Intrapulpal temperature during direct fabrication of provisional restorations

Measurements were made of the heat transferred to the pulp by different types of resins, different volumes of resin, and different types of matrices commonly used in the direct fabrication of extracoronal provisional restorations. A mandibular model was fabricated using extracted teeth that were prepared for extracoronal restorations. Provisional restorations were fabricated for the prepared teeth using conventional direct techniques, and the intrapulpal temperature rise was recorded. The temperature rise ranged from a low of 0.42 degrees C to a high of 7.21 degrees C. Of the three resins tested, the poly(methyl methacrylate) material induced the greatest temperature increase. The vacuum-formed matrix allowed a greater temperature increase than either of the impression material matrices.     

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.     

暂时冠桥修复材料聚合过程中髓腔内温度变化的体外研究

目的:体外测量6种暂时冠桥修复材料直接法制作暂时修复体时牙髓腔内温度的变化。方法:选取1个健康的人离体下颌第三磨牙,标准全冠预备后,将一热电偶置入髓腔,另一端与一电子温度计相连,将4种Bis-acryl复合树脂(Protemp3Garant、Luxatemp、ProtempⅡ和Fast-Temp)和2种聚甲基丙烯酸甲酯树脂(Quick Resin和Curefast)分别按照使用说明混合后,填入预先准备的硅橡胶印模中,在基牙上复位,记录实验材料聚合过程中髓腔内的温度变化。结果:ProtempⅡ组髓腔最大升温值(3.8℃)低于Protemp3Garant组(4.6℃)、Luxatemp组(4.8℃)和Fast-Temp组(4.8℃),有显著性差异(P<0.05),后三组之间无显著性差异(P>0.05)。4种Bis-acryl复合树脂最大升温值又显著低于QuickResin组(9.1℃)和Curefast组(8.7℃)(P<0.05),QuickResin和Curefast之间无显著性差异(P>0.05)。结论:4种Bis-acryl复合树脂聚合过程中髓腔升温低于两种聚甲基丙烯酸甲酯树脂,适合直接法制作暂时修复体。     

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.     

The modification of interim cylinders for the fabrication of cement-retained implant-supported provisional restorations

This article describes a technique for modification of metal interim cylinders and their use in the fabrication of cementable implant-supported provisional restorations. This chairside technique allows for direct provisionalization of single or multiple implants during or after second-stage surgery, especially when there is a high esthetic demand.     

Microwave techniques for fabrication of provisional facial prostheses

Timely rehabilitation of facial defects necessitates provisional prostheses during the period following surgery. The possibilities of using microwave radiation in the drying of gypsum casts, the preparation of stone molds, the curing of silicone elastomers, and the extrinsic coloring of silicone prostheses are presented. Microwave radiation has the potential for saving time, energy, and resources during the fabrication of provisional facial prostheses.     

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.     

直接法快速制作前牙临时冠

桩核烤瓷冠是前牙牙体缺损常见的修复方法。在以往制作修复体过程中,患者有5-7天等待铸桩核加工过程的时间,此期间患者因暴露残根、残冠影响美观。我们在临床上探索出直接快速制作临时冠的简便方法,解决了这一问题,取得了满意疗效。残根、残冠进行完善根管治疗2周后,无自发痛、     

Effect of composite temperature on in vitro intrapulpal temperature rise.

OBJECTIVES: To measure in vitro intrapulpal temperature when placing and restoring with either room-temperature or pre-heated (54 and 60 degrees C) composite. METHODS: A K-type thermocouple was placed in the pulpal chamber of an extracted, human bifurcated upper premolar which had a Class V preparation (1 mm remaining dentin thickness) on the facial surface. Tooth roots were immersed in a thermostatically controlled water bath and perfused with water at 1.25 microl/min to simulate physiological circulation in the pulp chamber. The thermocouple was connected to an analog-to-digital converter. The preparation was filled using composite either at room-temperature, or pre-heated to 54 or 60 degrees C with a commercial compule heater (Calset), using standard clinical procedures by one person while continuously monitoring intrapulpal temperature (n=5). Temperature rise over baseline values were determined at various stages during the restoration process: composite placement, contouring, prior to light-curing, and immediately after light-curing (20s, Optilux 501). At each measurement interval, intrapulpal temperature values were compared using ANOVA and the Tukey-Kramer post hoc test (alpha=0.05). RESULTS: Significant differences were found in intrapulpal temperature when comparing pre-heated and room-temperature composite treatments with respect to baseline among the stages of the restorative process. However, the extent of this increase with heated composite was only 0.8 degrees C. A 5 degrees C intrapulpal temperature rise was seen for all groups during photopolymerization. SIGNIFICANCE: Use of pre-heated composite only mildly increased intrapulpal temperature values when compared to composite delivered at room-temperature in an in vitro test environment. The largest temperature change occurred with application of the curing light.     

Finishing and polishing techniques: direct composite resin restorations.

Contemporary clinicians are responsible for delivering realistic restorations that closely resemble the existing natural tooth structures. In order to achieve such aesthetic results, the use of exemplary materials is required. Recent advancements in composite resin systems have improved the practitioner's ability to deliver optimal results using chairside techniques. The incorporation of a precise finishing and polishing protocol further allows the clinician to seal the restoration and maintain natural surface luster and contour. This article presents the necessary finishing and polishing protocol to ensure long-term aesthetic results.     

Increases in intrapulpal temperature during polymerization of composite resin

STATEMENT OF PROBLEM: The polymerization of dental composite resins can generate increases in intrapulpal temperature that may damage the pulp. The development of new polymerization devices such as the argon laser makes the assessment of these temperatures important. PURPOSE: This study compared increases in temperature generated by argon laser and halogen light when polymerizing a bonding system and a composite resin, and also sought to determine whether both types of polymerization lights generate temperature increases below the safe limit of 5.5 degrees C. MATERIAL AND METHODS: Thermocouples linked to a temperature reading system were positioned in the pulp chamber of 10 extracted bovine incisors. Class V cavities were prepared, etched, and filled with a 1-bottle bonding system (Single Bond) and composite resin (Z-100). The test groups were as follows (n = 5 for all groups): halogen light for bonding system (HB); halogen light for composite resin (HC); argon laser for bonding system (LB), and argon laser for composite resin (LC). The polymerization parameters were halogen light operated at 600 mW/cm2 for 40 seconds, which served as control, and argon laser operated at 200 mW for 10 seconds. Data were analyzed by a 2-way (light versus material) analysis of variance (ANOVA) (alpha = .05). RESULTS: The average temperature increases were 2.35 degrees C (HB), 2.69 degrees C (HC), 1.25 degrees C (LB), and 1.5 degrees C (LC). Significant differences between halogen light and argon laser (P = .002), but not between composite and bonding system, were demonstrated. CONCLUSIONS: The argon laser produced significantly lower increases in pulpal temperature than the halogen light, independent of the thickness of the polymerized material.