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The advent of "Adhesive Dentistry" has simplified the guidelines for cavity preparation enormously. The design and extent of the current preparations are basically defined by the extent and shape of the caries lesion, potentially slightly extended by bevelling the cavity margins in order to meet the modern concept of minimally invasive dentistry. New caries excavation techniques have been introduced, such as the use of plastic and ceramic burs, improved caries-disclosing dyes, enzymatic caries-dissolving agents, caries-selective sono/air abrasion and laser ablation. They all aim to remove or help remove caries-infected tissue as selectively as possible, while being minimally invasive through maximum preservation of caries-affected tissue. Each technique entails a specific caries-removal endpoint and produces residual dentin substrates of different natures and thus different receptiveness for adhesive procedures. This paper reviews the newest developments in caries excavation techniques and their effect on the remaining dentin tissue with regard to its bonding receptiveness. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this prospective randomized controlled clinical trial was to evaluate the 2-year clinical performance of a self-adhesive resin cement, RelyX Unicem (3M ESPE), used for cementation of ceramic inlays. In addition, the influence of selectively acid etching enamel prior to luting on marginal integrity, inlay integrity, tooth integrity, sensitivity, and complications of the restored teeth was assessed. The hypothesis tested was that there was no significant difference in these criteria between restorations with (Etch) or without prior enamel acid etching (Non-etch). Materials and Methods: Sixty-two IPS Empress 2 inlays/onlays were placed in 31 patients by two experienced clinicians. The restorations were luted with RelyX Unicem with (=experimental group; Etch) or without (=control group; Non-etch) prior enamel etching with phosphoric acid. At baseline, 6 months, 1 year and 2 years after placement, the restorations were assessed by two calibrated investigators using modified USPHS criteria. Results: The recall rate at 24 months was 96.6%. Two restorations were clinically unacceptable due to loss of retention, leading to a survival rate of 96.6% (Kaplan-Meier). No significant difference was noted between the experimental group and the control group regarding marginal integrity, inlay integrity, tooth integrity, complications and sensitivity (McNemar, p > 0.05). An obvious deterioration in marginal adaptation was observed after 24 months as only 21.7% (Etch = 23.4%; Non-etch = 20%) of the restorations exhibited an excellent marginal adaptation compared to 70.7% (Etch = 75%; Non-etch = 66.7%) at baseline. In 74.9% of the restorations, small, still clinically acceptable marginal deficiencies were observed (Etch = 76.6%; Non-etch = 73.2%). Conclusion: The self-adhesive resin cement RelyX Unicem showed acceptable clinical behavior after two years of clinical service. Selective enamel etching prior to luting had no significant influence on marginal integrity, inlay integrity, tooth integrity, sensitivity or complications of the restored teeth after 24 months. Longer term evaluation is needed to confirm this finding. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to examine whether one-step self-etching adhesives (1-SEAs) really have an advantage over multistep systems. Materials and Methods: Nine one-step self-etching adhesives (Absolute, Adper Prompt L-Pop, Clearfil S3 Bond, GBond, Hybrid Bond, iBond, One-up Bond F Plus, Optibond All-in-one and Xeno III) were included in this study. One twostep self-etching adhesive (Clearfil SE Bond) and one three-step etch-and-rinse adhesive (Optibond FL) served as controls. Their microtensile bond strength to bur-cut enamel and dentin was determined using a standardized protocol and the respective adhesive/dentin interface of these adhesives was characterized by transmission electron microscopy. Statistical analysis was performed with the Kruskal-Wallis nonparametric test. Results: Regarding bond strength, the control adhesives tended to perform superior to the one-step adhesives. However, a significant difference between the control adhesives and some one-step adhesives could not always be demonstrated, partly due to the statistical setup of this study. Interface analysis by electron microscopy showed wide variation among the one-step adhesives, depending on their composition and their acidity. 1-SEAs also exhibited two different kinds of droplets, depending on their hydrophilicity. Hydrophobic HEMA-free 1-SEAs such as G-Bond were prone to phase separation, while especially HEMA-containing hydrophilic 1-SEAs, such as Clearfil S3 Bond and Xeno III were predisposed to forming osmosis-induced droplets. Hybrid bond, Absolute, and iBond featured both phase separation as well as osmosis. Optibond All-in-one exhibited a clustering reaction of the filler particles upon solvent evaporation. All adhesives including the control adhesives showed signs of nanoleakage, indicating that all adhesives are to some extent permeable to water. A definitive conclusion with regard to quantitative assessment of nanoleakage was much hindered by inconsistencies in the silver deposition. The application procedure of some 1-SEAs sometimes proved as elaborate and time consuming as those of the two-step adhesive Clearfil SE Bond. Conclusion: Considering bond strength and application procedure, 1-SEAs are not always a better alternative to multistep adhesives. [ABSTRACT FROM AUTHOR]

