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PubMed2003

Effect of artificial saliva contamination on pH value change and dentin bond strength.

OBJECTIVE: This study was to examine the effect of artificial saliva contamination on pH change of the dentin surface and the micro-shear bond strength (MSBS) of the two bonding systems to contaminated dentin. METHODS: Fifty-six human dentin disks were tested with two resin bonding systems: a self-etching primer system, Clearfil SE Bond (Kuraray Medical Inc., Tokyo, Japan), and a one-bottle adhesive system, Single Bond (3M-ESPE, St. Paul, MN). Dentin surfaces were conditioned with the self-etching primer (primer) or phosphoric acid (etchant) and divided into four groups: conditioning without contamination (conditioning), contamination with artificial saliva (contamination), re-conditioning the contaminated dentin (re-conditioning), water-rinsing the contaminated dentin and re-conditioning (rinsing and re-conditioning). The pH change on the dentin surface was measured using a pH-imaging microscope (SCHEM-100, Horiba Ltd, Kyoto, Japan) to estimate the acid-base characteristics of the conditioned and contaminated dentin surface. The MSBS to the dentin was examined after storage in distilled water at 37 degrees C for 1 week. RESULTS: The pH of intact dentin surfaces was 6.9. Conditioning with the primer and etchant decreased the pH to 5.4 and 5.9, respectively. Saliva contamination increased the pH slightly, and re-conditioning decreased the pH again. The MSBS of the two bonding systems decreased after contamination. Re-priming restored the MSBS to control values, while re-etching did not. Rinsing and re-priming produced a reduction in MSBS, and rinsing and re-etching did not increase the MSBS. SIGNIFICANCE: The conditioning and saliva contamination changed the pH value of dentin surface. The MSBS decreased after contamination; however, re-priming with SE Bond primer was an adequate treatment to restore the bond strength.

Acid Etching, Dental↗

PubMed1997

In vitro interfacial relationship between human dentin and one-bottle dental adhesives.

OBJECTIVES: One-bottle dentin adhesives combine primer and adhesive resin into a single solution. This study was conducted to determine the bond strengths to dentin of four one-bottle bonding systems and to evaluate their SEM interfacial morphology. The hypothesis to be tested was that the water-based bonding system would produce lower bond strengths and less complete penetration into dentin than other bonding systems that are dissolved in organic solvents. METHODS: Forty extracted molars were ground to expose middle dentin and were randomly assigned to four groups (n = 10): Group 1--Experimental Single Bond (3M Dental Products Division); Group 2--Prime&Bond 2.1, pre-launch version (Dentsply DeTrey); Group 3--Syntac Single-Component (Vivadent); Group 4--Tenure Quik with Fluoride (Den-Mat Co.) The surfaces were treated according to manufacturers' instructions. After 24 h in water, the specimens were thermocycled, and the bond strengths were measured in shear. The data were analyzed with ANOVA and Duncan's test at a confidence level of 95%. Further, the adhesives were also applied to 600 microns thick dentin disks. After preparing polished cross sections, the bonded interfaces were demineralized, deproteinized, and observed under a FE-SEM. The morphological appearance of the resin-dentin interface surfaces was compared by screening the entire resin-dentin interface for each specimen. RESULTS: Two morphological characteristics were evaluated: 1) the depth of resin penetration into the tubules and 2) the thickness and density of the resin-dentin interdiffusion zone. Single Bond showed statistically higher mean shear bond strengths (p < 0.001) compared to the other three materials. Specimens prepared with Syntac Single-Component and Prime&Bond 2.1 were ranked in the intermediary Duncan's grouping. Specimens bonded with Tenure Quik with Fluoride exhibited the lowest mean shear bond strength. All materials penetrated and hybridized dentin. Single Bond formed a thick layer of adhesive resin on the top of the interdiffusion area without debonding, whereas some areas of debonding were observed on the top of the hybrid layers for Prime&Bond 2.1 and Syntac Single-Component. For the water-based adhesive Syntac Single-Component, the interdiffusion zone displayed a thick filigree pattern, containing scattered open spaces between the resin-enveloped collagen fibers. Tenure Quik with Fluoride did not thoroughly infiltrate the demineralized dentin zone, resulting in wide gaps in all specimens. Prime&Bond 2.1 formed the shortest resin tags, whereas Syntac Single-Component formed the longest resin tags. SIGNIFICANCE: Bonding to dentin remains unpredictable using one-bottle bonding systems. The chemistry of each individual material may be more important than the type of solvent.

