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1.
Aust Dent J ; 61(3): 366-73, 2016 09.
Article in English | MEDLINE | ID: mdl-26573239

ABSTRACT

BACKGROUND: The aim of this randomized controlled study was to evaluate the clinical performance of a highly filled flowable composite compared to a conventional paste-type composite in direct posterior restorations after 36 months. METHODS: A total of 58 mid-size to extensive posterior composite restorations were randomly placed in 32 patients, mean age of 43.9 years (range 25-76), using either a conventional composite Estelite Sigma Quick (Conventional) or a highly filled flowable composite G-aenial Universal Flo with a two-step self-etch adhesive. The restorations were evaluated after placement (baseline) and at 6, 12, 24 and 36 months according to the FDI criteria. RESULTS: At the 36-month follow-up, 42 restorations were evaluated in 21 patients. After 36 months, the difference between highly filled flowable and conventional restorations was not statistically significant with respect to all evaluation parameters (p < 0.05). No secondary caries was observed. CONCLUSIONS: The highly filled flowable composite showed a comparable clinical effectiveness as the conventional paste composite in posterior restorations over 36 months.


Subject(s)
Composite Resins/therapeutic use , Dental Caries/therapy , Molar , Adult , Aged , Dental Caries/pathology , Dental Restoration, Permanent/methods , Female , Follow-Up Studies , Humans , Male , Middle Aged , Treatment Outcome
2.
J Dent Res ; 91(4): 370-5, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22337700

ABSTRACT

The aim of this study was to assess the effect of chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and a low concentration of fluoride (F) on the hardness of enamel subsurface lesions, utilizing a double-blind, randomized, and controlled in situ model. Fifteen individuals wore removable lingual appliances with 3 bovine-enamel insets containing subsurface demineralized lesions. Three times a day for 14 days, they chewed one of the 3 chewing gums (placebo, POs-Ca, POs-Ca+F). After the treatment period, cross-sectional mineral content, nanoindentation hardness, and fluoride ion mapping by time-of-flight secondary ion mass spectrometry (TOF-SIMS) were evaluated. Although there were no statistical differences in overall mineral content and hardness recovery rates between POs-Ca and POs-Ca+F subsurface lesions (p > 0.05), nanoindentation at 1-µm distance increments from the surface showed statistical differences in hardness recovery rate between POs-Ca and POs-Ca+F in the superficial 20-µm region (p < 0.05). Fluoride mapping revealed distribution of the ion up to 20 µm from the surface in the POs-Ca+F group. Nanoindentation and TOF-SIMS results highlighted the benefits of bioavailability of fluoride ion on reinforcement of the superficial zone of subsurface lesions in situ (NCT01377493).


Subject(s)
Calcium Fluoride/administration & dosage , Cariostatic Agents/administration & dosage , Chewing Gum , Dental Enamel/drug effects , Tooth Demineralization/drug therapy , Animals , Biological Availability , Calcium Fluoride/pharmacokinetics , Cariostatic Agents/pharmacokinetics , Cattle , Dental Enamel/pathology , Double-Blind Method , Fluorides/analysis , Hardness , Humans , Microradiography , Minerals/analysis , Placebos , Spectrometry, Mass, Secondary Ion , Tooth Demineralization/pathology , Tooth Remineralization
3.
Aust Dent J ; 56(1): 40-7, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21332739

ABSTRACT

BACKGROUND: The aim of this study was to establish a new in vitro model for biofilm induced secondary caries studies using an oral biofilm reactor. METHODS: An approximately 2 × 3 × 2 mm(3) sized dentino-enamel Class I cavity was prepared in the middle of a square-shaped specimen from the mid-labial portion of bovine incisors. The cavities were partially filled with either Clearfil AP-X with SE-Bond or Clearfil AP-X without any bond. Artificial biofilms were then formed on the resin composite filled surfaces using three species of oral bacteria in an oral biofilm reactor for 20 hours followed by 7- or 30-day incubation periods. RESULTS: The lesions were clearly visible on fluorescence microscopy and by scanning electron microscopy in the enamel at the interface of resin restorations in all samples. The data from image analysis showed that the lesion size was largest in the No-bond samples with statistically significant differences (p < 0.05). Demineralization along the cavity wall extended deeper in No-bond compared to SE-Bond samples and penetration was significantly deeper in No-bond 30-day samples. CONCLUSIONS: A primary artificial secondary caries model was established using biofilms for in vitro studies and the significance of using a bonding system could also be verified.


