PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “DENTAL CAVITY LINING”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 73 records · Page 4Linked to original sources
PubMed1979

Reflectance spectra of composite resins on liners.

The reflectance spectra of two types of composite resins were determined on various backgrounds. It was found that the shade differences caused by different "whitish" liners were perceptible only for thin resin specimens and were smaller than those caused by varying the resin type and thickness. Employing a light brown liner gave rise to a difference in shade which was also perceptible on resin specimens of 2.5 mm thickness. Shade differences due to varying the thickness of the specimens were more pronounced on white than on black backgrounds. The clinical significance and the qualitative physical interpretation of the results were discussed.

Calcium Hydroxide↗
PubMed1981

Microleakage of composite resin inserted over an experimental liner: a laboratory study.

The purpose of this study was to evaluate, in the laboratory, marginal leakage of an experimental liner that expands upon setting. The expansion could be effective in minimizing leakage of the composite materials due to polymerization shrinkage. The expansion appeared to affect leakage only some of the restorations. Large restorations apparently have too great a bulk of composite resin to be affected by the expansion of the experimental liner. It is recommended that an acid-etch/unfilled resin system be used in conjunction with the experimental liner to minimize leakage.

Calcium Hydroxide↗
PubMed1990

Microleakage of extended and nonextended Class I composite resin and sealant restorations.

Favorable results of composite resin sealant restorations in narrow occlusal cavities raise the question of whether extended cavity preparation is justified. Larger restorations are subject to increased polymerization shrinkage. Microleakage of extended and nonextended composite resin sealant restorations was tested in this study. Forty extracted caries-free third molars were allocated to four experimental groups. Occlusal cavity preparations were prepared, varying from narrow cavities restricted to the central fossa to preparations eradicating all fissures. Composite resin restorations were inserted with or without a base and with or without a sealant. Control restorations were inserted in nonetched preparations. Microleakage occurred when cavities were not etched and occassionally when a sealant was not applied. Conclusions indicate that a class I composite resin restoration extended beyond the central fossa can be free of microleakage if covered with a fissure sealant.

Acid Etching, Dental↗
PubMed1991

Pulpal response to chemically cured and experimental light-cured glass ionomer cavity liners.

This investigation evaluated the effects of an experimental light-cured glass ionomer (LCGI) cavity liner and chemically cured Ketac-Bond glass ionomer restorative material on the pulpal tissues of monkeys. Class V cavities were prepared in 71 teeth of three adult Macaca mulatta monkeys at 7- and 35-day intervals. Ketac-Bond or LCGI cavity liners were placed in cavities with the smear layer intact (groups I and II) or with the smear layer removed (groups III and IV) and were restored with composite resin. Tissues were acquired, sectioned at 7 microns, stained for microscopic evaluation, or prepared for SEM evaluation. No statistically significant differences between materials existed at either time interval, regardless of smear layer presence. Histopathologic results demonstrated minimal pulpal reactions for groups I through IV. SEM analysis showed tenacious bonding of the LCGI material to prepared cavity walls, with absence of contraction gap formation. The results indicated excellent pulpal responses to both materials.

Acid Etching, Dental↗
PubMed1992

Effect of glass ionomer liners on bonding strength of laminate veneers.

This study compared shear bond strengths of porcelain laminate veneers, fabricated on refractory dies, which were lengthened incisally by 0.5 mm. Specimens were divided into four separate groups. In group A, the teeth were reduced 0.5 mm and the bonding was to enamel. The teeth of the remaining groups were reduced 1.0 mm and the bonding was to dentin. For two of the groups glass ionomer liners were applied before etching. Bonding to enamel was best, with cohesive fractures in porcelain. In the other groups, failure was adhesive in nature, occurring at the resin-tooth interface.

Composite Resins↗
PubMed1993

Saucer-shaped cavity preparation for composite resin restorations in class II carious lesions: three-year results.

This study determined the feasibility of saucer-shaped cavity preparations for composite resins in class II lesions. Saucer-shaped class II cavity preparations were restored with composite resin and subjected to clinical, radiographic, and replica cast evaluation (39 restorations) after 6, 18, and 36 months. The results indicated that the retention, resistance form, and wear resistance of the class II saucer-shaped cavity preparations were satisfactory after 3 years.

Acid Etching, Dental↗
PubMed1982

Pulpal effects of electrosurgery involving based and unbased cervical amalgam restorations.

The pulpal effects of electrosurgery involving unrestored enamel, cementum, calcium hydroxide-copal varnish-based restorations and unbased restorations were evaluated in extracted human teeth and posterior teeth of cynomolgus monkeys. Electrosurgery for all studies was performed with a fully rectified filtered unit under conditions of normal clinical usage. Studies in extracted human teeth measured the voltage potential generated between a reference probe in apical pulp tissue and an activated electrosurgery electrode placed on enamel, cementum, based restorations, and unbased restorations. Placement of a base reduced but did not prevent passage of electrosurgical current, and no measurable potential was associated with activated electrode contact on cementum or enamel. Studies in three cynomolgus monkeys included electrosurgery of based and unbased cervical silver amalgam restorations, electrosurgery of unrestored enamel, restored teeth not subjected to electrosurgery and teeth that were neither restored nor subjected to electrosurgery. Electrosurgery of restored teeth, regardless of the presence of a base, consistently resulted in pulpal damage characterized by an altered dentin matrix, necrosis adjacent to the cavity preparation, and a transition zone between necrotic and apparently vital pulp tissue. By 8 weeks following electrosurgery, the majority of specimens showed replacement of the odontoblastic layer and adjacent pulp tissue by dense connective tissue with areas of irregular calcification.

