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Advanced glycation end-products （AGEs） accumulate with aging or with diabetes. AGEs affect the physical properties of human dentin, resulting in fragility and browning. In particular, pentosidine, a cross-linked AGE, was found to be significantly increased in aged dentin or caries-affected dentin. The shorter fluorescence lifetime of dentinal collagen in carious teeth as compared to healthy teeth suggests that AGEs result in shortening of the fluorescence lifetime. AGEs are also thought to affect blood vessels in the pulp. In recent years, research has been conducted to mitigate the effects of AGEs with supplements or drugs. In this review, we present the details and latest findings of research related to glycation of dental tissue. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAP), a basic calcium phosphate, is the main component of tooth dentin. It is decomposed by acids produced by Streptococcus mutans, which is the mechanism of caries. That means that exposed dentin is less stable than dental materials used in restoration. Enamel protects dentin from demineralization and pulp from hypersensitivity and infection. So it is imperative that, after drilling with burrs, the prepared HAP does not come into contact with acids. Impermeable hybridized dentin was formed in the subsurface of prepared dentin by impregnation of new monomers and their polymerization in situ. This can stabilize dentin against acid demineralization in the mouth and increase the reliability of dental treatment. The IPN can protect HAP from contacting acids and furthermore helps that collagen is not hydrolyzed. [ABSTRACT FROM AUTHOR]

The article presents a study that evaluates the differences between the adhesion of resin cements to the root dentin and to the crown dentin. Tooth crown dentin indicated greater adhesion than tooth root dentin in resin cements four types. Removal of stained layers by preliminary treatment materials was noted in tooth crown dentin. Moreover, longer resin tags presence in tooth crown dentin was affirmed.

The article focuses on the recovery of adhesive strength reduced by bonding between dentin surface treated with sodium hypochlorite (NaOCl) and 4-META resin cement. Bacterial infection to the dentin surface of the prepared teeth is considered to be one of the important factors that cause pulpal inflammation or secondary caries. It finds a way to recover the adhesive strength of 4-META or MMA-TTBO resin cement to dentin after reduction by sterilization with NaOCl solution.

The article discusses a study on the prevention of carboxylate temporary cements adhesion to abutment teeth. It also aims to find solutions in order to remove easily the cements stuck on the dentin surface. The study found ammonia solution as a practical solvent for carboxylate temporary cements and had a little influence on shear bond strength of adhesive resin cements.

Firm adhesion of composite resin and dentin is the basic premise for building up resin composite cores successfully. To assess the efficacy of several caries detective methods (stained with Caries Detector and probing with sharp probe) for caries affected root canal dentin, microtensile bond strengths of resin composite to caries-affected root canal dentin and failure mode distribution were analyzed in this study. Color and hardness were used for assessment of root caries as follows: Dye stain group (pale pink stained with Caries Detector), Probing group (probing with sharp probe) and Sound dentin group (Control). The bond strengths (mean +/- standard deviation) of the Probing group (64.6 +/- 11.9 MPa) and the Sound dentin group (68.7 +/- 11.1 MPa) were significantly higher than those of the Dye stain group (46.9 +/- 7.9 MPa, p<0.05). However, there is no significant difference in fracture mode between the Dye stain group and the Probing group (p<0.05). This could be attributed to that the thick smear layer caused a loss of hybrid layer strength. In conclusion, the caries removal technique of the root canal dentin affected the bond strength of the resin composite.

Purpose: In this study, we investigated the conditioning efficacy of a self-etching primer consisting of methacrylamide, N-methacryloyl-omega-amino acid (M omega A) derivatives for enhancing the bond strength of resin to crown and root dentins., Methods: A series of four M omega A derivatives, with different methylene chain numbers, were synthesized, as follows. 1: N-methacrylole glycine (Gly); 2: N-methacrylole-beta-alanine (beta Ala); 3: N-methacrylole-4-aminobutyric acid (Bu); 4: N-methacrylole-5-aminovaleric acid (Va). The dissociation equilibrium pH (pKa) of carboxylic acid in each of the M omega A derivatives was determined. The shear bond strengths of resin to the crown and root dentins, primed with the Gly solution were measured for various conditioning times. We also measured the bond strength to both the dentins following application of the M omega A adhesives with different pKa values for 30 seconds., Results: For the Gly primer, the bond strength of resin to both dentins increased with the conditioning time until 30 seconds, leveled off thereafter by increase in the methylene chain number. The effects of conditioning time on the bond strength to the crown and the root dentin were the same. Furthermore, the bond strengths to the dentins, conditioned with each of the four M omega A derivatives for 30 seconds, were the same, even though the decalcified amounts of the dentin apatite noted following conditioning with Bu and Va were lower than that noted following conditioning with Gly. This was attributed to the pKa value of the acidic groups in the acidic monomer directly relating to the decalcified amount of dentin apatite., Conclusions: Application of the M omega A solutions, resulted in an increase in the bond strength of resin to both crown and root dentins. In particular, the Bu and Va primers were very useful as primers promoting the bond of resin to dentin, since the etching potential was very low.

