Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Compomers”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43Linked to original sources
PubMed2002

Comparative study of the physical properties of core materials.

This study was undertaken to measure physical properties of materials used for direct core buildups, including high-copper amalgam, visible light-cured resin composite, autocured titanium-containing composite, polyacid-modified composite, resin-modified glass-ionomer, and silver cermet cement. Compressive strength, diametral tensile strength, and flexural strength of six core materials of various material classes were measured for each material as a function of time up to 3 months at different storage conditions, using a standard specification test designed for the materials. Three different storage conditions (dry, humid, wet) at 37 degrees C were chosen. Materials were manipulated according to manufacturers' instructions for use as cores. Mean compressive, diametral tensile, and flexural strengths with associated standard deviations were calculated for each material. Multiple comparison and Newman-Keuls tests discerned many differences among materials. All materials were found to meet the minimum specification requirements, except in terms of flexural strength for amalgam after 1 hour and the silver cermet at all time intervals.

Cermet Cements↗
PubMedDate not supplied

Changes in flexural properties of composite restoratives after aging in water.

This study evaluated the changes in flexural properties of microfill (Filtek A110 [AO]), minifill (Filtek Z100 [ZO] and Z250 [ZT]), poly-acid modified (F2000 [FT]), and flowable (Filtek Flowable [FF]) composites after aging in water. The flexural strength and modulus of the composites were determined after one week and one month of aging in water at 37 degrees C. Samples were prepared and tested according to ISO specifications. Data was analyzed using ANOVA/Scheffe's test and independent samples t-test at significance level 0.05. Mean flexural strength (n=7) ranged from 66.61 to 147.21 and 68.74 to 142.69 MPa at one week and one month, respectively. Mean flexural modulus (n=7) at one week and one month ranged from 3.45 to 11.30 and 4.76 to 13.02 GPa, respectively. ZO and ZT were significantly stronger than AO, FT and FF and FF was significantly stronger than AO & FT at both time periods. At one week and one month, AO and FF were significantly more flexible than the ZO, ZT and FT. In addition, ZO and FT were significantly stiffer than ZT. With the exception of AO, a significant increase in flexural modulus was observed with all composites. Although flexural strength of FT and FF was significantly increased with aging in water, the flexural strength of ZT was significantly decreased.

Analysis of Variance↗
PubMedDate not supplied

Extent of the cariostatic effect on root dentin provided by fluoride-containing restorative materials.

This study evaluated the extent of the cariostatic effect on root dentin provided by four fluoride-containing restorative systems: Ketac-Fil/ESPE [Ke], Fuji II LC Improved/GC Corp [Fj], Dyract AP/Dentsply [Dy] and SureFil/Dentsply [Su], and one without fluoride: Z250/3M [control]. Ninety-five bovine root dentin fragments (5.0 x 6.0 mm) were obtained, embedded in polyester resin and planed. Cavities (1.5 x 3.5 x 1.0 mm) were made and restored by the five restorative systems (n=19) in a randomized complete block design according to the manufacturers' instructions. After 24 hours, the dentin/restoration surface was polished. The restoration surface and an adjacent area of 3.0 x 3.0 mm were demarcated and submitted to a pH-cycling model. Dentin surface Knoop microhardness values were obtained (5.0-g, 5.0-s) for 10 distances: 50, 100, 150, 300, 600, 900, 1200, 1500, 1800 and 2100 microm from the margin of the restoration. The dentin microhardness means for each restorative material at each distance was considered by the ANOVA multi-factor split-plot method. The interaction between the restorative system and distance was statistically significant (p<0.05). The Tukey test and the regression analysis showed that the means of [Ke] and [Fj] were similar up to 300 microm, the [Ke] means being higher than the [control] at distances 50, 100, 150 and 300 microm. The [Fj] means were higher than the [control] at distances 50, 100 and 150 microm. The microhardness means of [Dy] and [Su] were not statistically different from the [control] and remained steady throughout the studied distances. This study concluded that the extent of the cariostatic effect on root dentin was 300 microm for [Ke] and 150 microm for [Fj]. [Dy] and [Su] did not show any cariostatic effect.

Analysis of Variance↗
PubMed2002

Microleakage in class II composite resin restorations: total bonding and open sandwich technique.

