SEARCH · PubMed Health

Results for “Dentin”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources

PubMed1988

Bonding of restorative resins to dentine: status of dentine adhesives and impact on cavity design and filling techniques.

In conjunction with the acid etch technique for bonding of restorative resins to enamel, an effective bonding to dentine would eliminate the need for retentive undercuts and ensure a tight marginal seal. Bonding to dentine can be achieved through dentine adhesives. These may be divided into Ca2+-bonding and collagen-bonding types. Several Ca2+-bonding adhesives are based on phosphate methacrylates. Adhesives of this type mediate a bond strength to dentine not exceeding 10 MPa. In contrast, Bowen's bonding system and the Gluma system yield bond strengths higher than 10 MPa. The two latter systems have recently been conceived in simplified versions. In general, the higher the bond strength to dentine mediated by an adhesive, the smaller are the marginal gaps formed by a composite resin polymerizing in a dentine cavity treated by the adhesive. The size and the shape of the cavity influence the width of the marginal gaps. A cavity having a V-shape gives rise to smaller gaps than box-shaped cavities. A filling technique with two 'inclining' layers reduces the width of marginal gaps. Combination of certain Ca2+-bonding and collagen-bonding adhesives results in increased bond strength and smaller marginal gaps.

Adhesives↗

PubMed1980

Occlusion of dentinal tubules under superficial attrited dentine.

A scanning electron microscope (S.E.M.) was used to examine dentinal tubules transversely fractured approximately 1.5 mms below a superficial dentinal attritional surface. The material not only included vital teeth but also young, intact premolars implanted into removable dentures. In these teeth the enamel on the buccal cusps was removed and the dentine exposed to attrition for 3 years. For comparison the tubules of intact teeth transversely fractured at the same level were examined. Intact control revealed open tubules of normal size in the area examined. Under attrited surfaces many tubules on the same level were completely occluded with material similar to that seen in peri-tubular dentine. Other tubules had varying degrees of reduction of the tubule lumen. The situation was the same in 4 teeth attrited in removable dentures. The findings support the view that while tubules in sclerotic dentine in teeth subjected to attrition may be occluded by a continuous growth of peritubular dentine, the oral milieu and saliva may also contribute to this process.

Adolescent↗

PubMed2001

Tensile bond strengths of four different dentin adhesives on irradiated and non-irradiated human dentin in vitro.

This study evaluated the influence of irradiation on dentin bond strength. Sixty irradiated and 60 non-irradiated human third molars were used. The irradiation dose of 60 Gy was fractionally applied over 6 weeks (2 Gy day(-1), 5 days week(-1). All teeth were prepared in a special manner allowing the simulation of intra-pulpal pressure and dentin perfusion. Dentin specimens with a thickness of 2.0 mm were obtained under standardized conditions. The specimens were randomly assigned to four experimental groups. Tensile bond strength of four different dentin bonding agents (Scotchbond 1, Solobond Plus, Prime&Bond 2.1 and Syntac) was evaluated using an Instron Universal testing machine. Pairwise comparison did not show any significant differences between the irradiated and non-irradiated groups. The influence of the different dentin adhesives was significant (P=0.0001; ANOVA). Compared with Solobond Plus and Prime&Bond 2.1, the use of Scotchbond 1 resulted in a significantly higher tensile bond strength in non-irradiated specimen (P< 0.05; closed test procedure based on Kruskal-Wallis test). Within the limitations of an in vitro study, it can be concluded that adhesive restoration procedures can be successfully used in patients irradiated for cancer of the head and neck.

Adhesives↗

PubMed1995

The diameter of dentinal tubules in human coronal dentine after demineralization and air drying. A combined light microscopy and SEM study.

The diameter of dentinal tubules after demineralization and/or air drying has been quantified using light microscopy and scanning electron microscopy (SEM). The tubule diameter was assessed at a distance of about 1.5 mm (range 1.0-2.0 mm) from the pulp. Tubule diameter was measured in the wet state, after 10-min and 12-hour air drying as well as after critical point drying (CO2) by SEM. The results show that drying effects on tubule diameter are small in sound tissue, but are sizeable in demineralized dentine. Comparing light microscopic (wet) and SEM observations show that the differences in tubule diameter are small for sound but substantial for demineralized dentine. An important result is that in the wet state the diameters of the tubules (being 1.3 +/- 0.2 microns in sound dentine) are 2.5 +/- 0.3, 2.2 +/- 0.3 and 1.7 +/- 0.2 microns after 1, 2 and 3 weeks of demineralization, respectively. The decreased tubule diameter with increasing demineralization may be important for permeability and transport phenomena in dentine caries and presumably in hypersensitivity.

