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Assessment of Hydroxyapatite Nanospheres Incorporated Dentin Adhesive. A SEM/EDX, Micro-Raman, Microtensile and Micro-Indentation Study. COATINGS 2020. [DOI: 10.3390/coatings10121181] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hydroxyapatite (HA) delivery with resin adhesives has potential for re-mineralization of resin–dentin interface. The study prepared an adhesive containing HA and confirmed its presence in adhesive and interaction with the dentin using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Micro-Raman spectroscopy. The aim was to assess the influence of HA incorporation in dentin adhesive on its microtensile bond strength (μ-tbs) and Knoop microhardness (KHN). Thirty teeth each were bonded with CA and HA adhesive using a 10-s smear and photo-polymerized. The specimens in each adhesive group (CA and HA) were divided into sub-groups of 24 h, 8 weeks, and 16 weeks (n = 10) aging durations. μ-tbs was assessed at a crosshead speed of 0.5 mm/minute and bonded interface was analyzed using SEM (n = 20) and Raman spectroscopy (n = 10). Softening of HA adhesive and CA was assessed using KHN. HA adhesive presented higher μ-tbs compared to CA. With an increase in storage time, HA adhesive presented with 100% adhesive failure. Softening was less and KHN was higher for HA adhesive compared to CA (p < 0.05). KHN reduction was higher in CA [19.6 (5.1)%] compared to the HA adhesives [9.7 (4.5)%]. HA adhesive showed superior μTBS and microhardness compared to CA. In the absence of nanoleakage, HA modified adhesive exhibited enhanced bond integrity and better durability of resin dentin bond compared to control adhesive.
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Alshahrani A, Bin-Shuwaish MS, Al-Hamdan RS, Almohareb T, Maawadh AM, Al Deeb M, Alhenaki AM, Abduljabbar T, Vohra F. Graphene oxide nano-filler based experimental dentine adhesive. A SEM / EDX, Micro-Raman and microtensile bond strength analysis. J Appl Biomater Funct Mater 2020; 18:2280800020966936. [PMID: 33264047 DOI: 10.1177/2280800020966936] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
AIM The study aimed to assess graphene oxide (GO) adhesive and its dentin interaction using scanning electron microscopy (SEM), MicroRaman spectroscopy and Microtensile bond strength (μTBS). MATERIALS AND METHODS Experimental GOA and control adhesives (CA) were fabricated. Presence of GO within the experimental adhesive resin was assessed using SEM and Micro-Raman spectroscopy. Ninety specimens were prepared, sixty teeth were utilized for μTBS, twenty for SEM analysis of interface for CA and GOA and ten were assessed using microRaman spectroscopy. Each specimen was sectioned and exposed dentine was conditioned (35% phosphoric acid) for 10 s. The surface was coated twice with adhesive (15 s) and photopolymerized (20 s). Composite build-up on specimen was photo-polymerized. Among the bonded specimens, thirty specimen were assessed using Micro-Raman spectrometer, SEM and energy dispersive X-ray spectroscopy (EDX), whereas remaining specimens were divided in to three sub-groups (n = 10) based on the storage of 24 h, 8 weeks and 16 weeks. μTBS testing was performed at a crosshead speed of 0.5 mm/min using a microtensile tester. The means of μ-tbs were analyzed using ANOVA and post hoc Tukey multiple comparisons test. RESULTS No significant difference in μTBS of CA and GOA was observed. Storage time presented a significant interaction on the μTBS (p < 0.01). The highest and lowest μTBS was evident in CA (30.47 (3.55)) at 24 h and CA (22.88 (3.61)) at 18 weeks. Micro-Raman analysis identified peaks of 1200 cm-1 to 1800 cm1, D and G bands of GO nanoparticles in the resin. Uniform distribution of graphene oxide nanoparticles was present at the adhesive and hybrid layer. CONCLUSION GO showed interaction within adhesive and tooth dentin similar to CA, along with formation of hybrid layer. In ideal conditions (absence of nanoleakage), graphene oxide modified adhesive shows comparable bond strength and durability of resin dentine bond.