Acetone↗

PubMed2000

The effect of interface stiffness on dentin-composite interfacial fracture resistance.

OBJECTIVES: The dentin-composite interface should withstand stresses that develop initially during composite polymerization and later during clinical function. The elastic behavior of the dentin-composite interface, which could be represented by an interfacial stiffness parameter, is not completely understood. The purpose of this study was to measure the relative interfacial stiffness of dentin-composite interfaces formed using commercially available dentin bonding agents and to relate these relative interfacial stiffness results to previously reported interfacial fracture toughness (K(ICi)) values. METHODS: The miniature short-rod fracture toughness specimen geometry containing a dentin-composite interface was used for testing. Specimens were aged in distilled water at 37 degrees C for 180days prior to tensile loading at an extension rate of 0.5mm/min. The relative interfacial stiffness was determined from the initial slope of the force-displacement curve that was obtained from each fracture toughness test. ANOVA, Fishers LSD, and linear regression tests were used for statistical analyses (p<0.05). RESULTS: The relative interfacial stiffnesses ranged from 16 to 92N/mm. The groups containing dentin-composite interfaces with greater depths of surface dentin demineralization generally exhibited higher interfacial stiffness than those with less dentin demineralization. Bonding to "wet" dentin produced higher relative interfacial stiffness results than bonding to "dry" dentin. A significant positive linear relationship was found among the individual (p=0.0001,r(2)=0.58) and the mean (p=0.0004,r(2)=0.97) relative interfacial stiffness and K(ICi) results. CONCLUSIONS: The significant positive relationship between the relative interfacial stiffness and K(ICi) results suggest a benefit (increased interfacial fracture resistance) of a relatively stiff dentin-composite interface.

Acid Etching, Dental↗

PubMed1997

Effects of polyvalent alcohol solutions as dentine primers.

OBJECTIVES: The purpose of this study was to examine the bonding effect of polyvalent alcohols as dentine primers without a methacrylate group, which may cause contact dermatitis. METHODS: The efficacy of polyvalent alcohols as dentine primers was estimated by measuring the wall-to-wall polymerization contraction gap width of a light-activated resin composite filled in a cylindrical dentine cavity in an extracted human tooth. A dentine cavity was cleaned with ethylenediaminetetraacetic acid (EDTA) and primed with an aqueous solution of either ethylene glycol, glycerol, erythritol, xylitol or sorbitol at concentrations of between 25 and 75 wt%. A light-cured resin composite was filled after the application of a commercial dual-cured bonding agent. RESULTS: Contraction gap formation was completely prevented only in the group in which the dentine cavity had been primed with an aqueous solution of 62.5% wt% ethylene glycol. Furthermore, in the measurement of a tensile bond strength to a flat dentine surface, high tensile bond strength (17.5 +/- 4.4 MPa) was observed in the group that was primed with 62.5% ethylene glycol solution. CONCLUSION: These results suggest that it is not necessary to dissolve methacrylates in a dentine primer when the primer is dried with a blast of compressed air before application of a polymerizable, suitable bonding agent. It is concluded that a dentine primer composed of polyvalent alcohol solutions without a methacrylate group which may cause contact dermatitis, is effective as a dentine primer, affects the dentine surface, and promotes the efficacy of the dentine bonding system.

Acid Etching, Dental↗

PubMed2002

Micro-tensile bond strengths of bonding agents to pulpal floor dentine.

