Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DENTAL CAVITY LINING”

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 613 records · Page 34Linked to original sources
PubMed1990

Bond strength of a light-cured and two auto-cured glass ionomer liners.

Ninety-nine extracted human molar teeth were used in this study comparing the shear bond strengths on dentine of one light-cured and two auto-cured polyalkenoate (glass ionomer) cements. Bond strength can be influenced by differences in tooth structure. A balanced-incomplete block design (Hull and Nie, 1981) was used to reduce variation attributable to such differences. Cements were applied to paired dentine surfaces in combinations such that 66 tooth sides were treated with each material. A light-cured dentinal adhesive and composite resin restorative material were then placed and shear bond strength testing was conducted exactly 24 h after the completion of each specimen. Mean forces (MPa) for the three materials were compared using an appropriate analysis of variance model (balanced-incomplete-blocks) The shear bond strengths (MPa) of the light-cured liner (Espe, Seefeld/Oberbay, FRG) was 4.71 +/- 1.16. Vitrabond showed the greatest variance of all three materials tested, however this material's average bond strength was greater than the maximum achieved for the other materials. Student-Newman-Keuls comparison of means showed that all cements differed significantly from each other (alpha = 0.05). It is concluded that the light-cured glass ionomer liner exhibited significantly better shear bond strength performance than the two auto-cured glass ionomers tested.

Analysis of Variance↗
PubMed1990

Adaptation of two different calcium hydroxide bases under a composite restoration.

A preliminary scanning electron microscope (SEM) study was carried out to investigate how the adaptation of two calcium hydroxide bases (one chemically cured, one light cured) was affected by the polymerization contraction of a supervening light-cured composite resin restoration. Occlusal cavities were prepared in 40 sound extracted human premolars, divided into two equal groups. In the first group a chemically cured calcium hydroxide (Dycal, De Trey Dentsply, Konstanz, FRG) was placed as a base. In the second group a new light-cured calcium hydroxide product (Prisma VLC Dycal, De Trey Dentsply) was used. The restorations were completed with an acid-etched, incrementally placed composite resin. The specimens were sectioned vertically and debrided. A replica was made of each half-tooth. The interfaces between composite resin/base and base/dentine were viewed and photographed in the SEM. The marginal adaptation at these two interfaces was classified into three categories according to the extent of the gaps that were observed. Prisma VLC Dycal base was found to be pulled away from the dentine floor of the cavity as a result of an apparent adhesion to the composite resin during polymerization contraction. Dycal was better adapted to the cavity floor than Prisma VLC Dycal. Disorganization of the resin-bonded Prisma VLC Dycal was minimal even after acid etching the enamel, sectioning and ultrasonic debridement. Dycal appeared to be more friable, and occasionally exhibited marked disorganization as a result of these procedures.

Acid Etching, Dental↗
PubMed1990

In vitro marginal microleakage: examination of measurements used in assessment.

Premolar teeth with Class II amalgam restorations placed after the application of cavity varnish (Group A), a light cured glass ionomer base (Group B) and 40 per cent polyacrylic acid as a pretreatment agent, followed by unset cermet cement (Group C) were examined for marginal leakage using dye penetration and image analysis. Including amongst the parameters examined were linear leakage length and leakage area, which were found to have no consistent correlation. Group A and C did not generally show significant differences in the parameters examined, whereas Group B exhibited significantly less linear leakage (P less than 0.001), and significantly less leakage area when the stained area was expressed as a percentage of available dentine (P less than 0.001). While allowing some linear leakage, it was found that the light cured glass ionomer base appeared to prevent the dye from entering the dentine. It is concluded that an assessment based solely on the leakage length is inadequate and that some measurement of penetration into dentine should be included in order to fully assess the microleakage potential of a material or technique.

Acid Etching, Dental↗
PubMed1992

Microleakage of three generically different fluoride-releasing liner/bases.

Three generically different fluoride-releasing materials that function as a liner or base were assessed for their microleakage performance on enamel and dentine. Group 1 (light-cured liner/base) showed much more leakage, but less bulk absorption of tracer, than Group 2 (traditional glass ionomer) or Group 3 (light-cured glass ionomer). The response of the three materials to tracer penetration was consistent with what is known about their chemistry. The Group 2 and 3 materials are probably the materials of choice at the caries-vulnerable margins, which are not easily visible for inspection.

Acid Etching, Dental↗
PubMed1992

Evaluation of the interactions between amalgam, cement and gold castings.