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Affiliation(s)
- Abdullah Alshahrani
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Mohammed S Bin-Shuwaish
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Rana S Al-Hamdan
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Thamer Almohareb
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Ahmed M Maawadh
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Modhi Al Deeb
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Aasem M Alhenaki
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Tariq Abduljabbar
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Fahim Vohra
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
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Fawzy A, Daood U, Matinlinna J. Potential of high-intensity focused ultrasound in resin-dentine bonding. Dent Mater 2019; 35:979-989. [DOI: 10.1016/j.dental.2019.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/29/2019] [Accepted: 04/01/2019] [Indexed: 12/28/2022]
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Tran XV, Salehi H, Truong MT, Sandra M, Sadoine J, Jacquot B, Cuisinier F, Chaussain C, Boukpessi T. Reparative Mineralized Tissue Characterization after Direct Pulp Capping with Calcium-Silicate-Based Cements. MATERIALS 2019; 12:ma12132102. [PMID: 31261905 PMCID: PMC6650868 DOI: 10.3390/ma12132102] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 06/26/2019] [Accepted: 06/26/2019] [Indexed: 12/30/2022]
Abstract
Nowadays, the preservation of dental pulp vitality is an integral part of our daily therapies. The success of these treatments depends on the clinical situation as well as the biomaterials used. Mineral Trioxide aggregate and BiodentineTM are commonly used as pulp capping materials. One objective of vital pulp therapy is the repair/regeneration of the pulp. In addition to the initial inflammatory status of the pulp, the nature and quality of the new mineralized tissue obtained after pulp capping directly influence the success of the treatment. In order to characterize the reparative dentin, in the current study, the chemical composition and microstructure of the dentin bridge after direct pulp capping using Biodentine™ and mineral trioxide aggregate (MTA) was studied by using Raman microspectroscopy and scanning electron microscopy, respectively. The results showed that the reparative dentin bridge observed in both groups presented dentin tubules and chemical composition similar to primary dentin. With the limitations of this study, the calcium-silicate-based cements used as pulp capping materials provide an optimal environment for pulp healing, resulting in a reparative dentin resembling on certain points of the primary dentin and the regeneration of the pulp.
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Affiliation(s)
- Xuan Vinh Tran
- EA 2496, Laboratory of Orofacial Pathologies, Imaging and Biotherapies, Dental School, Paris Descartes University, Sorbonne Paris Cite, 1 rue Maurice Arnoux, 92120 Montrouge, France.
- Faculty of Odonto-Stomatology, University of Medicine and Pharmacy at Ho Chi Minh City (UMP), 217 Hong Bang street, Ward 11, Dist 5, Ho Chi Minh City, Viet Nam.
| | - Hamideh Salehi
- EA4203, Laboratory BioHealth and Nanosciences, Dental school, Montpellier University, avenue du Pr Jean-Louis Viala, CEDEX 5, 34193 Montpellier, France
| | - Minh Tam Truong
- Thanh Vu Medic Bac Lieu Hospital; Highway 1 bypass, Ward 7, Bac Lieu City, Bac Lieu province, Viet Nam
| | - Minic Sandra
- EA 2496, Laboratory of Orofacial Pathologies, Imaging and Biotherapies, Dental School, Paris Descartes University, Sorbonne Paris Cite, 1 rue Maurice Arnoux, 92120 Montrouge, France
| | - Jeremy Sadoine
- EA 2496, Laboratory of Orofacial Pathologies, Imaging and Biotherapies, Dental School, Paris Descartes University, Sorbonne Paris Cite, 1 rue Maurice Arnoux, 92120 Montrouge, France
| | - Bruno Jacquot
- EA4203, Laboratory BioHealth and Nanosciences, Dental school, Montpellier University, avenue du Pr Jean-Louis Viala, CEDEX 5, 34193 Montpellier, France
| | - Frédéric Cuisinier
- EA4203, Laboratory BioHealth and Nanosciences, Dental school, Montpellier University, avenue du Pr Jean-Louis Viala, CEDEX 5, 34193 Montpellier, France
| | - Catherine Chaussain
- EA 2496, Laboratory of Orofacial Pathologies, Imaging and Biotherapies, Dental School, Paris Descartes University, Sorbonne Paris Cite, 1 rue Maurice Arnoux, 92120 Montrouge, France
- AP-HP Department of odontology, Charles Foix and Bretonneau Hospitals, 12 avenue de la République, 94200, Ivry-sur-Seine, France and 12 rue Carpeaux, 75018 Paris, France
| | - Tchilalo Boukpessi
- EA 2496, Laboratory of Orofacial Pathologies, Imaging and Biotherapies, Dental School, Paris Descartes University, Sorbonne Paris Cite, 1 rue Maurice Arnoux, 92120 Montrouge, France.
