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PubMedDate not supplied

Influence of veneering composite composition on the efficacy of fiber-reinforced restorations (FRR).

This study investigated the influence of fiber reinforcement on the flexural properties of four commercial (Artglass, Belleglass HP, Herculite XRV and Solidex) veneering composites (Series A) and two experimental composites (Series B&C). This study investigated how the composition of the veneering composites influenced the enhancement of strength and modulus produced by fiber reinforcement. The formulation of the experimental composites were varied by changing the filler load (Series B) or the resin matrix chemistry (Series C) to assess the effect these changes would have on the degree of reinforcement. In Series A, the commercial veneering composites were reinforced by an Ultra-High-Molecular-Weight Polyethylene fiber (UHMW-PE/Connect) to evaluate flexural properties after 24 hours and six months. In Series B, experimental composites with the same organic matrix but with different filler loads (40% to 80% by weight) were also reinforced by Connect fiber to evaluate flexural properties. In Series C, experimental composites (Systems 1-4) with the same filler load (76.5% by weight) but with different organic matrix compositions were reinforced by Connect fiber to evaluate flexural properties. For Series B and C, flexural properties were evaluated after 24 hours water storage. All the samples were prepared in a mold 2 mm x 2 mm x 25 mm and stored in distilled water at 37 degrees C until they were ready for flexural testing in an Instron Universal Testing Machine using a crosshead speed of 1 mm/minute. The results showed no significant differences in the flexural strength (FS) between any of the commercial reinforced composites in Series A. The flexural modulus (FM) of the fiber-reinforced Belleglass HP group was significantly higher than for Artglass and Solidex. Water storage for six months had no significant (p>0.05) effect on the flexural strength of three of the four reinforced veneering composites. The flexural strength for Artglass was significantly reduced (p<0.05) by six-month water storage. In Series B, however, increasing the amount of filler loading improved the flexural modulus of the reinforced experimental composite but had no effect on its flexural strength. In Series C, changing the organic matrix formulation had no affect on flexural strength but affected the flexural modulus of the reinforced experimental composite.

Analysis of Variance↗
PubMed2001

Bonding of prosthetic composite material to Ti-6Al-7Nb alloy with eight metal conditioners and a surface modification technique.

PURPOSE: The purpose of the current study was to evaluate the adhesive performance of metal conditioners and a surface modification system when used for bonding between a prosthetic composite material and a titanium alloy. MATERIALS AND METHODS: Eight metal conditioners (Acryl Bond, All-Bond 2 Primer B, Alloy Primer, Ces II Opaque Primer, Eye Sight Opaque Primer, Metafast Bonding Liner, Metal Primer II, and MR Bond) and a bonding system (Siloc) were assessed. Cast disk specimens made of a titanium alloy (Ti-6Al-7Nb, T-Alloy Tough) were either primed with one of the eight primers or treated with the Siloc system and bonded with a light-activated prosthetic composite material (Artglass). Shear bond strengths were determined both before and after thermocycling (4 C-60 C, 60 s each, 20,000 cycles) for evaluation of the durability of the bonds. RESULTS: The results showed that the Siloc-treated group recorded the greatest post-thermocycling bond strength, followed by the two groups conditioned with the Cesead II Opaque Primer and Alloy Primer agents, both of which contain an identical hydrophobic phosphate-methacrylate functional monomer.

Alkanes↗
PubMedDate not supplied

Short-term clinical evaluation of inlay and onlay restorations made with a ceromer.

PURPOSE: This prospective clinical trial evaluated the clinical acceptability of a new material, ceromer, used for inlay and onlay restorations in single- or multisurface cavities of posterior teeth. MATERIALS AND METHODS: Forty-three Targis inlay and onlay restorations were placed in 25 patients and evaluated using the United States Public Health Service criteria. The laboratory work was conducted by three dental technicians according to the manufacturer's recommendations. Twenty-five restorations were luted with Syntac bonding system and Variolink II, and 18 were luted with Scotchbond Multi Purpose and Opal Luting Composite. The recalls were done at 6, 12, and 18 months. Restorations were evaluated for six parameters and scored as ideal (A), clinically acceptable (B), or clinically unacceptable (C). RESULTS: Indirect restorations received, after 18 months, scores of A at the following rates: color match 77%; marginal discoloration 93%; secondary caries 100%; anatomic form 93%; and marginal integrity 95%. For these parameters, statistical analysis indicated no significant differences at baseline and after 18 months. Postoperative hypersensitivity was reported by seven patients at baseline, but it decreased and there was no hypersensitivity at 12- and 18-month follow-ups. CONCLUSION: Over an 18-month period the Targis restorative system yielded good clinical service.

