Direct custom implant impression copings for the preservation of the pontic receptor site architecture

The direct custom implant impression coping technique is designed to record the periimplant gingiva and pontic receptor site after the tissues have been shaped with a provisional restoration. The technique prevents inaccurate recording of the gingival architecture by using a dual polymerizing composite resin placed into the sulcus and pontic receptor sites and adapted to the open tray implant impression copings. This technique may improve soft tissue accuracy between the clinical condition and the laboratory cast.     

Indirect implant-supported fixed provisional restoration in the esthetic zone: fabrication technique and treatment workflow

Treatment objectives of an implant-supported fixed provisional restoration include shaping/preservation of the gingival soft tissue contour, functional and esthetic substitution of the missing dentition during postsurgical healing, and definitive prosthesis fabrication stages. Fixed provisional restoration can also serve as an esthetic and functional blueprint in the fabrication of the definitive restoration. Despite its common use and important indications, limited information is available on the various aspects of the provisional fabrication and treatment. This article presents a production technique and treatment workflow of a laboratory-fabricated, screw-retained fixed provisional restoration. Provisional restoration is fabricated using layering technique and internal stain characterization. The soft tissue profile of the working cast is modified according to the coronal contour of the diagnostic wax-up. Upon delivery, the provisional contour is reevaluated and modified as necessary. The developed emergence profile of the provisional restoration is transferred to the master cast via customized impression copings. CLINICAL SIGNIFICANCE: Laboratory-fabricated implant-supported provisional restorations allow the esthetic and functional substitution of the missing dentition and the shaping of the soft tissue profile, and can act as a blueprint in the fabrication of definitive restorations.     

Implant Digital Impression in the Esthetic Area

The aim of this report is to describe two standardized protocols for digital impression when implant support rehabilitation is used in the esthetic area. The two techniques were used to transfer all provisional crown parameters to definitive restorations in different clinical scenarios. In the direct technique, an impression (STL1) is made of the provisional restorations attached to the implants, with surrounding gingival tissue. The second scan (STL2) captures the sulcular aspect of the peri‐implant soft tissue immediately after removal of the provisional restoration. The last impression (STL3) of the complete arch is made with a standardized scanbody attached to the implant to capture the 3D location of the implant. The direct technique is indicated when the peri‐implant soft tissues are stable upon removal of the provisional restoration. The indirect technique is used when the gingival tissue collapses rapidly after the removal of the provisional crown. The impressions of the provisional restoration and the position of the implant are similar to those obtained with the direct technique, and the shape of the peri‐implant tissue is extrapolated from the negative shape obtained from making the digital impression when the provisional restoration is taken out of the mouth. Finally, in both techniques the 3 scans are superimposed to obtain a file, which contains the details of the peri‐implant soft tissue. The direct and indirect digital techniques allowed realization of a predictable definitive restoration in the esthetic zone in different clinical scenarios, reducing the duration of clinical procedures.     

Simple method of fabricating an impression coping to reproduce peri-implant gingiva on the master cast

This article describes a simple technique in which a custom impression coping is fabricated with flowable composite and used to reproduce peri-implant soft tissues on the master cast. This procedure is designed to generate an accurate reproduction of the gingival contours surrounding the implant, thus contributing to a final restoration with favorable esthetics.     

Clinical application of surgical fixation screws in implant prosthodontics--Part II: Indexing implant position

The accurate transfer of intraoral implant position to the definitive cast in situations of immediate implant loading in completely edentulous patients is an important step and may be difficult to achieve with common transfer and impression methods. Intraoral fixed points of reference accurately transferred to the definitive cast are necessary to provide precise and stable placement of radiographic and surgical templates during the presurgical diagnostic phase, during implant placement, and during fabrication of an immediate provisional restoration. This article describes a technique using surgical microfixation screws to provide fixed reference points and transfer the position of the conventional implants to the definitive cast.     

1998 Judson C. Hickey Scientific Writing Award. 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.     

Evaluation of Accuracy of Direct Transfer Snapon Impression Coping Closed Tray Impression Technique and Direct Transfer Open Tray Impression Technique: An In Vitro Study

Accuracy of the implant impression technique is one of the key factor determining the strain free fit of the prosthesis fabricated which influences the treatment success. Two implant impression techniques namely the closed tray technique with transfer coping and open tray technique were evaluated for accuracy with stone casts obtained from them. Casts were evaluated using a custom constructed bar on strain gage (SYSCOM) and abutment coordinates using Coordinate Measuring Machine (TESA micro-HITE). The statistical analysis with one way ANOVA and Mann–Whitney tests show that the casts obtained with open tray technique were accurate than the casts of closed tray technique (significance P < 0.001). Direct transfer impression technique with less number of components ensures the high accuracy of transfer of implant positions from master cast to the laboratory cast compared to the indirect transfer impression technique.     