AIM: The purpose of this study was to characterize the dentine surface of the pulpal floor and to determine the micro-tensile bond strengths of two dentine adhesive systems used in conjunction with a resin composite core material to pulpal floor dentine. METHODOLOGY: Thirty-six extracted human molars were cut horizontally with a slow-speed diamond saw to expose the pulp chamber and the pulp tissue was removed. Eight teeth were used to investigate characteristics of untreated and etched dentine surfaces of the pulpal floor using SEM. Twenty-eight teeth were randomly allocated to two groups, each of 14 teeth. In group 1, a 'one-bottle' system (Prime & Bond NT) was used as dentine bonding agent and in group 2, a self-etching-priming system (Clearfil SE Bond) was applied. Pulp chambers of both groups were then filled with resin composite core buildup (FluoroCore) and kept moist in tap water at 37 degrees C for 24 h. Samples were prepared for micro-tensile bond testing by sectioning each tooth vertically in the mid-pulpal floor region and shaped to an hour-glass form of 1 +/- 0.2 mm(2) area at the bonded interface. Micro-tensile bond strengths were determined using a universal testing machine at a crosshead speed of 1 mm min-1. Fractured surfaces were examined by SEM. RESULTS: The intact pulpal floor showed numerous calcospherites with variable tubule density and few accessory canals. Etching the pulpal floor with 34% phosphoric acid gel resulted in an irregular surface with patent dentinal tubules and the dome-shaped calcospherites mostly lost. With self-etching primer, the superficial dentine surface was less demineralized and little peritubular dentine matrix was removed. Mean bond strength for the self-etching-priming (Clearfil SE Bond) specimens was significantly greater than for 'one-bottle' (Prime & Bond NT) specimens (P< 0.05, Student's t-test). The fracture mode of Clearfil SE Bond specimens was mostly partial cohesive failure within dentine, whilst Prime & Bond NT specimens mostly showed partial cohesive failure in bonding resin/composite. CONCLUSIONS: Despite an irregular surface morphology and absence of a smear layer, bonding to pulpal floor dentine was weaker than previously reported for cut coronal dentine. The self-etching-priming system bonded more strongly than the 'one-bottle' system.

Acid Etching, Dental↗

PubMed2001

The efficiency of dentine adhesives in treating non-caries cervical lesions.

The aim of this study was to prove the hypothesis that dentine adhesives can be used as therapeutic material in treating dentine hypersensitivity, regardless of aetiology. The research was conducted on 492 students of Zagreb University School of Dental Medicine (154 male, 338 female), 20-25-years-old. The defects of the tooth neck were found in 38 patients, on 133 teeth (38 of male patients, 95 of female) and dentine hypersensitivity was recorded according to the subjective sensations of patients. Therapeutic characteristics of three adhesive materials were examined simultaneously: All Bond 2, fourth generation adhesive, Syntac Single Component and One Step, fifth generation adhesives. Teeth treated with dentine lacquer Cervitec were used as a control group. Tooth necks were treated with selected materials according to instructions of a manufacturer. A completed statistical survey of the results has clearly shown that dentine adhesives can be used in symptomatic therapy of dentine hypersensitivity of the non-caries cervical lesions (NCCL). The survey has also shown that dentine adhesives of the fifth generation (Syntac Single Component and One Step) have much higher efficiency rate than dentine adhesives of the fourth generation (All Bond 2) and dentine lacquer (Cervitec). According to data complied through this study the conclusion can be brought forward that dentine adhesives are not a final solution to the problem of dentine hypersensitivity, because their efficiency decreases with time.

Adult↗

PubMed1989

Scanning electron microscopic characterization of sensitive vs. insensitive human radicular dentin.

Our aim was to investigate the structural changes of dentinal tubules in specimens obtained from both hypersensitive and naturally desensitized areas in wedge-shaped defects on the same exposed cervical dentin surface of a hypersensitive tooth. A new biopsy technique that makes use of a hollow, cylindrical diamond bur was designed so that specimens from exposed root dentin of vital teeth could be obtained. Twenty-two dentin biopsy pairs were divided into two groups; one was prepared for scanning electron microscopy (SEM) and the other for microradiography (MR). Small hypersensitive areas were identified by a scratch test on exposed human dentin in vivo. SEM observation of the dentin biopsies showed that the orifices of many dentinal tubules in hypersensitive areas were open and that membranous structures appeared on the walls of dentinal tubules. In naturally desensitized areas on the same dentin surface, most of the dentinal tubules were obturated with rhombohedral crystals of all sizes; membranous structures were not observed in these tubules. These results showed that hypersensitivity occurred on the exposed dentin when most of the tubular orifices were open.