Animals↗
PubMed1985

Tooth discoloration induced by dental materials.

Tooth discoloration after endodontic treatment is frequently attributed to drugs and filling materials. In this in vitro study the staining potential of various dental materials was investigated by means of a visual method to determine tooth color. Extracted human premolars were prepared, and the following materials were introduced into the pulp cavities: Cavit, Durelon, Dycal, Fletcher's cement, IRM, AH26-silver free, gutta-percha, Duo Percha, Fuji ionomer, and zinc phosphate cement. Before the materials were applied, the original tooth color was assessed on the external buccal tooth surfaces. Further color determinations were undertaken at regular intervals for 6 months after the materials were introduced. Durelon, Fuji ionomer, Fletcher's cement, and zinc phosphate cement did not induce measurable tooth discoloration. Cavit, Dycal, gutta-percha, and IRM caused a mild stain. For the teeth filled with AH26-silver free and Duo Percha, a moderate discoloration was recorded.

Color↗
PubMed1991

Marginal adaptation of Class V restorations using different restorative techniques.

This in vitro study compares the marginal adaptation of Class V restorations with margins located half in enamel and half in dentine, which were placed using different restorative techniques. Five operative procedures were evaluated both in saucer-shaped erosion lesions and in box-shaped cavities with bevels in enamel. The five procedures included a composite inlay technique using both the chemically and the light curing versions of a resin based composite cement, a bulk placement technique using a chemically curing composite resin, an incremental technique and an incremental technique combined with a built-up base, using a light curing composite resin. A combination of Gluma/Clearfil served as the dentinal adhesive. The micromorphology of the tooth/restoration interface was analysed before and after thermal cycling; the marginal seal was analysed after thermal cycling only. In the conventional cavities, the restorations showed less leakage, and micromorphologically a better, but statistically insignificant superior marginal adaptation. The inlay technique rendered the best marginal quality in both enamel and dentine before and after thermal cycling. Due to the unique curing characteristics of the chemically cured composite resin and cement resulting in a significantly reduced rigid contraction, the inlays cemented with the chemically curing cement and the restorations placed with the chemically curing composite resin were superior to their light cured counterparts. The built-up base yielding a reduction of the composite mass did not enhance marginal adaptation because of the partial replacement of the strong adhesion to dentine mediated by the Gluma/Clearfil combination by the weaker bond promoted by the etched glass ionomer cement.

Acid Etching, Dental↗
PubMed1992

In vitro evaluation of two microleakage detection tests.

Two microleakage detection tests were evaluated to compare their capabilities for revealing the extent of leakage at the interface between amalgam restorations and tooth structure. Class V cavities were prepared in the buccal surfaces of extracted human canine and premolar teeth and were treated in one of the following ways: no liner or varnish, a copal varnish, or an adhesive resin liner. The cavities were restored with a high-copper single composition spherical amalgam alloy and the specimens thermally cycled. Following storage for 6 months, the teeth were exposed to separate solutions of 45Ca and an ultraviolet fluorescing dye. The teeth were hemisected longitudinally and leakage was evaluated by determining the degree of penetration of the two tracers at the occlusal and gingival margins. Statistical analysis revealed a significant difference between the two leakage techniques (P less than 0.05). The radioisotope test generally indicated a greater degree of leakage than did the ultraviolet dye test.

Acid Etching, Dental↗
PubMed1993

Comparison of the marginal integrity of in vivo and in vitro Class II composite restorations.

In the present study Class II resin composite restorations were placed under in vivo and in vitro conditions. For the in vivo part. Class II preparations were cut in teeth destined for extraction for orthodontic reasons. The preparations were completed with the gingival margin in enamel and restored using six different combinations restorative techniques and materials. The teeth were extracted after 4-6 weeks. In the in vitro part similar preparations were cut in extracted teeth and restored using the selected material-technique combinations. The in vitro specimens were thermocycled and mechanically loaded at 125 N for a total of 4000 cycles. All in vivo and in vitro samples were stored in a dye solution, sectioned and inspected for microleakage. Microleakage was observed in all the in vivo specimens with only 60% of the in vitro specimens demonstrating microleakage. These results indicate the limitation of laboratory investigations in predicting the microleakage performance of Class II composite resin restorations under clinical circumstances.

Acid Etching, Dental↗
PubMed1993

Marginal adaptation.

A critical review of studies assessing the marginal adaptation of direct placement, plastic restorations is presented. The effects upon adaptation of cavity design and location of cavity margins are examined, together with the effects of differing placement and finishing techniques. Both the choice of restorative material and the use of liners/bases are shown to influence the quality of restoration margins. Techniques used in both in vivo and in vitro assessment are reviewed, however it appears that a wide variety of methodologies exist and the establishment of standard, published criteria for the qualitative assessment of marginal adaptation is recommended.

Composite Resins↗