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 631 records · Page 35Linked to original sources
PubMed1997

Influence of adhesive systems on the bonding of dental amalgam to glass ionomer cement.

STATEMENT OF PROBLEM: Dental amalgam restorations have traditionally been retained in cavity preparations by surgical procedures called retention form. In this procedure healthy dental structure is usually removed to create adequate retention. The increasing use of bonding systems for restorative procedures may result in more conservative cavity preparations. PURPOSE: The purpose of this study was to evaluate the tensile bond strength of the amalgam to glass ionomer cement under the influence of three adhesive systems (Panavia-EX, Vidrion F fresh mix, and Alpha Seal). MATERIAL AND METHODS: The bonded assemblies were stored in an environment of 100% relative humidity and 37 degrees C for 24-hour and 30-day storage periods. The test specimen was loaded in tension to failure on a universal testing machine with a crosshead speed of 6 mm/min. RESULTS: The results revealed that in the 24-hour period without acid etch fresh Vidrion F and Panavia Ex adhesives were stronger than autopolymerizing sealant. Panavia Ex adhesive was stronger in the 24-hour period with acid etch. CONCLUSIONS: The 30-day period with acid etch revealed no statistical difference among the adhesives. In the 30-day period without acid etch, the fresh Vidrion F adhesive recorded the greatest tensile bond strength.

Adhesives↗
PubMed1998

Long-term monitoring of microleakage of cavity varnish and adhesive resin with amalgam.

STATEMENT OF PROBLEM: The penetration of oral fluids and bacteria at the interface between the cavity walls and amalgam restorations, which is known as marginal leakage, is one of the problems facing restorative dentistry today. This may cause secondary caries and the irritation of the pulp. PURPOSE: This in vitro study tested and compared the sealing ability of a cavity varnish and a dental adhesive for decreasing the marginal leakage of high copper amalgam fillings by chemical diffusion technique. MATERIAL AND METHODS: The samples were randomly divided into three groups. The cavities in the first group were filled with high copper amalgam. In the second and third groups, the cavities were treated with Copalite and Panavia EX adhesives, respectively, before the amalgam fillings were performed. After the periods of 2 hours, 48 hours, 1 week, and 1.5 and 6 months, the amount of calcium diffused through the interface area into the deionized water was measured with inductively coupled plasma. RESULTS: Six-month results revealed that using a dental adhesive as an interfacial sealer had significant advantages to reduce microleakage when compared with a conventional copal varnish.

Analysis of Variance↗
PubMed1999

Surface quality achieved by polishing and by varnishing of temporary crown and fixed partial denture resins.

STATEMENT OF PROBLEM: Studies have suggested that coating a temporary restoration with varnish material could replace time-consuming polishing procedures needed for achieving an optimally smooth surface. PURPOSE: This study examined the surface roughness of acrylic resins after having been polished or coated with different varnish materials. MATERIAL AND METHODS: A total of 360 cylindrical specimens were fabricated from 9 brands of resin. One surface on each specimen was machined flat and subsequently either polished with rubber polishers or coated with 1 of 9 varnishes. Selected specimens were subjected to thermal cycling (5 degrees C to 55 degrees C, 2000 cycles). Surface quality was assessed by means of a profilometer and by SEM examination. RESULTS: Polished specimens had average surface roughness values (Ra) of 0.8 microm; differences in roughness between materials were small, but statistically significant. Type of coating had a significant influence on surface quality. Depending on the combination of materials used, the coating produced both smoother and rougher surfaces than polishing (0.4 microm < Ra < 4.6 microm). Five coatings were deemed not to be clinically applicable because of poor wetting properties. Thermal cycling did not significantly influence surface quality, but caused minute cracks in the cyanoacrylate coating. CONCLUSION: In regard to surface quality and applicability, the use of varnishes on temporary restorations is not advisable.

Acrylic Resins↗
PubMed1994

Microleakage of retrograde root fillings: assessment using a novel measurement system.

In the past, measurement of microleakage has been based on measurement of dye or radioactive isotope penetration. A method has been developed to allow electronic monitoring of microflow in the same specimen over a period of time. This method was used to compare previously reported retrograde materials with an amalgam/sealer combination. The material that performed best was amalgam/sealer, particularly in the first week. The role of cavity varnish in limiting leakage has been controversial, and the results in the present study do not indicate any significant benefit. The range of leakage measured for specimens in the same group suggests that in vivo the expected leakage could be considerable for the materials tested and that small differences in experimental leakage between groups may not have any practical significance.

Calcium Sulfate↗
PubMed1994

Influence of a base on coronal microleakage of post-prepared teeth.

