Effect of polyacrylic acid treatment of dentin on adhesion of glass ionomer cement

This investigation measured the effect of polyacrylic acid treatment of dentin on adhesion of glass ionomer cement. The dentin was ground on paper no. 220 or no. 500 and treated with a polyacrylic acid solution of 10% or 25% for either 10 or 30 sec. The differences observed in the scanning electron microscope between the differently treated dentin surfaces were not reflected in the bond strength results. Only variations in surface texture due to different coarseness of grinding influenced the adhesion. For specimens ground on paper no. 220, pretreatment with polyacrylic acid enhanced adhesion of glass ionomer cement. Polyacrylic acid had no effect on bonding between glass ionomer cement and dentin ground on paper no. 500.     

玻璃离子水门汀修复髓室底穿孔的临床研究

目的探讨光固化玻璃离子水门汀修复髓室底穿孔的临床效果.方法应用光固化玻璃离子水门汀修复髓室底穿孔, 然后按常规进行牙髓病治疗,共38例38颗患牙.结果治疗完毕后X线片显示有2颗治疗牙超填,占5.26%; 所有治疗牙随访观察1.5-2年,其中36颗治疗牙成功,2颗治疗牙失败,成功率为94.74%, 2颗失败牙均系超填患牙.结论光固化玻璃离子修复髓室底穿孔是可行的, 是修复髓室底穿孔一种较好的材料.     

Effect of a novel glass ionomer cement containing fluoro-zinc-silicate fillers on biofilm formation and dentin ion incorporation

Clinical Oral Investigations - This study is aimed at evaluating the effect of a new glass ionomer cement (GIC) containing fluoro-zinc-silicate fillers on biofilm formation and ion incorporation....     

Effect of chlorhexidine disinfectant on bond strength of glass ionomer cement to dentin using atraumatic restorative treatment

This study investigated the effect of 2% chlorhexidine gluconate (CHX) disinfectant on bond strength (BS) of high-density glass ionomer cement (HDGIC) to dentin following atraumatic restorative treatment (ART) and conventional preparations. Specimens were divided into four groups: Group 1--ART (control); Group 2--ART with CHX disinfection; Group 3--Conventional (control); Group 4--Conventional with CHX disinfection. HDGIC was packed in cylindrical molds placed over flat dentin surfaces; BS was measured after seven days. ART-prepared dentin surfaces disinfected with CHX provided bonding to HDGIC that was comparable to untreated dentin and to conventionally prepared dentin.     

Effect of different surface treatments on the shear and microtensile bond strength of resin-modified glass ionomer cement to dentin

Objective. The aim of this study was to evaluate the effect of different surface treatments on the microtensile bond strength (μTBS) and shear bond strength (SBS) of resin-modified glass ionomer cement (RMGIC) to dentin. Materials and methods. Fifty-two extracted human molars were flattened to obtain dentin surfaces. For SBS assessment 40 teeth were divided into four groups according to their surface treatments (acid etching, Er:YAG laser QSP mode, Er:YAG laser MSP mode and control-SiC) (n = 10). A plastic cylinder was placed over the differently treated dentin surfaces and RMGIC was placed into the rings and polymerized. Twelve teeth were used for the μTBS test. The treated dentin surfaces described above were restored with 4 mm high RMGIC and light cured; then, the specimens were sectioned into serial sticks (n = 15) and μTBS and SBS were tested for failure in a testing machine with a 1 mm/min crosshead speed. The data were analyzed by one-way ANOVA and Tukey HSD tests (α = 0.05). Results. Acid etching showed significantly higher SBS than the other groups (p < 0.05). Er:YAG QSP and MSP-treated groups showed higher SBS values than the control group, but the difference was not statistically significant (p > 0.05). Er:YAG MSP showed the highest μTBS value followed by acid etching, whereas the control group exhibited the lowest value (p < 0.05) and the differences between the control group and Er:YAG QSP were not significant (p > 0.05). Conclusions. The application of Er:YAG MSP mode and acid etching to dentin can be used for improving the bond strength of RMGIC.     