Subject(s)
Biofilms , Dental Caries/microbiology , Animals , Cattle , Dental Caries/pathology , Dental Cavity Preparation/classification , Dental Enamel/microbiology , Dental Enamel/ultrastructure , Dental Restoration, Permanent , Dentin/microbiology , Dentin/ultrastructure , Image Processing, Computer-Assisted , Materials Testing/instrumentation , Materials Testing/methods , Methacrylates/chemistry , Microscopy, Electron, Scanning , Microscopy, Fluorescence , Random Allocation , Recurrence , Resin Cements/chemistry , Streptococcus gordonii/physiology , Streptococcus mutans/physiology , Streptococcus sobrinus/physiology , Temperature , Time Factors , Tooth Demineralization/microbiology , Tooth Demineralization/pathology
4.
Aust Dent J ; 53(2): 140-4, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18494969

ABSTRACT

BACKGROUND: In 1959, Ericsson developed a laboratory buffer capacity test. Because the Ericsson test is not practical for use as a chair-side test, commercially available saliva buffering capacity tests have been developed for use in the dental office. The purpose of this study was to evaluate the correlation between a modified Ericsson test and three commercially available quantitative and colourimetric tests. METHODS: Stimulated saliva (by chewing paraffin wax) was collected from 113 patients. Individual saliva buffering capacity was assessed with the following four different methods: modified Ericsson test; quantitative test using a hand-held pH meter; paper strip; or liquid colourimetric test. The correlations of ranking results among the different tests were analysed using the Spearman Rank Correlation Test, p < 0.001. RESULTS: Spearman Rank Correlation indicated significant positive coefficients between the modified Ericsson test and the quantitative test (rho = 0.857), the paper strip colourimetric test (rho = 0.621) and the liquid-type colourimetric test (rho = 0.689). CONCLUSION: The detection level of medium and high buffering capacity was test dependent. The quantitative test using a hand-held pH meter showed a stronger positive correlation with the modified Ericsson test. The qualitative tests seemed less reliable, particularly for patients classified as having a medium buffering capacity.


Subject(s)
Reagent Kits, Diagnostic/standards , Saliva/chemistry , Adult , Aged , Buffers , Colorimetry/instrumentation , Colorimetry/methods , Female , Humans , Hydrogen-Ion Concentration , Male , Materials Testing , Middle Aged , Reagent Strips/standards , Saliva/physiology , Solutions
5.
Aust Dent J ; 53(2): 167-71, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18494973

ABSTRACT

BACKGROUND: The ion activity product for hydroxyapatite (Ip(HA)) is a comprehensive parameter reflecting pH, calcium and phosphate ion concentration in saliva which govern the degree of saturation with respect to the dissolving tooth mineral. The aim of this study was to evaluate the relationship between quantitative assessments of salivary buffering capacity and Ip(HA) in relation to cariogenic potential. METHODS: Stimulated whole saliva was collected from 33 patients, and the initial pH of samples was measured using a hand-held pH meter. Then samples were titrated with 0.1 N HCl to evaluate buffering capacities and divided into three groups (high, medium and low). After measuring concentrations of calcium and phosphate ions in the samples, Ip(HA) was calculated using the values of the ion concentrations and pH. Differences in the mean pH values, the concentrations of calcium, phosphate ions and log[Ip(HA)] among three groups were analysed using the Kruskal Wallis and the Mann-Whitney non-parametric test, p < 0.05. RESULTS: After HCl 50 microL titration, there were statistical differences of the mean pH and Ip(HA) among each buffering capacity group. Moreover, after 50 microL HCl titration, there was an excellent correlation between the buffer capacity and log[Ip(HA)]. CONCLUSIONS: The pH change for saliva after HCl titration has a significant influence on the rate of Ip(HA).


Subject(s)
Dental Caries/etiology , Durapatite/chemistry , Saliva/chemistry , Buffers , Calcium/chemistry , Colorimetry , Dental Enamel/metabolism , Female , Humans , Hydrochloric Acid/chemistry , Hydrogen-Ion Concentration , Male , Phosphates/chemistry , Saliva/physiology , Spectrophotometry, Atomic , Spectrophotometry, Ultraviolet , Tooth Demineralization/metabolism , Tooth Remineralization
6.
Aust Dent J ; 51(2): 170-4, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16848266