Purpose: In light of the concept of minimally invasive dentistry, erbium lasers have been considered as an alternative technique to the use of diamond burs for cavity preparation. The purpose of this study was to assess the bonding effectiveness of adhesives to Er,Cr:YSGG laser-irradiated dentin using irradiation settings specific for cavity preparation. Materials and Methods: Fifty-four midcoronal dentin surfaces, obtained from sound human molars, were irradiated with an Er,Cr:YSGG laser or prepared with a diamond bur using a high-speed turbine. One etch-and-rinse (Optibond FL/Kerr) and three self-etching adhesives (Adper Prompt L-Pop/3M ESPE, Clearfil SE Bond/Kuraray, and Clearfil S3 Bond/Kuraray) were used to bond the composite to dentin. The microtensile bond strength (μTBS) was determined after 24 h of storage in water at 37°C. The Kruskal-Wallis test was used to determine pairwise statistical differences (p < 0.05). Prepared dentin surfaces, adhesive interfaces, and failure patterns were analyzed using a stereomicroscope and Field-emission gun Scanning Electron Microscopy (Feg-SEM). Results: Significantly lower μTBS was observed to laser-irradiated than to bur-cut dentin (p < 0.05), irrespective of the adhesive employed. Feg-SEM photomicrographs of lased dentin revealed an imbricate patterned substrate and the presence of microcracks at the dentin surface. Conclusion: Morphological alterations produced by Er,Cr:YSGG laser-irradiation adversely influence the bonding effectiveness of adhesives to dentin. [ABSTRACT FROM AUTHOR]

Purpose: To determine the effect of thorough air drying on the static and dynamic bonding effectiveness of a HEMA-free all-in-one adhesive bonded to Class-I cavity-bottom dentin. Materials and Methods: G-Bond (GC, Japan) was applied to standard occlusal Class I cavities following either a gentle (1 bar) or strong (4 bar) air-drying technique. After restoring the cavity using a composite resin (Gradia Anterior, GC), microspecimens were prepared that were loaded until failure or inserted in a microrotary fatigue testing device. Results: Strong air drying had no effect on the static (39.1 vs 38.4 MPa) or the dynamic (19.0 vs 18.6 MPa) strength of the interface complex. Conclusion: Strong air drying did not improve the static or the dynamic bonding effectiveness, although a very thorough (4 bar) and long air-drying procedure was employed. SEM analysis revealed that even when the adhesive was strongly air dried, droplets originating from phase separations could still be observed, albeit to a reduced extent. Ineffective drying and pooling of the adhesive in a narrow cavity diminished the effect of strong air drying of the all-in-one adhesive. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this prospective randomized controlled clinical study was to evaluate the clinical performance of a "mild" two-step self-etching adhesive, Clearfil SE, in Class V restorations after 5 years of clinical functioning. Materials and Methods: Twenty-nine patients received two or four restorations following two randomly assigned experimental protocols: (1) a mild self-etching adhesive (Clearfil SE, Kuraray) was applied following manufacturer's instructions on both enamel and dentin (C-SE non-etch); (2) similar application of Clearfil SE, but including prior selective acid-etching of the enamel cavity margins with 40% phosphoric acid (C-SE etch). Clearfil AP-X (Kuraray) was used as the restorative composite for all 100 restorations. The clinical effectiveness was recorded in terms of retention, marginal integrity, marginal discoloration, caries recurrence, postoperative sensitivity, and preservation of tooth vitality after 5 years of clinical service. The hypothesis tested was that selective acid etching of enamel with phosphoric acid improved retention, marginal integrity, and clinical microleakage of Class V restorations. Results: Only one restoration of the C-SE non-etch group was lost at the 5-year recall. All other restorations were clinically acceptable. Marginal integrity deteriorated with time in both groups. The number of restorations with defect-free margins was significantly lower in the C-SE non-etch group (p = 0.0043). This latter group presented significantly more small incisal marginal defects on the enamel side (p = 0.0169). Superficial marginal discoloration increased in both groups, but was more pronounced in the C-SE non-etch group and was related to the higher frequency of small incisal marginal defects. Conclusion: The clinical effectiveness of the two-step self-etching adhesive Clearfil SE remained excellent after 5 years of clinical service. Additional etching of the enamel cavity margins resulted in an improved marginal adaptation on the enamel side; however, this was not critical for the overall clinical performance of the restorations. [ABSTRACT FROM AUTHOR]

