Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tooth Preparation, Prosthodontic”

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 19 recordsLinked to original sources

The periodontal-restorative interface in fixed prosthodontics: tooth preparation, provisionalization, and biologic final impressions--Part II.

The delicate dento-gingival attachment apparatus must be treated with utmost care during all phases of preparation in the crevicular region. There is little room for error within these minute dimensions. The learning objective of this article is to encourage the dentist to be ever vigilant when approaching the subcrevicular tissues during biomechanical tooth preparation, provisionalization, biologic final impressions, and final cementation. Part I, published in the January/February, 1994, issue of PP&A, discussed the emergence profile, retraction, preparation modalities, and provisionalization. Part II discusses final impressions and casts derived from information provided by morphologically correct provisionals, surgically directed provisionalization, and final functional and aesthetic rehabilitative results.

Adult↗

The periodontal-restorative interface in fixed prosthodontics: tooth preparation, provisionalization, and biologic final impressions. Part I.

The delicate dento-gingival attachment apparatus must be treated with utmost respect during all preparational maneuvers in the crevicular region. There is little room for error within these minute dimensions. To avoid irreparable harm during chemo-mechanical manipulation of the attachment apparatus, the dentist must always think on a histologic level in order to respect the cellular integrity of the periodontium. The learning objective of this article is to encourage the dentist to be ever vigilant when approaching the subcrevicular tissues during biomechanical tooth preparation, provisionalization, biologic final impressions, and final cementation. Part I discusses the emergence profile, retraction, preparation modalities, and provisionalization; it is presented in this issue. Part II will cover final impressions and casts, derived from information provided by morphologically correct provisionals, surgical provisionalization, and final rehabilitative results; it will appear in the April, 1994, issue of PP&A.

Crowns↗

The use of real time video magnification for the pre-clinical teaching of crown preparations.

OBJECTIVE: To investigate the effect on the undergraduate learning process of using an alternative method designed to enhance the visual demonstration of taper on full veneer crown preparations (better understanding of the value of taper on preparations early in the teaching programme in restorative dentistry). DESIGN: A comparison between the conventional teaching of full veneer crown preparations and the same teaching with the additional use of a magnified real time video display using a surgical microscope was investigated in this study. OUTCOME MEASURES: The degree of taper was measured for replica full crown preparations and results compared between different cohorts of undergraduates and experimental conditions. RESULT: Undergraduates taught using the real time video produced more accurately tapered preparations. This ability was retained over one year. CONCLUSIONS: A possible explanation for the result was that the use of magnification improved the undergraduates' precise understanding of taper by enhancing their ability to evaluate this critical measurement during the teaching process.

Calibration↗

A clinical study on abutment taper and height of full cast crown preparations.

Dental students at Tokyo Medical and Dental University are taught to prepare teeth for full cast crowns with a wall taper of 2 to 5 degrees and an occlusal clearance of 1.2 to 1.5 mm. However, it is difficult to achieve such an ideal taper. The objective of this study was to examine the abutment taper and height of teeth prepared for crowns by final-year dental students under clinical supervision. To evaluate the degree of taper and height of the prepared teeth, shadowgraphs of 63 working stone dies were traced. The angles and height of the abutments were then measured on the same tracing. Only 12.7% (8 out of 63 abutments) of the prepared teeth fell within the ideal range of 2 to 5 degrees, and the average taper was 9.5 degrees (19.0 degrees convergence angle). The average abutment height varied from 4.8 mm to 6.9 mm and showed a close relationship with the abutment taper. The average taper, 9.5 degrees, of the present study was larger than the ideal taper; however, it was thought to be clinically acceptable as it is difficult to achieve the ideal taper intraorally.

Crowns↗

Auxiliary retention and the role of the core in fixed prosthodontics.

Extensively damaged teeth frequently require placement of a core before preparation to receive an indirect restoration. Dentine pins have traditionally been used to enhance retention and resistance form when coronal dentine is significantly reduced; however, pins are invasive and may produce pulpal or periodontal problems. Cavity design features such as grooves, boxes or retentive pits may be better alternatives. The choice of the core material may also influence the outcome although reliable research data are scarce. Large cores should be considered to have a structural role in supporting the final restoration.

Adhesives↗

Foundation restorations in fixed prosthodontics: current knowledge and future needs.