ABSTRACT

BACKGROUND: Saliva collection can provide clinical information about individual patients. However, a correlation between ranking buffering capacity using resting and stimulated saliva is still unknown. The aim of this study was to evaluate the pH change after HCl titration into resting and stimulated saliva for a salivary buffering capacity test. METHODS: Resting and stimulated saliva (by chewing paraffin wax) were collected from 80 patients. After the pH of both saliva samples was measured using a hand-held pH meter, the saliva samples were titrated with 0.1N HCl to evaluate the buffering capacity. Correlations of ranking buffering capacity (high, medium, low) between stimulated saliva and resting saliva with 30 microL HCl titration and between stimulated saliva and resting saliva with 40 microL HCl titration were statistically analysed by Spearman Rank Correlation Test (p < 0.05). RESULTS: At 50 microL HCl titration, stimulated saliva buffering capacities were ranked into high (above pH 5.5), medium (pH from 5.5 to 4.5) and low (below pH 4.5). At 30-40 microL HCl titration, the resting saliva buffering capacities were ranked into the same categories. Spearman Rank Correlation indicated significant positive coefficients for the stimulated saliva and resting saliva buffering capacity at 30 microL titration and the stimulated saliva and resting saliva at 40 microL titration. CONCLUSION: Stimulated saliva is more resistant to variation in pH change during HCI titration than resting saliva. Stimulated saliva sampling is a good method to determine buffering capacity during a comprehensive oral health assessment.


Subject(s)
Hydrochloric Acid/pharmacology , Saliva/chemistry , Salivation , Adolescent , Adult , Aged , Aged, 80 and over , Buffers , Humans , Hydrogen-Ion Concentration/drug effects , Middle Aged , Saliva/drug effects , Secretory Rate , Statistics, Nonparametric , Titrimetry/methods
7.
Int Endod J ; 37(7): 455-62, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15189434

ABSTRACT

AIM: Acidic diffusion through bovine dentine was investigated by measuring pH changes on dentine surfaces after applying three adhesive systems. METHODOLOGY: Coronal incisor bovine dentine discs, 0.5 mm thick, were prepared from dentine close to the pulp chamber. A single-bottle adhesive system-Single Bond, a self-etching primer system-Clearfil SE Bond and an 'all-in-one' adhesive system-AQ Bond were used. The labial dentine surfaces were conditioned as follows: Single Bond groups: (SB-1) 35% phosphoric acid etchant was applied and left in place; (SB-2) the etchant was applied for 15 s and rinsed off for 10 s; (SB-3) application of adhesive agent and light curing following step SB-2; Clearfil SE Bond groups: (SE-1) SE primer was applied for 20 s and dried; (SE-2) application of adhesive agent and light curing following step SE-1; AQ Bond groups: (AQ-1) AQ Bond adhesive was applied for 20 s and dried, applied for additional 5 s and dried again; (AQ-2) light curing following step AQ-1. The pH change on the pulpal dentine surface was measured using a pH-imaging microscope. RESULTS: All the Single Bond groups revealed a lower pH on the pulpal surface (pH 6.25, 6.59 and 6.64 for SB-1, SB-2 and SB-3, respectively) compared with intact dentine. Clearfil SE Bond and AQ Bond groups showed no significant deference in pH value from intact dentine. CONCLUSIONS: Acid diffusion from phosphoric acid etching was observed when placed on 0.5 mm-thick dentine discs; however, there was only limited evidence of acid diffusion from SE primer and AQ Bond.


Subject(s)
Acid Etching, Dental/methods , Dentin Permeability , Dentin-Bonding Agents/pharmacokinetics , Resin Cements/pharmacokinetics , Animals , Bisphenol A-Glycidyl Methacrylate/pharmacokinetics , Cattle , Dental Pulp/chemistry , Dentin/metabolism , Diffusion , Hydrogen-Ion Concentration , Materials Testing , Phosphoric Acids/pharmacokinetics
8.
Int Endod J ; 36(9): 622-8, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12950577

ABSTRACT

AIM: To examine the changes in pH of luting cements and acid diffusion of luting cements through bovine dentine using a pH-imaging microscope (SCHEM-100; Horiba Ltd, Kyoto, Japan). METHODOLOGY: The pH of the surface of three conventional luting cements, glass-ionomer, zinc phosphate and zinc polycarboxylate was measured with SCHEM-100 for 1 month. The acid diffusion from the three luting cements through bovine dentine was investigated by measuring pH changes during the application of each luting cement on the bovine dentine surface. Coronal bovine dentine disks were prepared to thicknesses of 0.50 and 0.25 mm. Each luting cement was placed on the labial dentine surface, and the pH change of the pulpal surface was observed every 3 min for 30 min with SCHEM-100. RESULTS: Glass-ionomer showed the lowest pH values for longer times. Neutralization proceeded furthest in zinc polycarboxylate. The 0.5-mm-thick dentine disks showed no pH change on the pulpal side with all the three cements. The 0.25-mm-thick disks revealed evidence of acid diffusion on the pulpal side of the cemented dentine and significantly lower pH when cemented with glass-ionomer and zinc phosphate than with zinc polycarboxylates. CONCLUSIONS: This study demonstrated that glass-ionomer exhibited a lower setting pH than zinc phosphate and zinc polycarboxylate, and acid diffusions from glass-ionomer and zinc phosphate cements were observed when placed on 0.25-mm-thick dentine disks.


