201
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Cadenaro M, Pashley D, Marchesi G, Carrilho M, Antoniolli F, Mazzoni A, Tay F, Di Lenarda R, Breschi L. Influence of chlorhexidine on the degree of conversion and E-modulus of experimental adhesive blends. Dent Mater 2009; 25:1269-74. [DOI: 10.1016/j.dental.2009.05.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Accepted: 05/27/2009] [Indexed: 11/29/2022]
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202
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Komori PCP, Pashley DH, Tjäderhane L, Breschi L, Mazzoni A, de Goes MF, Wang L, Carrilho MR. Effect of 2% chlorhexidine digluconate on the bond strength to normal versus caries-affected dentin. Oper Dent 2009; 34:157-65. [PMID: 19363971 DOI: 10.2341/08-55] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study evaluated the effect of 2% chlorhexidine digluconate (CHX) used as a therapeutic primer on the long-term bond strengths of two etch-and-rinse adhesives to normal (ND) and caries-affected (CAD) dentin. Forty extracted human molars with coronal carious lesions, surrounded by normal dentin, were selected for this study. The flat surfaces of two types of dentin (ND and CAD) were prepared with a water-cooled high-speed diamond disc, then acid-etched, rinsed and air-dried. In the control groups, the dentin was re-hydrated with distilled water, blot-dried and bonded with a three-step (Scotchbond Multi-Purpose-MP) or two-step (Single Bond 2-SB) etch-and-rinse adhesive. In the experimental groups, the dentin was rehydrated with 2% CHX (60 seconds), blot-dried and bonded with the same adhesives. Resin composite build-ups were made. The specimens were prepared for microtensile bond testing in accordance with the non-trimming technique, then tested either immediately or after six-months storage in artificial saliva. The data were analyzed by ANOVA/Bonferroni tests (alpha = 0.05). CHX did not affect the immediate bond strength to ND or CAD (p > 0.05). CHX treatment significantly lowered the loss of bond strength after six months as seen in the control bonds for ND (p < 0.05), but it did not alter the bond strength of CAD (p > 0.05). The application of MP on CHX-treated ND or CAD produced bonds that did not change over six months of storage.
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Affiliation(s)
- Paula C P Komori
- Department of Restorative Dentistry, Dental Materials, Piracicaba School of Dentistry, University of Campinas, Brazil
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203
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Santos J, Carrilho M, Tervahartiala T, Sorsa T, Breschi L, Mazzoni A, Pashley D, Tay F, Ferraz C, Tjäderhane L. Determination of Matrix Metalloproteinases in Human Radicular Dentin. J Endod 2009; 35:686-9. [DOI: 10.1016/j.joen.2009.02.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 02/08/2009] [Accepted: 02/17/2009] [Indexed: 10/20/2022]
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204
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Affiliation(s)
- Z Mohammadi
- Department of Endodontics, School of Dentistry, Hamedan University of Medical Sciences, Hamedan, Iran.
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205
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Hosaka K, Nishitani Y, Tagami J, Yoshiyama M, Brackett WW, Agee KA, Tay FR, Pashley DH. Durability of resin-dentin bonds to water- vs. ethanol-saturated dentin. J Dent Res 2009; 88:146-51. [PMID: 19278986 DOI: 10.1177/0022034508328910] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Higher 24-hour resin-dentin bond strengths are created when ethanol is used to replace water during wet bonding. This in vitro study examined if ethanol-wet-bonding can increase the durability of resin-dentin bonds over longer times. Five increasingly hydrophilic experimental resin blends were bonded to acid-etched dentin saturated with water or ethanol. Following composite build-ups, the teeth were reduced into beams for 24-hour microtensile bond strength evaluation, and for water-aging at 37 degrees C for 3, 6, or 12 months before additional bond strength measurements. Although most bonds made to water-saturated dentin did not change over time, those made to ethanol-saturated dentin exhibited higher bond strengths, and none of them fell over time. Decreased collagen fibrillar diameter and increased interfibrillar spacing were seen in hybrid layers created with ethanol-wet-bonding. Increases in bond strength and durability in ethanol-wet-bonding may be due to higher resin uptake and better resin sealing of the collagen matrix, thereby minimizing endogenous collagenolytic activities.