Adult↗

PubMed1994

Acid profiles and pH of carious dentin in active and arrested lesions.

Organic acids in caries lesions play important roles in initiation and progress of dental caries. We investigated relationships between clinical types of dentin caries and acid profile or pH in the lesions. Caries lesions in dentin from 76 permanent teeth were classified into active, arrested, situated beneath a restoration, and unclassified types. The pH of carious dentin was distinctly lower than that of sound dentin (p < 0.001). Carious dentin with a high percentage of lactate had a lower pH than that with a high percentage of acetate and propionate (p < 0.001). Dentin from active lesions showed a mean pH of 4.9, and the dominant acid was lactate (mean percentage, 88.2). In contrast, carious dentin from arrested lesions showed a higher pH, 5.7, with acetate and propionate as the dominant acids (mean percentages of acetate and propionate, 64.0 and 18.2, respectively). The acid profile (mean percentages of acetate and propionate, 54.0 and 27.7, respectively) and pH (mean 5.8) of carious dentin sampled from lesions beneath a restoration were similar to those of dentin from arrested lesions. This study showed a clear relationship between clinical classification of dentin caries and acid profile and pH, suggesting that both factors are important in dentin caries etiology.

Acetates↗

PubMed1999

Effects of dentin depth and cavity configuration on bond strength.

During polymerization of resin composites, shrinkage stresses compete with resin-dentin bonds in a manner that can cause failure of the bond, depending upon the configuration of the cavity, its depth, and the restorative technique. The hypothesis tested in this study was that the effect of cavity configuration (C) and remaining dentin thickness (RDT) influence resin bond strength to the dentin of Class I cavity floors. The occlusal enamel was ground to expose a flat superficial dentin surface as a control (superficial dentin, C-factor = 1) in human extracted third molars. Cavities 3 mm long x 4 mm wide were prepared to a depth 2 mm below the ground dentin surfaces (deep dentin within cavity floor, C-factor = 3). To assess the relationship between C-factor and RDT, we removed the walls of cavities, making a deep flat surface for bonding (deep dentin, C-factor = 1). The teeth were restored with either Clearfil Liner Bond II (LB II), One-Step (OS), or Super-Bond D Liner (DL), followed by Clearfil Photo Posterior resin composite. After 24 hrs' storage in water, the teeth were sectioned vertically into 3 or 4 slabs (0.7 mm thick) and trimmed for the micro-tensile bond test so that we could determine the strength of the resin bonds to the pulpal floor. All groups gave high bond strengths to superficial dentin, but OS and DL gave significantly lower bond strengths to flat deep dentin when the C-factor was 1. When the C-factor was increased to 3 by the creation of a three-dimensional cavity preparation, the bond strengths of all materials fell (range, 21 to 35%), but the difference was significant (p < 0.05) only with DL. SEM observations of failure patterns showed that specimens with high bond strengths tended to exhibit cohesive failures within the hybrid layer, while specimens exhibiting low bond strengths showed failures at the top of the hybrid layer. Some adhesives do not bond well to deep dentin, making them more susceptible to polymerization shrinkage stress that develops in cavities with high C-factors.

Analysis of Variance↗

PubMed2000

An ultrastructural study of the influence of acidity of self-etching primers and smear layer thickness on bonding to intact dentin.