PURPOSE: The objective of this in vitro study was to evaluate gingival microleakage in Class II total bond resin restorations in comparison to open sandwich technique restorations using different materials. MATERIALS AND METHODS: Forty-eight human molar teeth were disinfected and stored in a 0.9% saline solution. In each tooth, two standardized Class II cavities (3 mm x 6 mm x 2 mm) were prepared with the gingival cavosurface margins located 1 mm below the cementoenamel junction. The teeth were divided into 4 equally sized groups (n = 12), and the proximal boxes were treated as follows: in Group 1, no base material was used and the cavity was restored using SyntacSprint (SS) and Tetric Ceram (TC); in Groups 2, 3, and 4 the gingival portion of the cavity was restored with different base materials (Group 2, Dyract; Group 3, Vitremer; Group 4, Chelon-fil) prior to the placement of the composite resin. After a storage time of 7 days, the restorations were finished and polished. Then, specimens were submitted to thermocycling (500 cycles, 5 degrees C to 55 degrees C, 15 s dwell time) and immersed in a 0.5% methylene blue solution for 24 h. After washing, they were sectioned in a mesio-distal direction. Each restoration was evaluated under a stereomicroscope at 20x by 2 examiners and scored on a 0 to 3 scale according to the marginal leakage. Kappa statistics were used to evaluate the agreement between the examiners. Given the ordinal nature of the scoring system, data were submitted to a nonparametric repeated measures ANOVA. The results were confirmed with a parametric repeated measures ANOVA. RESULTS: Significant differences (p < 0.001) among the four groups with respect to dye penetration were detected, with the association Vitremer/Tetric showing the best results. CONCLUSION: The use of Vitremer in the open sandwich technique presents the lowest degree of microleakage among the treatments considered in this study.

Analysis of Variance↗
PubMedDate not supplied

Restoring primary anterior teeth.

A variety of esthetic restorative materials are available for restoring primary incisors. Knowledge of the specific strengths, weakness, and properties of each material will enhance the clinician's ability to make the best choice of selection for each individual situation. Intracoronal restorations of primary teeth may utilize resin composites, glass ionomer cements, resin-modified ionomers, or polyacid-modified resins. Each has distinct advantages and disadvantages and the clinical conditions of placement may be a strong determining factor as to which material is utilized. Full coronal restoration of primary incisors may be indicated for a number of reasons. Crowns available for restoration of primary incisors include those that are directly bonded onto the tooth, which generally are a resin material, and those crowns that are luted onto the tooth and are some type of stainless steel crown. However, due to lack of supporting clinical data, none of the crowns can be said to be superior to the others under all circumstances. Though caries in the mandibular region is rare, restorative solutions for mandibular incisors are needed. Neither stainless steel crowns nor celluloid crown forms are made specifically for mandibular incisors. Many options exist to repair carious primary incisors, but there is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. This does not discount the fact that dentists have been using many of these crowns for years with much success. Operator preferences, esthetic demands by parents, the child's behavior, and moisture and hemorrhage control are all variables which affect the decision and ultimate outcome of whatever restorative treatment is chosen.

Child, Preschool↗
PubMedDate not supplied

A comparative evaluation of four adhesive tooth coloured restorative materials. An invitro study.

Four adhesive tooth colored restorative materials, Fuji II, Fuji II LC, Dyract and TPH composite resin were evaluated for the amount of microleakage in enamel and cementum. The TPH composite resin showed maximum microleakage, significantly higher than Fuji II, which showed least microleakage. All the four materials showed more micro leakage in cementum when compared to enamel.

Acridine Orange↗
PubMedDate not supplied

Determination of mode of fracture of adhesive restorative materials. An invitro study.

In the present invitro study, four adhesive restorative materials were evaluated for the determination of mode of fracture. The four materials chosen were TPH composite resin, Dyract, Fuji II LC and Fuji II. The mode of fracture was determined at a magnification of 10X. The TPH composite resin and Dyract showed adhesive fracture whereas the glass ionomer group showed cohesive fracture.

Adhesiveness↗
PubMed2002

Reliability of different techniques to assess marginal defects of Class II restorations in retrieved primary molars: a visual-tactile, SEM, dye penetration and polarized light microscopy study.