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Affiliation(s)
- K Hosaka
- Cariology and Operative Dentistry, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
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206
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Lehmann N, Debret R, Roméas A, Magloire H, Degrange M, Bleicher F, Sommer P, Seux D. Self-etching Increases Matrix Metalloproteinase Expression in the Dentin-Pulp Complex. J Dent Res 2009; 88:77-82. [DOI: 10.1177/0022034508327925] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In adhesive restorations, one major problem is hybrid layer degradation. At present, this deterioration is explained by the activation of the endogenous matrix metalloproteinases (MMPs) present in dentin due to the acidic property of adhesive systems. We hypothesized that self-etching adhesive should also stimulate the expression of MMPs in odontoblasts. In cultured tooth slices, we evaluated the changes in MMP-2 and proMMP-9 expression in the dentin-pulp complex after self-etching adhesive treatment on dentin cavities in immunochemistry and by zymography. The treatment resulted in increased MMP-2 expression in odontoblasts, as shown by immunohistochemistry. Zymography showed increased proMMP-9 and MMP-2 in dentin under self-etching treatment when pulp was present. These results showed that self-etching adhesive stimulates the secretion of MMPs from the dentin-pulp complex and, more precisely, by odontoblasts, suggesting that odontoblasts participate in hybrid layer degradation.
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Affiliation(s)
- N. Lehmann
- University of Lyon, F-69000, Lyon, France
- University of Lyon 1, F-69100, Villeurbanne, France
- ENSL, F-69007, Lyon, France
- CNRS UMR 5242, IGFL, F-69007, Lyon, France
- INRA UMR 1288, F-69007, Lyon, France
| | - R. Debret
- University of Lyon, F-69000, Lyon, France
- University of Lyon 1, F-69100, Villeurbanne, France
- ENSL, F-69007, Lyon, France
- CNRS UMR 5242, IGFL, F-69007, Lyon, France
- INRA UMR 1288, F-69007, Lyon, France
| | - A. Roméas
- University of Lyon, F-69000, Lyon, France
- University of Lyon 1, F-69100, Villeurbanne, France
- ENSL, F-69007, Lyon, France
- CNRS UMR 5242, IGFL, F-69007, Lyon, France
- INRA UMR 1288, F-69007, Lyon, France
| | - H. Magloire
- University of Lyon, F-69000, Lyon, France
- University of Lyon 1, F-69100, Villeurbanne, France
- ENSL, F-69007, Lyon, France
- CNRS UMR 5242, IGFL, F-69007, Lyon, France
- INRA UMR 1288, F-69007, Lyon, France
| | - M. Degrange
- University of Lyon, F-69000, Lyon, France
- University of Lyon 1, F-69100, Villeurbanne, France
- ENSL, F-69007, Lyon, France
- CNRS UMR 5242, IGFL, F-69007, Lyon, France
- INRA UMR 1288, F-69007, Lyon, France
| | - F. Bleicher
- University of Lyon, F-69000, Lyon, France
- University of Lyon 1, F-69100, Villeurbanne, France
- ENSL, F-69007, Lyon, France
- CNRS UMR 5242, IGFL, F-69007, Lyon, France
- INRA UMR 1288, F-69007, Lyon, France
| | - P. Sommer
- University of Lyon, F-69000, Lyon, France
- University of Lyon 1, F-69100, Villeurbanne, France
- ENSL, F-69007, Lyon, France
- CNRS UMR 5242, IGFL, F-69007, Lyon, France
- INRA UMR 1288, F-69007, Lyon, France
| | - D. Seux
- University of Lyon, F-69000, Lyon, France
- University of Lyon 1, F-69100, Villeurbanne, France
- ENSL, F-69007, Lyon, France
- CNRS UMR 5242, IGFL, F-69007, Lyon, France
- INRA UMR 1288, F-69007, Lyon, France
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207
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Erhardt MCG, Osorio R, Toledano M. Dentin treatment with MMPs inhibitors does not alter bond strengths to caries-affected dentin. J Dent 2008; 36:1068-73. [PMID: 18922612 DOI: 10.1016/j.jdent.2008.09.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Revised: 09/04/2008] [Accepted: 09/04/2008] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES This study aimed to investigate if the use of protease inhibitors (EDTA and chlorhexidine) may influence microtensile bond strength (MTBS) of an etch-and-rinse adhesive system to caries-affected human dentin. METHODS Flat middle coronal dentin surfaces with a central region of caries-affected dentin surrounded by sound dentin were bonded with Adper Scotchbond 1 after: (1) etching with 35% H3PO4; (2) etching with 0.1M EDTA and (3) 35% H3PO4-etching followed by 5% chlorhexidine application. Resin composite build-ups were constructed incrementally and trimmed to yield hourglass specimens (0.8mm2 bonded area) that contained sound or caries-affected dentin (confirmed after debonding by microhardness measurements - KHN). Bonded specimens were tensioned at 0.5mm/min. Data were analyzed by ANOVA and multiple comparisons tests (p<0.05). Failure mode analysis was performed by scanning electron microscopy (SEM). RESULTS H(3)PO(4), EDTA and chlorhexidine pre-treatments yielded similar MTBS values, in both dentin substrates. Bond strength to sound dentin was significantly higher than that to caries-affected dentin after H3PO4-etching. Caries-affected dentin exhibited lower KHN than sound dentin. CONCLUSIONS Conditioning of caries-affected dentin with EDTA or a combined use with H3PO4 and chlorhexidine may be proposed as these protease inhibitors do not reduce MTBS to caries-affected dentin if compared to conventional H3PO4 treatment.