Purpose: For the purpose of evaluating the flow properties influencing the formativeness of commercial hard resin pastes used in the construction of crowns and bridges, we examined the behaviors of various resin pastes and their temperature dependence during manipulation., Methods: Five types of hard resins currently in use for the construction of crowns and bridges in the clinical setting, namely, New Meta Color INFIS, Solidex, Ceramage, Gradia, and Estenia C&B, were examined. The components and flow properties of each resin paste were investigated in relation to the dentine and enamel colors. The viscosities of the resin pastes before curing were measured by a cone-plate viscometer., Results: Each resin paste demonstrated a non-Newtonian flow, and the flow curve showed a hysteresis loop, in which the upward and downward curves were different. When the shear stress at the beginning of the holding time of the flow curve (20 degrees C, 25 degrees C, 30 degrees C) of each resin paste was measured, the shear stress at 20 degrees C was found to be significantly higher than that at 25 degrees C and 30 degrees C, and the shear stress at 25 degrees C was found to be significantly higher than that at 30 degrees C. The viscosity was found to be higher at lower temperatures than at higher temperatures. Comparison of the shear stresses at the beginning and at the end of the holding time revealed that the stress at the beginning of the holding time was significantly higher than that at the end of the holding time for all except the Estenia C&B resin paste., Conclusions: Each of the resin pastes used in the present study showed temperature dependence of its characteristics in the temperature range examined (20-30 degrees C) and thixotropic fluidity. However, the flow characteristics of these resin pastes differed significantly, suggesting that the flow characteristics may affect the manipulation of resin formativeness.

The linear attenuation coefficient (mu) is an important coefficient in the study of diagnostic radiology. The mu values of dentin and enamel were rarely reported because they are thin and tightly connected to each other and are difficult to measure by thermoluminescent dosimeters or ion chambers. In this work, we used film densitometry to measure the radiation dose before and after they transmitted the 2 mm thickness tooth slice and used this data to calculate the mu values of enamel and dentin. The results show that the mu values of enamel at 70, 80, 90kVp are 2.97 +/- 0.71, 2.85 +/- 0.07, 2.70 +/- 0.16 cm-1, respectively. The mu values of dentin at 70, 80, 90kVp are 2.12 +/- 0.92, 1.81 +/- 0.23, 1.89 +/- 0.42 cm-1, respectively. The mu values may be affected by the equivalent energy of an x-ray generator operated under different kVp conditions and also by the density and calcification degree of the enamel and dentin. Nevertheless, the results obtained in this study still can severe as a reference for researchers.

The thermal properties (thermal diffusivity and thermal conductivity) of human teeth and some dental cements were measured. The temperature change at the pulp cavity was also measured before and after the restoration with the full metal crown. The thermal insulating efficiency of dental cement was discussed. The thermal diffusivity of human dentin, enamel and dental cements was 2.04 x 10(-3), 3.22 x 10(-3), and 0.99-1.87 x 10(-3) cm2/sec, respectively. The thermal conductivity was 1.36 x 10(-3), 1.84 x 10(-3), and 0.50-1.51 x 10(-3) cal/cm.sec.degrees C, respectively. The dental cement beneath the crown insulated the thermal shock to dental pulp and the thermal insulating efficiency was increased with the decrease in the thermal diffusivity and thermal conductivity of dental cement.