PURPOSE: The objectives of this study were (1) to determine the depth of demineralization into intact dentin using several self-etching primer systems with different pH values, and (2) to evaluate whether hybridization of intact dentin in Clearfil SE Bond may be affected by variation in the thickness of the smear layers. MATERIALS AND METHODS: Dentin disks were created from mid-coronal dentin in extracted, human third molars. Three self-etching primer systems (Clearfil Liner Bond II, Liner Bond 2V, and SE Bond) were applied separately to these disks to evaluate how deep self-etching systems penetrate through smear layers into intact dentin. Dentin treated with All-Bond 2 using the "no-etch" technique was used as a control group. In the second part of the study, dentin disks with different smear-layer thicknesses were produced. The cryofractured control group was devoid of a smear layer. The experimental teeth were ground with 60-, 180-, or 600-grit SiC paper and bonded using SE Bond. Dentin disks were bonded together and examined with TEM. RESULTS: All-Bond 2 did not etch beyond the smear layer. The three self-etching primers etched beyond the smear layer to form true hybrid layers within intact dentin. This layer was thickest with Liner Bond 2 (ca 1.2 to 1.4 microns), but very thin (0.5 micron) using both Liner Bond 2V and SE Bond. Application of SE Bond to dentin of different surface roughness produced hybridized smear layers of variable thickness. However, the thickness of the underlying true hybrid remained consistent for the four groups (ca 0.4 to 0.5 micron). CONCLUSION: Self-etching primers create thin hybrid layers that incorporate the smear layer. The suspicion that thick smear layers may interfere with the diffusion of self-etching primers into the underlying intact dentin was not confirmed.

Acid Etching, Dental↗

PubMedDate not supplied

Effect of caries disclosing agents on bond strengths of total-etch and self-etching primer dentin bonding systems to resin composite.

This study examined the effect of caries disclosing dyes on composite to dentin shear bond strengths of a total etch, one-bottle and two self-etching, non-rinsing primer dental adhesives. Two caries disclosing dyes were evaluated, Seek and Snoop, with three dentin adhesives, Prime & Bond NT, Prompt L-Pop and Clearfil SE Bond. Extracted human molars stored in 0.2% sodium azide were sectioned longitudinally to expose dentin and embedded in acrylic, leaving the dentin exposed. Each dentin adhesive had three test groups (n=12); a control and one with each of the caries disclosing dyes. The control group had the dentin conditioned and the adhesive applied following the manufacturer's instructions. The caries disclosing dye groups had the dentin first treated for 10 seconds with the disclosing dye, rinsed, then the dentin adhesives were applied as in the controls. A column of Tetric Ceram was bonded after dentin adhesive placement to each specimen and light cured. Specimens were stored in room temperature water for 24 hours, thermocycled for 1,000 cycles between 5 degrees C and 55 degrees C and tested in shear until failure. Mean +/- SD shear bond values (SBV) were determined in MPa. A one-way ANOVA and Student Neuman Keuls multiple comparison test within each DBS were performed at a significance level ofp<0.05 to analyze the caries disclosing dyes input on SBV versus the controls. Surface analysis to determine the nature of the type of dentin/composite fracture/ separation was also performed. For the fracture analysis data, a Chi-Square test was performed at a significance level of p<0.05. The results of this study indicate that using the two tested caries disclosing dyes, with a total etch, one bottle and two self-etching, non-rinsing primer dental adhesives did not negatively affect the dentin-to-composite shear bond strengths of the three tested dentin bonding systems (p>0.05).

Acid Etching, Dental↗

PubMed2004

[Bonding strength and interface effects of different dentin surface on acetone-based adhesives bonding].

PURPOSE: To study the influences on microstructure characteristic and bonding strength of acetone-based wet bonding systems when bonding on dry or wet dentin surface. METHODS: Three acetone-based wet bonding systems, Gluma One-Bond, Bond-1 and One-Step, were used to bond Chrisma composite resin to dry or moist dentin surface, and the bonding interface was observed with HITACHI S-2700 scanning electron microscope. Microtensile strengths of different groups were measured with Instro 1195. RESULTS: All three bonding systems can infiltrate well into dentin bonding interface in the wet groups. A hybrid layer of about 5microm could be observed with resin tags traversing from the resin layer above into the undemineralized dentin below and the lateral branch of dentinal tubule. In the dry groups, three zones, a surface and a basal hybrid layer sandwiching a middle hybridoid region, could be observed. The hybrid layer was very thinner. Microtensile strength had significantly decreased while bonding on dry dentin surface with acetone-based wet bonding systems, with the maximum decrease of 39% in Bond-1. CONCLUSION: Incompletely infiltrated adhesive on dentin bonding interface could be observed and microtensile strength had significantly decreased while bonding on dry dentin surface with acetone-based wet bonding systems. Moist dentin surface, which can maintain collagen-rich fibrous network of demineralized dentin, is necessary when bonding with acetone-based wet bonding systems. Microtensile strength approaches to the real dentin bonding strength.