Adult↗
PubMed1996

[Clinical relevance of fluoride release from restorative materials].

The observed reduced frequency of secondary caries around silicate cement restorations has initiated the development of various fluoride releasing products, to be used as restorative materials, lining cements, sealants and orthodontic cements. The fluoride release is substantial only in the period immediately following usage of the product (e.g. placement of the restoration). An elevation of the fluoride level in plaque or saliva is therefore only found in the immediate vicinity of the fluoride source. Initially, this results in a change of the plaque composition. As a small change in fluoride level affects the caries balance, it is conceivable that fluoride release from dental materials reduces secondary caries, or caries around orthodontic brackets.

Cariostatic Agents↗
PubMed2002

The influence of occlusal finish line configuration on microleakage of indirect composite inlays.

PURPOSE: The aim of this in vitro study was to evaluate the influence of occlusal finish line configuration on microleakage of indirect composite inlays. MATERIALS AND METHODS: Forty-five recently extracted premolars were randomly assigned into three groups with different types of occlusal finish line preparations: bevel, chamfer, and butt joint. All restorations were made in Artglass (Heraeus Kulzer) and luted according to the manufacturer's recommendations. The teeth were sealed and then thermocycled 500 times between 5 degrees C and 55 degrees C. After that they were immersed in a 2% methylene blue (pH 7.2) solution for 24 hours. Each tooth was bisectioned in the buccal/lingual direction and then examined microscopically at each section to evaluate the microleakage score. The data were analyzed with chi-square and Fisher's Exact tests. RESULTS: There were no significant differences between the buccal margins of maxillary premolars with occlusal bevel or butt joint; the chamfer had the worst performance. In the buccal margin of mandibular premolars, the bevel and chamfer showed significantly smaller amounts of leakage than the butt joint. No significant differences were observed between the three types of occlusal cavosurface preparations in the lingual margin of maxillary and mandibular premolars. CONCLUSIONS: The finish line configuration, the position of the teeth in the arch, and the margin (buccal vs lingual) influenced microleakage. Whenever microleakage was observed in this study, it was always observed at the tooth-cement interface.

Acid Etching, Dental↗
PubMedDate not supplied

Voids and porosities in class I micropreparations filled with various resin composites.

In this in vitro study, voids inside a minimal occlusal restoration using different consistencies of resin composite and various application techniques were investigated. One hundred and fifty-two simulated, minimally invasive preparations, including a prepared fissure and an excavated carious dentin lesion, were ground in perspex blocks. After applying an acrylic primer (Artglass Connector, Kulzer), the preparations were restored with the adhesive PhotoBond (Kuraray) and one of three resin composites: a packable composite (Prodigy Condensable-Kerr), a syringable composite (Clearfil Photo Posterior, Kuraray) and a flowable composite (Revolution, Kerr). The restorations were inserted according to eight protocols (n = 19). In three groups, the composite was placed in bulk. In another three groups, a layer of flowable composite was placed first, then cured, followed by a second layer of one of the three composites. In two groups, the first layer of flowable composite was left uncured before a second layer of a packable or syringable composite was inserted. The perspex blocks were sectioned and inspected for the presence of voids. Statistical analysis was conducted using Fischer's exact tests at p < 0.05. The results showed that restoring minimal preparations in the absence of porosities and voids was very difficult to achieve. Placing a layer of flowable composite that was left uncured, directly followed by injecting a medium-viscous composite, was the technique that resulted in the most homogeneous restoration.

Composite Resins↗
PubMedDate not supplied

Clinical evaluation of fiber-reinforced composite inlay FPDs.

