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PubMed2004

Microtensile bond strength of self-etching adhesives to enamel and dentin.

PURPOSE: To measure the microtensile bond strength to enamel and dentin of three self-etching adhesives in comparison with a total-etch two-step system as a control. MATERIALS AND METHODS: A total of 40 extracted human molars were stored in saline solution until use, then divided into 4 groups of 10 teeth (one group per adhesive system). Half of each of these groups underwent bond strength tests on enamel, and the other half was used for adhesion testing on dentin. The following experimental groups (n = 5) were then formed: E(1) Adper Prompt-L-Pop (AP, 3M ESPE) on enamel; E(2) Xeno CF II (X, Sanking Kogyo) on enamel; E(3) AdheSE (AS, Ivoclar-Vivadent) on enamel; E(4) Excite (EX, Ivoclar-Vivadent) on enamel; D(1) AP on dentin; D(2): X on dentin; D(3) AS on dentin; D(4) EX on dentin. Each tooth yielded 15 to 20 sticks about 0.9 x 0.9 mm in cross-sectional area for microtensile testing. Specimens were loaded in tension at a crosshead speed of 0.5 mm/minute, and bond strength at failure was calculated in MPa. A two-way ANOVA was applied to test for significance of the differences among the groups. RESULTS: The bond strength values of Excite (the control) were significantly higher than those of the test products on enamel (42.92+/-4.8 MPa) and on dentin (45.80+/-5.79 MPa). The self-etching adhesives AdheSE (28.48+/-4.71 MPa) and Xeno CF II (27.22+/-2.74 MPa) revealed significantly stronger adhesion than Adper Prompt-L-Pop (20.16+/-2.07 MPa) on dentin. On enamel, all self-etching test materials performed similarly. The substrate did not appear to have a significant influence on adhesion, as each material reached comparable levels of bond strength on enamel and dentin. CONCLUSION: On both substrates the self-etching adhesives tested performed significantly worse than did the total-etch system.

Acrylic Resins↗

PubMed2005

[The effect of matrix metalloproteinase-1 on root surface dentin matrix: a scanning electron microscope observation].

OBJECTIVE: To observe the effect of matrix metalloproteinase-1 (MMP-1) from human host on degradation of dentin organic matrix of root dentin. METHODS: The freshly extracted caries-free impacted teeth were selected. Teeth were cut transversely under the enamel-cementum junction into dentin sections with a thickness of about 5 mm. Then all sections with removal of cementum, pulp and predentin were randomly divided into four groups. In the first group, dentin sections were demineralized with acid solution for 21 days, and then incubated with MMP-1 solution for 7 days; the second group were only treated with acid solution for 21 days; the third group were only attacked by MMP-1 solution for 7 days; and the fourth group were untreated as a control. Then all sections were dehydrated in ascending strength of alcohol, critically dried, coated with platinum, and then observed under scanning electron microscope(SEM). RESULTS: The dentin sections of root surface attacked by acid and MMP-1 showed that demineralization of dentin mineral and degradation of dentin matrix fibrae synchronously happened. The dentin matrix fibrae wasn't degradated in the groups treated with acid or MMP-1. CONCLUSION: The proteinases from human host may play an important role in the development of root surface caries. MMP-1 may distinctly degradate the organic matrix of demineralized dentin.

Dental Cementum↗

PubMedDate not supplied

The microtensile bond strength of Fuji IX glass ionomer cement to antibacterial conditioned dentin.