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Affiliation(s)
- Maria Carolina G Erhardt
- Fellow Research, Department of Dental Materials, School of Dentistry. University of Granada, Granada, Spain
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208
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Hiraishi N, Yiu CKY, King NM, Tay FR, Pashley DH. Chlorhexidine release and water sorption characteristics of chlorhexidine-incorporated hydrophobic/hydrophilic resins. Dent Mater 2008; 24:1391-9. [PMID: 18439668 PMCID: PMC3886642 DOI: 10.1016/j.dental.2008.03.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 02/25/2008] [Accepted: 03/04/2008] [Indexed: 11/19/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate chlorhexidine release from unfilled non-solvated methacrylate-based resins of increasing hydrophilicity and to examine relationships among Hoy's solubility parameters, water sorption, solubility and the rate of chlorhexidine release. METHODS Resin discs were prepared from light-cured, experimental resin blends (R1, R2, R3, R4 and R5) containing 0.0, 0.2, 1.0 and 2.0 wt.% chlorhexidine diacetate (CDA). Discs were immersed in distilled water at 37 degrees C, and mass changes were recorded at different periods. Spectral measurements were made to follow change in optical densities of storage solution to examine chlorhexidine release kinetics. After a 28-day period, water sorption, solubility, and the cumulative chlorhexidine release were obtained. Additionally, antibacterial study was performed by observing the presence of inhibition zone against Streptococcus mutans. RESULTS The most hydrophilic resin (R5) exhibited the highest chlorhexidine release rate. The most hydrophobic resin (R1) exhibited the lowest rate. However, no inhibition zone was produced by any specimens stored in water for 2 weeks. The addition of CDA increased solubility significantly but had no effect on water sorption. Significant positive correlations were seen between water sorption and the cumulative chlorhexidine release. SIGNIFICANCE Chlorhexidine release from resins may be related to water-induced swelling, which in turn is enhanced by the hydrophilicity of cured polymer matrix.
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Affiliation(s)
- N Hiraishi
- Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Pokfulam, Hong Kong SAR, China.
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209
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Boukpessi T, Menashi S, Camoin L, Tencate JM, Goldberg M, Chaussain-Miller C. The effect of stromelysin-1 (MMP-3) on non-collagenous extracellular matrix proteins of demineralized dentin and the adhesive properties of restorative resins. Biomaterials 2008; 29:4367-73. [PMID: 18760468 DOI: 10.1016/j.biomaterials.2008.07.035] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Accepted: 07/26/2008] [Indexed: 10/21/2022]
Abstract
Dentin non-collagenous matrix components (NCPs) are structural proteins involved in the formation, the architecture and the mineralization of the extracellular matrix (ECM). We investigated here how recombinant metalloproteinase stromelysin-1, also termed MMP-3, initiates the release of ECM molecules from artificially demineralized human dentin. Analysis of the supernatants by Western blotting reveals that MMP-3 extracts PGs (decorin, biglycan), and also a series of phosphorylated proteins: dentin sialoprotein (DSP), osteopontin (OPN), bone sialoprotein (BSP) and MEPE, but neither dentin matrix protein-1 (DMP1), another member of the SIBLING family, nor osteocalcin (OC), a non-phosphorylated matrix molecule. After treatment of dentin surfaces by MMP-3, scanning electron microscope (SEM) examination of resin replica shows an increased penetration of the resin into the dentin tubules when compared to surfaces only treated by demineralizing solutions. This preclinical investigation suggests that MMP-3 may be used to improve the adhesive properties of restorative materials.