Purpose: Recently, highly flowable resin fillers have been proposed for filling root canals using a single-cone approach. The purpose of this study was to test the hypothesis that polymerization shrinkage, which is inherent to this type of filler, can break the close initial contact between the main core and the surrounding dentin even if root dentin infiltration has occurred. Materials and Methods: Twenty roots of anterior teeth were prepared chemomechanically and divided into 4 groups of 5 samples each. Groups 1 and 2: hydrophilic resin filler injected and spread, roots sectioned after setting; group 3: hydrophilic resin filler injected and spread, dental substrate dissolved after setting; group 4: hydrophobic resin sealer lentulo-spiraled and spread, roots sectioned after setting (as control). In groups 1, 2, and 3 the material was used following manufacturer's instructions. The section surfaces of groups 1 and 4, and the resin components of group 3 were processed for conventional FE-SEM. The section surfaces of group 2 were observed successively under environmental and high-vacuum conditions. Results: Microscopic examination of the resin-dentin interfaces of groups 1 and 2 showed the existence of resin- dentin interdiffusion zones (RDIZ); however, the close initial contact between the main core and the surrounding dentin was often lost. In group 3, resin tag morphology was well characterized. Identical morphological features were observed in the resin-dentin interfaces in group 4. Conclusion: Since the existence of resin tags did not exclude the existence of a gap between the main core and the adjacent RDIZ, our results confirmed the proposed hypothesis. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this in vivo study was to evaluate the clinical performance of porcelain veneers after 5 and 10 years of clinical service. Materials and Methods: A single operator placed porcelain laminates on 87 maxillary anterior teeth in 25 patients. All restorations were recalled at 5 years and 93% of the restorations at 10 years. Clinical performance was assessed in terms of esthetics, marginal integrity, retention, clinical microleakage, caries recurrence, fracture, vitality, and patient satisfaction. Failures were recorded either as "clinically unacceptable but repairable" or as "clinically unacceptable with replacement needed". Results: Porcelain veneers maintained their esthetic appearance after 10 years of clinical service. None of the veneers were lost. The percentage of restorations that remained "clinically acceptable" (without need for intervention) significantly decreased from an average of 92% (95 CI: 90% to 94%) at 5 years to 64% (95 CI: 51% to 77%) at 10 years. Fractures of porcelain (11%) and large marginal defects (20%) were the main reason for failure. Marginal defects were especially noticed at locations where the veneer ended in an existing composite filling. At such vulnerable locations, severe marginal discoloration (19%) and caries recurrence (10%) were frequently observed. Most of the restorations that present one or more "clinically unacceptable" problems (28%) were repairable. Only 4% of the restorations needed to be replaced at the 10-year recall. Conclusion: It was concluded that labial porcelain veneers represent a reliable, effective procedure for conservative treatment of unesthetic anterior teeth. Occlusion, preparation design, presence of composite fillings, and the adhesive used to bond veneers to tooth substrate are covariables that contribute to the clinical outcome of these restorations in the long term. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the microtensile bond strength (µTBS) of eleven contemporary adhesives to dentin, including three one-step self-etch systems, four two-step self-etch systems, three two-step total-etch systems, and one three-step total-etch system. Materials and Methods: Resin composite (Z100) was bonded to flat, mid-coronal dentin from 33 extracted human third molars using the adhesives strictly according to the respective manufacturer's instructions. After storage overnight in 37°C water, the bonded specimens were sectioned Into 3 to 6 slabs of approximately 1 mm thickness and 2.5 mm width. They were then trimmed into an hourglass shape resulting in an Interface area of approximately 1 mm², and subsequently subjected to µTBS testing with a crosshead speed of 1 mm/min. Results: The µTBS varied from 30.0 MPa for the one-step self-etch adhesive Prompt L-Pop 2 (ESPE) to 63.1 MPa for the three-step total-etch adhesive OptiBond FL (Kerr), the latter being the only one that significantly differed from all other µTBS values. Although not significantly different, one-step self-etch adhesives tended to have lower µTBS than two-step self-etch and two-step total-etch adhesives. Specimen failures during sample preparation occurred with Prompt L-Pop 2 (4 pretesting failures out of 17 specimens) and NRC/Prime&Bond NT (7 pretesting failures out of 14 specimens). Conclusion: Adhesives with simplified application procedures, either following a total-etch or self-etch approach, produced lower bond strengths to dentin than a conventional three-step total-etch adhesive. Some concern exists regarding the consistency in bonding effectiveness to dentin of some self-etch adhesives. [ABSTRACT FROM AUTHOR]