PURPOSE: The Ad Hoc Committee on Research in Fixed Prosthodontics established by the Academy of Fixed Prosthodontics publishes a yearly comprehensive literature review on a selected topic. The subject for this year is foundation restorations. METHODS: Literature of various in vitro and in vivo investigations that included technical and clinical articles was reviewed to provide clinical guidelines for the dentist when selecting methods and materials for restoration of structurally compromised teeth. Topics discussed and critically reviewed include: (1) desirable features of foundation restorations, (2) foundations for pulpless teeth, (3) historic perspectives, (4) cast posts and cores, (5) role of the ferrule effect, (6) prefabricated posts, (7) direct cores, (8) foundation restorations for severely compromised teeth, (9) problems and limitations, (10) future needs, and (11) directions for future research. CONCLUSION: This comprehensive review brings together literature from a variety of in vitro and in vivo studies, along with technique articles and clinical reports to provide meaningful guidelines for the dentist when selecting methods and materials for the restoration of structurally compromised teeth.

Dental Casting Technique↗

An up to 15-year longitudinal study of 515 metal-ceramic FPDs: Part 1. Outcome.

PURPOSE: This study reports on the outcome of 515 metal-ceramic fixed partial dentures (FPD) involving 1,209 abutments and 885 pontics placed by one operator in a specialist prosthodontic practice between January 1984 and December 1997. MATERIALS AND METHODS: Clinical and laboratory protocol was kept constant as much as was practical. Each FPD and abutment was given a subjective prognostic rating at the time of cementation. Patients were recalled in 1993 (review 1) and 1998 (review 2). Clinical examination by the author covered 85% of 342 FPDs at review 1 and 82% of 515 FPDs at review 2. At review 2, 37% had been in clinical service for 5 to 10 years (group b), and 34% had been in service for 10 to 15 years (group c). An objective classification protocol was used to assess outcome. RESULTS: At review 2, the FPDs had failure rates of 2%, 7%, and 11% in groups a, b, and c, respectively. There was a significant increase in the failure rate of group c at review 2 (11%) compared with review 1 (5%). Cumulative survival analysis indicated that FPDs have an expected survival rate of 96%, 87%, and 85% at 5, 10, and 15 years, respectively. The applied prognostic rating proved more accurate as clinical service time increased. Outcome was not related to number of units. Cantilevered FPDs, nonvital abutments, and anterior abutments had significantly greater failure rates. Of initially vital abutments, 2% were subsequently endodontically treated. CONCLUSION: Tooth-supported FPDs have an expected survival rate of 85% at 15 years when the described clinical and laboratory protocol is applied.

Adult↗

Effect of different surface textures on retentive strength of tapered posts.

STATEMENT OF PROBLEM: Tapered posts allow for the preservation of tooth substance in the fragile apical area and are advantageous in clinical situations where they conform to the root and canal configuration of endodontically treated teeth. However, their lower retention compared with passive parallel-sided or active threaded posts is a disadvantage. PURPOSE: This study determined the retentive strength of tapered titanium posts with different surface textures and examined the effect of roughening dentinal walls of the prepared post space. MATERIAL AND METHODS: Posts with four surface configurations (smooth, with and without grooves, and sandblasted, with and without grooves) were examined when cemented in extracted anterior teeth. RESULTS: The smooth post showed the lowest retentive strength. Sandblasting the smooth post more than doubled its retentive strength. The retentive strength of both smooth and sandblasted posts could be further increased by the addition of circumferential grooves. Roughening the dentinal walls of the prepared post space increased the retentive strength of sandblasted posts with and without grooves even more. CONCLUSIONS: These findings indicated that, when a tapered post is used, roughening the dentin canal wall, as well as sandblasting and grooving the post, can provide statistically significant additional resistance to dislodgment.

Analysis of Variance↗

Tooth structure loss apical to preparations for fixed partial dentures when using self-limiting burs.

STATEMENT OF PROBLEM: Burs with guide pins may be used to limit the depth of tooth preparation for fixed partial dentures. The effects of guide pins on tooth structure apical to the finish line after tooth preparation for fixed partial dentures has not been recorded. PURPOSE: This in vitro study recorded loss of tooth structure within 1.0 mm apical to the finish line of teeth prepared with straight cylinder and tapered cylinder self-limiting burs and one conventional bur. MATERIAL AND METHODS: Forty-five extracted human teeth were randomly divided into three groups. The facial surface of each tooth was prepared with two types of diamond burs with guide pins and a conventional diamond for the control. The surface was profiled before and after tooth preparation. Profiled surfaces were analyzed and the groups were compared using analysis of variance and the Tukey-Kramer HSD test (alpha = 0.05). RESULTS: No significant difference was recorded between the control group and the group prepared with a round-ended tapered cylinder self-limiting pin. However, there was a statistically significant difference between the control and cylindrical pin groups, and between the two groups prepared with self-limiting diamonds. CONCLUSION: This study revealed abrasion apical to the finish line of the preparation in all groups. The cylindrical guide pin group exhibited the greatest loss of tooth surface.

