Fabrication Of Provisional Restorations Research Articles

A Comparative Evaluation of Temperature Changes in the Pulpal Chamber during Direct Fabrication of Provisional Restorations: An In Vitro Study

To compare the temperature changes in the pulpal chamber during fabrication of provisional restorations by direct method. A total of 108 three-unit FPD provisional restorations were fabricated on a study model and divided into three main groups according to the material used for the fabrication of matrix. Group A-Alginate impression index group, Group B-Polyvinylsiloxane putty impression index group, Group C-Vacuum formed template group. Each group comprising of 36 specimens, was subdivided into three subgroups based on the provisional restorative material used: polymethylmethacrylate (subgroup 1), polyethylmethacrylate (subgroup 2), bis-acryl composite resin (subgroup 3). Intrapulpal temperature changes were observed with the help of a thermocouple probe (connected to a digital microprocessor thermometer) inserted into the pulp chamber of an extracted mandibular second molar mounted on a study model, during the fabrication of provisional restorations by direct method. The subgroups mean temperature rise observed in Group A-A1, A2, A3 was 2.6250±0.2491, 1.0500±0.1382, 0.4083±0.1165, respectively. The subgroups mean temperature rise observed in Group B-B1, B2, B3 was 4.6250±0.2454, 3.3750±0.3415, 2.5917±0.2678, respectively. The subgroups mean temperature rise observed in Group C-C1, C2, C3 was 4.7694±1.8361, 3.0611±1.5767, 2.3806±1.5713, respectively. The observations were statistically significant. The intrapulpal temperature rise during fabrication of a provisional restoration depended both on the type of provisional restorative material and the type of matrix used. The clinician should choose carefully the resin and the matrix material while fabricating provisional restorations with direct method.

Techniques of Fabrication of Provisional Restoration: An Overview

A properly fabricated provisional restoration is important in achieving a successful indirect restoration. The importance of provisional restorations as an integral part of fixed prosthodontic treatment is evident from the abundance of the literature pertaining to their importance regarding margin fidelity, function, occlusion, and esthetics. There are a variety of techniques available to suit the individual needs of the clinician and of the clinical situation, from a single unit to a complete-arch provisional fixed prostheses.

A TECHNIQUE TO FACILITATE THE FABRICATION OF PROVISIONAL RESTORATIONS FOR ITI SOLID ABUTMENTS

The aim of this technique report was to present a procedure for the fabrication of provisional restorations for ITI solid abutments using impression caps in the laboratory with a number of advantages over intraoral techniques. There may be no need for cementation, and elimination of cementation may assist tissue healing.

The effect of dentin desensitizer with different layers on thermal changes on the pulp during fabrication of provisional restoration

This study investigated the effects of different desensitizers and an adhesive material application on pulpal temperature rise during direct provisional restoration polymerization. Two dentin desensitizers (Systemp, Ivoclar; BisBlock, Bisco) and a dentin adhesive (Prime Bond, Dentsply) were applied to the dentin surfaces as single layer or double layer. One autopolymerizing methacrylate (Prevision, Heraeus Kulzer) and one light polymerizing composite (Revotek LC, GC) provisional restoration materials were used in this study. A total of 160 dentin disks were prepared from extracted molars. These dentin disks were placed on an apparatus developed to measure temperature rise. After the desensitizer or dentin adhesive application, provisional materials were polymerized according to the manufacturers' instructions. The temperature increase was measured under the dentin disk with a J-type thermocouple wire that was connected to a data logger. Differences between initial and highest temperature reading were taken, and 10 readings were averaged to determine the mean value in temperature rise. Statistical analysis was performed with three-way analysis of variance followed by Tukey HSD test (alpha = 0.05). Temperature rise varied according to the provisional restoration material used (composite resin, methacrylate) (p < 0.001), the agent thickness (single, double) (p < 0.001), and the agent (desensitizer, adhesive) (p < 0.001). The composite resin-based provisional material induced higher thermal changes than methacrylate based provisional material (p < 0.01). The thickness of desensitizing agents affected the thermal changes; however, the desensitizers did not affect on the intrapulpal temperature although the type of provisional material used may be effective.

