Use of Resin-Based Provisional Material to Create the Posterior Palatal Seal in Complete Denture Definitive Impressions.

The purpose of this article was to present an alternative procedure using resin-based provisional material to create the posterior palatal seal (PPS). This method offers more practicality in clinical routine and increased control for addition of material to create the PPS when compared to traditional techniques such as the use of impression wax.

Comparison of fit accuracy of pressed lithium disilicate inlays fabricated from wax or resin patterns with conventional and CAD-CAM technologies.

STATEMENT OF PROBLEM: The use of resin patterns to produce partial coverage restorations is poorly documented. PURPOSE: The purpose of this in vitro study was to compare the marginal and internal fit accuracy of lithium disilicate glass-ceramic inlays obtained from wax or resin patterns and fabricated with digital and conventional techniques. MATERIAL AND METHODS: A dentoform mandibular first molar was prepared for a mesio-occlusal ceramic inlay. Six groups of 15 inlays were obtained by conventional impression and manual wax (group CICW) or resin patterns (group CICR); conventional impression, laboratory scanning of the stone die, CAD-CAM milled wax (group CIDW), or polymethylmethacrylate (PMMA) blocks (group CIDR); and scanning of the master preparation with an intraoral scanner, CAD-CAM milled wax (group DSDW), or PMMA blocks (DSDR). The same design was applied to produce the wax and PMMA patterns in the last 4 groups. The replica technique was used to measure marginal and internal fit under stereomicroscopy. Mixed-model ANOVA was applied to assess differences according to the techniques, materials, and discrepancy location (α=.05). RESULTS: The results demonstrated significant effects of the technique (P<.001), material (P=.009), and discrepancy location (P<.001) on fit measurements. Marginal discrepancy was only affected by the technique (P<.001), with the digital approaches yielding the smallest marginal discrepancy (23.5 ±3.6 µm), followed by the conventional digital techniques (31.1 ±5.6 µm) and finally by the conventional (42.8 ±7.2 µm) techniques. Internal fit was significantly influenced only by the material with lower discrepancy in wax (75.2 ±9.0 µm) than in resin patterns (84.7 ±15.1 µm). The internal discrepancy was significantly larger than the marginal discrepancy in all groups (P<.001). CONCLUSIONS: Inlays generated from conventional wax and resin patterns tend to show higher marginal discrepancies than conventional digital and full digital patterns. Wax and resin materials yield similar marginal fit accuracies irrespective of the impression/manufacturing technique. Better internal fit was shown in wax than in resin patterns, regardless of the technique.

Evaluation of the Efficacy of Different Mixing Techniques and Disinfection on Microbial Colonization of Polyether Impression Materials: A Comparative Study.

AIM: This study aims to determine the role of mixing techniques of polyether impression materials and efficacy of disinfection on microbial colonization of these impression materials. MATERIALS AND METHODS: Polyether impression material was mixed using two methods: First by hand mixing (group I) and second using an automixer (group II) with a total of 100 samples. Four microbial strains were studied, which included Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. After incubation, the bacterial colonies were counted, and then, disinfectant solution was applied. The effect of disinfection solution was evaluated for each specimen. RESULTS: The surface of polyether impression materials mixed with an automixer has less number of voids and overall a smoother surface as compared with the hand-mixed ones. On comparing the disinfection procedures, i.e., specimens without any disinfection and specimens after disinfection, statistically highly significant difference was seen between all the groups. CONCLUSION: We can conclude that impression mixing procedures are important in determining the surface characteristics of the impression and ultimately the colonization of bacteria and also determine the importance of disinfection on microbial colonization. CLINICAL SIGNIFICANCE: This study emphasises the deleterious role of nosocomial infections and specific measures that should be taken regarding the prevention of such diseases. Dental impressions are proved to be a source of such infections and may lead to transmission of such diseases. Thus, proper measures should be taken right from the first step of impression taking to minimizing and preventing such kind of contaminations in clinical practice.

Dental Impression Materials and Techniques.

Dental impression making is the process of creating a negative form of the teeth and oral tissues, into which gypsum or other die materials can be processed to create working analogues. Contemporary dentistry generates new information every year and digital dentistry is becoming established and influential. Although dentists should stay abreast of new technologies, some of the conventional materials and time-tested techniques remain widely used. It is important to review the impression-making process to ensure that practitioners have up-to-date information about how to safely and effectively capture the exact form of the oral tissues to provide optimal patient management.