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Affiliation(s)
- T Boukpessi
- Groupe Matrice Extracellulaire et Biominéralisation (EA 2496), Faculté de Chirurgie Dentaire, Université Paris Descartes, 1 rue Maurice Arnoux, 92120 Montrouge, France
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210
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Rosa RG, Tarsitano CAB, Hyslop S, Yamada AT, Toledo OMS, Joazeiro PP. Relaxation of the mouse pubic symphysis during late pregnancy is not accompanied by the influx of granulocytes. Microsc Res Tech 2008; 71:169-78. [PMID: 18044701 DOI: 10.1002/jemt.20549] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In some animals, such as mice and guinea pigs, a hormonally controlled mechanism increases the flexibility of the pubic symphysis and enhances the cervical remodeling necessary for safe delivery. Cervical ripening during pregnancy is associated with a paradoxical influx of leukocytes. However, the changes in cell metabolism during relaxation of the mouse pubic symphysis for delivery have not been extensively studied. In this work, we used light microscopy and transmission and scanning electron microcopy, as well as immunohistochemistry and Western blotting for MMP-8, to investigate the involvement of granulocytes or resident stromal cells in the relaxation of the virgin pubic symphysis during late pregnancy (days 18 and 19, before delivery) in vivo and in explanted joints. MMP-8 was studied because this collagenase is a hallmark for cervical ripening associated with the influx of granulocytes during late pregnancy. Extensive dissolution and disorganization of the extracellular matrix was seen around fibroblastic-like cells in late pregnancy. In contrast to the cervix (positive control), morphological and immunohistochemical analyses revealed that there was no characteristic cellular inflammatory response in the interpubic tissue. Staining for MMP-8 was observed in chondroid and fibroblastic-like cells of virgin and relaxed interpubic ligament, respectively. However, no granulocytes were seen during the extensive remodeling of the pubic joint in late pregnancy. These results indicate that constitutive stromal cells may have an important role in tissue relaxation during remodeling of the pubic symphysis in pregnancy.
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Affiliation(s)
- Renata Giardini Rosa
- Department of Histology and Embryology, Institute of Biology, State University of Campinas (UNICAMP), 13083-970 Campinas, São Paulo, Brazil
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211
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Mazzoni A, Pashley DH, Tay FR, Gobbi P, Orsini G, Ruggeri A, Carrilho M, Tjäderhane L, Di Lenarda R, Breschi L. Immunohistochemical identification of MMP‐2 and MMP‐9 in human dentin: Correlative FEI‐SEM/TEM analysis. J Biomed Mater Res A 2008; 88:697-703. [DOI: 10.1002/jbm.a.31920] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Annalisa Mazzoni
- Department of SAU and FAL, University of Bologna, Bologna, Italy
| | - David H. Pashley
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912‐1129
| | - Franklin R. Tay
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912‐1129
| | - Pietro Gobbi
- Institute of Morphological Sciences; University of Urbino “Carlo Bo”, Urbino, Italy
| | - Giovanna Orsini
- Department of Biomorphology, University of Chieti‐Pescara, Chieti, Italy
| | | | - Marcela Carrilho
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912‐1129
- Department of Restorative Dentistry, Dental Materials Area, University of Campinas, Piracicaba School of Dentistry, Piracicaba/SP, Brazil
| | - Leo Tjäderhane
- Institute of Dentistry, University of Helsinki, Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital (HUCH), Helsinki, Finland
| | - Roberto Di Lenarda
- Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Trieste, Italy
| | - Lorenzo Breschi
- Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Trieste, Italy
- IGM‐CNR, Unit of Bologna c/o IOR, Bologna, Italy
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212
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Breschi L, Mazzoni A, Ruggeri A, Cadenaro M, Di Lenarda R, De Stefano Dorigo E. Dental adhesion review: Aging and stability of the bonded interface. Dent Mater 2008; 24:90-101. [PMID: 17442386 DOI: 10.1016/j.dental.2007.02.009] [Citation(s) in RCA: 683] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 02/23/2007] [Accepted: 02/23/2007] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Most of current dental adhesive systems show favorable immediate results in terms of retention and sealing of bonded interface, thereby counteracting polymerization shrinkage that affects resin-based restorative materials. Despite immediate efficacy, there are major concerns when dentin bonded interfaces are tested after aging even for short time period, i.e. 6 months. METHODS This study critically discusses the latest peer-reviewed reports related to formation, aging and stability of resin bonding, focusing