Modified clinical and laboratory procedures for fabrication of nasal prostheses

A modified procedure that aids in the fabrication of a nasal prosthesis has been described. This method offers several distinct advantages over traditional techniques. These are (1) use of the silicone putty impression material reduces sculpturing time, (2) the tinted wax allows improved patient acceptance of the wax model at the try-on, and (3) use of conditioning material at the try-on improves marginal adaptation.     

An Alternative Approach in Fabrication of Fixed Complete Dentures Using a Duplicate Denture

The traditional prosthetic steps in the fabrication of a fixed complete denture after implant osseointegration include final impression, verification of implant positioning in the working cast, mounting of the working cast, and mock denture wax trial insertion prior to the laboratory fabrication of the metal substructure; however, in patient scenarios of immediate loading of implants, the interim conversion prosthesis can be used to advance from the final impression to the milling of the underlying framework in one appointment. Consistency in the initial wax trial insertion, radiographic guide, and intraoral positioning of the conversion prosthesis can result in a well‐designed definitive prosthesis in less time with the use of the existing duplicate complete denture.     

Selective laser sintering technology for customized fabrication of facial prostheses

This article describes the use of SLS to produce a wax prototype for the fabrication of a partial nasal prosthesis. This technique may be an alternative to more conventional laboratory techniques for facial prosthesis fabrication and allows direct generation of definitive wax patterns. With the satisfying effect of nasal defect restoration, patients may be effectively rehabilitated and derive emotional and physical benefit from the treatment provided.     

An impression technique for implant-retained orbital prostheses

This article describes an impression technique for an implant-retained orbital prosthesis; in this situation, making the implant impressions in the conventional manner was not possible due to improper implant positioning. An advantage of this technique is that the acrylic resin transfer device that incorporates magnets is also used as the acrylic resin substructure for the silicone orbital prostheses. A disadvantage of the procedure is the requirement of an additional appointment to make the definitive impression. The effect of acrylic resin polymerization shrinkage is minimized by prefabricating the acrylic resin substructure that is used to splint magnets and corrected at the time that the definitive impression is made.     

A two-step functional impression technique for the fabrication of an implant-retained silicone auricular prosthesis

Excessive movement of the underlying tissue bed can lead to poor retention of an implant-retained silicone auricular prosthesis. This article describes a 2-step impression technique with a secondary functional pickup impression of the wax pattern. A wide range of tissue movements can be recorded while maintaining a stable relationship between the abutment analog assembly and retentive elements. The definitive cast is modified accordingly to provide an accurate reproduction of the patient’s tissues during function, thus, increasing the overall retention and stability of the definitive prosthesis.     

Abstracts from the Table Clinic Session of the Annual Session of the American College of Prosthodontists October 28, 2004

Yung-tsung Hsu , DDS MS Assistant Professor   UAB School of Dentistry
For a removable prosthesis, the best way to perform occlusal equilibration is to remount the prosthesis on the articulator. To remount a removable partial denture, a remount cast must be fabricated. Many techniques have been presented in the literature, including fabrication with stone, occlusal registration material, or silicone impression material. This presentation will compare several different techniques for making remount casts for removable partial dentures. A new technique of using the silicone impression material with acrylic resin and dental stone will also be demonstrated.     

A three-appointment alternative treatment protocol for fabricating an implant-supported milled bar overdenture

This article describes an alternative impression technique for the fabrication of an implant-supported bar overdenture using the duplicated satisfactory interim denture as a custom tray for the implant-level impression. The primary advantage of this technique is that all the information needed for the definitive prosthesis fabrication is obtained from the interim denture and then transferred to the laboratory in a single appointment. However, this technique may be contraindicated for severely misaligned implants that require extensive reduction of the duplicated denture.     

Issues in handling impression materials

Implant restorations require extreme accuracy since the implants are rigidly fixed. Although impression materials can be highly accurate, small inaccuracies are acceptable because the periodontal ligament allows for tooth movement. This luxury is not available with implants. A problem is the rotation of direct impression copings and distortion of interabutment positions in the master cast. Wee investigated the amount of torque required to displace a coping in eight impression material groups and the positional accuracy of the materials. The initial examination of torque narrowed the acceptable materials to a medium viscosity polyether, a high viscosity addition silicone, and a medium viscosity polysulfide-condensation silicones were eliminated. The results showed that the polyether and addition silicone produced casts with minimal distortion. Finally, it always is prudent to read the manufacturer's recommendations for use of impression materials. Catalyst-to-base ratios vary, as do working and setting times, depending on exact compositions. Impression materials also have various degrees of compatibility with stone, particularly the hydrocolloids, and it is advisable to use the recommended stone. Adhesives should be applied at least 15 minutes prior to loading the impression material. If at all possible, use of a rigid tray is recommended and impressions should be poured in the dental office; this minimizes the error produced at the beginning of the fabrication process. Elimination of errors early in fabrication of a prosthesis help prevent their magnification and result in a better-fitting restoration, requiring minimal adjustment in the end.     