Adolescent↗

PubMed2002

Dentine bonding agents--a review of adhesion to dentine.

Although constant innovation has improved the performance of dentine adhesives, the true mechanism of resin adhesion to dentine is still not clear and the optimal dentinal surface pretreatment has yet to be determined for adhesive integrity of resin to dentine. The integrity of the collagen fibrils left exposed upon acid etching seem to play a major role in the mechanism of adhesion and intermingling of the adhesive monomers with the filigree of collagen fibers or hybrid layer should be considered the paramount dentine bonding mechanism. Definite trends are emerging but more research is necessary before general conclusions can be made about the functions of different bonding agents. The all-in-one self-etching/self-primer bottle systems are relatively new to the market and need more research before they can be advocated as the agent of choice.

Acid Etching, Dental↗

PubMed1992

Dentin permeability and dentin sensitivity.

The hydrodynamic theory of dentin sensitivity is based on the premise that sensitive dentin is permeable throughout the length of the tubules. Such a condition may permit the diffusion of bacterial products across dentin to the pulp where they may cause irritation of pulpal soft tissues. However, the slow outward movement of dentinal fluid tends to flush the tubules free of exogenous substances. This balance between the inward diffusion of exogenous substances, whether bacterial or the active ingredients in desensitizing medicaments, and the cleansing action of dentinal fluid flow needs to be examined experimentally.

Dentin↗

PubMed1995

Resin-dentin interface of Scotchbond Multi-Purpose dentin adhesive.

PURPOSE: To evaluate the interface between dentin, Scotchbond Multi-Purpose (SMP), and resin composite (Z100) using confocal fluorescence microscopy. MATERIALS AND METHODS: Novel techniques were employed to view and record at video rate the application of the SMP primer and adhesive onto the dentin surface. The subsurface morphology of the dentin/restorative interface was also studied. To facilitate this study, the components of the adhesive system were labeled with fluorescent dyes. RESULTS: In an ideal situation, the primer and adhesive penetrated the dentin tubules, a distinct hybrid zone was formed and a thin layer of adhesive was observed at the interfacial region. However, the primed dentin surface was sensitive to disruption by the adhesive application brush during its placement, so that parts of the primer layer could be incorporated into the adhesive. This disruption could only be seen using confocal microscopy and a fluorescence labeling technique. Delamination of the primer layer was not observed when the adhesive film was thinned by air blowing. The application of an air stream to the cavity surface increased the penetration of the primer and adhesive along the dentin tubules, but also increased the thickness of the adhesive within irregularities on the cavity surface and at the cavity line angle. The cause of the problems in the handling properties of SMP may be the difference in viscosity between the two components (primer and adhesive) at the adhesive interface.

Composite Resins↗

PubMed2005

Dentin glycoprotein: the protein in the middle of the dentin sialophosphoprotein chimera.

Dentin sialophosphoprotein (DSPP) is a major secretory product of odontoblasts and is critical for proper dentin formation. DSPP is believed to be processed into only two structural/functional domains: dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). Here we report the isolation and characterization of a third domain of DSPP, designated dentin glycoprotein (DGP). DGP was isolated from a guanidine/EDTA extract of porcine tooth dentin by ion exchange, hydroxyapatite affinity, size exclusion, and RP-HPL chromatography. Endoproteinase lysine C digestion products of DGP were characterized by Edman sequencing and mass spectrometry. The porcine DGP backbone is the 81-amino acid segment of DSPP (Ser392 to Gly472) between the DSP and DPP domains. DGP has four phosphorylated serine residues (Ser453, Ser455, Ser457, and Ser462) and one glycosylated asparagine (Asn397). There are no other post-translational modifications. DGP is a stains-all positive protein with an apparent molecular mass on SDS-PAGE of 19 kDa, which is reduced by glycopeptidase A digestion to 16 kDa. A variety of glycans can be linked to Asn397. All are complex biantennary structures with a common N-linked pentasaccharide core (mannose3-N-acetylglucosamine2), most with a fucosyl residue on the innermost N-acetylglucosamine. The alpha1-3 and alpha1-6 arms are always galactose beta1-4 N-acetylglucosamine beta1-2 mannose, and either or both arms can be unsialidated or monosialidated. The calculated monoisotopic molecular masses of the different glycosylated forms of the DGP phosphoprotein are: unsialidated 10,523 and 10,670, monosialidated 10,815 and 10,961, and disialidated 11,106, and 11,252 Da, with the disialidated forms being the most abundant.

