Resin Copings Research Articles

A Final Esthetic Validation Technic in Fixed Prosthodontics for Special Needs Patients

Esthetic consideration is an important aspect for special needs patients who have deteriorated self-image with a loss of self-esteem and a lack of confidence in the eyes of others. In this situation, traditional protocol with wax-up and mock-up is difficult and not sufficient to validate the esthetic project because of major difficulties. Another technique is necessary to specify, simplify and take it into account with special needs patients. In this context, this paper presents a new system for final esthetic validation of fixed prosthetic restorations. This procedure uses resin coping carrying tooth wax with ideal form. This system is transferred directly in mouth for trial. It can be modified by the dentist until satisfaction by modeling the wax. After validation, it can offer a good way for the dental technician to reproduce exactly the project validated in mouth on final restoration. Final esthetic validation (FEV) technic is a good methodology to improve the esthetic approach for special needs patients. This procedure is safe, cheap, and ideal to be sure of the patient point of view.

Retention of different non-metal single crown coping supporting single implant mandibular overdenture (in - vitro study)

Purpose: This study aimed to evaluate the retention of single implant mandibular overdenture using different single crown coping materials. Materials and Methods: Clear acrylic resin mandibular cast was fabricated with single implant located in the mid-line of the cast. The cast with the implant was scanned for designing of nine copings of different materials using computer aided design computer aided manufacture CAD/CAM and according to material used for copings fabrication, models were categorized as follow: Poly etherether ketone (PEEK) group, Zirconium dioxide (ZrO2) group, hybrid composite resin coping group. Nine identical mandibular complete overdentures were constructed, tensile force for removing overdenture with copings was then recorded. Results: Comparison of recorded tensile strength results showed a significant difference among groups where the highest retention was recorded with Zirconia group, followed by PEEK and the lowest retention results were noted with Hybrid composite resin. Conclusion: Within the limitation of this in vitro study, it could be concluded that single crown that fabricated from ZrO2 for supporting implant supported overdenture showed better retention results in comparison to PEEK a hybrid composite one.

Satisfaction with resilient denture liner versus acrylic resin telescopic prostheses for patients with ectodermal dysplasia: A nonrandomized crossover clinical trial

Statement of problemPatients with ectodermal dysplasia are characterized by anodontia or oligodontia. How their challenging prosthodontic rehabilitation might be optimized is unclear. PurposeThe purpose of this crossover study was to evaluate the effect of resilient denture liner versus acrylic resin copings in complete overdentures for patients with ectodermal dysplasia. Outcome measures included patient satisfaction, retention, and periodontal health of the abutment tooth. Material and methodsTen partially edentulous participants diagnosed with ectodermal dysplasia were recruited from the Faculty of Dentistry, Cairo University, Egypt, and enrolled in this crossover clinical trial. All participants received acrylic resin coping-retained maxillary complete overdentures (group N, stage 1). The acrylic resin copings were then replaced by a resilient denture liner (group S, stage 2). Patient satisfaction, retention, and periodontal health parameters were evaluated 1 week and 3 months after the completion of each stage. Patient satisfaction was assessed with a validated, reliable questionnaire. The results of the periodontal probing depths were tested with repeated measures ANOVA followed by the Bonferroni correction for pairwise comparisons. Tooth mobility, patient satisfaction, retention, and gingival index were tested by using the Wilcoxon signed ranked test. Ordinal data as the sixth and seventh domains of patient satisfaction were tested by using the McNemar test for paired comparisons (α=.05). ResultsThree months after overdenture delivery, a statistically significant difference was found between the groups regarding retention (P=.025), probing depth (P<.001), and gingival index (P=.011) favoring the acrylic resin coping-retained overdentures. Results of tooth mobility (P=.035), overall attitude (P=.041), ease of eating (P=.023), denture comfort (P=.024), and degree of teasing (P=.038) on wearing the denture showed a statistically significant difference between the groups, favoring the resilient denture liner. ConclusionsIn children with oligodontia and ectodermal dysplasia, the resilient denture liner-retained maxillary complete overdenture enhanced patient satisfaction and tooth mobility of anterior teeth, while minimally jeopardizing the periodontal condition of the abutment teeth.