The aims of the present article were to assess the reliability of different techniques to assess marginal defects in Class II restorations in retrieved primary molars, and to determine the degree of agreement between the various assessment modalities. The material evaluated was comprised of 18 exfoliated primary molars that had been restored 20 to 22 months previously with a resin-modified glass ionomer (Vitremer--7 teeth), a hybridized composite resin (Z100 + Scotchbond Multipurpose--9 teeth), and amalgam (Dispersalloy--2 teeth). No significant differences could be observed between the groups. The majority of the restorations rated A at the buccal and lingual margins, but poor adaptation was disclosed at the cervical margin of the three types of restorations. SEM evaluation revealed that the highest percentage of defects was seen at the cervical margins with no statistically significant difference between the groups. No or minimal leakage was present at the occlusal margins and severe penetration of dye was seen at the cervical margins in all groups. Significantly less demineralization was seen adjacent to the Vitremer and Z100 restorations when compared to the Dispersalloy but no difference was found between the esthetic restorations. Except for the visual tactile examination, small marginal defects could be disclosed by the three assessment techniques (SEM, dye penetration, and polarized light microscopy). A good degree of agreement was observed between the three evaluation techniques.

Child↗
PubMed2002

Two-year clinical evaluation of Dyract in small Class I cavities.

PURPOSE: To evaluate the 2-year clinical performance of Dyract in small Class I cavities in non stress-bearing areas. MATERIALS AND METHODS: On 36 patients, 87 small cavity preparations were performed. The lesions were diagnosed macroscopically with a probe. They involved fissures, were shallow and had reached dentin but the lateral spread was limited and localized in dentin. Cavities were designed to be on non stress bearing areas. Cavities' average faciolingual widths were prepared to be 1/3 or less than the intercuspal width. At baseline, 1- and 2-year recalls, the restorations were evaluated according to the modified Ryge criteria by two calibrated, experienced examiners. RESULTS: None of the restorations was lost and retention rate was 100% at the end of 1 year. After 2 years, one restoration (1.1%) had to be replaced due to caries lesion adjacent to its margin and the rate of retention was 98.9%. At the 2-year recall, marginal discoloration (rated Bravo) was observed in 19.8% of the restorations but did not require the replacement of any restorations. Except the failed restoration, no other was clinically unacceptable in regard to color match, wear or loss of anatomic form, marginal discoloration, caries, marginal adaptation and surface texture.

Adolescent↗
PubMedDate not supplied

Effects of daily fluoride exposures on fluoride release by glass ionomer-based restoratives.

It is well documented that glass ionomer cements absorb and release fluoride following single fluoride exposures. This study examined fluoride release among three glass ionomer-based restorative materials following multiple daily exposures to three topical fluoride regimens. Using a Delrin mold, 32 cylindrical specimens, each of a glass ionomer (Ketac-Fil), resin-modified glass ionomer (Photac-Fil) and polyacid-modified resin (Dyract AP) were created. Each specimen was subjected to one of four daily treatments (n = 8): (1) no fluoride treatment (control); (2) application of a fluoride dentifrice (1000 ppm) for one minute once daily; (3) application of the same dentifrice for one minute twice daily; (4) the same regimen as (3), plus immersion in a 0.05% sodium fluoride (NaF) mouth rinse (225 ppm) for one minute immediately following the second dentifrice application. Each specimen was suspended in a polyethylene test tube containing 1.0 ml demineralizing solution (pH 4.3) at 37 degrees C for six hours, then transferred to a new test tube containing 1.0 ml remineralizing solution (pH 7.0) at 37 degrees C for 18 hours. Fluoride treatments were completed at the time of transfer daily for seven days. Media solutions were buffered with equal volumes of TISAB II; fluoride levels were measured using a digital ion analyzer and fluoride electrode. Fluoride release decreased significantly from Day 1 to Day 3 for all materials regardless of fluoride treatment (Repeated Measures ANOVA, Tukey HSD, p < 0.05). All specimens released significantly more fluoride in demineralizing solution than in remineralizing solution. For Days 2-7, Treatment 4 produced greater fluoride release than both the control and Treatment 2 for all three materials (p < 0.05); For each material, the fluoride release produced by Treatments 3 and 4 was statistically similar on most days throughout the study. By Day 7, Photac-Fil demonstrated both the greatest total fluoride release and the greatest rechargability, followed by Ketac-Fil and Dyract AP. Although subsequent daily fluoride release never approached that of Day 1, increasing daily fluoride exposures enhanced fluoride release for all three restorative materials.

Absorption↗
PubMed2002

Comparison of antibacterial activity of simplified adhesive systems.