Effect of denture base‐resin with prereacted glass‐ionomer filler on dentin demineralization

The demineralization of dentin was studied when placed adjacent to one of four experimental denture base‐resins. These experimental resins contained polymethylmethacrylate (PMMA) and 0, 5, 10, 20 or 30 wt% surface reaction‐type prereacted glass‐ionomer (S‐PRG) filler, respectively. A dentin thin‐section was sandwiched between these resins and subjected to demineralization for 1 wk. Microradiographic analyses showed that the mineral vol% of the surface was increased, and lesion formation was inhibited, in a dose–response relationship with the amount of S‐PRG filler. Moreover, the mineral loss decreased, by up to 60%, with an increasing amount of filler. These results indicate that denture base‐resins containing S‐PRG filler possess a substantial inhibition capability against demineralization, and this may thereby assist in preventing root caries of abutment teeth.     

不同根管内壁处理方法对玻璃离子水门汀与根管牙本质粘接强度的影响

目的：评价不同根管内壁处理方法对树脂改性玻璃离子水门扪‘与根管牙本质粘接强度的影响。方法：新鲜拔除的42个完整前牙或单根管前磨牙，于釉一牙骨质界处水平截断，根据不同处理根管壁＋粘接纤维桩的方法随机分为7组：A组：无酸蚀＋GC Fuji I；B组：酸蚀＋GC Fuji I；C组：酸蚀＋singlebond2＋GCFujiI；D组：无酸蚀＋GCFuji ⅡLC；E组：酸蚀＋GC VujiⅡLC；F组：酸蚀＋singlebond2＋GCVujiⅡLC：G组：酸蚀＋singlebond2＋ClearfilDCCoreAutomix。粘结处理后垂直牙根长轴切割成1mm厚薄片，在万能测试机上进行微推出测试。结果：7组粘接强度分别为A组（1．6367±0．2673）MPa；B组（1．9933±0．1906）MPa；C组（2．4800±0．5349）MPa；D组（3．1967±0．7068）MPa：E组（3．9385±0．2782）MPa；F组（5．5317±0．5545）MPa；G组（8．2510±0．7757）MPa。D组、E组、F组均相应高于相同根管内壁处理方法的A组、B组、C组（p〈0．05），但均低于G组如〈O．05）；F组〉E组〉D组（P（0．05），ABC三组间无显著差异（p〉O．05）。结论：不同方法处理根管内壁对粘接材料与根管牙本质间的粘接强度有影响。     

Effect of enamel etching on tensile bond strength of brackets bonded in vivo with a resin-reinforced glass ionomer cement

OBJECTIVE: To evaluate the influence of enamel etching on tensile bond strength of orthodontic brackets bonded with resin-reinforced glass ionomer cement. MATERIALS AND METHODS: The sample group consisted of 15 patients who had indications for extraction of four premolars for orthodontic reasons, equally divided into two different groups according to bracket and enamel preparation. Brackets were bonded in vivo, by the same operator, using a split mouth random technique: Group 1 (control), phosphoric acid + Fuji Ortho LC; Group 2, Fuji Ortho LC without acid conditioning. The teeth were extracted after 4 weeks using elevators. An Instron Universal Testing Machine was used to apply a tensile force directly to the enamel-bracket interface at a speed of 0.5 mm/min. The groups were compared using a Mann-Whitney U-test and Weibull analysis. RESULTS: Mean results and standard deviations (in MPa) for the groups were: Group 1, 6.26 (3.21), Group 2, 6.52 (2.73). No significant difference was observed in the bond strengths of the two groups evaluated (P = .599). CONCLUSIONS: Fuji Ortho LC showed adequate shear bond strength and may be suitable for clinical use.     