INTRODUCTION: Adding antibacterial agents to a dentin conditioner used for a glass ionomer cement (GIC) has been shown to be antibacterial; however, it is not known whether this antimicrobial conditioning agent affects the bond strength to dentin in situ. This study applied GIC to antibacterial conditioned dentin without rinsing and determined whether there is an affect on the material's bond strength. MATERIALS AND METHODS: Chlorhexidine acetate (CX), benzalkonium chloride (BC) and cetrimide (CT) were added to Dentin Conditioner (DC) (GC Corp, Japan) at 1% and 5% concentrations. Molars were sectioned coronally to expose dentin, onto which 50 microl of the test conditioners was applied for 20 seconds with a gentle scrubbing action and the residual liquid was blotted dry, as would occur under "field" conditions when performing atraumatic restorative therapy. To serve as the control, the DC was left in situ and compared to the DC that was washed off. Proportioned Fuji IX GIC (GC Corp, Japan) was built-up on the prepared dentin surface and varnish was applied and stored for 24 hours. An annular saw was used to create sticks of GIC bonded to dentin, with a bonding area 1 mm2. After 24 hours, the specimens were tested to failure in a Universal testing machine at a crosshead speed of 1 mm/minute. RESULTS: Five percent CX-DC was not tested, as it formed a precipitate. Results in MPa: DC-not washed, 9.3 +/- 2.4; DC-washed, 9.3 +/- 2.5; 1% BC-DC, 8.8 +/- 2.5; 1% CX-DC, 8.7 +/- 2.7; 1% CT-DC, 8.2 +/- 1.7; 5% CT-DC, 8.1 +/- 2.7; 5% BC-DC, 5.4 +/- 1.0. One-way ANOVA showed that there was a significant difference between the test groups (p < 0.05), and Tukey's studentized range test showed that only 5% BC-dentin conditioner left in situ was significantly different from the other groups. CONCLUSION: Under the conditions tested, only the 5% BC-DC left in situ affected the bond strength of Fuji IX to dentin.

Analysis of Variance↗

PubMedDate not supplied

Scanning electron microscopic analysis of dentin in vitamin D-resistant rickets--assessment of mineralization and correlation with clinical findings.

In vitamin D-resistant rickets, the basic dental defect is manifested in dentin. Structural investigations of rachitic dentin by light and scanning electron microscopy have revealed the presence of calcospherites separated by interglobular dentin. This occurs when calcospherites do not fuse. This study investigated the morphology and ultrastructure of rachitic dentin with three different clinical and histologic grades of severity to determine if dentin mineralization can be quantified by calcospherite size and degree of calcospherite fusion. The results showed that a correlation existed between calcospherite size, calcospherite fusion, and the degree of dentin mineralization. The present findings indicate that calcospherite size and calcospherite fusion are valid parameters for assessing and quantifying dentin mineralization. In addition, an SEM grading of severity was established based on these two parameters. The SEM grades correlated directly with the clinical and histologic grades, suggesting that the dental clinical manifestations are a reflection of the underlying morphology of the dentin and the extent of abnormal dentin mineralization.

Dentin↗

PubMed1991

[Bond strength of newer dentine adhesive systems].

Introduction of new dentine bonding agents in a practice of dentistry, variety of results on their crucial characteristics in foreign literature and lack of information in our literature led to a necessity to conduct own scientific research on dentine adhesives in order to facilitate the choice of available products. The purpose of this study was to estimate the adhesive strength of different dentine bonding agents to a treated human dentine immediately after light curing of a compatible composite material. Shear and tensile bond strength of Tripton, Gluma, Scotchbond-2 and Dentin Protector was measured. Control material was glass-ionomer base-cement Vitrabond. Human extracted premolars from both jaws were prepared to a flat surface from either occlusal or buccal aspect, and materials were applied, respectively. The results showed: a) values of shear bond strength ranged from 2.01-3.92 MPa with no statistical differences between tested systems; b) tensile bond strength varied from 13.7-26-84 MPa; the highest value showed Scotchbond-2, following by Gluma, but significantly lower values showed Tripton and Dentin Protector; c) the aspect of prepared tooth crown had no significant effect on bond strength with the exception of shear bond strength for Gluma-system, when applied on buccal surface showed significantly higher values than applied occlusally; d) dentine-bonding agents which dissolve smear layer with acid components and remove it from prepared dentine surface showed stronger adhesion than agents which leave this debris on a dentin surface.

Adhesiveness↗

PubMed1989

Micromorphologic features of dentin in vitamin D-resistant rickets: correlation with clinical grading of severity.

This study was a histological analysis of 20 primary teeth from 5 patients with 3 clinical grades of vitamin D-resistant rickets (VDRR). The results showed that the degree of globular dentin formation in the histological sections may be graded into Grades I-III in increasing order of severity. In Grade I, the amount of globular dentin was less than 50% of the total dentin thickness, and the interglobular spaces were small. By contrast, in Grade III severity, globular dentin extended throughout the entire thickness of dentin, and the interglobular spaces were large. In Grade II severity, the amount of globular dentin was more than half but did not involve the entire dentin thickness. These histologic grades of severity correlated directly with the clinical grades of the patients. In addition, the study found that lack of medical treatment in affected mothers might lead to globular dentin formation in the fetus in-utero. Conversely, adequate phosphate supplementation in a hypophosphatemic mother might prevent the formation of globular dentin in the fetus.