PURPOSE: To determine and compare the intrinsic antibacterial activity of commercially available simplified adhesive systems. MATERIALS AND METHODS: The antibacterial activity of five self-etching/priming one-step adhesives and three priming/bonding adhesives against Streptococcus mutans, Lactobacillus casei, and Actinomyces viscosus was assessed by the agar disc-diffusion test and determination of the minimum inhibitory/bactericidal concentration (MIC/MBC). Twenty microl of each adhesive was impregnated into a paper disc and placed on an agar plate inoculated with a bacterial suspension, with or without light-irradiation. The size of inhibition zones produced around the specimens was measured after 48 hours of incubation. The MIC values were measured by serial microdilution assays, visually examining the growth of bacteria after incubation with each adhesive for 24-48 hours. The subcultures were made on BHI agar plates from the wells showing no visible growth of bacteria, and the MBC values were determined based on production of colonies. Two primers in two-step self-etching systems and an experimental primer containing chlorhexidine were tested for reference. The results of disc-diffusion tests were analyzed by ANOVA and Fisher's PLSD test. RESULTS: The size of inhibition zones produced by adhesives varied among the brands. None of the available commercial adhesives showed significant inhibition against all three of the bacterial species tested. Light-irradiation reduced the size of inhibition zones for a few materials, but a similar trend to the effectiveness of non-irradiated specimens was observed. The antibacterial activity of commercial products determined in terms of MIC/MBC values were different from the results by disc-diffusion tests. The self-etching adhesives with low pH were not necessarily more effective than priming/bonding solutions, and no significant relationships between the acidity and antibacterial effects were found. Compared with commercial products, an experimental primer containing chlorhexidine produced significantly larger inhibition zones against all species (P < 0.05) and exhibited greater bacteriostatic/bactericidal activity, demonstrating lower MIC/MBC values.

Actinomyces viscosus↗
PubMed2003

The last post.

Explore the source record for details and available documents.

CD-ROM↗
PubMedDate not supplied

Microleakage evaluation of a flowable polyacid-modified resin composite used as fissure sealant on air-abraded permanent teeth.

This study evaluated the microleakage of a flowable polyacid-modified resin composite used as a fissure sealant on air-abraded teeth in comparison to a resin-based fluoride sealant. Sixty extracted human third molars were divided into six subgroups (n = 10) under two main groups (fissure sealant materials). The occlusal surfaces of the teeth were air-abraded at 80 psi using 50 microm particles of aluminum oxide for 30 seconds, followed by rinsing and drying. Delton FS+ (Dentsply International) and Dyract Flow (Dentsply DeTrey) were applied to the teeth in subgroups following application of: a) an acid etching and bonding agent, b) bonding agent alone or c) air-abrasion alone, respectively. Acid etching (Delton EZ Etch, Dentsply International) and bonding agent application (Prime & Bond NT, Dentsply DeTrey) were done according to the manufacturers' instructions. The teeth were thermocycled for 500 cycles between 5 degrees C and 55 degrees C with dwell time of 15 seconds. Basic fuchsin (0.5%) staining followed by buccolingual sectioning was performed. Microleakage was evaluated at 20x optical magnification. Kruskal-Wallis test was used to make comparisons among six subgroups. Pairwise comparisons were done with the Mann-Whitney U test with the level of significance set as alpha = 0.05. Dyract Flow application as a fissure sealant on air-abraded permanent teeth in combination with acid etching and/or bonding agent provided microleakage results comparable to Delton FS+. Results also showed that the use of air abrasion, alone, resulted in significantly higher microleakage scores.

Acid Etching, Dental↗
PubMedDate not supplied

Marginal microleakage of two fissure sealants: a comparative study.

PURPOSE: An in vitro study was conducted to evaluate enamel marginal microleakage following acid etching of two fissure sealants of established clinical efficacy. The purpose of this study was to assess sealant leakage following etching in combination with the use of latest-generation adhesives. METHODS: Clinicians removed 22 human premolars without caries for orthodontic reasons, stored them in distilled water, and sealed the occlusal surface. They used sealants Concise (3M) and Dyract seal (Dentsply DeTrey). They randomly distributed the premolars into two groups (N = 11) according to sealant used. The materials were manipulated according to the instructions of the manufacturer, and no invasive enamel preparing technique was used (enameloplasty). Staining was carried out with 2% fuchsin. The results were evaluated by the Mann-Whitney nonparametric test for the comparison of independent data samples. RESULTS: Concise sealant was seen to produce significantly greater marginal leakage than Dyract seal (P=.02). CONCLUSIONS: The application of an adhesive layer beneath the sealant afforded less microleakage than when no adhesive was used. Nevertheless despite the possibility of combining adhesives and sealant resins, with good bonding between both components over the entire fissure interface, microleakage was still observed, regardless of the material used. This suggests that presently there is no material is able to secure total sealing of the space between the material used and the dental tissue.