To get a more natural and harmonious color of porcelain-fused-to-metal restorations, an objective and precise systematic method from shade selection to color evaluation is needed. Thus, the absorption and scattering coefficients were determined to develop a CCM system for porcelain-fused-to-metal restorations. The Kubelka-Munk Theory was applied on the dental porcelain, opaque, dentin, and enamel. From these data, we predicted the color of the porcelain mixtures from the both coefficients. From the results of comparing the spectral curves and analyzing the color differences between measured values and predicted values of porcelain mixtures, the following was analysed; 1. In opaque, spectral curves of the predicted and measured values were exactly alike and the mean dE between two values was 0.39. 2. In dentin, the spectral curved of the predicted and measured values were exactly alike, and the mean dE was 1.13. The measured values indicated a slight increase in the level of chroma and lightness. 3. In enamel, the spectral curves were exactly alike and the mean dE was 1.16. The measured values indicated a slight decrease in the level of lightness. Therefore, it was possible to predict the color of opaque, dentin and enamel porcelain mixtures, by applying the Kubelka-Munk Theory.

The purpose of this study is to assess the dentifrice abrasivity of both commercially available products and test products. The assessment of abrasivity was carried out by the measurement of 32P released from tooth by using radioactive dentifrice abrasion (RDA) method. In dentine, RDA values, which show the polishing ability for dentine, were 65-100 with dentifrices with normal cleaning power and 106-182 with those with high cleaning power, respectively. On the other hand, REA values which show the polishing ability for enamel were 12-405 with both market products and test products. The difference of the REA values according to the dentifrices appears to be largely influenced by the difference of polishing agents of each dentifrice. It is concluded that RDA method is usefull for assessing of dentifrice abrasivity. However, particular attention should be given to the abrasion of dentine.

This study was designed to elucidate whether or not the root canal sealers, newly prepared here, show high affinities and promote the osteo-cicatric healing for the remaining dental pulp and periapical regions. For these purposes, I used two types of sealers, newly devised here and mainly composed of powdered corals mixed with propyreneglycol for the experiment 1 and powdered human dentins mixed with atelocollagen implant for the experiment 2. Guttapercha points with these sealers were applied in the premolar and molar tooth mesial or distal canals of 24 adult cats, whereas in controls guttapercha points with Canals, made commercially, were used instead of these sealers. After treatment, the periapical tissues and accessory root canal regions were histopathologically observed at different intervals throughout 30 to 130 days. The results obtained were as follows: 1. When guttapercha points were penetrated beyond the apical foramen and reached periapical tissues, prolonged inflammatory reactions of a slight or medium degree were observed in all three types of sealers. 2. When Canals were applied, prolonged inflammatory reactions were persistent if the sealer flooded out. In contrast, if they were in just-filling (Type-I, as termed in text), inflammatory reactions were often detectable at the accessory root regions. Many exudative inflammatory cells around the over-tip of guttapercha points were seen, as compared around the apicals of the dental root. 3. When powdered coral was used, strong inflammatory reactions was little found. Adjunction of the new bone was usually observed in the alveolar bone. The tendency of scar formations was seen in the periapical tissues where the inflammatory reaction was assumed to have occurred. 4. When powdered human dentin was used, in any experiments, inflammatory reaction were not seen with a few exceptions. However, if inflammatory responses were existed in a few cases, their degrees were relatively strong. 5. If the debris of dentin was blocked within the root canal apex, fine examples were seen regardless of the three types of the sealers. 6. Calcium in the powdered coral showed a conspicuous peak by energy X-ray analysis. The ratio of Ca and P of powdered human dentin was 1:1. From the above findings, both powdered coral and powdered human dentin could be useful as composites of sealers.

Although many studies have been made on the reinforcement of the bond between tooth and restorative resin, satisfactory results have not been obtained clinically. Attempts were made to obtain such a reinforced bonding using the aqueous solution of derivatives of amino acid, either N-methacryloyl alanine (MAL) or N-acryloyl alanine (AAL), and 2-hydroxyethyl methacrylate (HEMA). Following the treatment with these surfactants, a tensile bond strength of 103 kgf/cm2 (to enamel) and 80 kgf/cm2 (to dentin) was obtained by MAL-HEMA solution, and that of 99 kgf/cm2 (to enamel) and 58 kgf/cm2 (to dentin) in the case of AAL-HEMA solution. This is considered as the result of either the etching effect of the amino acid derivatives, effect of its reactive products with hydroxyapaptite or reaction between HEMA and an organic component of tooth structure, like a collagen.