Subject(s)
Dental Cements/chemistry , Dentin/metabolism , Acids , Analysis of Variance , Animals , Cattle , Dentin/anatomy & histology , Diffusion , Glass Ionomer Cements/chemistry , Hydrogen-Ion Concentration , Materials Testing , Microscopy , Polycarboxylate Cement/chemistry , Time Factors , Zinc Phosphate Cement/chemistry
9.
Dent Mater ; 18(3): 276-80, 2002 May.
Article in English | MEDLINE | ID: mdl-11823021

ABSTRACT

OBJECTIVES: This study was conducted to evaluate the tensile bond durability of two different types of 4-META containing resin cements over a period of 3 years. METHODS: Ten bovine dentin specimens were tested for tensile bond strengths with each of the following materials: Super Bond C&B: unfilled methyl methacrylate (MMA)/polymethyl methacrylate (PMMA) resin cement, MASA Bond (experimental material): filled dimethacrylate resin cement at 1 day, 6 months, 1 and 3 years. The mean bond strengths were compared statistically by two-way ANOVA and Fisher's PLSD test (P<0.05). The mode of failure was classified by SEM observation. Results for the mode of fracture were analyzed using the Mann-Whitney U test. RESULTS: Although there was no statistical difference in mean bond strength between Super Bond C&B and MASA Bond (P>0.05) during the experimental periods, the 1-day bond strengths were significantly greater than those at the other experimental periods except for 6 months (P<0.05). Regarding the fracture modes, at 6 months and 1 year, statistical differences were observed between Super Bond C&B and MASA Bond (P<0.05). SIGNIFICANCE: The bond strengths of both resin cements to dentin significantly decreased after 6 months, and the long-term failure patterns of the 4-META/TBB resin cements showed a marked change.


Subject(s)
Dental Bonding , Dentin-Bonding Agents/chemistry , Dentin/ultrastructure , Methacrylates/chemistry , Resin Cements/chemistry , Aminosalicylic Acids/chemistry , Analysis of Variance , Animals , Boron Compounds/chemistry , Butadienes/chemistry , Cattle , Materials Testing , Methylmethacrylate/chemistry , Methylmethacrylates/chemistry , Microscopy, Electron, Scanning , Polymethyl Methacrylate/chemistry , Polystyrenes/chemistry , Statistics as Topic , Statistics, Nonparametric , Surface Properties , Tensile Strength , Time Factors
10.
Int Endod J ; 35(12): 996-1004, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12653318

ABSTRACT

AIM: To assess the location, arrangement and possible function of interodontoblastic collagen fibres in association with calcium hydroxide-induced hard tissue bridges by using light and transmission electron microscopy techniques and immunohistochemical staining localization. METHODOLOGY: Prior to the study, an animal use protocol form was reviewed and approved by the Screening Committee for Animal Research of the Tokyo Medical and Dental University. Exposed monkey pulps were capped with a hard-set calcium hydroxide and histopathologically evaluated at 3, 14, 21, 30 and 90 days, using light microscopy with silver staining and transmission electron microscopy to differentiate structural features of interodontoblastic collagen fibres. In addition, an attempt was made to identify and to differentiate between several types of collagen and fibronectin using immunohistochemical localization techniques. RESULTS: At 14 days, interodontoblastic collagen fibres were observed extending from the original dentine, passing through the odontoblasts, and consisted of two portions: a thick fibril and a thin fibril. At 21 days, interodontoblastic collagen fibres were seen penetrating into the predentine and becoming incorporated into the mineralized dentine. At 30 days, interodontoblastic collagen fibres reached the cell process. Although interodontoblastic collagen fibres were no longer observed near the odontoblastoid cells at the area of the newly formed tubular dentine, interodontoblastic collagen fibres were observed embedded within the primary formed dentine bridge. Immunohistochemical staining demonstrated type I collagen and fibronectin within the interodontoblastic collagen fibres. CONCLUSIONS: Interodontoblastic collagen fibres were routinely detected throughout early dentine bridges. Interodontoblastic collagen fibres are thought to be important for initial dentine bridging to induce and support a dentinogenesis framework.