PURPOSE: This clinical study evaluated the behavior of inlay fixed partial dentures (IFPD) with conventional and modified framework designs over a period of 12 to 48 months. MATERIALS AND METHODS: Forty-one glass fiber-reinforced composite IFPDs were made to replace one missing maxillary or mandibular tooth. The frameworks were made only with parallel fibers in 19 restorations (group 1) and built with parallel and woven fibers modifying the design of the pontic element in 22 IFPDs (group 2) according to the manufacturer's instructions. All restorations were evaluated by color match, marginal discoloration, secondary caries, surface texture, marginal adaptation, fracture, and postoperative sensitivity. RESULTS: Three partial adhesive-cohesive veneering composite fractures occurred in the pontic element in group 1 after 3, 4, and 8 months, respectively. One cohesive fracture occurred in an abutment in group 2 after 46 months. Group 1 showed a 16% fracture failure rate; group 2 showed a 5% failure rate. However, no statistical difference was detected between the groups. IFPDs received the highest score at the following rates: color match 71%, marginal discoloration 96%, secondary caries 99%, surface texture 88%, marginal adaptation 98%, fracture 90%, and postoperative sensitivity 100%. Statistical analysis indicated significant deterioration of color match from baseline to last recall. CONCLUSION: There were nonsignificantly fewer fractures of the veneering composite with the modified design of the framework than with the conventional design. Repair of the fractured veneer of IFPDs may lengthen the lifespan of the restorations, but it is advisable only for slight damage.

Adolescent↗
PubMed2003

Restoration of endodontically treated teeth without posts.

PURPOSE: To describe the treatment of a patient with a dismal oral situation after successful cure for drug addiction. METHODS: After root canal treatment and surgical pretreatment, four maxillary glass-fiber reinforced composite fixed partial dentures, anchored by endo-crowns instead of post and core, were fabricated (Targis & Vectris). Additionally, full crowns on four dental implants and an inlay were produced of non-reinforced composite (Targis). All restorations were luted adhesively to abutments with a three component adhesive system (Syntac Classic), light-curing composite (Tetric) and an ultrasonic insertion technique. RESULTS: An esthetic and functional acceptable result was achieved. Excessive removal of tooth structure by post preparation may weaken the root.

Adult↗
PubMed1992

Development of an adhesive bonding system.

Building on findings concerning adhesion to enamel, R L Bowen and his colleagues at the Paffenbarger Research Center, National Institute of Standards and Technology began addressing and solving problems associated with (1) silicate cements and unfilled resins, (2) bonding in an aqueous environment, and (3) the development of an adhesion system for both dentin and enamel that could withstand various stresses. This article reviews the development of an adhesion system for bonding dental composites to dentin and enamel.

Benzoates↗
PubMed2004

An investigation of pH changes of various cements.

OBJECTIVE: In this study, the time-related pH changes that occur in cements having different structures were observed. METHOD AND MATERIALS: Eight cements consisting of four permanent and four temporary cements were used. The materials were prepared according to manufacturers' instructions. The materials were used in 0.100 +/- 0.02-g increments, with the purpose of standardizing the effect of massive differences. The 80 total specimens, including 10 from each cement type, were prepared, and the pH value of the distilled water was measured at 3,10,30,60, and 120 minutes, and then again 24 hours later. RESULTS: Analysis of variance showed the relation between the kind of cement and its pH change during the course of the study was statistically significant. CONCLUSION: Though temporary cements indicated neutral pH from the beginning of the study, the acidity of the other cements changed with time and took values approximate to neutral pH within 24 hours.

Dental Cements↗
PubMed1992

Effect of acid etching on the dental pulp in adhesive composite restorations.

Pulpal response to marginal enamel etching or both enamel and dentine etching with 37% phosphoric acid for adhesive composite restorations was studied in the teeth of the Japanese monkey (Macaca fuscata). Dentine etching irritated the pulp and caused moderate to severe initial changes along the odontoblastic layer at 3 days. When no bacteria were present along the cavity walls, the subsequent pulpal reactions at 30 and 90 days decreased with time and large amounts of irritation dentine were formed. These inflammatory reactions were less than those caused by enamel etching only, or zinc oxide/eugenol cement. Significant correlation (P less than 0.01) was found between the intensity of the inflammatory reactions and the degree of bacterial infection. The pulpal irritation caused by acid etching of dentine for composite restorations is transitory only when the fillings have a good marginal seal and wall adaptation.