Comparison of reconstruction of cement space in resin copings fabricated with the use of a 3D printer in single- and three-unit restorations

Marginal and internal gaps are very important factors in fixed prosthetic restorations. The marginal fit is affected by the cementing process of the restoration. One of the techniques used to create the required space between the prepared tooth and the crown is to use a die spacer. The aim of the current study was to assess the accuracy of reconstruction of the cement space in the resin copings of extracoronal restorations fabricated with the use of the 3D printing technique and compare it in single- and three-unit restorations. After taking impressions from the left maxillary first premolar and first molar teeth of a jaw model, a total of 20 models were prepared with the use of a 3D printer for single-unit and three-unit groups (a total of 120 samples) and cemented on their relevant dies. The samples were sectioned buccolingually. The images of the internal gaps were prepared under a light microscope and evaluated. The values in different groups were compared in relation to marginal and internal fit and analyzed with ANOVA (mixed models). Statistical significance was set at P&lt;0.05. Comparison of the accuracy of reconstruction of the cement space in resin copings fabricated with the use of a 3D printer showed that in the single-unit premolar tooth with a presumptive cement space of 45 µm the cement space was 30.45±20.01 µm (P&gt;0.001) at the margin and 36.01±13.52 µm (P&gt;0.001) in the internal area; in the reconstruction of the three-unit molar tooth with a presumptive cement space of 25 µm, the cement space at the margin was 105.97±33.7 µm (P&gt;0.964), with 120.09±63.15 µm (P&gt;0.005) in the internal area. It was concluded from the results of the present study that the accuracy of reconstruction of the cement space in resin copings fabricated with the use of a 3D printer in samples with a larger presumptive cement space was higher than that in samples with a smaller presumptive cement space. The accuracy of the reconstruction of the cement space in resin copings fabricated using a 3D printer in single-unit restorations was higher than that in three-unit restorations.

Reproducibility of different coping arrangements fabricated by dental micro-stereolithography: Evaluation of marginal and internal gaps in metal copings

Background/purposeTo evaluate the reproducibility of the marginal and internal gaps of metal copings fabricated using dental micro-stereolithography (μ-SLA), which is an additive manufacturing system. Materials and methodsA study cast of abutment tooth 46 was made from type-IV dental stone and was scanned to create a standard triangulation language file. Arrays of one (ORM), three (TRM), and six (SRM) resin copings were then fabricated on the μ-SLA build platform using investment, burnout, and casting (n = 12). The marginal and internal gaps of these metal copings were measured using a silicone-replica technique with a digital microscope (×160). The data obtained were analyzed using a non-parametric Kruskal–Wallis H test, a post-hoc Mann–Whitney U test, and a Bonferroni correction. ResultsThe mean and standard deviation of the marginal gap for each group were measured and found to be 81.1 and 53.2 μm, 68.3 and 44.8 μm, and 90.3 and 57.7 μm for ORM, TRM, and SRM, respectively. There were no statistical differences in the marginal gaps of the three groups (p > 0.05). ConclusionThe marginal and internal gap of ORM, TRM and SRM groups were considered clinically acceptable.

세 가지 방식으로 제작된 레진코핑의 내면적합성 평가: 3차원적 분석

Purpose: The purpose of this study was to evaluate the internal fitness of the resin coping that was fabricated by the traditional and Digital manufacturing methods through 3-dimensional analysis. Methods: maxillary right second molar was chosen implant master model. Custom-built impression trays were manufactured. After screwing the pick-up impression coping onto the master cast, impressions were made with silicone impression. The Working model was then made with type IV stone. The coping was fabricated: SLAC group (n=8), APPC group (n=8), LAPC group (n=8) Resin coping data was measured by using a three-dimensional evaluation program. Internal fitness was calculated by RMS (Root Mean Square).It measures mean and Standard Deviation (SD). Results: Three groups are measured 47.11±(3.08)㎛ total RMS of SLAC group, 48.35(±1.55㎛) for total RMS of LAPC group, 43.45±2.09㎛ for total RMS of APPC group. Measured value is gradually increased. Followed by autopolymerized pattern resin; Stereolithography resin, Light-activated pattern resin But there were no differences stastically(P>0.321). Conclusion: Evaluation of internal fitness on Resin copings was fabricated by three–ways methods showed that no differences statistically significant and clinically acceptable results

Evaluation of marginal and internal gaps of Ni-Cr and Co-Cr alloy copings manufactured by microstereolithography.