Subject(s)
Calcium Hydroxide/pharmacology , Collagen/ultrastructure , Dentin, Secondary/chemically induced , Animals , Cell Differentiation , Collagen/physiology , Dental Pulp Capping/methods , Dentin, Secondary/ultrastructure , Dentinogenesis/physiology , Extracellular Matrix/ultrastructure , Immunohistochemistry , Macaca , Odontoblasts/ultrastructure , Silver Staining
11.
J Dent ; 30(7-8): 297-304, 2002.
Article in English | MEDLINE | ID: mdl-12554110

ABSTRACT

OBJECTIVES: Following tooth pulp exposure, pulpal repair is accomplished by dentine bridge secretion by odontoblast-like cells. However, little information is available about the hierarchy of variables, which influence odontoblast-like cell numbers. The purpose of this study was to examine correlations between pulp capping events and odontoblast-like cell numbers. METHODS: Two hundred and fifty standardised pulp exposed cavities were prepared in non-human primate teeth according to ISO usage guidelines. Exposed pulps were capped with Calcium hydroxide [Ca(OH)(2)], and multi-step and self-etching primer composite resins. Teeth were collected from 3 to 60-days to observe pulp reactions. Statistical analysis was evaluated using analysis of variance. RESULTS: The hierarchy of variables correlated to odontoblast-like cells were the dentine bridge area (P = 0.0001), time since pulp exposure (P = 0.0001), odontoblast numbers opposite the exposure site (P = 0.0002), and pulp capping materials (P = 0.0313). Other pulp capping variables were found to be less likely to be correlated with odontoblast-like cell numbers. CONCLUSIONS: The area of dentine bridge formation is directly related to the numbers of odontoblast-like cells, cell activity is time dependent, and the cell numbers are much lower than original odontoblast cells. The time-lag between the appearance of odontoblast-like cells at the site of pulp exposure, and the limited numbers of these cells, explain why pulpal repair is difficult to achieve successfully following pulp exposure.


Subject(s)
Dental Pulp Capping/methods , Dental Pulp/cytology , Dentin, Secondary/drug effects , Dentin, Secondary/metabolism , Odontoblasts/metabolism , Animals , Calcium Hydroxide/therapeutic use , Dental Pulp/drug effects , Dental Pulp Capping/classification , Dental Pulp Exposure/therapy , Dentin, Secondary/cytology , Dentin-Bonding Agents/therapeutic use , Macaca , Methacrylates/therapeutic use , Minerals/therapeutic use , Odontoblasts/cytology , Odontoblasts/drug effects , Time Factors
12.
J Dent ; 29(2): 139-44, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11239589

ABSTRACT

OBJECTIVES: This study was conducted to evaluate the bond durability of three resin cements bonded to bovine dentine over a period of 3 years. METHODS: Ten bovine dentine specimens were tested for shear bond strengths with each of the following materials: Panavia 21, BISTITE resin cement, and MASA Bond (experimental resin cement) at 1 day, 6 months, 1 and 3 years after cementation of a composite rod. All specimens were stressed in shear at a crosshead speed of 1mm min(-1) until failure. The means of the bond strengths were compared statistically by two-way ANOVA and Fisher's PLSD test (P<0.05). The mode of failure was classified after fracture of the bonds by SEM observation. Results for the mode of fracture were analyzed using the Mann-Whitney U-test. RESULTS: The shear bond strengths (MPa+/-SD) for different times (1 day, 6 months, 1 and 3 years) were: Panavia 21 (15.2+/-3.6, 9.3+/-3.2, 8.5+/-2.1, 6.8+/-2.4), BISTITE (15.6+/-2.8, 11.0+/-1.4, 10.4+/-2.2, 9.0+/-2.7) and MASA Bond (29.6+/-9.5, 17.5+/-4.6, 19.6+/-4.5, 16.1+/-5.4). Panavia 21 and BISTITE strengths were significantly lower (P<0.05) at all times compared with MASA Bond, and 1 day strengths for all three materials were significantly higher (P<0.05) than 3 year strengths. Regarding the fracture modes after bond testing, there were statistical differences between the 1 day and the 1 year results for all cements (P<0.05). Although no Panavia 21 specimen showed complete cohesive failure in the demineralized dentine during the experiment, several BISTITE and MASA Bond specimens showed cohesive fracture in the demineralized dentine. For BISTITE, partially or complete demineralized dentine cohesive failures increased over time. CONCLUSIONS: The type of resin cement seemed to have an influence on the long-term durability of bonding to dentine.


