Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tooth Preparation”

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 541 records · Page 30Linked to original sources
PubMed1986

Etched-metal resin-bonded intracoronal cast restorations. Part I: The attachment mechanism.

Numerous attempts have been made to increase the adhesive qualities of the luting medium. Investigators have attempted to modify the metal surface, the tooth surface, the luting material, or combinations. Although investigations have achieved limited success, the adhesive cement remains an elusive goal of restorative dentistry. This article described the etched-metal attachment mechanism as an intermediate phase between luting medium and adhesive medium. However the bond of the resin to the etched enamel and etched metal is not adhesion. Nevertheless, the continuity and microscopic dimension of the mechanical bond mimics the adhesion desired. Until that adhesive material is developed, the bonding mechanism will serve as an effective substitute. The attachment mechanism described is the basis for an improved restoration. Resin-bonded retention can compensate for insufficient frictional retention or may completely substitute for frictional retention prescribed in a resin-bonded retainer prosthesis. Etched-metal procedures for intracoronal restorations permits conservative tooth preparation, greater retention, and improved support of remaining cusps.

Acid Etching, Dental↗
PubMed1986

Tissue retraction for esthetic ceramometal crowns.

The placement of subgingival margins in ceramometal restorations has been discussed. A method of visualizing the attachment and managing the gingival tissues during tooth preparation has been presented.

Crowns↗
PubMed1987

A study of bubbles in a rubber elastomer manipulated under clinical conditions.

One hundred addition reaction silicone impressions were made by students and faculty members using two types of syringes with two syringe tip sizes. A count of the bubbles in the impressions revealed a total of 439 with only one impression completely free of bubbles in either the posterior or anterior test regions. Faculty members, presumably more experienced, confirmed the last out-fewer bubbles hypothesis developed in a previous laboratory investigation, but some students did not. A pneumatically activated syringe produced no fewer bubbles than did the conventional hand-powered syringe but most of the students and faculty members thought it was advantageous. Half believed that more practice with it would be beneficial. We recommend that practicing dentists try to minimize bubbles by extruding the first part of the syringe contents onto the mixing pad or in a distant intraoral location before injecting around the critical tooth preparations.

Air↗
PubMed1989

A comparative study of the strength of aluminous porcelain and all-ceramic crowns.

This study compared the breaking strengths of all-ceramic crowns constructed with aluminous porcelain, the Cerestore system, and the Dicor system on an anterior tooth preparation. Fifteen crowns from each group were constructed to comparable dimensions on dies from the same master die. Ten crowns from the same group were cemented on the master die and loaded until catastrophic failure. Five crowns from each group were embedded and sectioned to examine internal adaptation. No significant difference was found between the load necessary to produce failure in the aluminous porcelain and Dicor crowns and the load needed to initiate crack formation in the Cerestore crowns. However, seven of the 10 Cerestore crowns showed a two-phase failure pattern; the difference between crack initiation and catastrophic failure was significant. Within the limitation of this study, neither the Cerestore (high alumina core) nor the Dicor (castable glass-ceramic) produced an all-ceramic crown superior to the current aluminous porcelain crown.

Aluminum↗
PubMed1989

The laminar impression technique.

The laminar impression technique is a precise, rapid, and predictable alternative to traditional methods of impression-making in fixed prosthodontics. A preliminary impression is made using plastic "triple-arch" type trays and high-stiffness vinyl polysiloxane jaw relation registration material. After tooth preparation, tissue management, and retraction this registration can be used for provisional fabrication. Two holes are then drilled through the facial wall of the tray into the region of the preparation. The tray is replaced in the mouth and light-bodied vinyl polysiloxane impression material is injected into the holes by using an "automixing" gun system.

Dental Impression Materials↗
PubMed1991

Effects of thermocycling on the margins of transitional acrylic resin crowns.

Transitional resin crowns were subjected to thermocycling and examined for marginal integrity since disturbance of the marginal seal is detrimental. Two groups of 10 crowns, one with a chamfer and the second with a shoulder finish line, were subjected to two series of 2500 thermocycles. In the first series, the crowns received cold thermocycling and in the second, hot thermocycling. Impressions were made of the facial margins before thermocycling, after cold thermocycling, and after hot thermocycling. The impressions were analyzed for loss of marginal integrity and changes in axial contour. Cold thermocycling resulted in only limited deterioration, but the changes after hot thermocycling were more pronounced. Tooth preparation designs did not influence the effects of thermocycling.

Cold Temperature↗
PubMed1991

Marginal adaptation of castable ceramic crowns.

Tooth preparations and seating techniques of castable ceramic crowns differ from metal ceramic crowns. This study evaluated the variable effects of cementation on the marginal adaptation of Dicor, Cerestore, and porcelain-fused-to-metal crowns. The shoulder preparation was maintained for ceramic crowns, and a cavosurface bevel was designed for metal ceramic crowns. Crowns were made with a replication size of 10, placed on master dies, and the marginal openings measured with a Nikon Measurescope 20 instrument. Thirty crowns were cemented with zinc phosphate cement and the recommended clinical force. Marginal adaptation was not improved with a gingival bevel preparation or an increased seating force. The best marginal adaptation was recorded for Cerestore crowns.