Adolescent↗

PubMed1989

SEM study on the dentin and cementum of oreodont teeth.

An SEM study on the dental hard tissue was conducted on the canines and molars removed from a fossil oreodont. The orthodentin was densely distributed with dentinal tubules measuring 2.2 microns in diameter; the tubules were filled with their related odontoblastic processes. They coursed in a parabolic fashion from the pulpal aspect towards the tooth surface. There were many fine lateral offshoots that branched from the tubules, such that the mantle dentin measuring 50 microns in thickness was mostly distributed with these terminal branches measuring 0.7 micron in diameter. However, they did not intrude into the enamel to form spindles and rods. SEM study indicated that the uneven surface of the tubular wall was due to a crisscross of the underneath dentinal matricial fibers, and the peritubular dentin was not observed. The superficial circumpulpal dentin was distributed with interglobular dentin, while the radicular dentin beneath the cementum was additionally distributed with a granular layer. We also observed concentric lamellae corresponding to incremental lines in the dentin, as well as a flat wavy dentinoenamel junction. We noticed the radicular dentin was covered with an acellular cementum except at the apical portion, where it was paved with cellular cementum.

Animals↗

PubMed1986

Mantle dentine in man--a quantitative microradiographic study.

50 microradiographs taken in a standardized manner of midsagittal ground sections of teeth of individuals aged 18 to 56 years were densitometrically evaluated along a track passing through enamel, dentine and an aluminium stepwedge. Semi-quantitative analysis of mineral density uniformly showed an irregular platform representing circumpulpal dentine and a peripheral down slope in the region of the amelodentinal junction, representing mantle dentine. The width of this less mineralized peripheral zone measured on densitometric recordings averaged 150 microns (+/- 50). Quantitative analysis of the two dentinal regions permitted the calculation of the mineral content in terms of volume percentage using both a graphic method and an electronic computer method. The sections were also examined by polarized light microscopy which clearly visualized the presence of peripheral mantle dentine. The mean mineral density of circumpulpal dentine was 46% according to both the graphic and the computer methods; mantle dentine yielded means close to 42% according by both methods. The 4% difference in density between circumpulpal dentine and mantle dentine proved to be statistically significant; there was no significant difference between the means obtained graphically and those obtained electronically. The need for further investigation of this region of the amelodentinal junction was stressed.

Adolescent↗

PubMed1985

A comparison of the effectiveness of dentine bonding agents.

Tensile and shear bond strengths between prepared surfaces of coronal dentine and cores of composite materials using different bonding systems were determined. Control procedures demonstrated that tensile bond strengths were approximately doubled by the use of bonding agents in systems requiring initial cleansing or etching of dentine. Similar increases were found in shear bond strengths. When bonding to different depths of dentine was compared shear and tensile bond strengths to the more occlusal dentine were greater than to more pulpally placed dentine. The factors which appear to affect bond strength under laboratory conditions are: etching of dentine (but beware of this procedure clinically); the smear layer and its removal; polymerization shrinkage of composite materials; the depth and plane of bonded dentine; the use of fresh or stored dentine; and the structure of the treated dentine.

Acid Etching, Dental↗

PubMed1982

[Studies on dental self-curing resins (20) - adhesion mechanism of 4-META/MMA-TBB resin to dentine (author's transl)].

Scanning electron microscopic studies on dentine surface cleaned with a mixture of citric acid and ferric chloride, fractured surfaces parallel to the tubules of dentine and dentine with the cured adhesive and the partially demineralized fractured surfaces, tensile fractured surface of the joint on the dentine and cured adhesive resin tags impregnated in tubules were carried out to clarify the adhesion mechanism. Infiltration of monomers into dentine is more important to get good adhesion with dentine than the interlocking at dentinal tubules due to impregnated resin. Monomers with both hydrophobic and hydrophilic groups like 4-META promote the monomer infiltration. The infiltrated and cured adhesive layer in dentine is observed at the subsurface dentine zone. This zone has excellent resistance against acid demineralization.

Acrylic Resins↗

PubMed1993

Effects of etchants, surface moisture, and resin composite on dentin bond strengths.