Evaluation of the sealing ability of amalgam,Cavit, and glass ionomer cement in the repair of furcation perforations

Perforations created in the pulpal floors of 30 extracted molars were repaired with amalgam, Cavit, and light cured glass ionomer cement. After the pulp chambers and access openings were filled with composite resin, the teeth were then immersed in 2% Erythrocin B solution for 1 week. After longitudinal sectioning of the teeth, dye penetration was measured. The results indicated significant differences between the three materials. Light cured glass ionomer exhibited the least dye penetration followed by Cavit and amalgam.     

Effect of region and dentin perfusion on bond strengths of resin-modified glass ionomer cements

OBJECTIVES: The purpose of this study was to evaluate the hypothesis that regional differences and pulpal pressure would significantly affect bond strengths of resin-modified glass ionomer cements to dentin. METHODS: Twenty-six extracted caries-free human third molars were ground to expose middle dentin and were randomly divided into two groups for bonding: no pulpal pressure and pulpal pressure of 15cm H(2)O. Fuji II LC, Vitremer, or Photac-Fil Quick were applied to the previously pre-treated surfaces and light-cured as recommended by the manufacturers. After immersion in water at 37 degrees C for 24h, the teeth were sectioned to 0.7mm thick slabs, divided into pulp horn, center, and peripheral regions according to visual criteria, and trimmed along the bonded interface for microtensile bond test to a cross-sectional area of 1mm(2). The slabs were subjected to tensile forces and the data analyzed using ANOVA and Fisher's PLSD at the 95% level of confidence. RESULTS: For Fuji II LC, bond strengths to the pulp horn regions were significantly lower than those to the other regions independent of pulpal pressure (p<0.05). On the other hand, regional bond strengths were not observed for Vitremer and Photac-fil Quick 0.05). CONCLUSIONS: Pulpal pressure had a stronger influence on bond strengths and failure modes of resin-modified glass ionomers than regional differences of the substrate.     

Antibacterial activity of resin adhesives, glass ionomer and resin-modified glass ionomer cements and a compomer in contact with dentin caries samples

A total of 103 clinical samples of carious dentin were used to study the antibacterial action of different dental resin adhesive materials (Gluma 2000, Syntac, Prisma Universal Bond 3, Scotchbond Multi-Purpose and Prime&Bond 2.0) glass ionomer cements (Ketac-Cem, Ketac-Bond, Ketac-Silver, Ketac-Fil) resin-modified glass ionomer cements (Fuji II LC, Vitremer and Vitrebond) and a compomer (Dyract). The agar plate diffusion method was used for the microbial cultures and a chlorhexidine control. The growth of the caries-producing microorganisms was effectively inhibited by the Vitremer and Vitrebond cements, and to a lesser extent by the Scotchbond Multi-Purpose adhesive system. Overall, there were statistically significant differences in the antibacterial activity of the products tested.     

Physiological remineralization of artificially demineralized dentin beneath glass ionomer cements with and without bacterial contamination in vivo

This study evaluated the physiological remineralization of artificially demineralized dentin beneath glass ionomer cements with and without bacterial contamination. The artificially demineralized dentin was produced on 84 monkey teeth using a decalcifying solution. Half the samples were left open to the oral cavity for one week, then, all cavities were restored with two glass-ionomer cements: Fuji IX or Fuji II LC improved (n = 7). The nanohardness of the artificially demineralized dentin at 3, 90 and 360 days was measured using a nanoindentation tester (ENT-1100, Elionix) and compared statistically by two-way ANOVA and Fisher's PLSD test (p < 0.05). Each mineral (Ca, Mg, P, F) within the demineralized dentin was also analyzed using Electron Probe Microanalysis. For the samples, the mean nanohardness of the three-day samples was significantly lower than the 360-day samples (p < 0.05). Although there was no significant difference in the mean nanohardness within all the bacterially-contaminated groups through the experimental periods (p > 0.05), the mean nanohardness of the bacterial-contaminated samples were significantly lower than the non-bacteria-contaminated samples (p < 0.05). From the EPMA results, fluoride release from both cements to the bottom of the artificially demineralized dentin was detected within three days. Although Ca density was sparse within this demineralized dentin lesion, for the Fuji IX sample, a high Mg density within this lesion was detected at 360 days.     

