the highest microleakage. The sealing ability exhibited by RelyX Unicem was satisfactory with both gold and porcelain inlays, and comparable to that of Fuji Cem and Variolink II. Conclusion: RelyX Unicem achieved an adequate seal on both enamel and dentin when used to lute in vitro gold and porcelain inlays. [ABSTRACT FROM AUTHOR]

Modern dentistry aims to preserve tooth structure using minimally invasive procedures. Chemomechanical removal of caries is a new method with the advantage of selective removal of severely demineralized dentin. In addition, the method enhances the clinician's ability to diagnose caries. Ensuring chairside caries diagnosis and removal, based on biologic principle, helps to preserve as much healthy tissue as possible. However, while this method is most comfortable for the patient, treatment time is prolonged. In most cases, the method has to be used in combination with a conventional bur. Also, caries lesions in which removal of enamel or a restoration is needed cannot be treated exclusively using the chemomechanical method. This article describes the mechanism of action of the chemomechanical method (CarisolvTM) for caries removal. Indications for use of the chemomechanical method as a first-choice treatment are presented. Clinical cases in which this new approach provides a significant clinical advantage are also described. [ABSTRACT FROM AUTHOR]