The hiding effect on color tone of discolored teeth restored with ceramic laminate veneer crown was examined. Translucent (T1, T2), Enamel (E1, E2, E3), Dentin (DA2, DA3, DB2, DB3), Masking dentin (MDA2, MDA3, MDB2, MDB3) in 13 colors and Modifire (M61, M62, M65, M66, M67, M68, M69, M70, M79) in 7 colors of the ceramic materials (Cosmotech porcelain G C Co., Ltd) were examined in this experiments. The colorimetric examination of the color tone backing with the white or black color was carried out by testing for color difference (delta E*ab), value difference (delta L*), chrom and hue of the samples. The result obtained were as follows; 1. Color difference was higher in order of T2 greater than T1 in Translucent greater than E1 greater than E3 greater than E2 in Enamel greater than DB3 greater than DA2 greater than DA3 greater than DB2 in Dentin greater than MDB3 greater than MDA2 greater than MDB2 greater than MDA3 in Masking dentin, and M69 greater than M79 greater than M70 greater than M68 greater than M66 greater than M61 greater than M62 greater than M67 greater than M65 in Modifire. 2. Value difference was higher in order of T2 greater than T1 in Translucent greater than E1 greater than E3 greater than E2 in Enamel greater than DB3 greater than DA2 greater than DB2 greater than DA3 in Dentin greater than MDA2 greater than MDB3 greater than MDB2 greater than MDA3 in Masking dentin, and M69 greater than M70 greater than M79 greater than M68 greater than M66 greater than M61 greater than M67 greater than M65 greater than M62 in Modifire.(ABSTRACT TRUNCATED AT 250 WORDS)

A new 4-META/MMA-TBB adhesive resin has been studied and the effectiveness on adhesion to tooth substrates and dental alloys was reported previously. Here we are showing affection of cleaner or etchants on the adhesion between dentines and the 4-META/MMA-TBB resin. The adhesive strength becomes superior, 18 MPa, when dentines have been cleaned with a 10% citric acid-3% ferric chloride solution. On the other hand an etchant, phosphoric acid or citric acid alone, is not so effective as the mixed solution and the strength decreases to 6 MPa. Scanning electron microscopic study on pretreated dentine with several solutions is also carried out and it is found that debris on dentine should be removed but that in tubules is not necessary to be cleaned up to get good adhesion.

The purpose of this study was to evaluate histological regeneration of epithelial and connective tissue attachment to the denuded dentin surface after hydroxyapatite ceramic granule (HAP) implantation. HAP (particle size 100-300 microns, burn temperature 900 degrees C) were implanted into dehiscent defects of alveolar bone which eliminated about a 1 x 1 mm area at mesial and palatal sites of the upper 1st molar in 20 male Wistar rats. Subsequently the root cementum was removed totally and dentin was denuded. Same osseous defects were formed but HAP was not implanted at any contralateral site for the purpose of control. Results of 8-week examination using light and electron microscopy were as follows: 1. In the HAP group junctional epithelium was regenerated on the denuded dentin surface 2 weeks after implantation and epithelial down growth was less than at the control site. 2. In the HAP group connective tissue reattachment with new cementum formation was observed at 2 to 4 weeks after implantation, the healing period tended to be shorter than at the control site and the connective tissue reattachment level was located more coronally. 3. In ultrastructural findings collagen fiber bundles attached to the denuded dentin surface had fibers continuing around HAP granules.

The authors devised a new handy apparatus for iontophoresis in order to prevent pulp irritation caused by tooth reduction. This study was intended to observe the ability of the device. 8% zinc chloride solution was iontophoresed in the dentin of extracted human and bovine teeth by the device. Then, the dye and microbial invasion tests were carried out to investigate how effectively it could seal the dentinal tubules. The following conclusions were drawn: 1. By the zinc iontophoresis, the zinc briefly penetrated into the deep portion of the dentin. 2. The zinc iontophoresis by using the new device showed enough ability to decrease the coloring and bacterial invasion into the dentin, although all of the dentinal tubules were not sealed. 3. The tensile strengths of an adhesive luting resin 'Panavia EX' to the bovine dentin decreased significantly by the zinc iontophoresis. This phenomenon could be partly due to the lack of resin tag formation into the dentinal tubules.

The tensile bond strength of new bonding agents on human dentin treated with 37% phosphoric acid solution for 60 sec to a photocurable composite resin was measured and the fractured surface was then observed by SEM. The new bonding agents consisted of various 20 wt% high molecular monomers (MW. 1500, 5000, urethane acrylate oligomer) as a base monomer. The best bonding agent was a mixture of 20 wt% 1500 molecular monomer as a base monomer and the value of the tensile bond strength was 91 +/- 17 kgf/cm2. The tensile bond test and SEM image of the fracture surface suggested that a high molecular monomer as a base monomer promoted the adhesive efficiency to human dentin.

