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At least 289 records · Page 16Linked to original sources
PubMed1994

Penetration of a dentin bonding agent into dentin.

PURPOSE: To examine how the priming agents of Scotchbond Multi-Purpose (SMP) influenced the wettability of collagen in the demineralized zone and hence the penetration and adaptation of its bonding monomers. MATERIALS AND METHODS: Freshly extracted bovine teeth were ground to dentin with SiC paper. SMP and Z100 resin were used. Shear bond testing was performed as well as scanning electron microscopic evaluation. RESULTS: In contrast to the manufacturer's instructions, a 26.3% increase in shear bond strength was obtained when a second coat of priming agent was applied. This increase was statistically significant at the 5% level of confidence. SEM examination of failed conventionally air dried (CAD) specimens showed the presence of voids in the demineralized layer. SEM examination of failed specimens prepared by a critical point drying (CPD) technique showed that these voids were filled with collagen fibrils. The CPD technique also clearly showed that collagen fibrils were incorporated in the unfilled resin. Although priming agents appear to facilitate the penetration of unfilled resin into the demineralized layer and the dentin tubules, areas of unincorporated collagen fibrils can be seen even after two or more applications of the priming agent.

Analysis of Variance↗
PubMed1986

Dentine hypersensitivity: effect of interactions between metal salts, fluoride and chlorhexidine on the uptake by dentine.

A large number of compounds may be applied to the teeth for preventive or therapeutic purposes, most notably in dentine hypersensitivity. The uptake of any one compound by tooth substances may clearly be affected by another to produce synergistic, additive or antagonistic effects. This study determined whether uptake interactions occurred between fluoride, chlorhexidine, strontium, tin and zinc. All compounds, in particular tin, showed considerable affinity for dentine. Fluoride reduced the uptake of zinc but not tin, strontium or chlorhexidine. Chlorhexidine increased the uptake of zinc, but not tin, strontium or fluoride. Zinc and tin decreased fluoride uptake but strontium had no such effect. Finally, chlorhexidine uptake was increased by zinc and tin but not by fluoride or strontium. Based on the theories proposed for the reaction of these various compounds with calcified tissues, explanations for the interactions can be made. The results appear relevant to some reported clinical effects of combinations of these compounds and indicate that such interactions may have advantageous or disadvantageous consequences depending on the basis for treatment.

Chlorhexidine↗
PubMed1990

Dentin dysplasia type II: absence of type III collagen in dentin.

A three-generation family with dentin dysplasia (DD) Type II is presented. Affected family members share common radiologic features with clinically varied expression of tooth discoloration and occlusal wear. Both the primary and the permanent dentition appear to be affected. No generalized connective tissue involvement is found. The mode of inheritance is autosomal dominant. Histologically, the findings are consistent with DD Type II. In indirect immunofluorescence, the irregular radicular dentin of an affected permanent tooth failed to stain with specific antibodies against Type III collagen and the N-terminal propeptide of Type III procollagen.

Collagen↗
PubMed1998

A scanning electron microscopic study of the effect of Gluma CPS bonding system on dentinal smear layers produced by different bur types and rotational speeds and on the resin-dentin interface.

OBJECTIVE: The purpose of this study was to investigate the effect of conditioners on smear layers produced by different bur types and rotational speeds and to study the interaction of subsequently applied primer and sealer with these conditioned surfaces. METHOD AND MATERIALS: Smear layers were produced on human teeth immediately after extraction by burs rotating at approximately 6,000 rpm without water spray and 400,000 rpm with water spray. Gluma CPS etchant was applied for 15, 30, and 60 seconds, and a 20% phosphoric acid liquid (control) was applied for 30 seconds to smear layers. The specimens were prepared by critical point drying for scanning electron microscopic imaging within 24 hours. Additional specimens were prepared and treated with Gluma CPS primer and sealer, according to the manufacturer's instructions. RESULTS: There were only small variations in the smear layer thicknesses with different bur types or speeds of rotation. Gluma CPS conditioner, applied for the recommended times, did not completely remove the smear layer. An altered smear layer, composed of a reaction product, remained on the dentinal surface. A zone of demineralization did occur, however, beneath the partially removed smear layer in both the 15- and 30-second specimens but was only partly filled by primer and sealer. Smear layers were completely removed by the 20% phosphoric acid liquid to expose a delicate collagen network. CONCLUSION: An understanding of the appropriate treatment for smear layers is crucial to the development of improved dentin bonding systems.

Acid Etching, Dental↗
PubMed1999

Influence of the time-point of salivary contamination on dentin shear bond strength of 3 dentin adhesive systems.