This study compared the coronal microleakage of post-prepared teeth with and without the placement of a zinc oxide-eugenol cement seal coronal to the gutta-percha. Forty single-rooted extracted teeth were prepared and obturated with sealer and gutta-percha. These teeth were divided into two groups of teeth 20 each. A post space was prepared for each tooth so that 5 to 6 mm of gutta-percha remained in one group and 3 to 4 mm in the other group. To the latter group, 2 to 3 mm of zinc oxide-eugenol cement base was placed directly coronal to the gutta-percha. The sealer was allowed to set for 48 h and the outer root surfaces of the teeth were covered with finger nail varnish and sticky wax, except for the access openings. The teeth were immersed in dye for 1 wk to allow coronal microleakage. The specimens were sectioned and measurements were made on the extent of dye penetration into the root filling. The teeth without a zinc oxide-eugenol base showed significantly greater microleakage than those protected with a zinc oxide-eugenol base.

Dental Cavity Lining↗
PubMed1992

Comparison of apical leakage in teeth obturated with a polyamide varnish or zinc oxide and eugenol cement using lateral condensation.

The sealing ability of copal varnish has been investigated when used as an adjunct in restorative procedures, retrofilling procedures, and dontic obturation procedures. Barrier, a polyamide-type polymer cavity varnish, has been compared with copal varnishes in restorative dentistry. This investigation compared the apical sealing properties of a zinc oxide and eugenol sealer (Roth) with a polyamide varnish (Barrier). Twenty-four teeth were instrumented and divided into two groups, one obturated with gutta-percha and Roth sealer and one with gutta-percha and Barrier, using submersion in methylene blue dye to demonstrate apical leakage. Roth sealer exhibited less dye penetration than Barrier when used as an endodontic sealant (p < 0.02).

Dental Cavity Lining↗
PubMed1990

Periapical tissue response to two calcium hydroxide-containing endodontic sealers.

One-hundred twenty root canals of dog teeth were cleaned, shaped, and obturated with gutta-percha and sealers using a lateral condensation technique. The sealers used were Sealapex, CRCS, and zinc oxide-eugenol. The animals were killed after 30 or 180 days and the specimens were examined histologically. Sealapex and CRCS caused a periapical tissue response similar to that found with the zinc oxide-eugenol. An ingrowth of connective tissue infiltrated with chronic inflammatory cells was noticed in cases where the filling material reached the apical stops. Regardless of sealer used, deposition of new hard tissue along the apical root canal walls was observed, which caused the partial closure of the apical opening. In the Sealapex and CRCS groups, sealer particles were found at a considerable distance from the apices. All overfilled specimens caused chronic inflammatory reactions in the periapical tissues.

Animals↗
PubMed1991

A 24-week study of the microleakage of four retrofilling materials using a fluid filtration method.

The microleakage after retrofillings of amalgam, amalgam with cavity varnish, silver-containing glass ionomer cement, and intermediate restorative material was compared in vitro. Thirty-six extracted human incisors and canines were instrumented, obturated with gutta-percha without sealer, subjected to apicoectomy, and retrofilled with the materials described above. After removal of the gutta-percha filling, the microleakage from both directions (apically and coronally) was measured quantitatively and longitudinally for 24 wk after filling by a fluid filtration technique. All four retrofilling materials revealed some apical and coronal leakage at all time periods. The amalgam group showed statistically significant (p less than 0.001) apical leakage at 1.5 h. The use of cavity varnish significantly reduced the apical leakage of the amalgam group at 1.5 h. The silver-containing glass ionomer cement and intermediate restorative material groups showed significantly (p less than 0.05) less coronal leakage compared with the amalgam group at 1.5 h. Scanning electron microscopy of selected samples showed marginal defects of approximately 5 microns between the root dentin and the retrofilling material.

Cermet Cements↗
PubMed1989

The effect of newly developed root canal sealers on rat dental pulp cells in primary culture.

Cytotoxicity was compared between new root canal sealers (New A, New B, and New B-2) and conventional root canal sealers (AH26, Diaket, Canals, Tubi-Seal, and Sealapex). Dental pulp cells of rats, obtained through primary cell culture, were used. In the experiments with the freshly prepared sealers, the incorporation of [3H]thymidine into cellular DNA was analyzed. In the experiments with the set sealers, the morphological changes of cells were microscopically examined. In the experiments with the fresh sealers, AH26 and Diaket showed strong inhibitive effects on the DNA synthesis, whereas no such effects were noted with the new sealers and Sealapex. On the other hand, in the experiments with the set sealers, the new sealers and Diaket exerted little influence on the cells. However, other sealers had considerable toxicity. These results suggest that the new sealers were the least toxic in vitro, compared with five conventional sealers.