PURPOSEThe purpose of this study was to evaluate the marginal and internal gaps of Ni-Cr and Co-Cr copings, fabricated using the dental µ-SLA system.MATERIALS AND METHODSTen study dies were made using a two-step silicone impression with a dental stone (type IV) from the master die of a tooth. Ni-Cr (NC group) and Co-Cr (CC group) alloy copings were designed using a dental scanner, CAD software, resin coping, and casting process. In addition, 10 Ni-Cr alloy copings were manufactured using the lost-wax technique (LW group). The marginal and internal gaps in the 3 groups were measured using a digital microscope (160 ×) with the silicone replica technique, and the obtained data were analyzed using the non-parametric Kruskal-Wallis H test. Post-hoc comparisons were performed using Bonferroni-corrected Mann-Whitney U tests (α=.05).RESULTSThe mean (±standard deviation) values of the marginal, chamfer, axial wall, and occlusal gaps in the 3 groups were as follows: 81.5±73.8, 98.1±76.1, 87.1±44.8, and 146.8±78.7 µm in the LW group; 76.8±48.0, 141.7±57.1, 80.7±47.5, and 194.69±63.8 µm in the NC group; and 124.2±52.0, 199.5±71.0, 67.1±37.6, and 244.5±58.9 µm in the CC group.CONCLUSIONThe marginal gap in the LW and NC groups were clinically acceptable. Further improvement is needed for CC group to be used clinical practice.

Reproducibility of different arrangement of resin copings by dental microstereolithography: Evaluating the marginal discrepancy of resin copings

Statement of problemMicrostereolithography (μ-SLA), a form of additive manufacturing, can produce one or more platforms of resin copings. However, no evaluation has been made of the variation in marginal discrepancy using this method, even though this is an important factor for a successful restoration. PurposeThe purpose of this in vitro study was to evaluate the reproducibility and marginal discrepancy of resin copings fabricated using dental μ-SLA. Material and methodsA master die of a mandibular right first molar tooth was made from Type IV stone and scanned to produce a stereolithography file. Resin copings were then fabricated using μ-SLA additive manufacturing by repeating 1, 3, or 6 arrays to give a total number of 18. The marginal discrepancies of these resin copings were measured using digital microscopy (at ×160 magnification), and the data obtained were analyzed using a nonparametric Kruskal-Wallis H test, post hoc Mann-Whitney U-test, and Bonferroni correction. ResultsThe mean ±SD total marginal discrepancies of 1, 3, and 6 arrays were found to be 72.2 ±39.1 μm, 61.2 ±37.3 μm, and 92.5 ±54.1 μm. Statistically significant differences were found among the compared groups (P<.05). ConclusionsBased on the marginal discrepancy, μ-SLA of additive manufacturing is more precise when 3 arrays are used than when 1 or 6 arrays are used on a single build platform. Because the fit is affected by the number of copings fabricated, further research of multiple resin copings is required.

Die spacer thickness reproduction for central incisor crown fabrication with combined computer-aided design and 3D printing technology: An in vitro study

Statement of problemThe inability to control die spacer thickness has been reported. However, little information is available on the congruency between the computer-aided design parameters for die spacer thickness and the actual printout. PurposeThe purpose of this study was to evaluate the accuracy and precision of the die spacer thickness achieved by combining computer-aided design and 3-dimensional printing technology. Material and methodsAn ivorine maxillary central incisor was prepared for a ceramic crown. The prepared tooth was duplicated by using polyvinyl siloxane duplicating silicone, and 80 die-stone models were produced from Type IV dental stone. The dies were randomly divided into 5 groups with assigned die spacer thicknesses of 25 μm, 45 μm, 65 μm, 85 μm, and 105 μm (n=16). The printed resin copings, obtained from a printer (ProJet DP 3000; 3D Systems), were cemented onto their respective die-stone models with self-adhesive resin cement and stored at room temperature until sectioning into halves in a buccolingual direction. The internal gap was measured at 5 defined locations per side of the sectioned die. Images of the printed resin coping/die-stone model internal gap dimensions were obtained with an inverted bright field metallurgical microscope at ×100 magnification. The acquired digital image was calibrated, and measurements were made using image analysis software. Mixed models (α=.05) were used to evaluate accuracy. A false discovery rate at 5% was used to adjust for multiple testing. Coefficient of variation was used to determine the precision for each group and was evaluated statistically with the Wald test (α=.05). ResultsThe accuracy, expressed in terms of the mean differences between the prescribed die spacer thickness and the measured internal gap (standard deviation), was 50 μm (11) for the 25 μm group simulated die spacer thickness, 30 μm (10) for the 45 μm group, 15 μm (14) for the 65 μm group, 3 μm (23) for the 85 μm group, and -10 μm (32) for the 105 μm group. The precision mean of the measurements, expressed as a coefficient of variation, ranged between 14% and 33% for the 5 groups. ConclusionsFor the accuracy evaluation, statistically significant differences were found for all the groups, except the group of 85 μm. For the precision assessment, the coefficient of variation was above 10% for all groups, showing the printer’s inability to reproduce the uniform internal gap within the same group.