This in vitro study evaluated the effects of etchant type, surface moisture, and resin composite type on the shear bond strength of dentin adhesives. Three adhesives which bond to etched dentin were used in the study: All-Bond 2, Amalgambond, and Clearfil Photo Bond. Occlusal enamel was removed from 200 human molars to expose dentin. The dentin surfaces were etched, treated with a dentin adhesive system, and bonded with resin composite. After thermocycling and storage, the composite columns were fractured from dentin using an Instron machine. Bond strengths were calculated and subjected to a statistical analysis. Etchant type, surface moisture, and resin composite type all had significant effects on dentin bond strengths. Overall, the highest bond strengths were obtained with 10/3 etchant, moist dentin, and hybrid composite. The highest bond strengths for All-Bond 2 and Amalgambond were obtained by using the manufacturer's recommended etchant, moist dentin, and a hybrid composite. The mean bond strengths for All-Bond and Amalgambond under these conditions were 22.5 and 19.0 MPa, respectively. Clearfil Photo Bond had significantly lower bond strengths, but was relatively unaffected by changes in experimental conditions.

Acid Etching, Dental↗

PubMed1997

Bonding mechanism of three "one-bottle" systems to conditioned and unconditioned enamel and dentin.

PURPOSE: This in vivo study investigated the formation of hybrid layer, resin tags and adhesive lateral branches, by use of the latest generation of enamel-dentin bonding systems ("one-bottle" systems) on conditioned and unconditioned enamel and dentin. MATERIALS AND METHODS: The dentin adhesives were tested on 24 flat dentin preparations made on facial surfaces of vital, periodontally compromised teeth. The experimental teeth were randomly divided in six groups of four samples each. Group 1: Prime & Bond 2.1 (conditioned dentin, CD); Group 2: Single Bond (CD); Group 3: Syntac Sprint (CD); Group 4: Prime & Bond 2.1 (unconditioned dentin, UD); Group 5: Single Bond (UD); Group 6: Syntac Sprint (UD). In the first three groups, the "one-bottle" systems were applied following the manufacturers' instructions, while in the other three groups the dentin and the enamel were not treated with phosphoric acid and the primer was applied directly on the prepared surfaces. On top of the primer-adhesive, a thin layer of resin was applied and light-cured for 20 seconds. The sample teeth were extracted immediately after the adhesive material was light-cured. All the samples were split-fractured along their long axis. Half of the samples were deproteinized and decalcified at the interface in order to visualize the hybrid layer and the other halves were completely dissolved in order to observe the morphology of resin tags by use of scanning electron microscopy. RESULTS: Groups 1-3: All the tested products showed the same micromechanical bonding mechanism to conditioned dentin with phosphoric acid: they formed hybrid layer, resin tags and adhesive lateral branches. In the samples of the first three groups, characteristic reverse cone-shaped tags with their corresponding adhesive lateral branches were evident. At the enamel site, traditional pattern of etch enamel was always observed. Groups 4-6: When the bonding systems were applied on unconditioned dentin, hybrid layer was not formed, resin tags were rarely noted and their shape was narrow and they did not completely seal the tubular orifices. The tubules remained mainly closed by smear plugs. At the enamel site, the unetched surface showed absence of characteristic etch pattern and of resin tags.

Acid Etching, Dental↗

PubMed1998

[Immunocytochemistry of proteoglycan in dentin and odontoblasts].

To clarify the distribution of proteoglycan (PG) and matrix metalloproteinase-3 (MMP-3) in the molar tooth germ dentin of rats, immunohistochemical investigation was performed using a antibody 2-B-6 specific for chondroitin 4 sulfate (Ch4-S) and dermatan sulfate (DS) of PG, antibody 3-B-3 specific for chondroitin 6 sulfate (Ch6-S) and chondroitin (Ch) of PG and anti-human-MMP3 antibody. 2-B-6 reacted with the predentin and dentinal tubules. However, there were no reactions around the calcification front or in the calcified dentin matrix other than the dentinal tubules. 3-B-3 and anti-MMP3 antibodies reacted with only the predentin. These results showed that PG containing Ch4-S and DS was present in the dentinal tubules, while PG containing Ch4-S, DS, Ch6-S and Ch as well as MMP-3 was present in the predentin. It is suggested that PG of the predentin is degraded by MMP-3 at the calcification front. In undecalcified sections, the reaction of the dentinal tubules with 2-B-6 was localized in electron-dense sites corresponding to the peritubular dentin, suggesting that PG at this site binds to hydroxyapatite. Furthermore, in odontoblasts, the localization of 2-B-6 was noted in secretory granules distributed in the Golgi region and the odontoblastic process. This suggests that PG is transported from the Golgi region to the odontoblastic process in the form of secretory granules. Immunoreactive secretory granules were also noted in the cellular process of the calcified dentin. PG of the peritubular dentin may be secreted by these secretory granules in the process.