Acetone↗

PubMed1992

Neurophysiological mechanisms of dentin hypersensitivity.

In hypersensitive teeth pain is typically induced by cold and hot fluids or foods brought to contact with the sensitive dentin or by osmotic and mechanical stimuli. The results of animal experiments indicate that intradental A-type nerve fibres are responsible for the sensitivity of dentin. They are most probably activated by the hydrodynamic mechanism. Thus, their activation is to a great extent dependent on the condition of dentin with either open or blocked dentinal tubules. Blocking of the tubules effectively prevents the nerve activation. Correspondingly, in human experiments, the condition of the dentinal tubules greatly affects dentin sensitivity. In clinical studies significantly more open tubules are found in sensitive compared to non-sensitive areas. However, hypersensitivity may sometimes persist despite of effective blocking of the tubules. This may indicate that some other mechanisms may operate in the nerve activation instead of, or in addition to the hydrodynamic one. Inflammation may sensitize the nerve endings to such an extent that smaller fluid shifts would be sufficient for nerve activation or, for example, thermal stimulation may activate the nerves by a direct effect. On the other hand, spontaneously occurring changes in the exposed dentin, which in many cases seem to block the tubules may reduce the responses to hydrodynamic stimulation and, thus, have an opposite effect on dentin sensitivity. The results of animal experiments indicate that functional changes of this kind may occur. These results also indicate that real dentin hypersensitivity can develop as a result of inflammation induced sensitization of the nerves in the pulp-dentin border in teeth with open dentinal tubules.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2006

An in-vitro investigation of the effect of a water additive and a new acidic primer on the tensile bond strength of composite resin to human enamel and dentine.

The aim of this study was to investigate the effect of a water additive on the bond strength of a composite restorative material to enamel and dentine which have undergone a range of surface treatments regimes. Human enamel and dentine specimens were prepared and divided into 3 surface treatment groups. Composite resin restorative material was bonded to the surface prepared enamel and dentine specimens. The tensile bond strength of the composite resin was measured using a Lloyd's testing machine. The tensile bond strength of composite resin to etched enamel surfaces using a standard etch technique was significantly greater than that to dentine (p < 0.05). For those specimens subjected to the addition of the water additive 'Alpron' the bond strength to the enamel was still significantly greater than to the dentine (p< 0.005). The addition of 'Alpron' to the water significantly improved the bond strength of composite to enamel and dentine when etched and placed with 'Prime&BondNT' (p < 0.05). There was no significant difference in bond strength of enamel and dentine specimens bonded using Xeno III (p> 0.05). However, the bond strength of dentine specimens bonded with Xeno III was significantly greater than other dentine specimens bonded with Prime&BondNT (p< 0.05). For those groups of specimens which included the water additive 'Alpron' in the regime, the tensile bond strength of the composite resin restorative material to enamel and dentine was greater than for those non water additive groups. The tensile bond strength of composite resin bonded to enamel surfaces prepared with 'Alpron' was significantly higher than that bonded to dentine surfaces.

Acid Etching, Dental↗

PubMed1991

Variability of clinical dentin substrates.

Clinical trials remain the only conclusive research of dentin adhesive performance, but variables unique to the oral environment may influence the results. Dentin variability is one factor that may account for extreme variations in clinical evaluations. Despite the encouraging results of laboratory studies, clinical trials with adhesive systems have been disappointing. Current adhesives are reported to react with dentin surfaces by chemical and/or micro-mechanical mechanisms. Dentin surfaces, such as cervical abrasions, are subject to intraoral changes and dentin tubules commonly become obturated by the growth of peritubular dentin or by the precipitation of calcific deposits within the tubules. The resulting sclerotic dentin may be less receptive to current dentin adhesives. An examination of clinically aged dentin surfaces has revealed an inordinate variability in tubular morphology. The more sclerotic dentin present, the less effective was dentin conditioning and resin composite adaptation. Early correlations with current clinical trials appear to substantiate that the greatest failure of restorations occurred in sclerotic lesions.