PURPOSE: The aim of this study was to evaluate the influence of the duration of salivary contamination at different stages during the bonding procedures on shear bond strengths (SBS) of 3 dentin adhesives. MATERIALS AND METHODS: Flat human dentin surfaces were produced by wet grinding on SiC paper 800. The adhesives used were Syntac Sprint (SS) (Vivadent), One Step (OS) (Bisco), Clearfil Liner Bond 2 (LB2) (Kuraray). Three durations of contamination (3 s, 10 s, and 20 s) at 3 stages (before adhesive application, after its application, and after its polymerization). In all cases the saliva was not rinsed off. Twenty-seven groups of 10 samples were studied according to 3 adhesives, 3 stages, and 3 durations of contamination. For each adhesive, 1 control group, 3 groups with contamination before adhesive application, 3 groups with salivary contamination on the uncured adhesive, and 3 groups with contamination after polymerization (except for SS) were studied. Composite cylinders (Z100, 3M; 3 mm Ø, 5 mm high) were polymerized on the surfaces and stored in 37 degrees C H2O for 48 hours prior to shear bond testing (v = 5 mm/min). RESULTS: Anova and Scheffe tests showed that for the one-bottle systems tested, salivary contamination prior to adhesive application had no adverse effect on bonding efficacy, SBS decreased significantly when saliva contamination occurred after adhesive application. The self-etching primer tested was more tolerant to salivary contamination, except when the salivary contamination occurred before the polymerization of the adhesive. CONCLUSIONS: Salivary contamination does not have the same influence at different stages of the bonding process with modern adhesives. Pending better knowledge of the mechanisms involved in the influence of salivary contamination on bonded assemblies, it seems necessary to continue to recommend using the rubber dam in adhesive dentistry.

Acrylates↗
PubMed2003

Influence of load cycling on marginal microleakage with two self-etching and two one-bottle dentin adhesive systems in dentin.

PURPOSE: To evaluate the influence of occlusal load cycling on cervical microleakage of proximal slot restorations located in dentin, using two self-etching and two one-bottle dentin adhesive systems. MATERIALS AND METHODS: 240 proximal slot cavities were prepared in 120 bovine teeth and divided into two groups, one with load cycling and one without. The groups were then subdivided into four subgroups according to the adhesive system used (Experimental EXL 547 Self-etching 3M, Clearfil SE Bond, Single Bond, and Optibond Solo Plus) and restored following the manufacturers' instructions. The teeth were then submitted to mechanical load cycling with a force of 80 N and a frequency of 5 Hz, simultaneously over both restorations of each tooth, for a total of 50,000 cycles per specimen. All specimens were subsequently immersed in a 2% methylene blue solution (pH 7.0), and sectioned to examine the extent of dye penetration under a stereomicroscope (40X). RESULTS: There was no statistically significant difference (p = 0.00002) between the loaded and unloaded teeth. However, a statistically significant difference was observed between the adhesive systems used. The experimental self-etching EXL 547 presented the lowest mean microleakage, but was only statistically significantly different from the Single Bond loaded and unloaded groups and the Clearfil SE Bond unloaded group. CONCLUSION: The application of 50,000 loading cycles did not affect the microleakage of the two self-etching and the two one-bottle adhesive systems evaluated. In vitro mechanical load cycling is an important factor to consider when evaluating the performance of adhesive systems under simulated masticatory conditions.

Animals↗
PubMed1998

Adhesion between collagen depleted dentin and dentin adhesives.

PURPOSE: To determine the influence of sodium hypochlorite treatment of dentin on shear bond strength and morphology. MATERIALS AND METHODS: Shear bond strengths of several dentin bonding agents were compared following specific surface treatments that included manufacturer's directions, etching plus sodium hypochlorite, and sodium hypochlorite alone. The treated surfaces and interfaces between bonding materials and treated surfaces were observed using an FE-SEM. RESULTS: Acetone-containing systems yielded equivalent or higher shear bond strengths when sodium hypochlorite was used following etching, as compared with normal procedures. In these cases it is proposed that the adhesive interacts strongly with the treated surface, that contains a high mineral content.

Acetone↗
PubMed1981

The incidence of dentinal tubules containing more than one process in the cuspal dentin of cat canine teeth.

The incidence of multiple processes within the tubules of the cuspal dentin of the cat's canine has been measured by counting directly from ultrathin sections examined in the electron microscope. The incidence is highly variable. The greatest incidence was found 1 mm below the cuspal dentino enamel junction where up to 75% of tubules in some areas contain more than one process. On average 33.6% of the tubules at this level contain multiple processes. The incidence declines linearly toward the apex with virtually no multiple processes occurring at 4 mm below the tip dentino enamel junction or beyond. Half of the "second processes" contain either mitochondria and/or vesicles. They are restricted to predentin where many of them end and to inner calcified dentin. Their distribution is similar to that described for nerve fibers in other studies. None of the processes participated in specialized junctions.