Acid Etching, Dental↗
PubMedDate not supplied

Curing units' ability to cure restorative composites and dual-cured composite cements under composite overlay.

This study compared the efficacy of using conventional low-power density QTH (LQTH) units, high-power density QTH (HQTH) units, argon (Ar) laser and Plasma arc curing (PAC) units for curing dual-cured resin cements and restorative resin composites under a pre-cured resin composite overlay. The microhardness of the two types of restorative resins (Z100 and Tetric Ceram) and a dual-cured resin cement (Variolink II) were measured after they were light cured for 60 seconds in a 2 mm Teflon mold. The recorded microhardness was determined to be the optimum microhard-ness (OM). Either one of the two types of restorative resins (Z100, Tetric Ceram) or the dual cured resin cement (Variolink II) were placed under a 1.5-mm thick and 8 mm diameter pre-cured Targis (Vivadent/Ivoclar AG, Schaan, Liechtenstein) overlay. The specimens that were prepared for each material were divided into four groups depending upon the curing units used (HQTH, PAC, Laser or LQTH) and were further subdi-vided into subgroups according to light curing time. The curing times used were 30, 60, 90 and 120 seconds for HQTH; 12, 24, 36 and 48 seconds for the PAC unit; 15, 30, 45 and 60 for the Laser and 60, 120 or 180 seconds for the LQTH unit. Fifteen specimens were assigned to each sub- group. The microhardness of the upper and and lower composite surfaces under the Targis overlay were measured using an Optidur Vickers hardness-measuring instrument (Göttfert Feinwerktechnik GmbH, Buchen, Germany). In each material, for each group, a three-way ANOVA with Tukey was used at the 0.05 level of significance to compare the microhardnesses of the upper and lower composite surfaces and the previously measured OM of the material. From the OM of each material, 80% OM was calculated and the time required for the microhardness of the upper and lower surface of the specimen to reach 100% and 80% of OM was determined. In Z100 and Tetric Ceram, when the composites were light cured for 120 seconds using the HQTH lamp, microhardnesses of the upper and lower surfaces reached OM. When they were cured with the PAC unit, only 48 seconds was needed for the upper and lower surfaces to reach OM. When they were cured using the laser, the lower surface did not reach OM in any of the groups. When the specimens were cured using the LQTH lamp, 180 seconds of curing was needed for Z100 to reach OM, whereas Tetric Ceram did not reach OM. In Z100, 60, 12, 30 and 60 seconds were needed in HQTH, PAC, Laser and LQTH, respectively, for the specimens to reach 80% OM. Tetric Ceram was needed 60,24,45 and 180 seconds to reach 80% OM. In the Variolink II specimen, microhardness of the upper and lower surfaces did not reach OM even though they were light cured with the HQTH lamp for 120 seconds. When they were cured with the PAC unit, 48 seconds was insufficient for them to reach OM. When they were cured with laser for 45 and 60 seconds, microhardness reached OM on the upper surface but not on the lower surface. However, when they were cured using the LQTH lamp, microhardness did not reach OM on the upper and lower surfaces even though the curing time was extended to three minutes. In Variolink II, 120, 36, 45 and >180 seconds were needed in HQTH, PAC, Laser and LQTH, respectively, for the specimens to reach 80% OM. In conclusion, the PAC system is the most effective curing system to cure the restorative composite and dual cured resin cement under the 1.5 mm Targis overlay, followed by the laser, HQTH and LQTH units. In addition, the restorative composites cured more efficiently than the dual-cured resin cements.

Composite Resins↗
PubMed1979

[Biological responses to filling materials with special reference to the composite material evicrol--an experimental study (author's transl)].

The biological responses to the composite filling material Evicrol were tested by temporarily differentiated implants in rats. Type and degree of the inflammatory reaction as well as the intensity of connective tissue fiber formation were used as criteria for evaluation of the histocompatibility of the subcutaneous implants. As compared to other composite filling materials, Evicrol was found to produce a relatively severe irritation of the tissue. In comparison with silicate cements and also with silicopolyacrylate cement, composite materials including Evicrol were responded to by for less pronounced chronically toxic effects.

Composite Resins↗
PubMed2004

Fracture resistance of resin-based composite and ceramic inlays luted to sound human teeth.