Aging↗

PubMed1990

Polymeric adhesion to dentin: contrasting substrates.

Clinical research has shown that resin dentin adhesive materials often fail prematurely despite encouraging laboratory-derived data. Current adhesives are reported to react with dentin surfaces by chemical and/or micro-mechanical mechanisms. The ionic bonding to calcium and the covalent coupling to collagen are representative chemical strategies employed today. Recent findings suggest that the mechanical interlocking of resins into open dentinal tubules may play an even more important role with present adhesive systems. Dentin surfaces, such as cervical abrasions, undergo changes in the oral cavity and dentinal tubules may become partially or completely obturated by the growth of peritubular dentin or by the precipitation of mineral salts within the tubules. The resulting sclerotic dentin may be less receptive to current dentin adhesives. An examination of clinically aged dentin surface types revealed extreme variability in tubular morphology. The more sclerotic dentin presented, the less effective was dentin conditioning and resin adaptation. Early correlations with ongoing clinical trials appear to substantiate this finding with the greatest failure of restorations occurring in more sclerotic lesions.

Adhesives↗

PubMedDate not supplied

Bond strength of composite to air-abraded enamel and dentin.

Human enamel and dentin were prepared with an air abrasion unit (KCP-2000), using two particle sizes (27 micrometers and 50 micrometers) of aluminum oxide. In vitro tensile bond strengths of a composite resin were determined after three enamel and three dentin surface treatments. Enamel treatments were: air abraded only, E-1; air abraded + adhesive, E-2; air abraded + acid etch + adhesive, E-3. Dentin surface treatments were air abraded only, D-1; air abraded + adhesive/no primer, D-2; air abraded + primer + adhesive, D-3. Etched enamel and dentin prepared with 600-grit SiC paper and adhesive served as controls. There were 10 replications for each condition. A dentin bonding system (Optibond) and a composite resin (Herculite XRV) were bonded to treated surfaces by light curing in an inverted, truncated cone die with a bond diameter of 3 mm. Samples were stored at 37 degrees C and 100% relative humidity for 24 hours and debonded in tension using a Universal Testing Machine at a 0.05 cm/min crosshead speed. Based on analysis of variance, there was no statistical difference between 27 micrometers and 50 micrometers aluminum oxide abrasive for both enamel and dentin. For enamel bond strengths, E-2 was significantly higher than E-1, and E-3 was significantly higher than E-1 and E-2. E-1 and E-2 were significantly lower than the control, while E-3 was not significantly different from the control (P < or = 0.05). For dentin bond strengths, D-2 was significantly higher than D-1, and D-3 was significantly higher than D-1 and D-2. All treatments except D-3 were significantly lower than the control (P < or = 0.05). Air-abrasion treatment of enamel and dentin alone resulted in reduced in vitro bond strengths as compared to etched enamel and dentin prepared with dentin adhesive and dentin primer.

Acid Etching, Dental↗

PubMed1994

Dentin surface treatment and bond strength of glass ionomers.

This study evaluated the effect of dentin surface treatment on shear bond strengths of two light- cured glass ionomer restorative materials to dentin. Cylinders of Fuji II LC and VariGlass VLC were bonded to dentin surfaces that were untreated, treated with a 10% polyacrylic acid (GC Conditioner), or treated with a dentin bonding agent primer (Prisma Universal Bond 3 Primer). Specimens were thermocycled and tested in shear at 7 days. Data for each restorative material were subjected to one way ANOVA and Tukey's procedure at the 0.05 probability level. For Fuji II LC, mean bond strength to conditioner-treated dentin was significantly higher than mean bond strength to primer-treated dentin and to untreated dentin. For VariGlass VLC, mean bond strength to primer-treated dentin was significantly higher than mean bond strength to untreated dentin. Bond strengths to primer-treated dentin and conditioner-treated dentin were not significantly different.

Acrylic Resins↗