Aluminum Oxide↗
PubMed1992

Resin-bonded prostheses for posterior teeth.

This study evaluated fixed partial dentures bonded with resin to dentin on posterior teeth with minimal tooth preparation. The patients included were missing at least one premolar or first molar. The abutment teeth next to the modification spaces were moderately restored with MOD or class II restorations on most of the teeth. A total of 20 patients with 23 fixed partial dentures were included in the study. After removal of existing restorations, the abutment teeth were prepared to eliminate undercuts on the perimeter of the preparations. Undercut areas within the preparation were not filled but were blocked out later in the laboratory. The fixed partial dentures employed inlays as retainers for a metal ceramic pontic. The metal framework was cast in a high noble gold alloy. The areas of the retainers to be bonded were treated with the Kulzer Silicoater method. Immediately before cementation, enamel was etched and exposed dentin was treated with Gluma. Kerr's resin bonded bridge cement was used for cementation. Patients were recalled after periods of 1 week, 1 month, 6 months, 1 year, 2 years, and 4 years for evaluation. None of the restorations lost retention and no major adverse effects were observed in the 4-year follow-up period.

Adhesives↗
PubMed1992

Improved retention of acid-etched fixed partial dentures: a longitudinal study.

Debonding of acid-etched fixed partial dentures has been a problem since their introduction. A study was conducted to determine whether this problem could be resolved by modifying the mechanical retention of tooth preparations. Retentive grooves were prepared at the line angles to create mechanical locks for the resin bonded fixed partial denture. The 4-year retention of posterior resin-bonded fixed partial dentures improved from 60% to 95% by the placement of the proximal grooves. This study was conducted in a dental school clinic during a period of 10 to 52 months. The results demonstrated that design modifications were necessary to improve clinical longevity so that the restoration could be considered "permanent" in the traditional sense. The less-experienced dentist may be more confident of the treatment with the recommended modifications and projected longevity.

Acid Etching, Dental↗
PubMed1992

Periodontics and prosthodontics: goals, objectives, and clinical reality.

Prosthodontics and periodontics are collaborative disciplines. A successful prosthesis depends on a healthy periodontal environment, and periodontal health depends on the continued integrity of the prosthodontic restoration. To facilitate this collaboration, prosthodontists should not only appreciate the periodontic implications of gingival displacement procedures and tooth preparation, but should be knowledgeable about the types of gingival tissues, osseous topography, occlusal effects, and their implications for abutment choice. Working as a team, the periodontist can identify for the prosthodontist a patient's periodontal strengths and limitations. In that way, the prosthodontist can then assume responsibility for a given treatment plan based on a mutual understanding of the critical factors involved.

Denture Design↗
PubMed1993

Review of the pH of hemostatic agents used in tissue displacement.

Newer hemostatic agents such as the tetrahydrozolines and oxymetazolines have a more acceptable pH and should be kinder to tooth structure and soft tissue than the conventional solutions. Although additional study is needed, it would seem prudent to be cautious in using low pH hemostatic agents and avoid the exposure to sensitive intraoral tissues-particularly delicate tissues--or tooth preparation close to the dental pulp.

Alum Compounds↗
PubMed1994

In vivo microleakage of luting cements for cast crowns.

Standardized tooth preparations were completed on previously intact human molars in vivo, and castings were made with a precious metal ceramic alloy by conventional techniques. The castings were randomly assigned to the following luting agents: zinc phosphate, composite resin-glass ionomer hybrid, and a composite resin-glass ionomer hybrid with a dentinal bonding agent and were cemented in a standardized manner to periodontally compromised molars. After 6 months the teeth were carefully extracted, stained, embedded, and sectioned, and the in vivo microleakage was measured. ANOVA disclosed significant differences between groups, and a multiple comparisons test revealed that the zinc phosphate group leaked significantly more than other cement groups.

Adult↗
PubMed1994

Fracture strength of full-contoured ceramic crowns and porcelain-veneered crowns of ceramic copings.

This is vitro study compared the fracture strength of Dicor ceramic crowns with a 1 mm axial wall thickness and a 2 mm occlusal thickness with Dicor copings veneered with Vitadur-N or Dicor-Plus porcelain to create similar contours. Tooth preparations for complete crowns were made on human molars with a 10-degree total convergence and a 1 mm shoulder. The artificial crowns were internally etched, given an application of silane, and cemented with a dual-cured resinous cement. After thermocycling, each sample was loaded to failure with a vertical load on the occlusal surface. There were no significant differences in fracture strength between full-contour Dicor crowns and crowns of copings veneered with either Vitadur-N or Dicor-Plus porcelain.

Analysis of Variance↗
PubMed1994

Longitudinal clinical evaluation of fiber-reinforced composite fixed partial dentures: a pilot study.