Animals↗
PubMed1989

A dye penetration study of retrofilling materials.

The apical sealing ability of amalgam, cold-burnished gutta-percha, amalgam with cavity varnish, and SuperEBA cement was evaluated in extracted human teeth. For each experimental group, the roots of 20 single-rooted teeth were sectioned from their crowns. Canals were cleaned, shaped, and obturated with vertically condensed warmed gutta-percha and Kerr Pulp Canal Sealer. Following apical preparation and placement of test materials, root ends were placed in 1% methylene blue dye for 2 wk, after which the roots were sectioned longitudinally, and linear measurements of dye penetration were recorded. Results demonstrated statistically less linear dye penetration in the test group sealed with amalgam and cavity varnish. Statistical differences were not detected among the other test groups.

Dental Amalgam↗
PubMed1989

Experimental bacterial anachoresis in dog dental pulps capped with calcium hydroxide.

The pulps of 36 permanent dog teeth were mechanically exposed and capped with Dycal, calcium hydroxide powder mixed with saline, or Teflon. At 2, 14, and 28 days postoperatively, nine teeth treated with the materials were extracted (treated control teeth): A suspension of streptococci was then injected intravenously. Twenty-four h later the dogs were killed and both the 27 treated teeth (experimental group) and 6 unoperated control teeth were removed in tissue blocks. Tissue sections were examined for the presence of bacteria, hard tissue formation, inflammatory cell response and necrosis. Bacteria were not observed in the unoperated and treated control teeth or in three of four teeth capped with Teflon for 29 days. In all the remaining specimens colonies of gram-positive cocci were found.

Animals↗
PubMed1989

Permeability of apical barriers.

The purpose of this work was to measure the permeability (hydraulic conductance) of root canal apical barriers in vitro. In 30 extracted teeth, the pulp tissue was removed and the apical opening standardized and enlarged using endodontic files. One-millimeter thick barriers of either autogenous dentin chips, calcium hydroxide powder, or durapatite particles were placed just inside the apical opening. The prepared teeth were mounted in a special chamber, fluid pressure applied, and the resultant flow measured. The permeability of dentin chip barriers in 10 additional teeth with nonstandardized apical openings was measured also. The standardized canals with the autogenous dentin chip barriers had a mean permeability of 0.0010 microliter/s/psi at 20 psi applied pressure. Teeth with calcium hydroxide barriers averaged 0.0012 microliter/s/psi. The durapatite particle barriers were much more permeable and averaged 0.0220 microliter/s/psi. It was concluded that this technique is useful in evaluating the effectiveness of apical barrier materials. For the materials tested, autogenous dentin chips and calcium hydroxide barriers have significantly lower permeability than durapatite barriers (p = 0.05).

Calcium Hydroxide↗
PubMed1996

Evaluation of coronal microleakage after endodontic treatment.

A new method is suggested for placing a coronal seal in the orifice of the root canal right after root canal therapy. Root canal therapy was done on 94 extracted human maxillary centrals. Three mm of the coronal gutta-percha was replaced by either Cavit, TERM, or amalgam with cavity varnish. After thermocycling and 2 wk of immersion in dye, the amount of dye penetration was measured. The results showed that amalgam with two coats of cavity varnish sealed significantly better than Cavit and TERM. However, Cavit and TERM were still significantly better than a positive control group.

Calcium Sulfate↗
PubMed1991

In vitro microleakage associated with posterior composite restorations used with different base/bonding system combinations.

The study aimed to determine the base/restoration combination which allowed the least microleakage in Class II cavities. One hundred premolar teeth were prepared with a standardized, minimal two-surface cavity and randomly ascribed to ten equal groups. The cavities were restored by use of one of ten different material/technique combinations. Restored teeth were sealed to within 1 mm of the restoration margins with nail varnish prior to the immersion of the crowns in 5% (buffered) eosin for 48 h. The teeth were then hemisected longitudinally, in a mesio-distal plane, through the midline of the restoration by means of a diamond disc with water coolant, and one half of each tooth was then photographed. The transparencies were examined by image analysis programmed to facilitate calculation of the percentage of the tooth/restoration interface and of the crown dentin exhibiting dye penetration. Light- and chemically-cured glass-ionomer-based restorations showed similar amounts of leakage when expressed as a percentage area of crown dentin. This was significantly (p less than 0.05) less than that shown by cavities both etched and bonded. Cavities restored without enamel etching or involving the use of a bonding system exhibited significantly (p less than 0.05) greatest leakage.

Acid Etching, Dental↗