Comparative Evaluation of Marginal Discrepancy in Tooth Colored Self Cure Acrylic Provisional Restorations With and Without Reinforcement of Glass Beads: An In-Vitro Study.

This invitro study was conducted to compare and evaluate marginal discrepancy in two types of tooth colored self cure provisional restorative materials {DPI&UNIFAST TRAD} before and after reinforcement of glass beads. The aim of the present study was to evaluate and compare marginal discrepancy in two types of provisional restorative materials (DPI and UNI FAST TRAD) before and after reinforcement with Glass beads. Tooth shaped resin copings were fabricated on custom made brass metal die. A total of 60 resin copings were fabricated in which 30 samples were prepared with DPI and 30 samples with UNIFAST material. Each group of 30 samples were divided in to two sub groups in which 15 samples were prepared with glass bead reinforcement and 15 samples without reinforcement. The marginal discrepancy was evaluated with photomicroscope {Reichet Polyvar 2 met} by placing the resin copings on custom made brass resin coping holder. Measurements obtained were statistically analysed by unpaired t-test to know any significance between two variables. Unreinforced DPI specimens had shown lower marginal discrepancy (442.82) than reinforced specimens (585.77). Unreinforced UNIFAST specimens have shown high values of marginal discrepancy (592.83) than reinforced specimens (436.35). p-value between reinforced and unreinforced specimens of DPI (p=0.0013) and UNIFAST (p= 0.0038) has shown statistical significance. This in-vitro study revealed that unreinforced DPI specimens have shown lower marginal discrepancy than reinforced specimens and unreinforced UNIFAST specimens have shown higher values of marginal discrepancy than reinforced specimens.

Linear dimensional changes in plaster die models using different elastomeric materials

Dental impression is an important step in the preparation of prostheses since it provides the reproduction of anatomic and surface details of teeth and adjacent structures. The objective of this study was to evaluate the linear dimensional alterations in gypsum dies obtained with different elastomeric materials, using a resin coping impression technique with individual shells. A master cast made of stainless steel with fixed prosthesis characteristics with two prepared abutment teeth was used to obtain the impressions. References points (A, B, C, D, E and F) were recorded on the occlusal and buccal surfaces of abutments to register the distances. The impressions were obtained using the following materials: polyether, mercaptan-polysulfide, addition silicone, and condensation silicone. The transfer impressions were made with custom trays and an irreversible hydrocolloid material and were poured with type IV gypsum. The distances between identified points in gypsum dies were measured using an optical microscope and the results were statistically analyzed by ANOVA (p < 0.05) and Tukey's test. The mean of the distances were registered as follows: addition silicone (AB = 13.6 µm, CD=15.0 µm, EF = 14.6 µm, GH=15.2 µm), mercaptan-polysulfide (AB = 36.0 µm, CD = 36.0 µm, EF = 39.6 µm, GH = 40.6 µm), polyether (AB = 35.2 µm, CD = 35.6 µm, EF = 39.4 µm, GH = 41.4 µm) and condensation silicone (AB = 69.2 µm, CD = 71.0 µm, EF = 80.6 µm, GH = 81.2 µm). All of the measurements found in gypsum dies were compared to those of a master cast. The results demonstrated that the addition silicone provides the best stability of the compounds tested, followed by polyether, polysulfide and condensation silicone. No statistical differences were obtained between polyether and mercaptan-polysulfide materials.