The purpose of this study was to determine the interactive effects between a dental amalgam, cements and a gold alloy and therefore evaluate cements as barriers to corrosion. There were 48 castings cemented to either simulated amalgam cores or teeth using zinc phosphate (ZnPO4) or glass polyalkenoate (ionomer) cement. An additional 12 castings were placed in direct contact with the amalgam restoration. Half of the specimens were thermocycled between 5 degrees and 50 degrees C for 12 weeks. The other half were stored at 37 degrees C for the same period of time. The specimens were then encased in epoxy resin and sectioned. The sectioned specimens were examined for cement loss, as well as evidence and extent of corrosion. Significantly more cement loss occurred with the ZnPO4 compared with the glass polyalkenoate (ionomer) cement when the castings were cemented to amalgam cores. Evidence of corrosion was apparent in all specimens; thermocycling produced significantly more corrosion than the 37 degrees C environment. The direct-contact group produced significantly more corrosion compared with the specimens where castings were cemented with ZnPO4.

Corrosion↗
PubMed1993

Change in pH during setting of polyelectrolyte dental cements.

The change in pH during setting has been studied for five different glass polyalkenoate (ionomer) cements and for two different zinc polycarboxylate cements using a flat-headed combination electrode on both the fresh cement and on a slurry of the set cement. The results show that the pH of the glass ionomers was slightly lower in the early stages of setting than was the pH of the zinc polycarboxylates and also that the pH of glass ionomers rises more slowly. For anhydrous cements (i.e. those formulated from dried polymer) pH was found to rise quicker than for hydrous cements (i.e. those prepared from aqueous solutions of polymer). Previous workers have assumed that anhydrous cements undergo slower rises in pH than hydrous ones. Our results clearly refute this assumption, and also suggest that the reported pulpal irritation associated with the use of anhydrous glass ionomers may be due to something other than low pH.

Acrylic Resins↗
PubMed1995

Thermographic measurement of temperature change during resin composite polymerization in vivo.

OBJECTIVES: To use the technique of infrared thermography for non-invasive monitoring of temperature changes during polymerization of resin composite by measuring the infra-red emission from the surfaces of resin composite restorations during photocuring. METHODS: In this study 10 patient volunteers had resin composite restorations placed in upper incisor teeth and during photocuring the temperature rise within the composite was measured using the Thermovision 900 infra-red scanning system. RESULTS: The results demonstrate that the exotherm is almost instantaneous, occurring as soon as the light source is activated and rising to a peak at approximately 30 s before levelling off. The measurements suggest that a maximum temperature increase of 12 degrees C could occur, although this may only be for a short period (< 15 s). CONCLUSION: The range of temperature rise measured in this study (mean 5.4 degree C +/- 2.5 degree C) would suggest that the pulp may be endangered by the temperature rise which occurs during resin composite polymerization in vivo.

Composite Resins↗
PubMed2006

A retrospective clinical study on longevity of posterior composite and amalgam restorations.

OBJECTIVES: The purpose of this study was to evaluate retrospectively the longevity of class I and II amalgam and composite resin restorations placed in a general practice. METHODS: Patient records of a general practice were used for collecting the data for this study. From the files longevity and reasons for failure of 2867 class I and II amalgam and composite resin restorations placed in 621 patients by two operators between 1990 and 1997 were recorded in 2002. RESULTS: 912 amalgam restorations (502 by operator 1 and 410 by operator 2) and 1955 posterior composite resin restorations (1470 by operator 1 and 485 by operator 2) were placed. One hundred and eighty-two amalgam and 259 posterior composite resin restorations failed during the observation period. The main reasons for failure of the restorations were caries (34%), endodontic treatment (12%) and fracture of the tooth (13%). Life tables calculated from the data reveal a survival for composite resin of 91.7% at 5 years and 82.2% at 10 years. For amalgam the survival is 89.6% at 5 years and 79.2% at 10 years. Cox-regression analysis resulted in a significant effect of the amount of restored surfaces on the survival of the restorations. No significant effect of operator, material as well as combination of material and operator was found. SIGNIFICANCE: In the investigated general practice, two dentists obtained comparable longevity for amalgam and composite resin restorations.

Acid Etching, Dental↗
PubMed2004

In vitro microleakage of adhesive-sealed dentin with lactic acid and saliva exposure: a radio-isotope analysis.

OBJECTIVES: The aim of this study was to evaluate the dentin-protective potential of two dentin-bonding systems (Syntac and Clearfil SE Bond) on artificial saliva and lactic acid exposure. METHODS: Radiochemical analysis in combination with polarization-microscopy was used in the current study. Different applications in MOD preparations in irradiated human molars were compared. Untreated cavities and cavities covered with flowable resin served as controls. Forty-eight specimens were immersed in artificial saliva (pH 7.5), 48 in lactic acid (pH 4). Activity of (32)P was measured between days 1 and 21 and loss of mineralized tissue was estimated. RESULTS: In lactic acid, cavities sealed with single bond, double bond or bond plus cavity sealer application resulted in significantly lower mineralized tissue loss compared to negative controls (p < 0.05). Upon both saliva and lactic acid exposure, bonding plus sealer application proved to be the most protective treatment (p < 0.05). CONCLUSIONS: Based on these in vitro findings it may be advisable to use a filled cavity sealer or a flowable resin to protect dentin from demineralization. The radiochemical analysis appeared to be valuable in evaluating the protective potential of bonding agents against dentin demineralization.