Preservation of soft tissue contours with immediate screw-retained provisional implant crown

When a patient with a missing or failing maxillary anterior tooth desires immediate tooth replacement, fabrication of a provisional restoration can be challenging. Due to individual anatomical variations in tooth shape, size, and supporting soft and hard tissue structures, there are no premanufactured components with an anatomical emergence profile that universally suits all individual situations. This article describes the fabrication of a screw-retained immediate provisional restoration that fulfills anatomic, biologic, and esthetic requirements.

Comparison of temperature increase in the pulp chamber during the polymerization of materials used for the direct fabrication of provisional restorations

Polymerization of resin materials used for the fabrication of provisional restorations is associated with an exothermic reaction. This temperature rise may present a serious biological problem, since it can cause iatrogenic thermal trauma to the pulp. This in vitro study compared the temperature increase in the pulp chamber of a molar placed in contact with different resins used for the direct fabrication of provisional restorations. Polymethyl methacrylate (Jet), polyethyl methacrylate (Snap), polyvinylethyl methacrylate (Trim), Bis-acrylic composite (Protemp II), and a VLP urethane dimethacrylate (Revotec LC) were compared with respect to their exothermic reaction properties during polymerization. A mandibular molar prepared for a complete coverage restoration was placed in an acrylic resin block. A thermal probe connected to a digital thermometer was placed into the pulp chamber. Specimens were submerged in a water bath to simulate intraoral conditions. The provisional resin materials tested were measured and mixed according to manufacturer's instructions. The resin mixture was placed into a vacuum-formed acetate template and was then positioned on the prepared molar tooth. The temperature was recorded during polymerization at 30-second intervals until it was evident that the peak temperature had been reached. Temperature increase was measured ( degrees C) for both the initial crown fabrication and the reline procedures. Data were analyzed with descriptive statistics, 1-way analysis of variance, and Tukey Honestly Significant Difference tests (alpha=.05). One-way ANOVA revealed significant differences (F=57.010, P<.0001) in temperature rise for different provisional resin materials. Mean temperature increase for the provisional crown fabrication ranged from 37.76 degrees C for the polyvinylethyl methacrylate to 39.40 degrees C for the polymethyl methacrylate. Mean temperature rise for the reline procedures ranged from 36.80 degrees C for the polyvinylethyl methacrylate to 37.69 degrees C for the polymethyl methacrylate. All of the tested materials produced an exothermic chemical reaction. Polymethyl methacrylate produced the higher exothermic reaction in both initial crown fabrication and reline procedures. Polyethyl methacrylate, polyvinylethyl methacrylate, and Bis-acrylic resins tested were not significantly different from each other.

Direct Technique for the Fabrication of Acrylic Provisional Restorations

Provisional restorations are fabricated to protect the prepared tooth structure during the period between tooth preparation and insertion of the definitive restoration. These restorations are also referred to in the literature as interim, temporary, or provisional restorations (prostheses). Such restorations should be uncomplicated and inexpensive to fabricate in a short period of time. Several laboratory and clinical techniques for the fabrication of provisional restorations have been described in the literature, such as the indirect technique, direct technique, and indirect-direct techniques for both single and multiple unit restorations. This article describes a step by step clinical technique for the fabrication of a direct provisional restoration to satisfy the issues of esthetics, patient comfort, speech and function, maintenance of periodontal health, and maxillomandibular relationships while wearing the restoration.

Technique for fabricating a cement-retained single-unit implant-supported provisional restoration in the esthetic zone

The fabrication of provisional restorations is an important stage in implant treatment. In the esthetic zone, the potential for error without the use of provisional restorations in the selection of the abutments, framework design, appropriate vertical dimension of occlusion, occlusal profile, and the esthetic interpretation may be significant. Provisional restorations are indicated in esthetic zones, for the contouring of the gingiva, to achieve an acceptable emergence profile, to have custom-guided tissue healing, and to induce appropriate soft-tissue topography. This article describes the fabrication of a provisional restoration for a single-unit implant-supported crown.