- AP-HP Department of odontology, Charles Foix and Bretonneau Hospitals, 12 avenue de la République, 94200, Ivry-sur-Seine, France and 12 rue Carpeaux, 75018 Paris, France.
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de Oliveira Ferraz LC, Ubaldini ALM, de Oliveira BMB, Neto AM, Sato F, Baesso ML, Pascotto RC. Analytical method to estimate resin cement diffusion into dentin. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:55003. [PMID: 27232592 DOI: 10.1117/1.jbo.21.5.055003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 04/27/2016] [Indexed: 06/05/2023]
Abstract
This study analyzed the diffusion of two resin luting agents (resin cements) into dentin, with the aim of presenting an analytical method for estimating the thickness of the diffusion zone. Class V cavities were prepared in the buccal and lingual surfaces of molars (n=9). Indirect composite inlays were luted into the cavities with either a self-adhesive or a self-etch resin cement. The teeth were sectioned bucco-lingually and the cement–dentin interface was analyzed by using micro-Raman spectroscopy (MRS) and scanning electron microscopy. Evolution of peak intensities of the Raman bands, collected from the functional groups corresponding to the resin monomer (C─O─C, 1113 cm(−1)) present in the cements, and the mineral content (P─O, 961 cm(−1)) in dentin were sigmoid shaped functions. A Boltzmann function (BF) was then fitted to the peaks encountered at 1113 cm(−1) to estimate the resin cement diffusion into dentin. The BF identified a resin cement–dentin diffusion zone of 1.8±0.4 μm for the self-adhesive cement and 2.5±0.3 μm for the self-etch cement. This analysis allowed the authors to estimate the diffusion of the resin cements into the dentin. Fitting the MRS data to the BF contributed to and is relevant for future studies of the adhesive interface.
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Affiliation(s)
| | - Adriana Lemos Mori Ubaldini
- State University of Maringá, Department of Dentistry, Av. Mandacaru 1550, 87080-0009, Maringá, Paraná, Brazil
| | | | - Antonio Medina Neto
- State University of Maringá, Department of Physics, Av. Colombo 5790, 87020-900, Maringá, Paraná, Brazil
| | - Fracielle Sato
- State University of Maringá, Department of Physics, Av. Colombo 5790, 87020-900, Maringá, Paraná, Brazil
| | - Mauro Luciano Baesso
- State University of Maringá, Department of Physics, Av. Colombo 5790, 87020-900, Maringá, Paraná, Brazil
| | - Renata Corrêa Pascotto
- State University of Maringá, Department of Dentistry, Av. Mandacaru 1550, 87080-0009, Maringá, Paraná, Brazil
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Daood U, Swee Heng C, Neo Chiew Lian J, Fawzy AS. In vitro analysis of riboflavin-modified, experimental, two-step etch-and-rinse dentin adhesive: Fourier transform infrared spectroscopy and micro-Raman studies. Int J Oral Sci 2015; 7:110-24. [PMID: 25257880 PMCID: PMC4817549 DOI: 10.1038/ijos.2014.49] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2014] [Indexed: 11/11/2022] Open
Abstract
To modify two-step experimental etch-and-rinse dentin adhesive with different concentrations of riboflavin and to study its effect on the bond strength, degree of conversion, along with resin infiltration within the demineralized dentin substrate, an experimental adhesive-system was modified with different concentrations of riboflavin (m/m, 0, 1%, 3%, 5% and 10%). Dentin surfaces were etched with 37% phosphoric acid, bonded with respective adhesives, restored with restorative composite–resin, and sectioned into resin–dentin slabs and beams to be