Since base materials are used in the construction of abutment teeth and the cavity walls of the teeth with healthy pulp, they need considerable bonding and mechanical strength depending on the site of application. In the present study we examined bonding strength, Martens-Mayer hardness and Vickers hardness of base materials in comparison with natural dentin in order to reevaluate them in terms of prosthetic materials and to provide assessment criteria for their application to prosthetic treatment. The results were as follows: 1) The bonding test showed the lowest value (4.6kgf/cm2) in calcium hydroxide FR (HFR) and the highest (47.9kgf/cm2) in HY-Bond polycarboxylate cement (CHC), a type of polycarboxylate cement. 2) In the test of bonding strength with various types of cement, calcium hydroxide preparations and zinc phosphate cement showed low values (4.6-23.5kgf/cm2) while polycarboxylate cement and glass-ionomer cement showed relatively high values (17.8-40.5kgf/cm2). 3) The Martens-Mayer hardness test showed the highest value (10.82 x 10(4] in dentin cement (GDE) and the lowest (1.09 x 10(4] in propack (EPR). 4) The Vickers hardness test showed the highest value (82) in neo-protect cement (ZPR) and the lowest (1) in propack (EPR). 5) In both Martens-Mayer and Vickers hardness tests with various types of cement, zinc phosphate cement and glass- ionomer cement showed high values, while low values were obtained in calcium hydroxide preparations and zinc-oxide eugenol cement. 6) Zinc phosphate cement and glass-ionomer cement showed no statistically significant differences from natural dentin in either Martens-Mayer hardness or Vickers hardness.

Bovine tooth surface pretreated with dental medicaments-Eugenol cement (ZOE), CC, FC was used to adhere to acrylic rod by adhesive resins-Clearfil F II and 4 META-MMA-TBB-O. The effects of the dental medicaments on the bonding strength of the adhesive resin were measured. The results were showed as follows: (1) Any pretreatment of the three medicaments reduced the bonding strength of Clearfil to both enamel and dentin surface. With 4-META-MMA-TBB-O resin system the bonding strength was reduced by ZOE and CC while it was increased by FC pretreatment. (2) On the enamel tooth surface premedicated with ZOE, FC or CC, the alcohol rinsing or mechanic grinding reduced the decrease of the bonding strength of Clearfil. With 4-META-MMA-TBB-O resin, the mechanic grinding of the premedicated enamel tooth surface increased the bonding strength. (3) On the premedicated dentin tooth surface, the mechanic grinding reduced the decrease of the bonding strength of 4-META-MMA-TBB-O. Alcohol rinsing, on the contrary, decreased the bonding strength. (4) On both fresh and premedicated dentin surface the bonding strength of Clearfil was lower than 3 MPa.

Twelve aliphatic methacrylates with a carboxylic group [succinate (2 MES, 5 MPeS and 10 MDS), methylsuccinate (2 MEMS, 5 MPeMS and 10 MDMS), maleate (2 MEM, 5 MPeM and 10 MDM) and citraconate (2 MEC, 5 MPeC and 10 MDC)] were synthesized by the addition of four dicarboxylic acid anhydrides to each of three different alkylene chain length hydroxy methacrylates to investigate the relationship between the methacrylate structure and its bonding to tooth. The bond strength of methacrylates to polished tooth surface decreased with increasing alkylene chain lengths under dry conditions, but water immersion reduced this change. The bond strength of succinate and maleate to polished tooth surface was higher than that of methylsuccinate and citraconate under dry conditions. All methacrylates showed high bond strength to etched enamel, with maleate showing the highest bond strength. On the other hand, the bond strength of 2 MEM and 5 MPeM to etched dentin was markedly high, and about 5 microns thick resin reinforced dentin at the interface between etched dentin and resin (2 MEM or 5 MPeM) was observed by SEM and EPMA analysis.