Animals↗

PubMed2001

Aggressiveness of contemporary self-etching systems. I: Depth of penetration beyond dentin smear layers.

OBJECTIVE: This study examined, with the use of transmission electron microscopy (TEM), the aggressiveness of three self-etching adhesive systems in penetrating dentin smear layers of different thickness. METHODS: Dentin disks were produced from extracted human third molars. For the control group, the middle dentin surface was cryofractured to create a bonding surface that was devoid of a smear layer. The experimental teeth were polished with wet 600 or 60-grit SiC paper to produce bonding surfaces with thin and thick smear layers. They were bonded using one of the three self-etching systems: Clearfil Mega Bond (Kuraray), Non-Rinse Conditioner and Prime&Bond NT (Dentsply DeTrey) and Prompt L-Pop (ESPE). Bonded specimens were then demineralized and embedded in epoxy resin for TEM examination. RESULTS: For Mega Bond, thin authentic hybrid layers between 0.4-0.5 microm were found. Smear layer and smear plugs were retained as part of the hybridized complex. For Non-Rinse Conditioner/Prime&Bond NT, the authentic hybrid layers were between 1.2-2.2 microm thick. Smear layer and smear plugs were completely dissolved in dentin with thin smear layers, but were partially retained as part of the hybridized complex in those with thick smear layers. For Prompt L-Pop, authentic hybrid layers were 2.5-5 microm thick and smear layer and smear plugs were completely dissolved even in dentin with thick smear layers. SIGNIFICANCE: Contemporary self-etching systems may be classified as mild, moderate and aggressive based on their ability to penetrate dentin smear layers and their depth of demineralization into the subsurface dentin. The more aggressive system completely solubilized the smear layer and smear plugs and formed hybrid layers with a thickness approaching those of phosphoric acid conditioned dentin.

Acid Etching, Dental↗

PubMed2002

Micro-tensile bond strengths to sclerotic dentin using a self-etching and a total-etching technique.

OBJECTIVES: To evaluate the in vitro regional micro-tensile bond strengths of a self-etching/self-priming adhesive system to sclerotic dentin, in the absence or presence of phosphoric acid conditioning. METHODS: Naturally-occurring, non-carious cervical lesions on extracted premolars were hand-cleaned with a slurry of pumice and chlorhexidine, then bonded without further cavity preparation. One group was bonded using Clearfil Liner Bond 2V (Kuraray Co. Ltd., Osaka, Japan). The other group was first conditioned with K-etchant; 40% phosphoric acid gel (Kuraray) prior to the application of the self-etching primer. Artificially prepared wedge-shaped cavities were also made in sound premolars and bonded with the two methods as controls. Resin composite build-ups were made using Clearfil Protect Liner F and AP-X resin composite (Kuraray). After storage in water for 24h, the teeth were sectioned into 0.7 x 0.7 mm composite-dentin beams along the occlusal and gingival walls, and at the apex of the lesions. The use of two conditioning methods, two substrate types, and three different locations yielded 10-14 beams for each of the 12 groups. After testing for the microTBS, representative beams that were stressed to failure were examined with SEM. Remaining fractured beams were demineralized and processed for TEM examination. Statistical analysis was performed using a three-way ANOVA and Student-Newman-Keuls tests. RESULTS: Regardless of the conditioning methods, bond strengths to sound dentin were significantly higher than to sclerotic dentin (P< 0.05). With sclerotic dentin, there was no significant difference for the conditioning methods used, except that K-etchant significantly improved the bond strength at the gingival aspect of the lesions. Fractographic analysis revealed that the self-etching primer could not etch beyond the surface hypermineralized layer of sclerotic dentin. Interfacial failure occurred along the surface of the mineralized intermicrobial matrix and/or hypermineralized layer. With the use of phosphoric acid, a hybrid layer was only seen when the surface layers were thin. Incompletely removed sclerotic casts were evident in both groups. SIGNIFICANCE: Removal of the surface layers of sclerotic dentin and/or conditioning with stronger acids may be beneficial to obtain stronger bonding to sclerotic dentin.