stored for 24 h or 9 months in artificial saliva. Micro-tensile bond testing was performed with scanning electron microscopy to analyse the failure of debonded beams. The degree of conversion was evaluated with Fourier transform infrared spectroscopy (FTIR) at different time points along with micro-Raman spectroscopy analysis. Data was analyzed with one-way and two-way analysis of variance followed by Tukey's for pair-wise comparison. Modification with 1% and 3% riboflavin increased the micro-tensile bond strength compared to the control at 24 h and 9-month storage with no significant differences in degree of conversion (P<0.05). The most predominant failure mode was the mixed fracture among all specimens except 10% riboflavin-modified adhesive specimens where cohesive failure was predominant. Raman analysis revealed that 1% and 3% riboflavin adhesives specimens showed relatively higher resin infiltration. The incorporation of riboflavin in the experimental two-step etch-and-rinse adhesive at 3% (m/m) improved the immediate bond strengths and bond durability after 9-month storage in artificial saliva without adversely affecting the degree of conversion of the adhesive monomers and resin infiltration.
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Affiliation(s)
- Umer Daood
- Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, Singapore
| | - Chan Swee Heng
- Laboratory technologist, Discipline of Oral Sciences, Biomaterials and Biophotonics, National University of Singapore, Singapore, Singapore
| | - Jennifer Neo Chiew Lian
- Discipline of Prosthodontics, Operative Dentistry and Endodontics, National University of Singapore, Singapore, Singapore
| | - Amr S Fawzy
- Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, Singapore
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Sato M, Miyazaki M. Comparison of depth of dentin etching and resin infiltration with single-step adhesive systems. J Dent 2005; 33:475-84. [PMID: 15935267 DOI: 10.1016/j.jdent.2004.10.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Revised: 10/21/2004] [Accepted: 10/25/2004] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES Adhesion of resin composites to dentin is currently believed to result from impregnation of adhesive resin into superficially demineralized dentin. The purpose of this study was to use micro-Raman spectroscopy and scanning electron microscopy (SEM) to investigate the extent of resin penetration into etched dentin with single-step adhesive systems. METHODS Adhesive systems used were One-Up Bond F (Tokuyama Dental) and Reactmer Bond (Shofu, Inc.). A self-etching primer system Mac Bond II (Tokuyama Dental) was employed as a control. Resin composites were bonded to bovine dentin with the adhesive systems, and specimens were sectioned parallel to dentinal tubules. Raman spectra were successively recorded along a line perpendicular to the dentin-adhesive interface in steps of 0.2 microm and the spectra were obtained. SEM observations of the resin-dentin interface were also conducted. RESULTS The dentin-resin interface of single-step adhesive systems showed a gradual transition in the relative amount of adhesive from the resin side to dentin side. The widths of resin penetration into demineralized dentin detected by Raman microscopy were greater than those obtained by the morphological analysis using SEM. CONCLUSIONS From the results of this study, a gradual variation in the composition of the dentin-resin interface was detected, and the degree of resin impregnation observed with SEM observation was less than that detected with the Raman microscopy.