on the micro and nano-phenomena related to adhesive interface degradation. RESULTS Most simplified one-step adhesives were shown to be the least durable, while three-step etch-and-rinse and two-step self-etch adhesives continue to show the highest performances, as reported in the overwhelming majority of studies. In other words, a simplification of clinical application procedures is done to the detriment of bonding efficacy. Among the different aging phenomena occurring at the dentin bonded interfaces, some are considered pivotal in degrading the hybrid layer, particularly if simplified adhesives are used. Insufficient resin impregnation of dentin, high permeability of the bonded interface, sub-optimal polymerization, phase separation and activation of endogenous collagenolytic enzymes are some of the recently reported factors that reduce the longevity of the bonded interface. SIGNIFICANCE In order to overcome these problems, recent studies indicated that (1) resin impregnation techniques should be improved, particularly for two-step etch-and-rinse adhesives; (2) the use of conventional multi-step adhesives is recommended, since they involve the use of a hydrophobic coating of nonsolvated resin; (3) extended curing time should be considered to reduce permeability and allow a better polymerization of the adhesive film; (4) proteases inhibitors as additional primer should be used to increase the stability of the collagens fibrils within the hybrid layer inhibiting the intrinsic collagenolytic activity of human dentin.
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Affiliation(s)
- Lorenzo Breschi
- Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Via Stuparich 1, Trieste, Italy.
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213
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Boushell LW, Kaku M, Mochida Y, Bagnell R, Yamauchi M. Immunohistochemical localization of matrixmetalloproteinase-2 in human coronal dentin. Arch Oral Biol 2007; 53:109-16. [PMID: 18001692 DOI: 10.1016/j.archoralbio.2007.09.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 09/20/2007] [Accepted: 09/24/2007] [Indexed: 11/19/2022]
Abstract
UNLABELLED While it is known that matrixmetalloproteinase-2 (MMP-2) is present in dentin, its distribution and role in human dentin formation and pathology are not well understood. OBJECTIVE To characterize the distribution of MMP-2 in human coronal dentin. METHODS Immunohistochemistry was used to investigate the distribution of MMP-2 in coronal dentin. Freshly extracted human premolars and third molars (age range 12-30) were fixed with formaldehyde, demineralized with 10% EDTA (pH 7.4) and embedded in paraffin. Serial sections were made and subjected to immunohistochemical analysis using a specific monoclonal anti-MMP-2 antibody. Immunoreactivity was visualized with 3,3'-diaminobenzidine substrate and observed under light microscopy. ImageJ software was used to calculate the relative amount/distribution of MMP-2. RESULTS The analysis revealed immunoreactivity for MMP-2 throughout human coronal dentin. However, intense immunoreactivities were identified in a 90-200 microm zone adjacent to the pre-dentin as well as a 9-10 microm wide zone adjacent to the dentinoenamel junction (DEJ). CONCLUSION MMP-2 has a specific distribution in human coronal dentin indicating it's involvement in extracellular matrix organization in predentin and the establishment of the DEJ.
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Affiliation(s)
- Lee W Boushell
- Department of Operative Dentistry, UNC School of Dentistry, University of North Carolina, Chapel Hill, NC 27599-7450, USA.
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214
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Abstract
Dentin, the most abundant tissue in teeth, is produced by odontoblasts, which differentiate from mesenchymal cells of the dental papilla. Dentinogenesis is a highly controlled process that results in the conversion of unmineralized predentin to mineralized dentin. By weight, 70% of the dentin matrix is mineralized, while the organic phase accounts for 20% and water constitutes the remaining 10%. Type I collagen is the primary component (>85%) of the organic portion of dentin. The non-collagenous part of the organic matrix is composed of various proteins, with dentin phosphoprotein predominating, accounting for about 50% of the non-collagenous part. Dentin defects are broadly classified into two major types: dentinogenesis imperfectas (DIs, types I-III) and dentin dysplasias (DDs, types I and II). To date, mutations in DSPP have been found to underlie the dentin disorders DI types II and III and DD type II. With the elucidation of the underlying genetic mechanisms has come the realization that the clinical characteristics associated with DSPP mutations appear to represent a continuum of phenotypes. Thus, these disorders should likely be called DSPP-associated dentin defects, with DD type II representing the mild end of the phenotypic spectrum and DI type III representing the severe end.