Purpose: The objectives of this study were (1) to compare the hybridization effectiveness of two adhesive systems that are applied in respectively three and two steps, and {2} to determine the best resin-dentin interface preparation technique for atomic force microscopy (AFM). Materials and Methods: The resin-dentin interface produced by the three-step OptiBond Dual-Cure (Kerr} and its simplified two-step successor OptiBond Solo (Kerr)was ultramorphologically examined using transmission electron microscopy (TEM) and AFM. Four different methods were used to prepare interface specimens for AFM: (1) polishing to a 0.1pm finish with a silicon oxide suspension, (2) polishing to a 0.05-pm finish with an aluminum oxide suspension, (3) argon-ion etching, and (4) sectioning with a diamond knife. Results: Both TEM and AFM demonstrated that some collapse of the exposed collagen fibril network, due to gentle postconditioning air-drying of the dentin surface, may not have been totally recovered through hybridization by the two-step adhesive formulation as opposed to the three-step precursor. From the four interface preparation methods, only diamond-knife sectioning revealed sufficient ultramorphologic detail and high resolution that can capitalize on the high resolution offered by AFM. Conclusion: First, the findings suggest that simplifying the application procedure of adhesives by combining the primer and adhesive resin into a single application step may reduce hybridization effectiveness. Future research should confirm this effect for other two- versus three-step adhesive systems. Second, diamond-knife sectioning should be used for future topographic imaging and physicomechanical testing of resin-dentin interfaces by AFM. [ABSTRACT FROM AUTHOR]

Purpose: In light of the concept of minimally invasive dentistry, erbium lasers have been considered as an alternative technique to the use of diamond burs for cavity preparation. The purpose of this study was to assess the bonding effectiveness of adhesives to Er,Cr:YSGG laser-irradiated dentin using irradiation settings specific for cavity preparation., Materials and Methods: Fifty-four midcoronal dentin surfaces, obtained from sound human molars, were irradiated with an Er,Cr:YSGG laser or prepared with a diamond bur using a high-speed turbine. One etch-and-rinse (Optibond FL/Kerr) and three self-etching adhesives (Adper Prompt L-Pop/3M ESPE, Clearfil SE Bond/Kuraray, and Clearfil S3 Bond/Kuraray) were used to bond the composite to dentin. The microtensile bond strength (microTBS) was determined after 24 h of storage in water at 37 degrees C. The Kruskal-Wallis test was used to determine pairwise statistical differences (p < 0.05). Prepared dentin surfaces, adhesive interfaces, and failure patterns were analyzed using a stereomicroscope and Field-emission gun Scanning Electron Microscopy (Feg-SEM)., Results: Significantly lower microTBS was observed to laser-irradiated than to bur-cut dentin (p < 0.05), irrespective of the adhesive employed. Feg-SEM photomicrographs of lased dentin revealed an imbricate patterned substrate and the presence of microcracks at the dentin surface., Conclusion: Morphological alterations produced by Er,Cr:YSGG laser-irradiation adversely influence the bonding effectiveness of adhesives to dentin.

Purpose: To evaluate how six different test parameters (TP) of the microtensile bond strength (microTBS) methodology influence the test outcome., Materials and Methods: The microtensile bond strength of adhesives bonded to dentin was measured, and the resultant failure patterns and stress-time graphs were analyzed, varying the microTBS specimen-fixation mode (TP1), the microspecimen geometry (TP2), the microspecimen bond surface area (TP3), the remaining dentin thickness of the microspecimens (TP4), the procedure employed to glue the microspecimen to the microTBS jig (TP5), and the microTBS crosshead speed (TP6)., Results: The orientation of the microspecimens to the actual interface primarily influenced the resultant microTBS value and the eventual failure pattern. A notched jig consistently yielded significantly higher mciroTBS values than samples fixed onto a flat jig or following a "top-bottom" design (TP1). A higher bond strength, a lower standard deviation/coefficient of variation, a failure closer to the interface, and a more representative number of specimens per tooth were obtained for nontrimmed, square microspecimens (TP2). The most reproducible results were obtained using square specimens of 1 mm2 (TP3), which could also be most easily prepared. The remaining dentin thickness (TP4) was an influential factor as well, whereas the microspecimen gluing protocol (TP5) and the crosshead speed (TP6) appeared less influential., Conclusion: As several test parameters significantly influenced the microTBS outcome, sufficient attention should be paid to these methodology variables with regard to the microTBS-test reliability and reproducibility.