An alternative method for restoring single-tooth implants

BACKGROUND: Having laboratory technicians prepare soft-tissue casts and implant abutments with or without concomitant removable temporary prostheses during the restorative phase of single-tooth replacement is an accepted practice. It can, however, result in functional and esthetic intraoral discrepancies. CASE DESCRIPTION: Single-tooth implants can be restored with crowns (like those for natural teeth) fabricated at a dental laboratory on casts obtained from final impressions of prepared implant abutments. In the case reported, the restorative dentist restored the patient's single-tooth implant after taking a transfer impression. He constructed a cast simulating the peri-implant soft tissue with final impression material and prepared the abutment on this model. His dental assistant then fabricated a fixed provisional restoration on the prepared abutment. At the patient's next visit, the dentist torqued the prepared abutment onto the implant, took a final impression and inserted the provisional restoration. A crown was made conventionally at the dental laboratory and cemented in place at the following visit. CLINICAL IMPLICATIONS: This alternative method for restoring single-tooth implants enhances esthetics by more accurately simulating marginal gingival architecture. It also improves function by preloading the implant through fixed temporization after the dentist, rather than the laboratory technician, prepares the abutment to the dentist's preferred contours.     

Comparison of impression techniques for a five-implant mandibular model.

Production of an accurate dental cast framework that meets the implant objective of passive fit demands an understanding of potential processing errors. Working casts fabricated from impressions using two different transfer copings, as provided by a leading implant manufacturer, were investigated for differences in accuracy. A five-implant mandibular model was used to produce seven casts by both the indirect and direct transfer coping techniques. Comparison was made by using a dental cast framework fitted to the master cast. Differences in distances measured between each group and the master cast were analyzed to establish differences between methods. For the model used, the direct technique produced more accurate working casts. A concern for potential impression distortion given the specific clinical situation underscores the method of choice.     

A Technique to Simultaneously Fabricate Multiple Custom Impression Posts for Implant‐Supported Restorations in the Esthetic Zone

Peri‐implant transmucosal tissue, an essential element of peri‐implant esthetics, is critical to the success of prostheses in the esthetic zone. The optimal transmucosal tissue profile can be transferred to the master cast with the aid of custom impression posts. In this clinical technique, the initial cast used to fabricate provisional prostheses was conveniently used to aid in the time‐efficient fabrication of multiple custom impression posts simultaneously using self‐cured acrylic resin. This technique also applies to single restorations. In addition, the use of an initial cast as holder makes it easy to transfer custom impression posts to the mouth accurately and efficiently.     

Modified soft tissue cast for fixed partial denture: a technique

In process of fabrication of a fixed partial denture, dies are trimmed to expose margins of the preparations. The need for the soft tissue cast is quite evident as the soft tissue emergence profile that surrounds the prepared tooth is destroyed in the process of fabrication. This article describes a modified technique to fabricate the soft tissue cast for the conventional fixed partial denture. The impression made with the polyvinylsiloxane was first poured to prepare the die cast. After retrieval of the cast, the same impression was poured second time with the resin based resilient material to cover the facial and proximal gingival areas. The remaining portion of the impression was poured with the gypsum material. This technique does not require additional clinical appointment, second impression procedure, technique sensitive manipulations with impression, or cumbersome laboratory procedures. The simplicity of this technique facilitates and justifies its routine use in fabrication of the fixed partial denture.     

Fabrication of removable stone dies using cemented dowel pins.

Proper dowel pin placement in the working cast is important in the fabrication of a cast restoration. A technique is suggested whereby the dowel pin is orientated and cemented after the working cast has been separated from the impression. This procedure produces a working die that has a correctly positioned dowel pin, is stable, and can be repeatedly returned to its original relationship. A technique is suggested whereby the dowel pin is orientated and cemented after the working cast has been separated from the impression. This procedure produces a working die that has a correctly positioned dowel pin, is stable, and can be repeatedly returned to its original relationship.     

Immediate provisional restorations to aid in gingival healing and optimal contours for implant patients

A procedure for making an impression at stage I implant surgery is described, and the sequential laboratory procedures for fabricating a custom provisional restoration are presented. The provisional restoration is delivered at the uncovering of the implant, providing a template for the tissue healing with desired contours. This procedure facilitates the fabrication of implant restorations with optimal gingival contours and esthetics.     

Digital transfer of the subgingival contour and emergence profile of the provisional restoration to the final bone-anchored fixed restoration

Purpose

This report was written to introduce an attempt at clinical application of our newly developed digital workflow to reproduce the morphology of the subgingival contour and the emergence profile of the provisional restoration within the final bone-anchored fixed restoration, using a bounded unilateral edentulous case.