Acid Etching, Dental↗
PubMed2005

Long-term monitoring of microleakage of different amalgams with different liners.

STATEMENT OF PROBLEM: Microleakage is a major factor contributing to the occurrence of secondary caries around amalgam restorations. Purpose The purpose of this study was to evaluate the effect of amalgam type, liner type, and storage period on microleakage. MATERIAL AND METHODS: Two hundred seventy bovine incisors were divided into 18 groups (n = 15). Two high-copper amalgam alloys (admixed and spherical type) and 3 liner options (no liner, varnish, and adhesive) were used to restore Class V preparations. After placement of restorations, the teeth were stored for 3 different periods (1 day, 1 week, and 12 months) in saline solution, After storage, the specimens were immersed in 0.5% methylene blue for 24 hours, sectioned, and then mean depth of dye penetration was measured separately for the incisal and cervical areas with the use of a binocular microscope (x200). Scores were assigned to a millimeter scale (+/- 0.2 mm). The data were analyzed with a 3-way analysis of variance and the Tukey Honestly Significant Different test (alpha = .05). RESULTS: The 3-way interaction was significant (P < .001 for the cervical and occlusal margins). After short-term storage (1 day and 1 week), the admixed alloy showed significantly lower leakage values than the spherical alloy only in cervical margins (1.45 and 1.56 for the admixed and 1.62 and 1.50 for the spherical alloy at the cervical [P = .034] and incisal margins [P = .702]), respectively. After 12 months, values decreased significantly for both amalgams, which were similar and lower than for the short-term storage period (short-term values of 1.62 and 1.39 for the admixed and 1.69 and 1.46 for the spherical alloy at the cervical and incisal margins, respectively; long-term values of 0.22 and 0.20 for the admixed and 0.33 and 0.36 for the spherical alloy at the cervical and incisal margins, respectively [P < .019]). When the adhesive was used, significantly superior sealing was observed for both amalgams. For the no liner and cavity varnish groups, the admixed alloy showed superior performance compared to the spherical alloy (with no liner, 1.11 and 0.98 for the admixed and 0.83 and 1.08 for the spherical alloy at the cervical and incisal margins, respectively; with varnish, 1.19 and 1.22 for the admixed and 1.63 and 1.34 for the spherical alloy, at the cervical and incisal margins, respectively [P < .037]). CONCLUSION: In the short-term, the lowest degree of leakage was found when adhesive was used. After 1 year, no differences were detected, regardless of the amalgam type and liner used.

Analysis of Variance↗
PubMed1991

Leakage of a light-activated base: effect of dentin bonding agents.

This study investigated the sealing properties of Cavalite light-activated base material in conjunction with various dentin bonding agents. Thirty extracted molars were selected and cleaned. Slot preparations with standard dimensions were made. The prepared cavities were filled with Cavalite material after application of the dentin bonding agents Gluma, Prisma Universal Bond, Scotchbond 2, and Tenure. Samples were thermocycled for 180 cycles between 3 degrees C and 60 degrees C, then immersed in 0.05% crystal violet solution for 2 hours. The samples were embedded in clear casting resin, sectioned, and examined with a light microscope. Results indicated that Cavalite material used alone, without a dentin bonding agent, allowed the greatest degree of dye penetration. Cavalite material with Tenure bonding agent had the lowest degree of leakage. Cavalite material used with Scotchbond 2, Gluma, or Prisma Universal Bond bonding agents allowed an intermediate degree of dye penetration. According to an analysis of variance, however, there was no statistical difference in the effects of Tenure, Scotchbond 2, and Gluma bonding agents.

Acrylic Resins↗
PubMed1995

Effect of dimension of luting space and luting composite on marginal adaptation of a class II ceramic inlay.

This study evaluated the in vitro marginal quality at the interproximal cervical margin of class II Cerec restorations. Marginal quality was evaluated separately by (1) SEM analysis before and after simultaneous thermocycling and mechanical loading for the integrity of the restoration surface and (2) dye penetration after thermocycling and mechanical loading to evaluate the strength of the bond within the depth of the cavity. The results reveal that marginal integrity is influenced by the width of the luting space and the luting composite. With a luting space of 100 microns, marginal quality with as little as 3% to 14% loss of adhesion can be obtained. Luting spaces greater than 100 microns can partially be compensated by the luting composite. For Cerec inlays, highly filled luting composites with a high viscosity are recommended.

Adhesiveness↗
PubMed1997

Facial approach to stabilization of mobile maxillary anterior teeth with steep vertical overlap and occlusal trauma.

The necessity for splinting and the advantages of some types of permanent, semipermanent, and temporary splinting are given. Specific step-by-step instructions are given for a special purpose splint that can be used for stabilizing mobile maxillary teeth when the patient has thin teeth faciolingually and a steep vertical overlap. This can be the treatment of choice for such patients.

Acid Etching, Dental↗