Subject(s)
Dental Bonding , Dentin , Resin Cements/chemistry , Analysis of Variance , Animals , Cattle , Compressive Strength , Dentin-Bonding Agents/chemistry , Drug Storage , Equipment Failure Analysis , Materials Testing , Microscopy, Electron, Scanning , Statistics, Nonparametric , Tensile Strength , Time Factors
13.
J Dent ; 28(3): 193-8, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10709341

ABSTRACT

OBJECTIVES: The aim of this in vivo study was to investigate the biocompatibility and microtensile bond strength of a one-application resin bonding system. METHODS: Class V cavities were prepared on the facial surfaces of 36 intact monkey teeth, and the cavities were restored with an experimental one-application resin bonding system (TOF-1; Tokuyama Corp., Tokuyama, Japan) and a hybrid resin composite (PALFIQUE ESTELITE; Tokuyama Corp., Tokuyama, Japan). Histopathological changes of the restored teeth were evaluated at 3, 30 and 90 days after operation (N = 10). Microtensile bond tests were performed at 3 and 90 days after operation (N = 10). RESULTS: Only two of 30 pulps showed a slight inflammatory cell infiltration. There were no statistically significant differences in the incidence of slight inflammatory cell infiltration among time periods. Bacterial penetration along the cavity walls could not be detected in any specimen. The mean microtensile bond strength at 3 days after operation was 20.6 MPa, and that at 90 days was 14.9 MPa. Differences in bond strengths between the 3 day specimen and the 90 day specimen were statistically significant (p < 0.05). CONCLUSIONS: The one-application resin bonding system exhibited acceptable biologic compatibility to the monkey pulp. Although there were statistically significant differences in bond strengths between the 3 day specimen and the 90 day specimen, this material provided a hermetic seal, eliminating bacterial microleakage.


Subject(s)
Biocompatible Materials/adverse effects , Dental Bonding/methods , Dental Pulp/drug effects , Resin Cements/adverse effects , Acid Etching, Dental/methods , Analysis of Variance , Animals , Biocompatible Materials/chemistry , Dental Bonding/statistics & numerical data , Dental Cavity Preparation/methods , Dental Pulp/pathology , Dental Restoration Failure , Haplorhini , Materials Testing/methods , Materials Testing/statistics & numerical data , Pulpitis/chemically induced , Pulpitis/pathology , Resin Cements/chemistry , Statistics, Nonparametric , Tensile Strength , Time Factors
14.
Article in English | MEDLINE | ID: mdl-10673661

ABSTRACT

OBJECTIVE: The aim of this investigation was to assess the role of the von Korff-like fibers (VKF) during the process of dentin bridging. STUDY DESIGN: The monkey pulps, exposed to a hard-set calcium hydroxide, were evaluated at 3, 7, 14, 21, 30, 90, and 180 days. RESULTS: At 21 days, longitudinal and transverse collagen fibrils were organized as lamellar structures in close proximity to and subjacent to the newly formed predentin. VKF bundles were present between newly formed odontoblastoid cells. The VKF were bundles of thin collagen fibrils inserted into the predentin, which consisted of thick collagen fibrils. At 30 days, the exposure site was completely occluded with a new predentin matrix; lamellar structures and VKF were no longer present. CONCLUSIONS: The VKF may play a role in the connective tissue attachment to the dentin bridge, early in its formation.


Subject(s)
Dental Pulp Exposure/physiopathology , Dental Pulp/ultrastructure , Dentin, Secondary/growth & development , Animals , Calcium Hydroxide , Collagen/ultrastructure , Dental Pulp Capping , Macaca , Microscopy, Electron , Odontoblasts/ultrastructure
15.
Dent Mater ; 16(1): 1-6, 2000 Jan.
Article in English | MEDLINE | ID: mdl-11203517