Effect of multi-step dentin bonding systems and resin-modified glass ionomer cement liner on marginal quality of dentin-bonded resin composite Class II restorations

The use of resin composites in the restoration of Class II cavities with gingival margins located in dentin is still controversial. The purpose of this in vitro study was to evaluate the effect of four state-of-the-art multi-step dentin-bonding systems (A. R. T. Bond, Syntac, OptiBond DC, Scotchbond Multipurpose) on marginal adaptation and microleakage of dentin-bonded composite Class II restorations. A total of 72 Class II cavities with gingival margins in dentin were prepared in extracted molars and filled with fine-hybrid composites using a three-sited light curing technique. In one half of the cavities the pulpal wall was lined with a resin-modified glass ionomer cement liner (RM-GIC), in the other half a total bonding technique was applied. A. R. T. Bond and Syntac were tested with selective enamel etching (SE) and total etching (TE). Marginal adaptation was evaluated in a scanning electron microscope before and after thermocycling (TC). Microleakage was determined by dye penetration. After TC the proportions of continuous margin in dentin ranged from 37% (Syntac/SE) to 91.2% (A. R. T. Bond/TE). Scotchbond Multipurpose exhibited the lowest degree of microleakage (0.22 mm). Marginal enamel fracture was the most prevalent marginal defect at the enamel margins (8.3–22.2%). The use of the RM-GIC had no beneficial effect on any of the marginal parameters, either in dentin or in enamel. It is concluded that low degrees of marginal gap formation and microleakage can be achieved in totally bonded composite Class II restorations when using state-of-the-art multi-step bonding systems in combination with a meticulous incremental filling technique. Received: 6 April 1998 / Accepted: 25 August 1998     

Stimulation of epithelial cell matrix metalloproteinase (MMP‐2, ‐9, ‐13) and interleukin‐8 secretion by fusobacteria

Background/aims: Bacterial pathogens involved in periodontal diseases exert their destructive effects primarily by stimulating the host cells to increase their secretion of proinflammatory cytokines and matrix metalloproteinases (MMPs). This study aimed to determine the epithelial cell matrix metalloproteinase and interleukin‐8 (IL‐8) secretion upon exposure to fusobacteria. Methods: Eight different oral and non‐oral Fusobacterium strains were incubated with HaCaT epithelial cells. Gelatin zymography and Western blot analysis were performed to detect collagenase 3 (MMP‐13), gelatinase A (MMP‐2), gelatinase B (MMP‐9), and IL‐8 secretion by epithelial cells. Results: All Fusobacterium strains, especially Fusobacterium necrophorum ATCC 25286, Fusobacterium nucleatum ATCC 25586, and Fusobacterium varium ATCC 51644, increased MMP‐9 and MMP‐13 secretion. Fusobacterium simiae ATCC 33568, and to a lesser extent F. nucleatum and F. necrophorum, increased epithelial MMP‐2 secretion. F. nucleatum and F. necrophorum also increased IL‐8 secretion. F. varium ATCC 27725, a strain that only weakly stimulated MMP production, strongly increased the IL‐8 production, suggesting that their expression is differently regulated. Conclusion: We conclude that the pathogenic potential of fusobacteria may partly result from their ability to stimulate secretion of MMP‐9, MMP‐13, and IL‐8 from epithelial cells.     

Effect of interim cement application on bond strength between resin cements and dentin: Immediate and delayed dentin sealing

Statement of problem

Despite the advances in materials and techniques, adhesion to dentin is challenging because of the complex composition of dentin’s mineral, organic, and fluid phases.