Technique for transferring the path of insertion of a removable partial denture to a CAD-CAM-generated implant surgical template.

A technique is described that uses a surveyor, gutta percha points, and a computer-aided design and computer-aided manufacturing (CAD-CAM)-guided implant surgery system to predetermine and transfer the ideal angulation of the implant to be placed.

Development and capture of soft tissue contours at time of implant placement.

A technique is described which will generate a customized healing abutment for a dental implant to allow the development of ideal soft tissue contours. With implant position and soft tissue contours defined at surgery, customized impression techniques can be used to capture those details and help generate the definitive implant-supported restoration. This workflow reduces the number of patient visits.

An alternative impression technique for mobile teeth.

The impression technique described combines elastomeric impression materials and irreversible hydrocolloid to make an accurate preliminary impression of extremely mobile and misaligned teeth. Upon setting, the materials are removed from the mouth in 3 different directions and reassembled extraorally. This technique provides an alternative, easy, accurate, and safe way to make a preliminary impression of mobile, periodontally involved teeth.

Technique to verify the accuracy of a definitive cast before the fabrication of a fixed dental prosthesis.

This report describes a straightforward technique for verifying the accuracy of a definitive cast by using a maximal intercuspation record fabricated from polyvinyl siloxane occlusal registration material. This precise verification method detects inaccurate casts before the dental prosthesis is fabricated, thus saving chairside and laboratory time while reducing the number of costly prosthesis remakes.

Planning extensive esthetic restorations for anterior teeth: use of waxed-up study casts and composite resin mock-ups.

The aim of this case report is to highlight the importance of appropriate planning protocols when direct composite resin restorations are used to solve extensive esthetic problems. A 30-year-old patient complained about her small maxillary anterior teeth and short upper lip. All teeth were healthy and light colored, and the patient exhibited good oral hygiene. The anterior teeth were relatively short, resulting in a compromised esthetic relationship between height and width. The maxillary and mandibular right central incisors were in an edge-to-edge relationship. After diagnostic casts and waxed-up study casts were obtained, occlusal adjustment and recontouring of the incisal and labial surfaces of the mandibular right central incisor were performed to increase overjet. To increase the volume of the upper lip, composite resin restorations were planned for the maxillary anterior teeth. To confirm that the contours and color of the new smile were acceptable to the patient, composite resin esthetic mock-ups were made directly in the mouth before the definitive procedure. After definitive restoration of the anterior teeth, additional occlusal adjustments were performed. At the 36-month follow-up, no fracturing or severe wear of the restorations was observed. The restored anterior guidance provided excellent function after 3 years of clinical service.

Simplified custom impression post for implant-supported restorations.

The esthetic outcome of an implant-supported restoration is greatly influenced by the relationship between the contours of the definitive prosthesis and the periimplant tissues. In this clinical technique, an implant analog holder and autopolymerizing acrylic resin were used to accurately register the soft-tissue transition zone created by the interim restoration and transfer it to the impression post during the definitive impression.

Analysis of Different Impression Techniques and Materials on Multiple Implants Through 3-Dimensional Laser Scanner.

OBJECTIVE: The aim of this study was to evaluate the accuracy of 7 different implant impression techniques for full-arch prostheses. MATERIALS AND METHODS: A master cast simulating an edentulous arch with 4 implants was used. Seven impression techniques were tested: open tray with polyether Impregum (OTI); open tray with splint-polyether Impregum (OTSI); closed tray with polyether Impregum; open tray with polyether Ramitec; open tray with splint-polyether Ramitec; closed tray with polyether Ramitec (CTR); open tray with impression plaster (OTP). Five impressions of the master cast were taken for each technique using an impression simulator device. Casts were realized based on those impressions (n = 35). Median values of deviation from the master cast were recorded for each cast through a 3-dimensional laser scanner. RESULTS: Only OTI (P = 0.028) and OTSI (P < 0.001) presented a statistically significant difference compared to the master cast. OTP (P = 0.99) and CTR (P = 0.10) showed median values of deviation close to zero (-0.001 and -0.003 mm, respectively). CONCLUSION: Stiff impression materials (such as plaster or rigid polyether) guarantee greater accuracy in cases of multiple implant impressions of patients with full-arch rehabilitations. Splinting of impression copings with acrylic resin did not improve accuracy.