Acid Etching, Dental↗
PubMed2002

Direct composite resins: an update.

Esthetic restorative materials require a bonding procedure to achieve durability and reliability. To accomplish this, the bonding system and restorative material must be biocompatible and bond well to both dentin and enamel. The direct restorative must have sufficient strength to resist masticatory forces as well as mechanical properties close to those of natural tooth structure. These materials should be resistant to degradation in the oral cavity and easy to use. This article reviews the published literature on direct composite restorative materials.

Ceramics↗
PubMed2003

Glass ionomers in contemporary restorative dentistry--a clinical update.

Glass ionomers are applicable to many restorative situations, both as stand-alone restoratives and in conjunction with composite resins. This article reviews the clinically relevant properties of glass ionomers, the differences between them and composite resins, and their clinical applications. An understanding of these concepts is into common restorative essential for the optimal incorporation of these material's attributes and utilization.

Adhesiveness↗
PubMedDate not supplied

Increment technique for extended Class V restorations: an experimental study.

The application and polymerization of composite or polyacid-modified resin composites in thin layers (increment technique) for filling cavities might partially compensate for the stress associated with polymerization shrinkage. In this study, the effect of this technique on the marginal integrity of Class V polyacid-modified composite restorations was investigated. In 30 extracted premolars, extended Class V cavities were prepared with the apical margin in root dentin and the coronal margin in enamel. They were then subjected to different treatments (10 teeth in each case): a) placement and polymerization of a thin resin composite layer (Dyract-Dyract PSA) in the coronal part of the cavity (plus one increment for the residual part) (Group 1), b) a thin layer at the apical part of the cavity (plus one increment for the residual part) (Group 2) and c) restoration of the entire cavity with one increment (bulk technique) (Group 3). Following three days' storage in water, the teeth were subjected to cyclic thermal loading (4 degrees C <-> 55 degrees C, 2,000 cycles). The percentages of defective bonding detected along the total length of the restoration margin were assessed before and after thermocycling by scanning electron microscopy. Following loading and thermocycling, no significant differences were found at the restoration-enamel interface. Fewer gaps were found at the restoration-dentin interface in Group 1 (18.7 +/- 25.7%) and Group 2 (20.5 +/- 22.8%) compared to the reference Group 3 (42.2 +/- 30.6%) (Mann-Whitney U test: p<0.05). Moreover, there were no significant differences between the two increment groups (1 and 2). In a significantly larger number of cases, a completely intact dentin restoration margin was detected when a coronal increment (Group 1) (44.4%) was used instead of the bulk technique (Group 3) (13.6%) (Chi square test: p<0.05). These results indicate that gap formation can be significantly minimized by using an increment technique to restore extended Class V cavities with polyacid-modified composite materials.

Chi-Square Distribution↗
PubMed2003

Effect of the cavity configuration factor on the marginal microleakage of esthetic restorative materials.

PURPOSE: To evaluate the effect of the cavity configuration factor (CF) on the marginal microleakage of cervical restorations with four aesthetic restorative materials. MATERIALS AND METHODS: Conventional cavities, 2.9 mm in diameter and 1.5 mm deep, with CF=2.7 and "saucer"-shaped ones with CF=2 were created in 60 extracted premolars. The following groups were established: G1: Z100/Single Bond, G2: Freedom/Stae, G3: Vitremer/Primer and G4: Durafill/Durafill Bond, following each manufacturer's directions. Thermocycling of the specimens was performed in an aqueous solution of 2% buffered methylene blue, with the temperature varying between 5 to 55 degrees C, for a total of cycles of 60 minutes per day, for 7 days. The specimens were then sectioned and evaluated by two observers using photographs acquired from a stereomicroscope. The values were subjected to Kruskal-Wallis analysis and the Dunn and Wilcoxon test. RESULTS: The averages of the microleakage scores observed in the conventional and "saucer"-shaped cavities were respectively: G1: 0.66/0.46; G2: 0.92/0.69; G3: 1.8/1.86; G4: 3.54/2.3.

Bisphenol A-Glycidyl Methacrylate↗