Analysis of Variance↗

Survival of Dicor glass-ceramic dental restorations over 14 years. Part II: effect of thickness of Dicor material and design of tooth preparation.

STATEMENT OF PROBLEM: The influence of different restorative design features on the long-term survival of Dicor glass-ceramic restorations is not well understood. PURPOSE: This study examined the relationship of different types of restorations and methods of preparation with the survival of Dicor glass-ceramic restorations functioning in vivo. MATERIAL AND METHODS: A total of 1444 Dicor glass-ceramic restorations were placed on the teeth of 417 adults. Failure was defined as a restoration that required remake because of material fracture. Survival of restorations of different types and with different methods of preparation was described by using Kaplan Meier survivor functions. Statistical significance between restoration type and preparation method was determined with the log rank test. RESULTS: Probability of survival of a typical partial coverage restoration was 92% at 11.3 years. There was no statistically significant difference between the survival of inlay or onlay restorations. For the 91 cores used for pulpless teeth, none failed over a total cumulative monitoring period of 419 years. There was no significant difference in survival of acid-etched Dicor restorations that were placed on shoulder or chamfer preparations. Thickness measured at the midpoint of the labial, lingual, mesial, distal, and midocclusal surfaces did not relate to risk of failure. CONCLUSIONS: The majority of Dicor glass-ceramic partial coverage inlay and onlay restorations and cores survived over time. Survival of restorations with either chamfer or shoulder preparations did not differ whether the restoration was acid-etched. Thickness of the restoration measured at the midaxial point of each surface did not relate to survival.

Acid Etching, Dental↗

Interdisciplinary management of dental implant patient: a case report.

Maxillary molars can over-erupt when their antagonists are lost and there are no replacements. When the opposing molars severely extrude into the edentulous space, it is difficult to replace the missing teeth with either fixed or removable prostheses. We present the following case report, providing a solution for this type of problem. A two-stage posterior subapical osteotomy was used to reestablish the intermaxillary space. Following orthodontic treatment and implant placement, the patient regained occlusal harmony and normal masticatory function.

Adult↗

An in vitro study into the effect of the ferrule preparation on the fracture resistance of crowned teeth incorporating prefabricated post and composite core restorations.

AIM: This in vitro study investigated the effect of a ferrule preparation on the fracture resistance of crowned central incisors incorporating a prefabricated post (Parapost) cemented with Panavia-Ex and with a composite core. METHODOLOGY: The test group consisted of 10 post crowned natural central incisor teeth with a 2-mm wide ferrule preparation, whilst the control group of 10 teeth had no ferrule. The specimens were mounted on a Lloyd universal testing machine and a compressive load was applied at an angle of 135 degrees to the palatal surface of the crown until failure occurred. RESULTS: In both groups, failure occurred at higher loads compared with previous studies. The mean failure load was 1218 N for the unferruled group and 1407 N for the ferruled group. Statistical analysis showed no significant difference between the groups. CONCLUSIONS: Under the conditions of this study, when composite cement and core materials are utilized with a Parapost prefabricated system in vitro the additional use of a ferrule preparation has no benefit in terms of resistance to fracture.

Cementation↗

Pulp reactions to different preparation techniques on teeth exhibiting periodontal disease.

To evaluate the histopathological outcome of two preparation techniques (featheredge preparation/shoulder preparation) on teeth exhibiting pulp reactions due to age and periodontal disease, 11 teeth were prepared for full veneer crowns. Laboratory made resin crowns were fixed with a zinc phosphate cement for a period of 90 days. After extraction, adjacent pulpal areas were histopathologically rated according to the BRD criteria comprising the parameters (i) Bacterial invasion, (ii) Regenerative parameters, (iii) Degenerative parameters. Degenerative reactions were more correlated with tooth preparation than with advanced periodontal disease. The severity of endondontal reactions depends more on remaining dentin thickness than on the type of preparation.

Acrylic Resins↗