A technique for immediately restoring single dental implants with a CAD-CAM implant-supported crown milled from a poly(methyl methacrylate) block

This technique is used when a single dental implant is placed. A stent made of autopolymerized acrylic resin was used to transfer the implant position to the laboratory. Once the implant position was transferred, the stone cast was scanned, and a computer-aided design and computer-aided manufacturing (CAD-CAM) interim implant-supported crown was milled from a poly(methyl methacrylate) (PMMA) block. A titanium insert, in contact with the implant platform and not the PMMA material, was used to support the crown. The interim prosthesis was then placed intraorally. The soft tissues were sutured, and the interim prosthesis was left for a period of at least 3 months to confirm osseointegration and allow the soft tissue to heal. A CAD-CAM titanium impression coping was made and used for the definitive impression. The contours of the impression coping were identical to the contours of the interim restoration. The data of the digital design of the interim prosthesis were saved, and the definitive prosthesis was fabricated with contours identical to those of the interim prosthesis.     

Cast impression coping technique

A laboratory cast impression coping has been designed to capture accurate crown and bridge impressions, even in the most challenging circumstances. The designed technique is similar to copper band techniques and likewise does not require gingival retraction. The design includes a flat, nail-shaped head for proper finger pressure during the wash impression phase. Beads enhance the nail head design, allowing the impression-filled coping to be captured properly in the master tray or over-impression.     

A fully digital approach to replicate functional and aesthetic parameters in implant-supported full-arch rehabilitation

Purpose

The aim of this technical procedure was to use a fully digital technique (FDT) for full-arch implant support rehabilitation. The FDT was used to transfer the provisional restoration parameters to definitive restorations using intraoral scanners.

Technique for achieving a passive framework fit: a clinical case report

The clinical application of a 4-step technique for achieving the passive fit of an implant-supported cast bar or framework is reported. Implant-level transfers were attached, splinted intraorally with pattern resin, picked up in an open-tray elastomeric impression, and used to fabricate a working cast containing implant analogs. A light-cured template was used to verify master cast accuracy. A ceramometal fixed partial denture restoration was fabricated on the working cast with a preliminary try-in of the cast metal framework. A passive prosthesis fit was achieved. Failure to create an accurate working cast can distort the intended fit of a cast framework on the abutments in the patient's mouth. Optimal positioning of the implant analog in the master cast depends on (1) the transfer technique and (2) the ability of the system to maintain precise rotational orientation of the transfer components. The splinted transfer technique developed 20 years ago has sometimes been effective in improving the accuracy of framework fit with external hexagon implant-abutment connections, but it has not been documented with newer implant-abutment connections. Techniques for reestablishing master cast accuracy and correcting the superstructure are presented. The use of the presented technique resulted in a passive-fitting framework.     

Provisional crown failures in dental school predoctoral clinics

Following a preliminary study indicating that at least 10 percent of single-unit crown temporary restorations failed in patients who received treatment by predoctoral students, a comprehensive examination of provisional crown failure was initiated to identify strategies to reduce the failure rate. For all provisionalized, natural tooth, single-unit crown preparations in University of North Carolina School of Dentistry predoctoral clinics for one year (N=1008), we noted tooth type, type of crown, student level, faculty coverage experience, treatment clinic, temporary material and luting agent, and retreatment (failure) of the provisional restoration. For failures, we also noted the stage of crown preparation at failure and the time since initial placement of the temporary. We analyzed these data using simple cross-tabs and logistic regression on need for retreatment (alpha =0.05). The failure rate was 18.75 percent (N=189). The median time to failure was twelve days; the 25(th) and 75(th) percentiles were six and twenty-six days. Significant risk factors, in order of odds ratio estimates, were molar tooth, second- or third-year student, and inexperienced faculty. Most provisional failures occurred during the final preparation phase of treatment. Provisional restoration failure is more frequent than was initially suspected from preliminary studies. Strategies for institutional intervention to reduce provisional restoration failure include greater attention to evaluating provisional crowns placed by inexperienced students (sophomores and juniors) and placing more emphasis on the retentiveness of provisional restorations reused following the final impression. Review of provisional evaluation procedures is also indicated for faculty who do not routinely supervise these procedures.     

Use of Implant‐Supported Custom Milled Impression Copings to Capture Soft‐Tissue Contours and Incisal Guidance

A technique is presented where a custom milled impression coping is used to replicate the clinically established anterior incisal guidance to the definitive prosthesis when multiple implants are restored in the esthetic zone. A conventional impression is initially made, then the stone cast is scanned, and a digitally designed custom screw‐retained, implant‐supported interim prosthesis is milled from a polymethylmethacrylate (PMMA) billet. This is aimed to digitally design the pontic areas, contour the gingival soft tissue, and establish an anterior incisal guidance. A custom milled impression coping (CMIC) is then fabricated. The CMIC has contours similar to the contours of the interim prosthesis and is fabricated from a PMMA billet. Titanium inserts are placed in the interim prosthesis and the CMIC. The CMIC is inserted intraorally and used for the final impression by using a custom tray and by following the open tray impression protocol. With the proposed technique, the exact contours of the digitally designed and clinically verified interim prosthesis are used to fabricate the definitive restoration.