Development of complete dentures based on digital intraoral impressions—Case report

Patient

A 60-year-old man presented for refabrication of his maxillary complete denture. In this case, a digital process was chosen to replace the ill-fitted complete maxillary denture. A specialized scan retractor was used to retract the mobile tissues of the lips, cheeks and vestibule while taking a digital impression. The interocclusal record obtained in the patient’s mouth was scanned in order to digitally register the occlusal vertical dimension. The denture base and teeth were designed on virtual models that were mounted at the occlusal vertical dimension, and were made using CAD/CAM technology.

Microstomia in a maxillectomy patient: A prosthetic challenge

The provision of a satisfactory denture in case of reduced stomal inlet has always been a trouble for the patient and a challenge to the prosthodontist. Fabrication of complete and removable partial denture prosthesis requires accurate diagnostic impression and diagnostic casts for the development of custom trays and final impression. The decreased mouth opening, technically called "Microstomia," poses problems in tray selection, impression making, jaw records and denture insertion. The causes for microstomia are numerous, one major cause being the after-effect of radiation therapy. Whatever the cause, the ability to make impressions and jaw records becomes taxing. A variety of impression techniques using modifications in the nature of the tray and impression materials are required. The present case report highlights an innovative and different aspect of impression making and fabrication of an obturator prosthesis for a microstomic patient who underwent maxillectomy.     

The Use of Digital Impressions to Fabricate Tooth‐Supported Partial Removable Dental Prostheses: A Clinical Report

Impression making is a critical step in the fabrication of a partial removable dental prosthesis (RDP). A technique is described for making final impressions to fabricate partial RDPs for Kennedy class III patients using a computer‐aided design and computer‐assisted manufacturing digital impression system.     

A Technique for Digital Impression and Bite Registration for a Single Edentulous Arch

Few studies have reported the application of digital technology for the process of impression and interocclusal recordings in edentulous patients. This article describes a digitizing system for generating digital edentulous models with a jaw relationship by taking direct digital impressions and a virtual bite registration using intraoral digital scanning. A specialized scan retractor was used to make digital impressions of edentulous jaws in patients’ mouths using an intraoral scanner. Virtual bite registration was obtained with optical scanning of the buccal surfaces of both jaws at the occlusal vertical dimension. The registration was then used as a reference for aligning both jaws. Digital edentulous models that include the jaw relationship would be clinically beneficial for the fabrication of complete dentures in edentulous patients.     

Digital impression and jaw relation record for the fabrication of CAD/CAM custom tray

Purpose

This article describes the protocol of a digital impression technique to make an impression and recording of the jaw relationship of edentulous patients for the fabrication of CAD/CAM custom tray using computer-aided design and manufacturing (CAD/CAM) technology.

Intraoral Digital Impression Technique: A Review

With the techniques of computer‐aided design and computer‐aided manufacturing (CAD/CAM) being applied in the field of prosthodontics, a concept of intraoral digital impressions was put forward in the early 1980s. It has drawn comprehensive attention from dentists and has been used for dental prosthesis fabrication in a number of cases. This new digital impression technique is expected to bring about absolute digitization to the mode of prosthodontics. A few published articles have indicated that dental prostheses fabricated from intraoral digital impressions have exhibited remarkable advantages over those from conventional impressions in several respects. The present review discusses intraoral digital impression techniques in terms of the following aspects: (1) categories and principles of intraoral digital impression devices currently available; (2) operating characteristics of the devices; and (3) comparison of the manipulation, accuracy, and repeatability between intraoral digital impression and conventional impression.     

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.     