ABSTRACT

OBJECTIVES: This study was conducted to determine the influence of storage solution on the bond durability of three resin cements to bovine dentin over the period of 1 year. METHODS: Ten bovine dentin specimens were tested for shear bond strength with each material (Panavia 21, Kuraray Co.; BISTITE, Tokuyama Co; MASA Bond, Sun Medical Co.) and storage mode, listed below. Four storage environments were studied as follows: water changed every day for 1 year; water unchanged for 1 year; Phosphate Buffered Saline (PBS) changed every week over 1 year; PBS unchanged for 1 year. Ten teeth were also tested for each material at 1 day as a control. The mode of failure was classified after fracture of the bonds by SEM observation. The means of the bond strengths were compared statistically by two-way ANOVA and Fisher's PLSD test (p < 0.05). Results for the mode of fracture were analyzed using the Mann-Whitney U test. RESULTS: Although there was no statistical difference in the mean bond strengths between the water and PBS storage solutions (p > 0.05) in all cements, the results for the shear bond strengths in the changed storage solution groups were significantly lower than those where the storage solution remained unchanged (p < 0.05). There were statistical differences between the 1 day results and the changed water groups among all cements (p < 0.05). SIGNIFICANCE: The storage condition influenced the long-term durability of dentin bonding with resin cements.


Subject(s)
Dental Bonding , Dentin-Bonding Agents/chemistry , Resin Cements/chemistry , Adhesiveness , Analysis of Variance , Animals , Cattle , Drug Storage , Materials Testing , Microscopy, Electron, Scanning , Sodium Chloride , Solutions/chemistry , Statistics, Nonparametric , Tensile Strength , Water
16.
Oper Dent ; 25(3): 155-62, 2000.
Article in English | MEDLINE | ID: mdl-11203810

ABSTRACT

Dentin bridging of 150 mechanically exposed monkey pulps to two adhesive resins [BondWell LC (BW); Clearfil Liner Bond II (LB)] and a calcium hydroxide cement [Dycal (DY)] were histopathologically evaluated at 3, 7, 14, 30, and 60 days after operation (n = 10). The dentin bridge structure was three-dimensionally reconstructed from serial sections using a computer-aided reconstruction system. At three and seven days, in all pulps, no necrotic tissue and slight inflammatory cell infiltration was observed just below the exposure site. At 14 days, spindle-shaped fibroblast cells could be detected at the wound surface. All dentin chips showed reparative dentin deposition along the periphery of the wound surface. From this stage, the formation of secondary dentin from the pulpal wall at the periphery of the exposed area was recognized in all pulps. At 30 days, initial signs of dentin bridging were observed at the wound surface with a well-organized layer of odontoblastoid cells. The exposed area became occluded with a dentin bridge as the observation period increased. Group DY showed significantly higher incidence of dentin bridging than other groups at 30 days (p < 0.05). However, no significant difference of dentin bridge formation was found between Group DY and Groups BW and LB at 60 days. Bacterial penetration along the cavity walls and pulp tissue could not be detected in all groups. Histopathological observations and three-dimensional image analysis suggested that dentin bridge formation may occur following three patterns: (1) formed from the periphery of the residual dentin chip at the wound surface within 14 days, (2) formed within 14 days from the periphery of the cavity floor and with formation of reparative dentin by stimulation during the cavity preparation, and (3) formed from the wound surface within 30 days after exposure.


Subject(s)
Dental Pulp Capping , Dental Pulp Exposure/therapy , Dentin, Secondary/pathology , Dentin-Bonding Agents , Animals , Calcium Hydroxide/chemistry , Dental Pulp/pathology , Dentin/pathology , Dentin, Secondary/physiology , Dentin-Bonding Agents/chemistry , Fibroblasts/pathology , Follow-Up Studies , Image Processing, Computer-Assisted , Incidence , Leukocytes/pathology , Macaca , Methacrylates/chemistry , Minerals/chemistry , Odontoblasts/pathology , Wound Healing
17.
J Dent ; 27(4): 257-63, 1999 May.
Article in English | MEDLINE | ID: mdl-10193102

ABSTRACT

The aim of this in vivo study was to evaluate the effects of direct pulp capping techniques on the short-term response of mechanically exposed pulps using three commercially available adhesive resin systems. Class V cavities were prepared on the facial surface of 200 intact monkey teeth. Pulps were exposed with a carbide bur on the cavity floor. Each exposed pulp was capped with one of three commercially available adhesive resins or a hard-setting calcium hydroxide liner. All cavities were sealed with an adhesive resin, and were restored with hybrid resin composites. Inflammatory cell infiltration and dentine bridging of the exposed pulp and protrusion of the exposed pulp tissue into the cavities were evaluated histologically at 3, 7, 14, 30 and 60 days. A slight inflammatory cell infiltration was the principal reaction of the exposed pulp. The exposed area was occluded over time with dentine bridging in all groups. However, a protrusion of pulp tissue into the prepared cavity was observed at the periphery of the exposed area in all groups. These tissues communicated with the underlying pulp. The incidence of pulp tissue protrusion was ranked in order of increasing severity: Liner Bond II < Dycal < Bondwell LC = Super Bond C&B. Following pulp capping of the mechanical exposures, slight inflammation was the main reaction. Exposures became occluded with a dentine bridge over time. However, the protrusion of pulp tissue into cavities varied, depending on the materials used.