This report describes a clinical pilot study that monitored a group of 12 patients who have received 14 single tooth replacement experimental restorations made with prefabricated continuous fiber-reinforced composite (FRC) frameworks. Because these restorations represent a purely adhesive restorative system, tooth preparation was not performed. The Kaplan-Meier survival probability at 12 months was approximately 50%. The restoration with the longest service life was a mandibular molar replacement that has remained in service 24 months. With improved survival times, bonded FRC definitive restorations should be plausible.

Adult↗
PubMed1989

Resin bonded bridgework: a review.

The use of resin bonded bridgework has become accepted as a routine procedure in restorative dentistry. The aim of this paper is to assess the performance of this type of restoration based upon the evidence of published studies. The opening section describes the evolution of the various designs of framework for this type of bridge. The use of in vitro testing to determine possible clinical effects is then discussed. Clinical aspects of the use of resin bonded bridgework are described including abutment tooth preparation and the use of cementing resins, as well as the chemically adhesive materials. Factors influencing the retention of resin bonded bridgework are also discussed. Finally, the clinical performance of these bridges is considered.

Acid Etching, Dental↗
PubMed1994

A multicentered clinical study on posterior resin-bonded bridges: the 'Manchester trial'.

This study was designed to investigate and identify factors relevant to the success and failure of posterior resin-bonded bridges (PRBBs) related to the patient, technique, operator and bridge design. It was a long-term controlled clinical trial and formed part of a multicentered study on PRBBs. Data are presented 2.5 years from the start of the study. Following a strict protocol for case selection, 54 posterior, resin-bonded, fixed-fixed, three unit bridges were placed in 45 patients. Twenty-four patients with 27 PRBBs attended for 2.5-year recall. Treatment variables were limited to one of two operators and either a conventional tooth preparation or a more extensive modified preparation was performed. The allocation of treatment modalities was performed using a computer program to balance patient variables such as age, gender, location of bridge, restoration of abutment teeth. All bridges were produced in one laboratory, treated to produce a silicate-coating bond and placed using Microfill Pontic C (Kulzer, Wehrheim, Germany). Data relating to the patients, the open spaces, bridge preparation, bridge placement and subsequent annual evaluation were recorded. The survival of PRBBs in the maxilla was 77% and in the mandible 47%.

Adolescent↗
PubMed2006

Implantation of an RFID-tag into human molars to reduce hard forensic identification labor. Part I: working principle.

Recently the tsunami disaster, the London bombings and the landfall of hurricane Katrina demonstrated once more the need for an accurate, quick and easy to handle identification system. The implantation of a radio frequency identification (RFID) tag into a human tooth and the read-out of its information may give an answer to this problem. A description is given of the modification of an existing RFID-tag that was made for veterinary use. This modified system was implanted in human molars using directly bonded resin composites. A protocol for tooth preparation and tag implantation was developed. A study of tag read-out patterns, revealed their accurate read-out distance range, the optimal site of RFID-tag implantation, assemblage of its components, and dimensions of the primary coil. It was found that disassembling the commercial RFID-tags was practically feasible and resulted in a properly working set-up. Further research is needed to optimize the design and the stability of RFID-tags for human identification purposes.

Disasters↗
PubMed2003

Pulpal temperature increases with Er:YAG laser and high-speed handpieces.

STATEMENT OF PROBLEM: During tooth preparation, both high-speed handpieces and lasers generate heat, which, if not controlled, can cause pulpal necrosis. PURPOSE: The aim of this study was to compare temperature increases produced by a high-speed dental handpiece with those produced by a relatively new instrument, the Er:YAG (erbium: yttrium-aluminum-garnet) laser. MATERIALS AND METHODS: Thirty bovine mandibular incisors were reduced to an enamel/dentin thickness of 2.5 mm. Class V preparations were completed to a depth of 2.0 mm, measured with a caliper or by a mark on the burs. A thermocouple was placed inside the pulp chamber to determine temperature increases (degrees C). Analysis was performed on the following groups (n=10): Group I, high-speed handpiece without water cooling, Group II, high-speed handpiece with water cooling (30 mL/min), and Group III, the noncontact Er:YAG laser (2.94 microm at 350 mJ/10 Hz) with water cooling (4.5 mL/min). The temperature increases were recorded by a computer linked to the thermocouples. The data were analyzed using the Kruskal-Wallis test. The Dunn multiple comparison test was used as post hoc test (alpha=.05). RESULTS: The average temperature rises were: 11.64 degrees C (+/- 4.35) for Group I, 0.96 degrees C (+/- 0.71) for Group II, and 2.69 degrees C (+/- 1.12) for Group III. There were no statistical differences between Groups II and III; both II and III differed from Group I significantly (P=.000 and P=.002, respectively). CONCLUSION: The preparations made with the high-speed and the laser instrument generated similar heat increases under water cooling. Water cooling was essential to avoid destructive temperature increases when using both the high-speed handpiece and laser.

Aluminum Silicates↗