The effect of dentin desensitizers on thermal changes in the pulp chamber during fabrication of provisional restorations.

The purpose of this study was to evaluate the effect of two dentin desensitizers on the pulp chamber temperature increase during fabrication of provisional restorations by a direct method. Sixty intact extracted mandibular third molars were prepared for a metal-ceramic complete crown. Then the teeth were randomly divided into three groups of 20 each. Group 1, no dentin desensitizer was used as the control group; group 2, a resin-based dentin desensitizer was selected; and group 3, the prepared teeth surfaces were coated with polyurethane cyanoacrylate adhesive. Each of the three groups was further divided into two polymerizing systems (autopolymerizing and a photopolymerizing) of 10 each. After insertion of the resin-filled matrix, the temperature change in the pulpal chamber was recorded with thermocouple connected to a data logger. anova indicated no significant differences for all combinations of desensitizing agents and curing methods (P > 0.05). When light cured composite or chemical curing acrylics were used to make temporary crowns, the presence of desensitizing agent did not reduce the temperature transmitted from the provisional material; the residual temperature rise transmitted was of such a magnitude as to cause concern regarding possible thermal injury to pulp.

Expedient direct approach for esthetic and functional provisional restorations

This article describes a direct procedure for the expeditious fabrication of provisional restorations for extensive fixed prosthodontic applications. Customary indirect or indirect-direct approaches require extensive clinical time as well as laboratory support for their successful application. Provided that the necessary preoperative steps are followed precisely, this treatment method allows for excellent clinical results while being less time consuming. (J Prosthet Dent 2003;89:319-22.)

Options for the fabrication of provisional restorations for ITI solid abutments

In this article, 4 techniques for fabricating provisional restorations for ITI solid abutments are described. The use of a burn-out coping, acrylic resin coping, impression cap, and protective cap are presented, and the advantages and disadvantages of each are discussed. (J Prosthet Dent 2001;86:658-61.)

Use of a flexible cast for the indirect fabrication of provisional restorations

Efficient fabrication of a clinically acceptable provisional restoration for a fixed partial denture is an important part of treatment success. Fabrication of provisional restorations that uses the indirect technique produces accurate fitting provisional restorations without the chemical and thermal irritation associated with direct fabrication. With a typodont model, an indirect method is presented that uses an elastic cast for fabrication of multiple unit provisional restorations for fixed partial dentures. The cast is available within 6 minutes of impression making, can be trimmed with a sharp scalpel, and provides flexibility that allows easy separation of the acrylic provisional from the cast. The cast can also be used to evaluate the clinical acceptability of the preparations before impression making. This method has also been successfully used for the fabrication of acrylic provisional restorations for onlay preparations. (J Prosthet Dent 1999;82:90-3.)

Color stability of provisional resin restorative materials

Statement of problem. Use of temporary crowns and fixed partial dentures is especially relevant when the treatment plan requires restorations for long interim periods, and the in-service discoloration of provisional restorative materials is a major drawback. Purpose. This study evaluated the discoloration effect of coffee and tea on some materials that are commonly used in the fabrication of provisional restorations. Material And Methods. Six commercially available provisional resins (Jet, Caulk TBR, Protemp Garant, Luxatemp Solar, Provipont DC and SR-Ivocron-PE) were evaluated after 1 day, 7 days, and 30 days of immersion in various staining solutions. Color measurements were obtained by using a Dr Lange Micro Color tristimulus colorimeter and color differences (ΔE*) were estimated. Results. The 2 chemically activated resins (Jet and Caulk TBR) and the heat-cured resin (SR-Ivocron PE) exhibited the least color changes, whereas the Provipont-DC resin was the least color stable. After immersion for 30 days, the combination with the coffee solution resulted in unacceptable discoloration for all the tested materials. Conclusions. Provisional restorative materials, staining solutions, and immersion time were significant factors that affected color stability. After immersion for 7 days, all materials showed observable color changes. The composite-based materials, especially light-curing composites, were the least color stable. The coffee solution exhibited more staining capacity than the tea solution. (J Prosthet Dent 1998;80:533-9.)