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Affiliation(s)
- Mitsuo Sato
- Operative Dentistry, Nihon University Graduate School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
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Miyazaki M, Onose H, Iida N, Kazama H. Determination of residual double bonds in resin-dentin interface by Raman spectroscopy. Dent Mater 2003; 19:245-51. [PMID: 12628438 DOI: 10.1016/s0109-5641(02)00039-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES The quality of the hybrid layer is believed to be more important than the thickness of this layer. The purpose of this study was to investigate a method to analyze the percentage of adhesive resin residual double bonds in the dentin-resin interface using laser Raman spectroscopy. METHODS Bovine dentin was treated with dentin adhesives and resin composite was bonded according to the manufacturers' instructions. The specimens were sectioned parallel to dentinal tubules and the surfaces were then polished to 1 microm diamond pastes. Raman spectra were recorded along a line perpendicular to the dentin-resin interface in steps of 0.2 microm. The measurement of residual C=C bond was made on a relative basis by comparing the C=C unpolymerized methacrylate stretching vibration (1638 cm(-1)) against the C=O stretching mode of the ester group (1719 cm(-1)). The percentage of residual double bonds including pendant and monomeric double bonds was calculated by comparing the obtained ratio with that of uncured adhesive resin. RESULTS The amount of residual double bonds in the hybrid layer varied from 10 to 25% compared to the uncured adhesives, a relatively higher percentage was detected for Fluoro Bond (12.3-23.6%) and Single Bond (9.5-21.8%), and lower for Mac Bond II (10.6-18.0%) and Mega Bond (10.7-16.3%). No relationship was seen between the percentage of remaining double bonds and the location within the resin-dentin interface. SIGNIFICANCE Laser Raman microscopy used was a useful tool for measuring the residual double bonds in the dentin-resin interface.
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Affiliation(s)
- M Miyazaki
- Department of Operative Dentistry, Nihon University School of Dentistry, 1-8-13, Kanda Surugadai, Chiyoda-Ku, 101-8310, Tokyo, Japan.
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Miyazaki M, Onose H, Moore BK. Analysis of the dentin-resin interface by use of laser Raman spectroscopy. Dent Mater 2002; 18:576-80. [PMID: 12385898 DOI: 10.1016/s0109-5641(01)00093-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES Adhesion of resin-bonding agents to dentin is currently believed to result from impregnation of adhesive resin into superficially demineralized dentin. The purpose of this study was to investigate the chemical composition of the resin-impregnated dentin (hybrid) layer using a micro-Raman spectroscopy. METHODS Resin composites were bonded to bovine dentin with the two-step bonding systems, and specimens were sectioned parallel to dentinal tubules. These surfaces were then polished down to 1 microm diamond pastes. Raman spectra were successively recorded along a line perpendicular to the dentin-adhesive interface by steps of 0.2 microm on a computer controlled X-Y stage. The relative amounts of hydroxyapatite (960 cm(-1), P-O), adhesive resin (640 cm(-1), aromatic ring), and organic substrate (1450 cm(-1), C-H) in the dentin-adhesive bonding area were calculated. RESULTS From the Raman spectroscopy results, the hybrid layer represents a gradual transition in the relative amount of adhesive from the resin side to dentin side. Evidence of poor saturation of the adhesive resin in the demineralized dentin with the one-bottle adhesive system was detected. SIGNIFICANCE From the results of this study, inhomogeneity of the hybrid layer composition was detected, and the degree of resin impregnation was found to be different between the bonding systems tested.
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Affiliation(s)
- M Miyazaki
- Department of Operative Dentistry, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-Ku, 101-8310, Tokyo, Japan.
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Vaidyanatha J, Vaidyanathan TK, Yadav P, Linaras CE. Collagen-ligand interaction in dentinal adhesion: computer visualization and analysis. Biomaterials 2001; 22:2911-20. [PMID: 11561897 DOI: 10.1016/s0142-9612(01)00038-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The objective of this study was to characterize the interactions of selected ligand molecules with collagen structure through computer visualization of the reacting molecules and the resulting complexes. Five ligand molecules were studied. They were 2-Hydroxyethyl methacrylate, Glutaraldehyde-HEMA adduct, Glyceryl dimethacrylate, Methacryloyloxyethyl maleate and Acryloyloxyethyl citraconate. These ligands were selected with oxygen as a common heteroatom for a reactive or functional site. Energy minimized 3-D structures of the molecules were generated by Sybyl molecular modeling software. The structures were subjected to a systematic conformational search, yielding conformations of the molecules with a common recognition site with both steric and electrostatic complementarity to appropriate receptor sites in a type I collagen molecular structure. The ligands were also docked to collagen receptor by autodock procedures and the receptor sites where docking occurred were evaluated. The energy of the molecules and their complexes with collagen was evaluated and compared. The computer visualization results reveal that steric complementarity between receptor sites in collagen and optimally configured ligands may be the basis of micromechanical bonding between collagen and the ligands. Typically, ligands docked on the cavities of collagen molecular surface and wrapped around the cavities which follow the helical turns of the collagen macromolecule. In addition, analysis of electrostatic potential features revealed electrostatic complementarity as an additional source of interaction. Hydrogen bonds between ligands and collagen molecule were detected in the complexes of several of the conformations of all the ligands. Thus computer simulation studies show that steric and electrostatic complementarity and consequent interactions form the potential basis of binding between dentin adhesive ligands and type I collagen.