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Affiliation(s)
- P Suzanne Hart
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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215
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Carrilho MRO, Geraldeli S, Tay F, de Goes MF, Carvalho RM, Tjäderhane L, Reis AF, Hebling J, Mazzoni A, Breschi L, Pashley D. In vivo preservation of the hybrid layer by chlorhexidine. J Dent Res 2007; 86:529-33. [PMID: 17525352 DOI: 10.1177/154405910708600608] [Citation(s) in RCA: 377] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Host-derived proteases have been reported to degrade the collagen matrix of incompletely-resin-infiltrated dentin. This study tested the hypothesis that interfacial degradation of resin-dentin bonds may be prevented or delayed by the application of chlorhexidine (CHX), a matrix metalloproteinase inhibitor, to dentin after phosphoric acid-etching. Contralateral pairs of resin-bonded Class I restorations in non-carious third molars were kept under intra-oral function for 14 months. Preservation of resin-dentin bonds was assessed by microtensile bond strength tests and TEM examination. In vivo bond strength remained stable in the CHX-treated specimens, while bond strength decreased significantly in control teeth. Resin-infiltrated dentin in CHX-treated specimens exhibited normal structural integrity of the collagen network. Conversely, progressive disintegration of the fibrillar network was identified in control specimens. Auto-degradation of collagen matrices can occur in resin-infiltrated dentin, but may be prevented by the application of a synthetic protease inhibitor, such as chlorhexidine.
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Affiliation(s)
- M R O Carrilho
- Department of Restorative Dentistry, Dental Materials Area, University of Campinas, Piracicaba School of Dentistry, Piracicaba/SP, Brazil
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216
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Carrilho MRO, Carvalho RM, de Goes MF, di Hipólito V, Geraldeli S, Tay FR, Pashley DH, Tjäderhane L. Chlorhexidine preserves dentin bond in vitro. J Dent Res 2007; 86:90-4. [PMID: 17189470 PMCID: PMC2248723 DOI: 10.1177/154405910708600115] [Citation(s) in RCA: 268] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Loss of hybrid layer integrity compromises resin-dentin bond stability. Matrix metalloproteinases (MMPs) may be partially responsible for hybrid layer degradation. Since chlorhexidine inhibits MMPs, we hypothesized that chlorhexidine would decelerate the loss of resin-dentin bonds. Class I preparations in extracted third molars were sectioned into two halves. One half was customarily restored (etch-and-rinse adhesive/resin composite), and the other was treated with 2% chlorhexidine after being acid-etched before restoration. Specimens were stored in artificial saliva with/without protease inhibitors. Microtensile bond strengths and failure mode distribution under SEM were analyzed immediately after specimens' preparation and 6 months later. With chlorhexidine, significantly better preservation of bond strength was observed after 6 months; protease inhibitors in the storage medium had no effect. Failure analysis showed significantly less failure in the hybrid layer with chlorhexidine, compared with controls after 6 months. In conclusion, this in vitro study suggests that chlorhexidine might be useful for the preservation of dentin bond strength.
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Affiliation(s)
- M. R. O. Carrilho
- Department of Restorative Dentistry, Dental Materials, Piracicaba School of Dentistry, University of Campinas, Piracicaba, SP, Brazil
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, GA, USA
| | - R. M. Carvalho
- Department of Prosthodontics, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil
| | - M. F. de Goes
- Department of Restorative Dentistry, Dental Materials, Piracicaba School of Dentistry, University of Campinas, Piracicaba, SP, Brazil
| | - V. di Hipólito
- Department of Restorative Dentistry, Dental Materials, Piracicaba School of Dentistry, University of Campinas, Piracicaba, SP, Brazil
| | - S. Geraldeli
- Dows Institute for Dental Research and Department of Operative Dentistry, University of Iowa, Iowa City, USA
| | - F. R. Tay
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, GA, USA
| | - D. H. Pashley
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, GA, USA
| | - L. Tjäderhane
- Institute of Dentistry, University of Helsinki, PO Box 41, 00014 University of Helsinki, and Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Helsinki, Finland
- corresponding author,
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