Fabrication of long-span provisional restorations with multiple pontics: A modified method by using a vacuum-formed matrix

The vacuum-formed matrix has been applied in the fabrication of provisional restorations for about three decades,1-5 but for long-span provisional restorations with multiple pontics, excessive shrinkage of cold-curing acrylic resin in the pontic area is still a problem. The following procedure uses denture teeth in the pontic area, and the provisional restorations are fabricated with an indirect technique. This procedure can reduce the bulk of the cold-curing acrylic resin and can improve the situation with the reduction of excessive shrinkage of the provisional restorations.

Mechanical properties of a light-polymerizing provisional restorative material with and without reinforcement fibers

Interim restorations are vulnerable to inadvertent fracture during mastication. Autopolymerizing acrylic resins have traditionally been selected for fabrication of provisional restorations. Triad light-polymerizing tooth-colored acrylic resin was recently introduced as an alternative material for this procedure. This material does not contain methyl methacrylate monomer and permits an increased working time. Heavy occlusal forces may initiate cracks within these restorations, and propagation of these cracks may ultimately lead to failure. Various forms of reinforcement fibers are available and are marketed for strengthening dental resins used for provisional restorations. Investigators have demonstrated that the mechanical properties of acrylic resins may be improved with the incorporation of reinforcing fibers, but a published evaluation of fiber-reinforced light-polymerizing provisional restorative materials is lacking. This investigation recorded and compared two mechanical properties of one light-polymerizing provisional restorative material with and without incorporation of vertically and horizontally oriented woven, matted, polyethylene fibers. No significant difference in modulus of rupture was recorded between groups with and without fibers. The mean flexural elastic modulus of the group with the horizontally oriented fibers was significantly greater than the mean flexural elastic modulus of the specimens without incorporated fibers.

A Direct Provisional Restoration for Decreased Occlusal Wear and Improved Marginal Integrity: A Hybrid Technique

A direct technique for the fabrication of provisional restorations is described. Occluding surfaces of the provisional restoration are veneered with a light-cure composite resin for increased wear resistance and improved occlusal stability. Also described is a method for reestablishing the provisional restoration's margins to achieve optimal tissue health.

The effect of vacuum-mixed autopolymerizing acrylic resins on porosity and transverse strength

Three brands of autopolymerizing acrylic resin were mixed and polymerized three different ways and tested for transverse strength and porosity. The procedures tested were bench-curing at ambient temperatures, vacuuming the mix before bench-curing, and curing in a pressure device. The data indicate that both vacuuming the mix and pressure-curing are successful in reducing porosity and increasing transverse strength. These improved properties would be valuable in the fabrication of provisional restorations and occlusal splints. The following conclusions can be drawn: 1. Use of a pressure device decreases porosity and increases the transverse strength in samples of autopolymerizing acrylic resin. 2. Use of a vacuum device on the mixed acrylic resin works as well as pressure polymerizing. 3. Use of either technique is indicated to improve the quality and longevity of autopolymerizing acrylic resin restorations, orthodontic appliances, and occlusal splints.

Effect of contaminants on the adhesion of light-bodied silicones to putty silicones in putty-wash impression technique

This study was concerned with the adhesion of a light-bodied silicone to a putty silicone in a putty-wash impression technique when the preliminary putty impression was contaminated with human saliva or residues from acrylic resins used in the fabrication of provisional restorations by direct technique. Data indicated that condensation and addition silicones differed in their susceptibility toward the tested contaminants. Salivary contamination and chemical residues from the autopolymerizing acrylic resins weakened the bond strength and caused adhesive failure dependent upon the type of silicone impression material used.