As a model experiment to understand the mechanism of adhesion of the MMA/TBBO resin to dentin, polymerization of MMA/TBBO was investigated in the presence of a collagen sheet treated with the aqueous citric acid (CA) solutions of copper fluoride (CF), ferric fluoride (FF), or ferric chloride (FC), which is usually used as a treating agent in bonding of the resin to dentin. The curing time of MMA/TBBO resin was considerably reduced in the presence of collagen treated with CF-CA or FF-CA solutions when compared to that with FC-CA solution. Molecular weight of PMMA depended on the site of polymerization; PMMA polymerized inside the collagen sheet was the highest and that polymerized outside was the lowest. Bond strength to dentin treated with CF-CA, FF-CA solutions was as strong as that treated with FC-CA solution. Treatment of dentin with CF-CA or FF-CA was as effective as that with FC-CA in bonding the MMA/TBBO resin. These results suggested that ferric compounds adsorbed to collagen are involved in polymerization of MMA and thus influence bond strength of the MMA/TBBO resin to dentin.

A graft polymerization of MMA onto silk was carried out under several conditions and the relationship between the grafting and the bond strength to dentin was compared in the case of a MMA-TBB resin. Phosphoric acid, EDTA 5-0 and EDTA 3-2 pretreatments to silk decreased the degree of grafting. On the other hand, 10-3 pretreatment increased it. The conformation of silk peptides was changed by the pretreatments and it was responsible for the diffusion of MMA and sites of grafting. Ferric ion absorbed on the silk enhanced the graft polymerization of MMA. Pretreatment which gave higher grafting onto silk did not always promote the bond strength to the dentin pretreated by the same pretreatments. We concluded that the graft polymerization of MMA on collagen was not necessary for the adhesion of resin to dentin.

Gypsum crystal growth on human dentin surface was investigated using a crystal growth agent composed of 4-20% ammonium sulfate and 5-60% acrylic acid aqueous admixtures. In the treatment with 4% ammonium sulfate which contains the concentration of acrylic acid from 5% to 60%, fine half-spherical aggregates of 25 microns in diameter of needle-like crystals were obtained from 35% acrylic acid and large ones from 30% acrylic acid. Using the crystal growth agent of 4% ammonium sulfate-35% acrylic acid aqueous admixture, the human dentin surface pretreated with sulfates of different cations was evaluated from crystal growth. All sulfates without 4% ZnSO4 formed half-spherical aggregates of needle-like crystals. Diameter of their half-spherical aggregates increased as follows; 4% Na2SO4 less than none-treatment less than saturated CaSO4.2H2O less than 4% K2SO4 less than 4% MgSO4 less than 4% ZnSO4. The half-spherical aggregates from sulfates of Na+ and K+ (alkali metal) grew finer than those from sulfates of Ca2+ and Mg2+ (alkali-earth metal) and Zn2+ (zinc) and their area on dentin surface increased more with sulfates of alkali metal than with those of alkali-earth.

The objective of this study was to prepare a new type water soluble bonding agent, methyl methacrylate (MMA)-p-styrene sulfonic acid copolymer (MS), and to investigate the effect of MS on bonding between resins and tooth substrates. MS is cross-linked with Ca2+ supplied by hydroxyapatite in a smeared layer on ground enamel and dentin and sticks to their surface. Samples were prepared by bonding an acrylic rod with MMA-TBB resin to ground enamel and dentin coated with an aqueous mixture of FeCl3 and 10 wt% MS. After immersed in water for 24 hrs, the tensile bond strength was measured. The bond strengths to both enamel and dentin were higher than 11 MPa and cohesive failure of cured MMA-TBB resin was observed in every case. This suggested that MS could adhere to tooth substrates with a new bonding mechanism different from the previously reported mechanism of the monomer interpenetration and polymerization.

An adhesion promoting monomer of 3-methacryloyloxybenzoic acid (3-MBA) was utilized as an ingredient of experimental dental photocurable bonding resins. Effects of the monomer compositions of the resins on the bond strength to tooth substrates were examined. The bond strength of the light-cured resin was enhanced by the addition of 3-MBA. When 3-MBA was incorporated with Bis-MPEPP2.6E, TEGDMA or their binary comonomers, the bond strengths obtained were ca. 130 kgf/cm2 for the enamel treated with an aqueous solution of 10% citric acid and 3% FeCl3 and ca. 50 kgf/cm2 for the dentin. SEM examination revealed that the acid resistant dentin layer was formed by the infiltration and polymerization in situ of the monomer of the 3-MBA bonding resin. However, bond strengths of less than 50 kgf/cm2 obtained on treated dentin could be explained by the extent of the tag formation in dentinal tubules.