Full-arch implant fixed prostheses: a comparative study on the effect of connection type and impression technique on accuracy of fit.

PURPOSE: The aim of this study was to assess the effect of connection type and impression technique on the accuracy of fit of implant-supported fixed complete-arch dental prostheses (IFCDPs). MATERIALS AND METHODS: An edentulous mandibular cast with five implants was fabricated to serve as master cast (control) for both implant- and abutment-level baselines. A titanium one-piece framework for an IFCDP was milled at abutment level and used for accuracy of fit measurements. Polyether impressions were made using a splinted and non-splinted technique at the implant and abutment level leading to four test groups, n = 10 each. Hence, four groups of test casts were generated. The impression accuracy was evaluated indirectly by assessing the fit of the IFCDP framework on the generated casts of the test groups, clinically and radiographically. Additionally, the control and all test casts were digitized with a high-resolution reference scanner (IScan D103i, Imetric, Courgenay, Switzerland) and standard tessellation language datasets were generated and superimposed. Potential correlations between the clinical accuracy of fit data and the data from the digital scanning were investigated. To compare the accuracy of casts of the test groups versus the control at the implant and abutment level, Fisher's exact test was used. RESULTS: Of the 10 casts of test group I (implant-level splint), all 10 presented with accurate clinical fit when the framework was seated on its respective cast, while only five of 10 casts of test group II (implant-level non-splint) showed adequate fit. All casts of group III (abutment-level splint) presented with accurate fit, whereas nine of 10 of the casts of test group IV (abutment-level non-splint) were accurate. Significant 3D deviations (P < 0.05) were found between group II and the control. No statistically significant differences were found between groups I, III, and IV compared with the control. Implant connection type (implant level vs. abutment level) and impression technique did affect the 3D accuracy of implant impressions only with the non-splint technique (P < 0.05). CONCLUSION: For one-piece IFCDPs, the implant-level splinted impression technique showed to be more accurate than the non-splinted approach, whereas at the abutment-level, no difference in the accuracy was found.

Use of a bite registration vinyl polysiloxane material to identify denture flange overextension and/or excessive border thickness in removable prosthodontics.

Vinyl polysiloxane (VPS) has multiple applications in prosthodontics. This article describes how a bite registration fast-set VPS material was used to identify length overextension and/or excessive border thickness of denture flanges. In addition, the advantages of VPS over conventional materials are presented.

In Vitro Implant Impression Accuracy Using a New Photopolymerizing SDR Splinting Material.

PURPOSE: The study aims to evaluate three-dimensionally (3D) the accuracy of implant impressions using a new resin splinting material, "Smart Dentin Replacement" (SDR). MATERIALS AND METHODS: A titanium model of an edentulous mandible with six implant analogues was used as a master model and its dimensions measured with a coordinate measuring machine. Before the total 60 impressions were taken (open tray, screw-retained abutments, vinyl polysiloxane), they were divided in four groups: A (test): copings pick-up splinted with dental floss and fotopolymerizing SDR; B (test): see A, additionally sectioned and splinted again with SDR; C (control): copings pick-up splinted with dental floss and autopolymerizing Duralay® (Reliance Dental Mfg. Co., Alsip, IL, USA) acrylic resin; and D (control): see C, additionally sectioned and splinted again with Duralay. The impressions were measured directly with an optomechanical coordinate measuring machine and analyzed with a computer-aided design (CAD) geometric modeling software. The Wilcoxon matched-pair signed-rank test was used to compare groups. RESULTS: While there was no difference (p = .430) between the mean 3D deviations of the test groups A (17.5 µm) and B (17.4 µm), they both showed statistically significant differences (p < .003) compared with both control groups (C 25.0 µm, D 19.1 µm). CONCLUSIONS: Conventional impression techniques for edentulous jaws with multiple implants are highly accurate using the new fotopolymerizing splinting material SDR. Sectioning and rejoining of the SDR splinting had no impact on the impression accuracy.