PURPOSE: To assess the fracture resistance of resin-based composites (Zeta, Targis, Solidex,) and ceramic (Vitadur Alpha) inlays luted to extracted sound human premolars and classify their fracture modes. METHODS: 40 extracted sound human premolars were prepared to receive an indirect inlay restoration. They were divided into four different restorative materials groups as follows: Group A, Vitadur Alpha; Group B, Zeta; Group C, Targis; and Group D, Solidex. All restorations were luted with a resin luting cement (Opal). Specimens were loaded to failure in compression, and statistically analyzed (ANOVA). Fracture modes were recorded. RESULTS: There were no statistical differences among the four groups (A, 1,070 +/- 313.8 N; B, 942.4 +/- 172.4 N; C, 1,039 +/- 271.9 N; D, 1,022 +/- 186.3 N). The predominant failure mode was a severe fracture of tooth and/or restoration.

Aluminum Oxide↗
PubMed1991

Marginal leakage around V-shaped cavities restored with glass-ionomer cements: an in vitro study.

The object of this investigation was to assess the degree of marginal leakage around V-shaped cervical glass-ionomer cement restorations and compare it to that around composite resin restorations. Three different glass-ionomer cements and one composite resin control were assessed by means of dye penetration. Severe microleakage at the occlusal margins was found in 70% of the glass-ionomer cement restorations, but in only 10% of the composite resin restorations. A considerable amount of dye penetration was observed at the cervical margins of all restorations, including the controls. None of the glass-ionomer cements tested showed superiority in preventing marginal leakage occlusally or gingivally.

Bicuspid↗
PubMed1990

[Analysis of enamel thickness of anterior teeth and its relation to preparation for porcelain veneers].

The development of porcelain, acrylic and mixed crowns is not under discussion. In the same way, it should not be discussed now the evolution of silicate cements, the acrylics, the glass ionomer and the composite resins in their different techniques. We only want to analyze concisely the actual condition of the investigation and of the clinic, as regards the reconstruction with lamellas of the front part of the mouth. Lit can be deduce from the researches that the measurement of the vestibular thickness of y the enamel upon the incisives, laterals and canines specifies that: 1. As regards form, the most suitable elements for the laying of the porcelain laminate are the square, then the ovoid and finally the triangular ones. 2. The central incisives are the best; secondly the canines and then the laterals (this is directly related to the convexity of the fronts and to the amount of residual enamel). 3. It is advisable to finish the peripheric edge of the cavity 1 mm, above the anatomic neck to assure an adequate thickness of enamel in order to obtain a good adherence of the porcelain laminate veneers. 4. It is convenient to use appropriate techniques during the adamantine preparation in order to control its depth (for example diamond-like stones with ends).

Adult↗
PubMed1989

[Antimicrobial action of dental materials used in operative dentistry: a review].

This is a review of the literature about the antimicrobial action of dental materials used in operative dentistry. There are referred to the usefulness of the antimicrobial action of dental materials, and to the methods used by the investigators for the study of the antimicrobial properties. The methods used were: the examination of the in vitro antimicrobial action of the materials against several microbes, The in vivo antimicrobial action of the materials against the microbes that are enclosed underneath them in dental cavities, where some carious material was left on the floor of the cavities. Some other methods, as so as the adsorption of microbes on the experimental materials, in vivo and in vitro. There are presented the results of a lot of investigators for the antimicrobial action of dental amalgams, composite resins, silicate cements, glass-ionomer cements, zinc-phosphate, zinc oxide-eugenol and polycarboxylate cements, calcium hydroxide bases and also for varnishes and liners, since the time of Miller (1890) up to now. From these researches we can come to the following conclusions: 1) All dental materials have some antibacterial activities against several microbes when they are freshly mixed. Their action reduces with the past of time. 2) The responsible antibacterial factors are unknown. May be more than one factors. 3) In clinical practice it is not known what material is better, because the conditions are different from tooth to tooth and from mouth to mouth. 4) More researchers are necessary for this purpose because the antibacterial properties must be regarded as a part of the other biological properties of dental materials and the recurrent caries may be inhibited because of the antibacterial properties of filling and base materials.

Anti-Infective Agents↗