Animals↗
PubMed2001

Characterization of interglobular dentin and Tomes' granular layer in dog dentin using electron probe microanalysis in comparison with predentin.

The interglobular dentin (IG) and the Tomes' granular layer (TGL) as well as predentin are hypomineralized regions in dentin. Some previous studies proposed that the IG and the TGL are identical with difference only in size, whereas other suggested that they are distinct structures. In order to characterize their matrix components, the present study was designed to analyze the elements of calcium (Ca), phosphorus (P), and sulfur (S) in the IG and the TGL in comparison with predentin using the Electron Probe Microanalysis (EPMA). The TGL was highest in the concentration of both Ca and P among the hypomineralized regions followed by the IG and predentin, whereas predentin was the highest in the concentration of S followed by the IG and the TGL. Alcian blue staining suggested that the S elements identified with the EPMA are incorporated into the sulfated glycosaminoglycan chains of proteoglycans. The present study first demonstrated distinct characteristics of matrix components in the IG and the TGL, i.e., the IG is poorer in mineralization but much richer in a proteoglycan content than the TGL. The IG may originate from predentin because of their analogy, whereas the TGL may follow a different ontogeny.

Alcian Blue↗
PubMed1992

Mitogenic and dentin-inductive effects of crude bone morphogenetic protein from bone and dentin in primary adult pulp cell culture.

The effects of crude bone morphogenetic protein (BMP) derived from bone and dentin matrix on proliferation, production of extracellular matrix, and biologic function of the pulp cell were examined in the primary cell culture from permanent dental pulp. BMP from bone and from dentin matrix stimulated iodine 125-deoxyuridine incorporation in the absence of 10% calf serum. They increased sulfur 35-sulfate incorporation in proliferating stage and had no effects in stationary stage of culture. Alkaline phosphatase activities were inhibited in proliferating, stationary, and multilayered stages of culture. Osteocalcin synthesis was increased in culture treated with BMP from day 2 to day 10. These findings suggest that crude BMP might have mitogenic activity and some role in regulation of differentiation of pulp cells into odontoblasts.

Alkaline Phosphatase↗
PubMed2005

Micro-shear bond strength of five resin-based composites to dentin with five different dentin adhesives.

PURPOSE: To test whether the combination of dentin adhesive and resin-based composite from the same manufacturer had higher micro-shear bond strength than the other combinations of different manufacturers. METHODS: 25 experimental micro-shear bond test groups were made from the combination of five resin-based composites and five dentin adhesives (three total-etch adhesives and two self-etch adhesives) with extracted human molars stored in saline for 24 hours. The test was performed with the wire-loop method using a universal testing machine, and the micro-shear bond strengths were calculated. SEM photomicrographs of fractured sites were taken to check the failure mode. RESULTS: The combinations from same manufacturers failed to show higher bond strengths than the other combinations. Self-etch adhesives showed significantly higher micro-shear bond strengths than total-etch adhesives (P < 0.05). In total-etch adhesives, the kind of resin composite was important and in self-etch adhesives, the kind of adhesive had significant effect on micro-shear bond strength (P < 0.05). All sites showed mixed fractures.

Acrylic Resins↗
PubMedDate not supplied

Effect of dentinal pretreatment on bond strength between glass-ionomer cement and dentin.

Removal of the dentinal smear layer prior to placement of glass-ionomer cement is thought to maximize the strength of glass-ionomer cement/dentin bonding. This study evaluated the effect of three polyacrylic acid pretreatments on bond shear strength between glass-ionomer cement and dentin. Extracted human molars were divided into four groups of 30 specimens each. One group (the control) received no pretreatment. Specimens in the remaining groups were pretreated with one of three commercially available polyacrylic acid conditioners, used according to the manufacturers' recommendations. The results indicated significant differences in shear strength among pretreatment conditions. Since the manufacturers' recommendations varied, it is not clear if these results were due to differences in polyacrylic acid concentration or to other factors, such as application time or placement procedure.

Dental Bonding↗
PubMed1994

Aspects of dentinal and pulpal pain. Pain of dentinal and pulpal origin--a review for the clinician.