Subject(s)
Composite Resins/pharmacology , Dental Pulp Capping/adverse effects , Dental Pulp/drug effects , Analysis of Variance , Animals , Composite Resins/adverse effects , Dental Pulp/pathology , Dental Pulp Capping/methods , Drug Evaluation, Preclinical , Macaca , Time Factors
18.
Am J Dent ; 12(5): 217-21, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10649911

ABSTRACT

PURPOSE: To investigate with the scanning electron microscopy (SEM) the inner surface of the resin restorative used as a direct pulp capping. MATERIALS AND METHODS: Class V cavities were prepared on the facial surfaces of 90 intact monkey teeth, and the pulps were intentionally exposed with a carbide bur through the cavity floor. Each exposed pulp was capped with one of three commercially available adhesive resin systems (BondWell LC, GC; Imperva Bond, Shofu; Clearfil Liner Bond II, Kuraray). The cavities were restored with an adhesive resin and a hybrid resin-based composite. Histopathological changes of the mechanically exposed pulp were evaluated at 3, 30 and 60 days postoperatively. The interface between the resin and pulp tissues on the inner surface of the resin restorative was observed by SEM. RESULTS: Bacterial penetration along the cavity walls and pulp tissue could not be detected in any specimen. Slight inflammatory cell infiltration was the main initial reaction, while dentin bridge formation was the major long-term reaction in all groups. The resin surface adjacent to the etched cavity floor contained numerous resin tags corresponding to the dentin tubules. Remnants of pulpo-dentin complex, such as fragments of blood clots, pulpal cell, and dentin were also seen scattered along the inner resin surface.


Subject(s)
Dental Pulp Capping/methods , Dental Pulp/ultrastructure , Dentin-Bonding Agents , Resin Cements , Animals , Dental Pulp/microbiology , Dental Pulp Cavity/microbiology , Macaca , Methacrylates , Microscopy, Electron, Scanning
19.
Oper Dent ; 23(6): 308-17, 1998.
Article in English | MEDLINE | ID: mdl-9855854

ABSTRACT

Monkey pulpal responses to four adhesive resin systems used as direct pulp capping agents were histopathologically evaluated at 3, 7, 14, 30, and 60 days after operation. No serious inflammatory reaction of the pulp, such as necrosis or abscess formation, was observed. Slight inflammatory cell infiltration was the main inflammatory reaction of the exposed pulp, and the exposed area became occluded with dentin bridging as the observation period increased. Healing of exposed dental pulp beneath adhesive resin capping slightly differed depending on the materials used.


Subject(s)
Dental Pulp Capping/methods , Dental Pulp/drug effects , Dentin-Bonding Agents/pharmacology , Methacrylates/pharmacology , Analysis of Variance , Animals , Boron Compounds/pharmacology , Calcium Hydroxide/pharmacology , Dental Pulp Capping/adverse effects , Dental Pulp Exposure/therapy , Dentin, Secondary/drug effects , Dentin, Secondary/growth & development , Macaca , Methylmethacrylates/pharmacology , Minerals/pharmacology , Statistics, Nonparametric
20.
Oper Dent ; 23(1): 21-9, 1998.
Article in English | MEDLINE | ID: mdl-9610329

ABSTRACT

Monkey pulpal responses to metal inlays luted with a combination of an adhesive resin and luting composite and conventional dental cements were histopathologically evaluated. Initial pulpal responses caused by re-exposure of the cut dentin surfaces and luting procedure under hydraulic pressure subsided at 90 days after final cementation. There was no significant difference among pulpal reactions to conventional dental cements and a combination of an adhesive resin and luting composite. The adhesive resin coating of freshly cut dentinal walls/floors immediately after cavity preparation seems to provide protection for the dentin and pulp in indirect restorations requiring temporary sealing.


Subject(s)
Dental Cements/pharmacology , Dental Pulp/drug effects , Analysis of Variance , Animals , Dental Cements/adverse effects , Dental Cements/chemistry , Glass Ionomer Cements/pharmacology , Haplorhini , Inlays , Odontoblasts/drug effects , Resin Cements/pharmacology , Statistics, Nonparametric , Stress, Mechanical
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