Acetylglucosamine↗

PubMed2005

Dentin phosphoprotein compound mutation in dentin sialophosphoprotein causes dentinogenesis imperfecta type III.

A rare compound mutation involving a 36 bp deletion and 18 bp insertion within exon 5 of the dentin sialophosphoprotein (DSPP) gene has been identified in a family with dentinogenesis imperfecta type III (DGI-III). The DSPP gene encodes two major tooth matrix proteins dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). DSPP mutations associated with DGI-III results in an in frame truncation of the serine aspartic acid triplet repeat found in DPP near the highly conserved carboxyl terminal region shortening the protein by six amino acids. Clinically this family presents with discolored amber opalescent teeth and severe attrition of the tooth structure. This study is the first report of a mutation within DPP associated with a genetic dentin disease. Our study indicates that DGI-III is allelic with some forms of DGI-II with and without progressive hearing loss and dentin dysplasia type II that have been shown to be caused by mutations within the DSP coding or signal peptide regions.

Amino Acid Sequence↗

PubMed1992

Dentine bonding agents--characteristic bond strength as a function of dentine depth.

The tensile bond strength to dentine of four dentine bonding agents has been measured at various depths within dentine and the results analysed using Weibull analysis. There were significant differences in the bond strength values among the four products particularly with near-surface dentine. Despite the differences in chemical composition among the materials the trend of decreasing bond strength with increasing depth of dentine was common to them all. This suggests that the underlying mechanism of adhesion may be common to all four products despite their differing chemical compositions.

Adhesiveness↗

PubMed2000

Resistance of two dentin-bonding agents and a dentin densensitizer to acid erosion in vitro.

OBJECTIVES: To determine the resistance of two dentin-bonding agents (DBAs) and a dentin desensitizer to simulated dental erosion. METHODS: Twenty teeth in each of three groups of selected premolars, with exposed cervical dentin, were treated with one of three dentin surface treatment systems: Gluma Desensitizer (Heraeus Kulzer (UK) Ltd), One Coat Bond (Whaledent (UK) Ltd), and Optibond FL (Kerr (UK) Ltd) and exposed to water (control) and an erosive challenge (Coca Cola) for 14 days. Sequential tracings of the specimens were taken, superimposed and the mean reduction in densensitizer or DBA thickness and or tooth loss determined. RESULTS: A mean loss of 77 microns (s.d. 14.6 microns) of tooth tissue over the untreated sites following 14 days exposure to Coca Cola was observed. The application of DBAs, as opposed to Gluma Desensistizer alone, over exposed dentin surfaces afforded substantial protection against erosion by Coca Cola over the period of study. The mean change in vertical profile of teeth treated with a DBA was 20 microns (s.d. 14.7 microns), almost four times less than that seen over untreated sites. SIGNIFICANCE: With the exception of Gluma Desensitizer, which was lost completely, One Coat Bond and Optibond FL demonstrated levels of acid dissolution resistance, which would be of potential value clinically.

Analysis of Variance↗

PubMed1996

Correlative transmission electron microscopy examination of nondemineralized and demineralized resin-dentin interfaces formed by two dentin adhesive systems.

The resin-dentin interface formed by two dentin adhesives, Optibond (OPTI, Kerr) and Scotchbond Multi-Purpose (SBMP, 3M), was ultramorphologically examined by transmission electron microscopy (TEM). Ultrastructural information from nondemineralized and demineralized sections was correlated. It was hypothesized that the different chemical formulations of the two adhesives would result in a different morphological appearance of the hybrid layer. Ultrastructural TEM examination proved that each of the two dentin adhesive systems was able to establish a micromechanical bond between dentin and resin with the formation of a hybrid layer. However, the interfacial hybridization process that took place to produce this resin-dentin bond appeared to be specifically related to the chemical composition and application modes of both systems. OPTI consistently presented with a hybrid layer with a relatively uniform ultrastructure, electron density, and acid resistance. These three parameters were found to be more variable for the hybrid layer formed by SBMP. Characteristic of SBMP was the identification of an amorphous phase deposited at the outer surface of the hybrid layer. Although both adhesive systems investigated follow a total-etch concept, their specific chemical formulations result in different interfacial ultrastructures that are probably related to different underlying bonding mechanisms. The clinical significance of these morphological findings, however, is still unknown.