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Affiliation(s)
- J Vaidyanatha
- Department of Prosthodontics and Biomaterials, NJ Dental School, Newark 07103, USA.
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Leung Y, Morris MD. Characterization of the chemical interactions betwen 4-MET and enamel by Raman spectroscopy. Dent Mater 1995; 11:191-5. [PMID: 8600012 DOI: 10.1016/0109-5641(95)80017-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES The goal of this investigation was to use Raman spectroscopy to study the chemical interactions between 4-methacryloxyethyltrimellitic acid (4-MET), a hydrolized form of 4-methacryloxyethyltrimellitate anhydride (4-META) and powdered substrates such as bovine enamel powder and synthetic carbonate-containing apatite. METHODS Powdered samples were prepared by immersing them in 4-MET/methylmethacrylate (MMA) solution for 15 min, 3 h and 24 h. They were then dried for spectroscopy. An experimental Raman microprobe equipped with a cryogenically-cooled camera was employed to acquire spectra of the samples. RESULTS Spectra of samples wetted for 24 h strongly indicate that there is strong ionic interaction between Ca2+ ions on the powdered sample surface and 4-MET. Spectra of the 15-min samples, however, suggest only some degree of hydrogen bonding. The spectrum of the 3-h 4-MET/enamel powder sample showed features intermediate between the two. SIGNIFICANCE Results presented in this paper show that salt formation between 4-MET and dental substrates is not likely to be instantaneous. On the contrary, the rate of such reaction is probably too slow relative to that of polymerization of the co-monomers to be important under clinical conditions. The function of the 4-MET in the 4-MET/MMA resin system appears, therefore to be wetting the tooth surface through hydrogen bonding, which then allows MMA monomers to diffuse and penetrate deeper through the surfaces. The primary bonding mechanism of this system is more likely due to a micro-mechanical locking mechanism.
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Affiliation(s)
- Y Leung
- Department of Chemistry, University of Michigan, Ann Arbor, USA
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Tam LE, Pilliar RM. Fracture surface characterization of dentin-bonded interfacial fracture toughness specimens. J Dent Res 1994; 73:607-19. [PMID: 8163731 DOI: 10.1177/00220345940730030601] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Although the current trend in dentin bonding favors the development of a hybrid layer interdiffusion zone for micromechanical bonding, the exact nature of the dentin-composite bond is still unclear. The objective of this study was to characterize the fracture surfaces of specimens used to measure interfacial fracture toughness. Morphological (SEM) and chemical (EDS and XPS) surface analyses were used for characterization. Fracture toughness specimens generally failed along the dentin-bonded interface in agreement with observed clinical failure modes. Four sites of bond failure were identified within the dentin-composite interfaces when All-Bond 2, Scotchbond Multi-Purpose, and Scotchbond 2 were used as the dentinal adhesives. These were located within (1) the smear layer, (2) a resin-modified layer between the interdiffusion zone and the adhesive resin, (3) a well-infiltrated hybrid interdiffusion zone, and (4) a non-infiltrated unsupported collagen layer. The interfacial region had a complex architecture which varied with the nature of the dentin, the dentin surface treatment, and the dentin bonding system. The sites of bond failure appeared to correlate with the interfacial fracture toughness and the extent to which polymerized resin infiltrated and acted to support the organic dentinal structures.
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Affiliation(s)
- L E Tam
- Department of Restorative Dentistry, Centre for Biomaterials, Faculty of Dentistry, Toronto, Ontario, Canada
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