The laminar impression technique

The laminar impression technique is a precise, rapid, and predictable alternative to traditional methods of impression-making in fixed prosthodontics. A preliminary impression is made using plastic "triple-arch" type trays and high-stiffness vinyl polysiloxane jaw relation registration material. After tooth preparation, tissue management, and retraction this registration can be used for provisional fabrication. Two holes are then drilled through the facial wall of the tray into the region of the preparation. The tray is replaced in the mouth and light-bodied vinyl polysiloxane impression material is injected into the holes by using an "automixing" gun system.     

Provisional restoration for abutment of an existing removable partial denture

The abutment of an existing removable partial denture may require a crown restoration. Fabrication of a provisional restoration to fit the existing clasp assembly requires special consideration. This article presents a simple technique for fabrication of such provisional restorations. An alginate impression is made of the arch with the removable partial denture in place. The abutment tooth is then prepared, providing adequate clearance between the clasp assembly and the tooth preparation. Cold curing acrylic resin of proper shade is mixed and poured in the impression of the abutment tooth. The impression is then seated in the mouth and removed before the acrylic resin is completely polymerized. The provisional restoration is then separated from the partial denture, finished and polished.     

A provisional restoration technique for laminate veneer preparations

A direct construction technique for laminate veneer provisional restorations uses autocuring acrylic resin and other available armamentarium to facilitate construction. Only a slight preparation modification of the tooth to be treated is necessary to retain the provisional prosthesis.     

A three-die cast technique for duplicating free gingival form in zirconia crowns: two case reports

This report describes a duplication technique of free gingival form from a provisional restoration to a zirconia crown. Three die casts were manufactured from a silicone impression with an acrylic resin ring tray. The first die cast was for the zirconia framework, the second for the provisionalized transfer coping, and the third for relining the provisional restoration. A free gingival impression was taken using a provisionalized transfer coping, and a soft gingival cast was manufactured. The depth of free gingival transparency was measured using a zirconia shade plate. Then, the zirconia framework was customized to allow for subgingival porcelain space. This technique seems to contribute to the clinical-laboratory interface in computer-aided design/computer-assisted manufacture restorations.     

A modified indirect working die technique for fabricating provisional restorations for multiple teeth.

The "modified" indirect working die technique is introduced. The technique expands the capabilities of the indirect working die technique, which features flexible removable dies for fabricating provisional restorations. The modified technique is distinguished by its potential for restoring multiple teeth, up to and including the complete arch, by utilizing a complete-arch impression tray to which a simple modification is made. It is an accurate, timesaving, and laborsaving method for fabricating provisional restorations.     

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.     

Effect of impression tray design and impression technique upon the accuracy of stone casts produced from a putty-wash polyvinyl siloxane impression material.

This study examined the accuracy of stone casts produced from impressions taken in stock polycarbonate trays, some of which had been strengthened with autopolymerizing polymethyl methacrylate resin. Three techniques were used to make the impression of an acrylic master model of the mandibular arch on which two extracoronal preparations for bridgework and one intracoronal inlay preparation had been carried out. Each preparation had been indented with a reference point for later measurement. The impression material was a putty-wash polyvinyl siloxane material. Five impressions were taken for each type of tray for each impression technique and these were cast in die-stone after 24 h. The distances between the points were measured with a reflex microscope and the means determined for each design of tray. The mean difference between casts produced from the various tray designs and the acrylic master model were determined for each of the distances between the three measuring points for the various impression techniques. Statistical analysis showed that, with the polycarbonate stock trays, there were significant differences between some of the modifications and between them and the acrylic model, for the three distances (P less than 0.05). These differences were limited to one measurement for one design of tray for each of the two-stage impression methods. With the one-stage technique the unreinforced tray and those reinforced with acrylic, over the heels and anteriorly, and the barred design were statistically significantly different from the acrylic model for measurement A-B.(ABSTRACT TRUNCATED AT 250 WORDS)     

Interocclusal wax impressions for use in provisional and associated fixed prosthodontic procedures

A procedure is presented for the construction of a direct provisional acrylic resin restoration by means of an interocclusal wax impression. This technique requires no preparation or laboratory time and quickly results in a restoration that accurately covers all margins of the preparation and restores proper contact, contour, and occlusion. This procedure can also be used for large restorations, immediate fixed partial dentures, final impressions of preparations, provisional crowns to fit existing removable partial dentures, and some office emergencies.     

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.     

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.     

A provisional and new crown to fit into a clasp of an existing removable partial denture

A technique that forms an abutment crown to fit into an existing clasp of a removable partial denture by relining an acrylic resin pattern is described. The outer contour of the pattern is made within an irreversible hydrocolloid impression by use of Duralay autopolymerizing acrylic resin applied with precision dispensers. The pattern is formed before tooth preparation and is made approximately 0.4 mm thick. After tooth preparation, the shell pattern is relined with the same autopolymerizing resin and the existing removable partial denture is fitted over it. The gross pattern is trimmed and the margins refined on a die made from an elastomer impression. The refined pattern is cast and finished, avoiding reduction of the contours established. A second crown is similarly formed in tooth-colored autopolymerizing acrylic resin. It serves as a provisional restoration that allows the patient to wear the removable partial denture while the laboratory procedures are performed.     