Comparative evaluation of the effects of implant position, impression material, and tray type on implant impression accuracy.

PURPOSE: To evaluate the effect of implant position, impression, and tray material on the accuracy of implant impressions of edentulous arches with multiple implants. MATERIALS AND METHODS: Four experimental groups were produced; medium-viscosity polyvinyl siloxane (PVS) was used in 3 groups and polyether was used in 1 group. In PVS groups, different tray types were used; metal stock trays, custom acrylic tray, and full-arch perforated plastic trays. In polyether group, custom acrylic trays were used. The discrepancies in 3 dimensions were measured. RESULTS: The casts obtained exhibited small deviations (7.50-9.71 µm) from the master cast. There was no statistically significant difference between the polyether and PVS groups. Similarly, different tray materials did not produce any statistically significant discrepancies within the PVS groups. There was no significant difference among the groups when the accuracy of anterior implants were compared, but within-the-group comparisons showed that except group 1 (GR1), the posterior implants demonstrated more accuracy than anterior ones. CONCLUSIONS: Polyether and PVS can safely be used for the impressions of the edentulous arches with multiple implants and different tray types produce similar accuracy results.

Accuracy of an open-tray implant impression technique with 3 splinting materials: an in vitro study.

This study compared the accuracy of impressions using 3 types of splinting materials: a pattern acrylic resin (Group 1), an acrylic resin (Group 2), and a dual-cured composite resin (Group 3). A total of 60 impressions (n = 20) were made. Implant positions were compared against the master model using a coordinate measuring machine with ANOVA comparison (P = 0.05). The minimum and maximum differences in the x axis were found in Groups 2 and 3, respectively. For the y axis, Groups 2 and 1 showed the minimum and maximum differences, respectively. The minimum and maximum differences in the z axis were found in Groups 3 and 1, respectively. All differences in the axes were statistically significant (P < 0.05). These findings indicated that the composite resin demonstrated better accuracy than the other tested splinting materials.

Novel management of intractable chylous fistula with the application of an impression paste.

Chylous fistula is a kind of complication during neck dissection that rarely happens, but might lead to some serious clinical outcome. The standard treatments include local compressive bandaging, negative pressure drainage, ligation of the fistula orifice, alimentary control, and, occasionally, the use of somatostatin. Among them, the simplest is compressive bandaging, but the bandage can easily become loosened and cannot achieve the necessary pressure effect. In this paper, the novel application of an impression paste, which is normally used in prosthodontic treatments, will be introduced. It might be a very practical method for the treatment of these surgical complications in hospitals where advanced treatment modalities are not available.

Efectos de los desinfectantes en impresiones de siliconas / Effects of disinfectants in silicone impressions

Las siliconas son materiales utilizados para obtener impresiones dentales, sus propiedades permiten obtener gran exactitud. Las impresiones no deben representar vehículo de transmisión de microorganismos que puedan generar contaminación cruzada entre pacientes, personal dental y de laboratorio. Hoy en día es obligatoria la desinfección por inmersión o aspiración de las impresiones antes de enviarlas a laboratorio. La naturaleza del desinfectante, el tiempo que actúa sobre la impresión, la técnica de desinfección utilizada y la concentración de los desinfectantes influyen sobre las propiedades de las impresiones. Una adecuada interacción entre los agentes químicos desinfectantes y los materiales de impresión trae como resultado modelos de trabajos libres de contaminación, sin sacrificar la exactitud y las dimensiones lineales de la impresión dental. Los objetivos del presente trabajo son: describir método de desinfección de impresión de silicona, los desinfectantes utilizados en cuanto a su composición y forma de uso, además los efectos producidos por los mismos sobre el material de impresión. El propósito es proporcionar al odontólogo general información sobre el uso de desinfectantes sobre las impresiones de silicona de manera a evitar las infecciones cruzadas y mantener las propiedades del material. Se concluyó que las siliconas de condensación y adicción pueden ser desinfectadas mediante inmersión o aspiración con distintas soluciones certificadas, teniendo en cuenta la correcta manipulación y el tiempo necesario para que se produzca la eliminación de microorganismos y evitar los efectos adversos sobre las propiedades del material.