Intraoral Acrylic Resin Coping Fabrication for Making Interocclusal Records

A safe and accurate method for the fabrication of acrylic resin copings to be used for interocclusal registration is described. Copings are fabricated on vital prepared teeth using visible light-cured acrylic resin, and the records are then obtained with autopolymerizing acrylic resin. This allows for an interocclusal recording to be obtained at the final impression appointment.

Effect of cervical relining of acrylic resin copings on the accuracy of stone dies obtained using a polyether impression material

The purpose of this study was to evaluate the accuracy of the respective dies after polyether elastomeric procedure in the presence or absence of cervical contact of the acrylic resin shell with the cervical region, establishing a comparison to dies obtained with stock trays. This study consisted of three groups with 10 specimens each: 1) acrylic copings without cervical contact, (cn); 2) acrylic copings with cervical contact (cc); 3) perforated stock tray, (st). The accuracy of the resulting dies was verified with the aid of a master crown, precisely fit to the master steel die. ANOVA test found statistically significant differences among groups (p<0.001). Tukey's test found that the smallest discrepancy occurred in group cn, followed by cc, while the st group presented the highest difference (cc x cn: p=0.007; st x cn: p<0.001; st x cc: p<0.001).

Composite resin root coping with a keeper for magnetic attachment for replacing the missing coronal portion of a removable partial denture abutment

Numerous methods for replacing missing removable partial denture abutments have been introduced, however, most of them are time consuming and require several visits to complete the procedure. Since magnetic attachments can provide support and bracing as well as retention for overdenture abutments, the remaining tooth root structure can be used to support the coping with the keeper. Through the use of composite resin and adhesive material, improved retention of the keeper to the root may be achieved, along with improved esthetics. This article describes a method for replacing the missing abutment of a removable partial denture with a magnetic attachment, and a composite resin coping with a keeper.

A procedure for fitting a fixed partial denture to an existing removable partial denture

An indirect technique for fitting a new cast gold crown or fixed partial denture (FPD) to an existing removable partial denture (RPD) is presented. This method uses an acrylic resin coping made on a definitive cast fit directly to the patient's RPD intraorally, with the new FPD subsequently completed on the cast. The patient does not have to relinquish the RPD for laboratory procedures, although an appointment is required to fit the coping intraorally where contact is made with the RPD.

Technique to help verify the accuracy of a stone cast for fabrication of a multiple-unit fixed prosthesis

J Prosthet Dent 2002;87:462-3.

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.)

New impression system for ITI solid abutment cementable restoration

Dental implantology has provided substantial advances in selection and placement of implants. An innovative implant impression and restorative system was recently introduced by ITI Strauman (Institut Strauman AG, Waldenburg, Switzerland), which provides an uncomplicated approach to quality restorations. This system includes analogs of solid abutments and premade castable resin copings that facilitate fabrication of individual or multiple unit cemented implant restorations.

印象法の違いが作業模型の寸法精度に及ぼす影響について

The purpose of this study was to evaluate the impression techniques for polyvinyl siloxane impression materials in terms of the accuracy of the resultant stone casts. An acrylic resin maxillary model with nature dentition was prepared as the original model. Four impression techniques with or without undercut blockout were selected to make the impressions, using stock tray only, custom tray only, custom tray with resin copings for abutment teeth and custom tray with bridge copings. The dimensional changes of the anterior bridge area and posterior bridge area of stone casts were compared. The results obtained were as follows : 1. The effect of undercut blockout on the accuracy of stone cast was more significant in the anterior bridge area than in the posterior bridge area. 2. The dimensional changes of the anterior abutment teeth were more significantly affected by the impression techniques than those of the posterior. 3. It would appear from this study that the impressions made by custom tray with bridge coping were superior to those by the other techniques in terms of the dimensional accuracy and stability of the stone casts.

A procedure for making an interocclusal record without the use of record bases for a combined fixed/removable prosthesis

This article describes a procedure for making an interocclusal record for a remount procedure after tryin of the castings. This method can also be used for the initial mounting by substituting autopolymerizing acrylic resin copings for the metal castings.