间接法制作个别取模器龈下取模技术的临床应用评价

目的：介绍一种简便高质量的龈下取模技术，解决龈下肩台边缘至龈沟底之间的牙体，牙龈外形精确复制问题。方法：在备牙的同时制作个别取模器，采用一次调和两步取模法。结果：可清晰、准确、完全地取得基牙肩台及肩台下精细结构的外形，经20例患者76颗基牙固定修复一年半的随访，修复质量明显提高。结论：个别取模器龈下取模技术操作简便易学，可大幅度改善固定修复颈缘质量，值得推广。     

IMMEDIATE DENTIN SEALING FOR INDIRECT BONDED RESTORATIONS

For laboratory-fabricated, resin-bonded indirect restorations, clinicians usually prepare the tooth, make an impression, and cement a provisional restoration at an initial appointment. A few weeks later, after the definitive restoration has been tried in and adjusted, it is bonded with some combination of adhesive and resin cement. Another approach—most commonly called "immediate dentin sealing"—has been suggested. This technique involves placement of a resin coating on the dentin immediately after preparation. Several advantages have been cited for immediate dentin sealing. Prominent among those are a reduction in tooth sensitivity during the provisional phase and the potential for better bonding of the restoration to dentin. This Critical Appraisal reviews several in vitro research studies on the immediate dentin sealing technique.     

Immediate loading of two single tooth implants in the maxilla: preliminary results after one year

This clinical report describes the traumatic avulsion of the left maxillary central and lateral incisors with minimal tissue trauma, followed by placement of provisional restorations of two root-form implants in a 14-year old female patient. Ten days following the avulsion, implant therapy was performed with Summers osteotomes and flapless technique using a root-form 3i osseotite NT. Angulated abutments and acrylic provisional crowns were placed. No occlusal contact was detected. An impression was made 30 days after implant insertion and ceramic restorations were placed 3 months later. No significant soft tissue contraction was observed during the provisional period. The patient exhibited no clinical or radiologic complications for 8 months after loading. In carefully selected under-aged patients implant therapy and immediate loading in the anterior maxilla for traumatic tooth avulsion may prove to be valuable to avoid soft tissue contraction, alveolar bone resorption, and positive esthetic/psychological response.     

A modified impression technique for implant-supported restoration

An impression technique is proposed for construction of implant-borne restorations that uses a modified autopolymerizing resin custom tray to allow splinting of the impression copings directly to the tray. This method eliminates the use of the dental floss-autopolymerzing resin complex, thus decreasing resin distortion and simplifying the clinical procedures.     

Nontraumatic Final Impressions for Fixed Partial Dentures

A nontraumatic, nonretraction impression technique is presented which uses the fabrication of an acrylic resin shell from an interocclusal wax impression. A crucial step in the procedure is obtaining the complete finish line of the preparation within the resin. This tray, which is filled with an elastomeric impression material, is combined with a triple tray of the same material to provide all the necessary relationships to construct a crown or coping. This procedure is especially efficient for multiple abutments during fixed partial denture construction.     

Maintaining and enhancing gingival architecture in fixed prosthodontics

The long-term success of fixed prosthodontic restorations is greatly dependent upon the health and stability of the surrounding periodontal structures. This article deals with the interrelationship between fixed prosthodontic procedures and the stability and health of the periodontium. The commonly encountered problem of alterations in gingival architecture is examined in relation to tooth preparation as well as soft tissue preparation. In addition, the ability of the provisional restoration to guide soft tissue form is discussed as well as the role of the final restoration in providing long-term tissue maintenance. Key factors such as margin placement, tissue damage during tooth preparation, the role of the provisional restoration, tissue injury during impression procedures, crown contour, pontic design, and embrasure design are covered in detail.     

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.     

A direct technique for fabricating esthetic anterior fixed provisional restorations using polycarbonate veneers

Fabrication of esthetic interim restorations by a chairside technique often challenges the clinician with regard to the required time and skills, as well as meeting the expectations of the patient. Autopolymerizing polymethyl methacrylate resin has been reported to be the most popular material for fabricating provisional restorations. However, this material does not routinely yield esthetic provisional restorations via a chairside technique. This article describes a simple technique to overcome some of the disadvantages of this material by using prefabricated polycarbonate facings backed with autopolymerizing acrylic resin. This technique can be used chairside for fabricating esthetic anterior interim restorations, utilizing the beneficial properties of both materials. It exploits the manufactured smooth-surface finish, superior esthetics, color stability, and durability of polycarbonate facings, as well as the marginal adaptation, strength, and low cost of autopolymerizing acrylic resin.     

Impression material thickness in stock and custom trays

This study did not examine the accuracy of the resultant impressions. Rather, the impression material thickness in impressions made using both the highly advocated custom acrylic resin tray and in the highly used manufactured stock tray was examined. Comparison between the material thickness at the prepared tooth area revealed a mean difference in material thickness of less than 1 mm. The question of the significance of this difference remains to be answered. If the difference is not significant in the success of the impression and the resultant casting, then there are several advantages in using the manufactured stock tray; the first is economy. The average cost of a custom acrylic full arch impression tray is $3.65, compared with an average cost of slightly over $0.30 for the stock tray. The second advantage is the convenience factor. Making a custom tray requires planning, study models, laboratory time, curing interval, and finishing time. In contrast, the stock tray can be selected, adapted, and used in a single visit for both anticipated and unanticipated situations. If the difference in material thickness is significant, the custom tray is indicated. However, attention to detail in making and inserting the tray in the mouth must be observed to maximize the benefits of the custom tray.