Acid Etching, Dental↗

PubMed2002

Effect of surface conditioning and restorative material on the shear bond strength and resin-dentin interface of a new one-bottle nanofilled adhesive.

OBJECTIVES: To determine the effect of different combinations of surface conditioning (DeTrey Conditioner 36, NRC, no etching) and restorative materials (Dyract AP, Spectrum TPH) on the shear bond strength of Prime and Bond NT to enamel and dentin, and to characterize the resin-dentin interface produced by these combinations. METHODS: Shear bond strength was tested on 30 enamel and 30 dentin flat labial surfaces of extracted bovine teeth. The enamel and dentin specimens were randomly assigned to six groups of five teeth each and treated using different combinations of surface conditioners and restorative materials with Prime and Bond NT. Scanning electron microscope (SEM) observation of argon-ion-etched specimens was done to evaluate the resin-dentin interface. RESULTS: The type of surface conditioning and restorative material had significant effects on dentin bond strengths. Etching the dentin prior to application of Prime and Bond NT significantly increased bond strength and caused formation of a hybrid layer for Spectrum TPH. For Dyract AP, dentin etching generally did not improve bond strength despite the formation of a hybrid layer. On enamel, Prime and Bond NT had consistently high bond strengths on etched specimens. SIGNIFICANCE: The results showed that Dyract AP and Spectrum TPH, when used with Prime and Bond NT have different bonding mechanisms and the effect of surface conditioning on their shear bond strength differs. Clinicians should be aware of these effects in order to optimize bonding.

Acid Etching, Dental↗

PubMed1998

The effects of Pain-Free Desensitizer on dentine permeability and tubule occlusion over time, in vitro.

The purpose of this in vitro study was to evaluate the efficacy of a new resin emulsion (Pain-Free Desensitizer) treatment for dentine hypersensitivity, for its ability to decrease dentine permeability. Crown segments were prepared from extracted, unerupted human 3rd molars by horizontal sectioning to remove occlusal enamel and the roots. The specimens were allocated in one of two groups: In group 1, the dentine surface was acid-etched to simulate the patent tubules of hypersensitive dentine. In group 2, the mineralized dentine surface was polished free of smear layer using a hydroxyapatite paste and ultrasonication. The hydraulic conductance of each specimen was then measured to obtain a pretreatment of control value. After a single treatment with resin desensitizer, the permeability was remeasured at 5 min, 1 day, 1 week and 1 month. Between measurements, the specimens were stored in buffer solution to simulate the solubilizing effects of saliva. Parallel specimens were followed by SEM examination. The results showed that a single treatment with resin desensitizer produced large, immediate, reductions in dentine permeability in both acid-etched and mineralized surfaces. In the acid-etched (group 1) specimens, the permeability returned to control values within 7 days, while the permeability of the group 2 specimens remained low even after 30 days of soaking. This simple treatment for occluding dentinal tubules may provide sufficient temporary reduction in dentine permeability to permit the development of natural desensitization.

Analysis of Variance↗

PubMed2006

Immunohistochemical study of small integrin-binding ligand, N-linked glycoproteins in reactionary dentin of rat molars at different ages.

Small integrin-binding ligand, N-linked glycoproteins (SIBLING) are believed to play key roles in the process of biomineralization. Reactionary dentin (RD), formed by odontoblasts in response to external stimuli, differs morphologically from primary dentin (PD). To test our hypothesis that the microscopic changes reflect variations in molecular mechanisms involved in formation of the two forms of dentin, and to characterize RD further, we compared the distributions of four SIBLING proteins [bone sialoprotein (BSP), osteopontin (OPN), dentin matrix protein 1 (DMP-1) and dentin sialophosphoprotein (DSPP)] in naturally occurring RD with those in PD. Molars of rats aged 12, 18, 24 and 36 wk were analyzed using immunohistochemistry with antibodies against BSP, OPN, DMP-1, and dentin sialoprotein (a fragment of DSPP). Differences in the distribution of the four SIBLING proteins were evident. Bone sialoprotein, not seen in PD, was consistently observed in RD. Osteopontin, almost absent from PD, was clearly observed in RD. The expression levels of DMP-1 and DSP in RD were lower than in PD. Elevated expression of BSP and OPN, along with a marked decrease of dentin sialoprotein and DMP-1 in RD, suggests a difference in the mechanism of formation of the two forms of dentin.

Age Factors↗