Recent advances in understanding the mechanisms of pain arising from the dental pulp serve to benefit patients by improving the clinician's ability to diagnose and treat pain. There are two types of pain arising from the pulp which are mediated by entirely different nerve fibres, each with their own individual characteristics. One is a short, sharp fast pain which is induced by stimuli which cause a rapid fluid flow within the dentinal tubules. Such stimuli include cold, heat, air, drilling, and osmotic stimuli. Once the affected teeth are identified, they can often be treated by sealing the open, exposed dentine. The second type of pain is experienced as a slow, dull, aching, poorly localized pain which is mediated by pain fibres activated by stimuli which are noxious to the pulp, such as prolonged damaging heat and inflammatory mediators. Pain of this character can be difficult to diagnose and often indicates serious pulp damage necessitating removal of the offending pulp by endodontic therapy.

Dental Pulp↗
PubMed1994

Cloning and sequence determination of rat dentin sialoprotein, a novel dentin protein.

Dentin sialoprotein (DSP) is a 53-kDa protein isolated from rat dentin. It contains 29.6% carbohydrate (including 9% sialic acid) and has an overall composition similar to that of the bone sialoproteins osteopontin and bone sialoprotein (i.e. rich in Asp, Ser, Glu, and Gly). Using a monospecific anti-DSP polyclonal antibody to screen a rat incisor odontoblast cDNA library, a cDNA clone was isolated and sequenced. This approximately 750-base pair clone contained a DNA sequence corresponding to the NH2-terminal 9 amino acids of DSP. A second cDNA clone was isolated by using the first cDNA as a probe to rescreen the library. This second clone had the full-length DSP coding region. From the sequence, we deduced that the DSP cDNA coded for 366 amino acids, predominantly Asp, Ser, Glu, and Gly. The amino acid composition calculated for this sequence was very similar to that for purified DSP reported earlier; likewise the deduced molecular weight (53,045) was essentially identical to that determined by sedimentation equilibrium. Six potential N-linked glycosylation sites were present in the predicted DSP sequence. No Arg-Gly-Asp sequence was found, and the sequence for DSP was dissimilar to those of osteopontin and bone sialoprotein. Multiple transcripts near 4.6 and 1.5 kilobases were detected by Northern blot analysis in the incisor of 21-day-old rat and the tooth germ of the newborn rat. Consistent with previous immunohistochemical findings, no transcripts were detected in brain, salivary gland, heart, muscle, spleen, kidney, intestine, lung, liver, pancreas, tibia, calvaria, or osteoblast-like osteosarcoma (ROS 17/2.8) cells, indicating that DSP is specifically expressed by odontoblasts and related cells.

Amino Acid Sequence↗
PubMed1989

Dentin perfusion effects on the shear bond strengths of bonding agents to dentin.

The effect of pulpal pressure on the shear bond strength of Scotchbond and Gluma was evaluated in the presence and absence of smear layers. There was no statistically significant difference in bond strength for either Scotchbond or Gluma on dentin with a smear layer in the presence or absence of 32 cm of hydrostatic pulpal pressure. When no pulpal pressure was present and the smear layer was removed, the bond strength of Scotchbond fell while that of Gluma nearly doubled. When 32 cm of pulp pressure was applied, the bond strength of Scotchbond/Silux fell 86% and that of Gluma fell 75% in 24 hours.

Dental Bonding↗
PubMed2004

Comparison of using calcium hydroxide or a dentine primer for reducing dentinal pain following crown preparation: a randomized clinical trial with an observation time up to 30 months.

The purpose of this study was to evaluate effect of a calcium hydroxide suspension [Ca(OH)2] or glutaraldehyde based dentine primer (GDP) to reduce tooth sensitivity after full crown preparation. Thirty-six patients were treated with Ca(OH)(2) on one tooth and with GDP on another. Patients completed a questionnaire regarding sensitivity during crown preparation, when the not-anaesthetized abutments were irritated [cotton pellet (20 degrees C)]. The teeth were tested before (T(0)) and after using the desensitizer (T(1)), again after 7 days (T(2)), 6 months (T(3)) and 30 months (T(4)). The results were registered on a visual analogue scale [0 (no pain)-100 (severe pain)]. The changes of tooth sensitivity between different testing times were analysed. The median and the (interquartile range) for the different time intervals for Ca(OH)(2) were DeltaT(0)-T(1): 5 (6-17), DeltaT(0)-T(2): 17 (14-32), and for GDP, DeltaT(0)-T(1): 9 (7-18) DeltaT(0)-T(2): 18 (16-33), the decreases in sensitivity were lower for DeltaT(0)-T(1) than for DeltaT(0)-T(2) for both desensitizers (P < 0.001). There was no statistical difference (P > 0.05) between the agents (DeltaT(0)-T(1), DeltaT(0)-T(2), DeltaT(3)-T(4)). Both substances might be useful in reducing tooth sensitivity after crown preparation, but no differences in the efficacy were found when comparing the materials.

Adult↗