The importance of a two‐step impression procedure for complete denture fabrication: a systematic review of the literature

The literature has questioned the real need for some clinical and laboratory procedures considered essential for achieving better results for complete denture fabrication. The aim of this study was to review the current literature concerning the relevance of a two‐step impression procedure to achieve better clinical results in fabricating conventional complete dentures. Through an electronic search strategy of the PubMed/MEDLINE database, randomised controlled clinical trials which compared complete denture fabrication in adults in which one or two steps of impressions occurred were identified. The selections were made by three independent reviewers. Among the 540 titles initially identified, four studies (seven published papers) reporting on 257 patients evaluating aspects such as oral health‐related quality of life, patient satisfaction with dentures in use, masticatory performance and chewing ability, denture quality, direct and indirect costs were considered eligible. The quality of included studies was assessed according to the Cochrane guidelines. The clinical studies considered for this review suggest that a two‐step impression procedure may not be mandatory for the success of conventional complete denture fabrication regarding a variety of clinical aspects of denture quality and patients’ perceptions of the treatment.     

Fabrication Method for a Mounting Jig and Cast Support for Mounting Complete Dentures

In complete denture fabrication, the definitive maxillary cast is mounted on an articulator using a facebow transfer or mounting jig, and the mandibular cast is mounted using an interocclusal record. The technique presented describes an easy and inexpensive method for fabrication of a mounting jig and rigid cast supports for mounting complete dentures.     

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.     

Vinyl polysiloxane impression material in removable prosthodontics. Part 2: Immediate denture and reline impressions

Accurate impressions are important elements in both the fabrication and maintenance phases of complete denture therapy. For patients possessing nonrestorable, periodontally hopeless residual dentitions, immediate denture therapy is often the treatment of choice. An impression procedure capable of accurately registering functional vestibular anatomy facilitates successful therapy. For complete dentures currently in function, periodic assessment and correction of fit extends long-term prosthesis performance. To maintain optimal tissue-base relationships, use of specialized impressions, and subsequent laboratory reline procedures is often indicated. For both of these impression procedures (ie, immediate denture impressions and denture reline impressions), vinyl polysiloxane (VPS) impression material offers distinct advantages. Part 2 of this article series reports on the use of VPS for immediate denture and reline impression procedures.     

Modified functional impression technique for complete dentures

This report describes the use of a removable acrylic resin tray handle that can be easily attached to custom impression trays to produce an improved peripheral sealing zone. This device can be indicated to develop functional impressions for complete dentures using the patient-conducted muscular motion technique. In upper trays, the handle is fixed in the midline with acrylic resin, while in lower trays the centrally positioned handle is removed before border molding. This removable handle allows patient's suction and free tongue movements. Final impression is carried out in two stages: peripheral sealing (low fusion compound) and recording of the main supporting region of the denture (zinc oxide and eugenol paste). All border records are obtained from the patient's own movements (handle suction and tongue motion). The removable handle is simple to use, is reusable, can be adapted to any individual acrylic resin trays and allows accurate registration of the peripheral sealing zone (border tissues).     

A simplified technique for making an interocclusal record in fixed prosthodontics

A technique for using flowable composite resin for making interocclusal records in cases involving fixed prosthodontics is described. The precise relation of maxillary and mandibular casts is an essential step in developing accurate occlusion in fixed prosthodontics. This technique consists of direct intraoral fabrication of transfer copings and an interocclusal record using flowable, light-activated composite resin. The technique is simple, does not require advance preparation and can be done during the final impression appointment.     

不同颌位关系记录法对全口义齿再修复患者义齿调胎量影响的研究

目的通过研究3种方法记录颌位关系的全口义齿再修复患者义齿调胎量的差异,为此类患者探寻最佳颌位记录方法,并为临床提供参考。方法随机选择20名全口义齿再修复患者,采用自身对照的研究,对患者分别采用直接咬合法、哥特式弓描记法、哥特式弓联合面弓转移颌位关系法制作3副全口义齿,并比较不同方法在调殆前后覆殆、覆盖的差异。结果用哥特式弓联合面弓转移颌位关系法制作的全口义齿调验前后覆殆、覆盖的变量差异大于直接咬合法及哥特式弓描记法,其差异具有统计学意义（P〈0.05）。直接咬合法与哥特式弓描记法转移颌位关系法之间无明显差异（P〉O.05）。结论使用哥特式弓描记法与哥特式弓联合面弓转移颌位关系法确定的颌位更符合生理功能,为全口义齿再修复患者提供更可靠的颌位记录方法,提高医生的工作效率和患者的满意度。     