Acid Etching, Dental↗

PubMed2001

Influence of environmental conditions on dentin bond strengths of recently developed dentin bonding systems.

A study was conducted to investigate the influence of temperature and relative humidity (RH) on the bond strengths of several recently developed dentin bonding systems. Six environmental conditions, (A) 25+/-0.5 degrees C, 50+/-5% RH, (B) 25+/-0.5 degrees C, 80+/-5% RH, (C) 25+/-0.5 degrees C, 95+/-5 % RH, (D) 37+/-0.5 degrees C, 50 +/-5 % RH, (E) 37+/-0.5 degrees C, 80+/-5% RH, (F) 37+/-0.5 degrees C, 95+/-5 % RH were used. Bovine mandibular incisors were mounted in self-curing resin and the facial surfaces were ground on wet #600 SiC paper to expose the dentin. After the tooth surface had been treated according to each manufacturer's instructions, adhesives were applied, followed by condensation of resin composites into a mold placed on the dentin surface. Fifteen specimens per group were stored in distilled water at 37 degrees C for 24 h, and then shear-tested at a cross-head speed of 1.0 mm/min. Statistical analysis was carried out with two-way ANOVA followed by Tukey's test (P<0.05). Dentin bond strengths decreased with increasing relative humidity but were not influenced by environmental temperature. Even though one-bottle adhesive systems require a wet dentin surface, their bond strengths are affected by an increase in environmental humidity.

Alkanes↗

PubMedDate not supplied

Morphological and mechanical characterization of the acid-base resistant zone at the adhesive-dentin interface of intact and caries-affected dentin.

This study examined the ultrastructure of both intact and caries affected dentin-adhesive interface after artificial secondary caries formation, using scanning electron microscopy and nanoindentation testing. Half of the prepared specimens were bonded with Clearfil SE Bond (Kuraray Medical, Japan) and a resin composite (Metafil Flo, Sun Medical, Japan) for the nanoindentation test. The other specimens were stored in a buffered demineralizing solution for 90 minutes, then observed using SEM. An acid-base resistant zone (ABRZ) was observed beneath the hybrid layer, distinguished by argon-ion etching. The ABRZ of caries-affected dentin was thicker than that of normal dentin, while its nanohardess was lower than normal dentin (p<0.05). It is suggested that the monomer of Clearfil SE Bond penetrated deeper than previously reported, creating a so-called "hybrid layer." However, its physical properties depended on the condition of the dentin.

Acids↗

PubMed2001

Effect of dentin adhesives on the enamel-dentin/composite interfacial microleakage.

PURPOSE: To evaluate the microleakage at the enamel-dentin resin-based composite (RBC) interface of 4 dentin bonding systems (DBS). MATERIALS AND METHODS: Standardized kidney-shaped Class V cavities were prepared on the buccal and lingual surfaces at the cemento-enamel junction of 90 extracted human teeth and restored with a microhybrid RBC (Filtek P60) following application of either Excite (EXC), a single component adhesive; Prompt L Pop (PLP), a self-etching priming bonding adhesive; Clearfil SE Bond (SEB), a self-etching adhesive; or OptiBond Solo (OPS), a single component adhesive. The teeth were thermocycled, immersed in a dye solution and sectioned. The enamel failures and the occlusal and cervical dentin microleakages were measured. RESULTS: Significant differences were evident between the self-etching adhesives and the adhesives using phosphoric acid (P 0.05) for the enamel. The occlusal dentin microleakage was similar for the four DBS. PLP presented the worst values at the cervical dentin margin compared to the three other DBS. Significant differences were noted between PLP and EXC and OPS, which performed better.

Acid Etching, Dental↗

PubMedDate not supplied

The influence of dentin adhesives on the demineralization of irradiated and non-irradiated human root dentin.