Clinical factors and clinical variation influencing the reproducibility of interocclusal recording methods

OBJECTIVE: The reproducibility of clinical records of the occlusion was assessed in three dimensions using mounted casts. Three distinct areas were examined: 1) mandibular positions (intercuspal position (IP) or retruded contact position (RCP)), 2) materials used in recording the occlusion, 3) clinical variation. DESIGN: Interocclusal records were made in a random order of three patients: one fixed prosthodontics case, one removable partial denture case and one complete denture case, with two different types of waxes, record rims, two different brands of vinyl polysiloxanes and one irreversible hydrocolloid. SETTING: Private practice and Karolinska Institute, Huddinge, Sweden. SUBJECTS: One general dental practitioner and three voluntary patients. RESULTS: Point estimation of variance components indicate that 70-93% of the variation of the positions of the mounted casts are caused by: 1) clinical variation for all three cases and in three directions, 2) the influence of recording materials 0-29%, and 3) mandibular positions (IP/RCP) 0-11%. The ranges of the positions of the mounted casts were lower for the dentate case (0.04-1.39 mm) than for the partially dentate case (0.17-2.65 mm), which in turn was lower than those for the edentulous case (1.42-5.59 mm). CONCLUSION: Clinical variation seems to dominate the variation in positions of mounting casts when making interocclusal records, rather than mandibular position or the recording materials used. Therefore a dentist who makes one single interocclusal record cannot presume that it will reproduce the interocclusal relationship intended, which in the present study was most obvious for the edentulous case. The results showed that impression materials stabilised by a tray did not differ significantly from waxes and record rims concerning the reproducibility. Therefore the stabilised impression materials are an alternative, which also give additional advantages like reduction of appointments as well as superior accuracy.     

Double arch impressions for simplified restorative dentistry

Use of a double arch, closed-mouth technique as described in this article enables dentists to obtain cast and die placement in centric occlusion in a single step. Complete closure of the teeth is mandatory for registering the interocclusal relationship correctly. The accuracy of the interocclusal relationship is more likely because of the decreased number of steps in the technique. Several different trays are available for the double arch impression technique. The more rigid trays buttress the impression material and reduce the possibilities of distortion in the final impression. Several variations in the double arch impression technique are possible, and tray selection is dependent on the demands of each patient.     

Biometric trays for complete denture construction

Biometric impression trays are designed to support the lips and cheeks in their pre-extraction positions. The tray design is based on the average buccolingual breadth measurements of the dentulous alveolar process. The transference of these measurements is possible as the remnants of the lingual gingival margins can be identified on edentulous casts. The method of making the trays is described. The advantages of biometric impression trays are such that over the past five years they have replaced conventional impression trays for complete denture work in Edinburgh.     

A denture tray technique for remake dentures

A technique is described to fabricate a replacement denture for your patient. It reduces patient and laboratory time. The technique does not compromise the patient's existing denture, the impression, jaw relation records, or esthetics. It provides superior trays and effective occlusion rims, thus simplifying recording techniques. A denture duplicating flask     

Complete denture covering mandibular tori using three base materials: a case report

The torus mandibularis presents many challenges when fabricating a complete denture. The mucosa tends to be thin and will not tolerate normal occlusal loads on a denture. Large mandibular tori can prevent complete seating of impression trays and denture. To address this problem, we fabricated a new mandibular complete denture incorporating a combination of soft acrylic flanges and liners.     

Setting the Sagittal Condylar Inclination on a Virtual Articulator Using Intraoral Scan of Protrusive Interocclusal Position and Cone Beam Computed Tomography

The articulator is a prerequisite device for the analysis of occlusion and prosthodontic treatment, and it is required to simulate patient jaw movements. This article describes the technique to obtain sagittal condylar inclination (SCI) using cone beam computed tomography (CBCT) data and intraoral scan of the protrusive interocclusal position. The SCI can be used on a virtual articulator in a computer‐aided design software, and it can assist in the fabrication of prosthesis which is harmonious with the mandibular movement of individual patient.