This study determined the caries-protective effects of two different dentin bonding systems (Syntac, Scotchbond) on sound and irradiated root surfaces in vitro. The root surfaces of 30 freshly extracted caries-free human molars were used. The teeth were bisected in the mesio-distal direction and all lingual halves of the teeth were irradiated. The irradiation dose of 60 Gy was fractionally applied over six weeks (2 Gy/day, 5d/wk). All halves were then coated with acid-resistant nail varnish, exposing two rectangular windows 6 mm2 each on the dentinal root surface. One window served as an untreated control, while the other was treated with one of the above mentioned dentin adhesive systems. The specimens were randomly distributed among the four experimental groups as follow: Group A: Syntac, non-irradiated; Group AR: Syntac, irradiated; Group B: Scotchbond, non-irradiated; Group BR: Scotchbond, irradiated. Subsequently, all specimens were demineralized for 14 days with acidified gel (HEC, pH 4.8, 37 degrees C). From each window, two dentinal slabs were cut. The slabs were ground to a thickness of 80 microm and submerged in water. The depth of the lesions was determined using a polarized light microscope. The non-irradiated control specimens showed lesions with an average depth of 63 microm (+/-10,2 microm). In the case of the irradiated control specimen, the lesion depth was not significantly different. In all experimental groups, the lesion depth was significantly reduced compared to the control groups. Statistical analysis revealed no significant differences between the irradiated and non-irradiated specimens. It can be concluded that demineralization of the root surface can be hampered by application of the dentin adhesive systems tested. In this study, no differences between irradiated and sound root surfaces could be detected.

Analysis of Variance↗

PubMed2004

Influence of different dentin etching times and concentrations and air-abrasion technique on dentin microtensile bond strength.

PURPOSE: To determine the influence of different dentin treatments on the microtensile bond strengths of adhesive resins to dentin. METHODS: Fifteen human molars were ground to 600-grit to obtain flat root-dentin surfaces. Five different dentin treatments were evaluated: Group 1--10% phosphoric acid for 30 seconds; Group 2--37% phosphoric acid for 15 seconds; Group 3--air-abrasion for 10 seconds followed by 10% phosphoric acid for 30 seconds; Group 4--air-abasion for 10 seconds followed by 37% phosphoric acid for 15 seconds. The dental adhesive (OptiBond Solo Plus) was applied according to manufacturer's instructions and followed by composite (Z100) application to provide sufficient bulk for microtensile bond testing. All samples were placed in distilled water for 24 hours at 37 degrees C, thermocycled for 500 cycles in distilled water at 10 degrees C and 50 degrees C, and serially sliced perpendicular to the adhesive surface and subjected to tensile forces (0.5 mm/minute). Additional samples were prepared for SEM to observe the adhesive interface. RESULTS: Group 2 exhibited significantly (P < 0.05) lower bond strength values than all other treatments. The bond strengths of the different conditions were (in MPa): Group 1: 43.0 +/- 16.1; Group 2: 29.2 +/- 8.3; Group 3: 48.1 +/- 14.2; Group 4: 41.0 +/- 9.3. The dentin treated with phosphoric acid 37% for 15 seconds showed the lowest values of microtensile bond strength. The results obtained with Groups 1, 3 and 4 were statistically similar.

Acid Etching, Dental↗

PubMedDate not supplied

Effect of dentin age on effectiveness of dentin bonding agents.

The purpose of this research effort was to investigate the effect of age changes in dentin on the effectiveness of two dentin adhesives in minimizing microleakage at the tooth-restoration interface. Cavities were prepared in permanent teeth extracted from patients below 20 years or over 55 years of age. Wedge-shaped cervical preparations were made with the gingival cavosurface margin on dentin. Treatment groups were randomly restored with one of two composite restorative materials, together with the appropriate dentin adhesives. The control group specimens were restored with the respective composite restorative materials without the adhesives. All specimens were thermocycled, then placed in 0.5% basic fuchsin dye solution for 24 hours and subsequently sectioned longitudinally. Microleakage at the tooth-restoration interface was assessed by dye penetration. The results showed that the use of adhesives significantly reduced microleakage along the tooth-restoration interface. The adhesive formulated with glycidyl methacrylate was significantly more effective in reducing microleakage in dentin of the over-55 age group.

Adhesives↗