Fabrication of fixed implant prostheses using function bite impression technique (FBI technique)

PatientThe patient was partially edentulous, lacking both the first mandibular molars. The FBI and the conventional impression technique were used for the fabrication of implant-fixed prosthesis replacing the right and left molars, respectively. In the FBI technique, the definitive impression was made under occlusal force and functionally generated path (FGP) recording at the same time. The right and left occlusal contact areas were compared after completing the implant-fixed prosthesis rehabilitation.DiscussionIt has been suggested that accuracy of the impression and maxillomandibular registration is necessary to ensure a satisfactory long-term clinical outcome. The transfer of the exact position of the implants to the working cast is even more important because implants lack the mobility of natural teeth. There are displacement differences between implants and natural teeth under occlusal force. The FBI technique may compensate for this difference in accuracy.ConclusionUsing the FBI technique, a precise prosthesis could be produced by completing simultaneously the maxillomandibular registration, impression and FGP.     

Using digital technology to create a custom esthetic bandage for patients after rhinectomy

Patients undergoing partial or total rhinectomy surgeries are left with a lifelong facial defect that poses psychosocial and functional challenges. The extended postoperative healing period after rhinectomy can delay the timely restoration of a patient’s nose by definitive prosthesis when conventional impression methods are used. The treatment workflow for fabricating a custom esthetic nasal bandage with the use of digital technology is introduced to avoid the conventional preoperative impression, as well as to allow for immediate delivery at the postoperative follow-up visit.     

Nasal conformer to restore facial contour

Surgical removal of the nose may have devastating psychologic effects on the patient. This article describes the fabrication and use of a nasal conformer to restore facial contour until a definitive nasal prosthesis can be made.     

Single-visit hollow obturators for edentulous patients.

A method of fabricating a simple hollow obturator for edentulous patients was described. This procedure can be accomplished in a single office visit using readily available materials. The use of a relatively long-lasting soft reline material for obturators allows stable, comfortable, and effective obturation for many edentulous patients with recently created maxillary defects (Fig. 6). The hollow prosthesis is lightweight and sufficiently flexible to allow relatively simple placement in retentive undercut regions. Direct finger placement of the material insures complete duplication of all desired tissue undercuts. The soft reline material may also serve as a final impression of the defect when fabrication of the definitive prosthesis is undertaken.     

Fabrication of a custom pediatric nasal mask for noninvasive ventilation using a maxillofacial elastomer: A straightforward technique

The facial masks commercially available for noninvasive positive pressure ventilation therapy for children with clinical conditions of hypoventilation are limited by size and hardness. The present report describes a straightforward method of developing a nasal mask from a room-temperature vulcanizing silicone elastomer for daily contact with the nasal mucosa of babies during noninvasive positive pressure ventilation. The fabrication of the silicone mask with nasal tubes is based on maxillofacial prosthesis techniques, with retention with steel prongs and elastics.     

Light-weight RTV silicone for maxillofacial prostheses.

Weight is a problem in retention of large skin-textured maxillofacial prostheses. The purpose of this investigation was to test the feasibility of mixing foam RTV silicone rubber with conventional RTV silicone rubber to obtain a light-weight material. Various mixtures of foam and conventional silicone rubber were formulated and tested for strength, accuracy of molding, color application, color stability, and texture. A special flask to support the mold was necessary in order to overcome expansion problems associated with gas formation of the foam silicone rubber. The mold required venting to release the gas and to reduce the expansion of the prosthesis in order to maintain accuracy. Molding, accuracy, texture, and color problems were overcome. Reduction of weight proportionate to reduction of tear strength of the material formulated, however, did not allow routine use of mixtures of foam and conventional silicone. When the weight of a prosthesis is critical and excessive and thickness is sufficient to give adequate strength, the foam and conventional silicone mixture can be used.     

CAD-CAM high-density polymer implant-supported fixed diagnostic prostheses

Computer-aided design and computer-aided manufacturing (CAD-CAM) complete-arch implant-supported fixed prostheses have become popular in recent years and offer several advantages over traditional fabrication techniques. However, they also present challenges, and careful treatment planning is required, particularly for zirconia implant-supported fixed prostheses layered with feldspathic porcelain. This clinical report describes the use of a CAD-CAM high-density polymer implant-supported diagnostic prosthesis to verify the accuracy of the implant impression and evaluate the maxillomandibular relationship, esthetics, and phonetics of the planned CAD-CAM definitive implant-supported fixed prosthesis before CAM processing.     

Alternative method to fabricating an immediately loaded mandibular hybrid prosthesis without impressions: a clinical report

Immediate loading procedures may cause discomfort to the patient and increase the possibility of damage to the surgical site during prosthetic restorations. The aim of this clinical report is to describe an alternative method to fabricating a mandibular hybrid prosthesis in 3 days without taking an impression. Five implants were placed in the anterior region of an edentulous mandible and restored with a definitive mandibular hybrid prosthesis using a unique acrylic resin framework. This acrylic resin framework enabled the fabrication of the metal framework of the mandibular hybrid prosthesis without taking a final impression. The step-by-step technique is described.     

Silicone nasal radiation carriers.

A technique for fabrication of a flexible shielded afterloaded silicone nasal radiation carrier is described. The technique uses a rubber base impression of the nasal cavity from which a silicone radiation carrier is made. Plastic tubes for afterloading of the radioactive sources and a lead shield were incorporated into the carrier. The carrier permitted accurate location of the radioactive sources in the nasal cavity and reduced the radiation exposure.     

A technique for fabrication of interim midfacial prostheses

The interim midfacial prosthesis uses a rigid backing support with flexible margins and can be made with most types of commercially available medical grade silicone elastomers. The technique may be modified for fabrication of definitive midfacial prostheses. The disadvantage of the technique is that an extra step is required to make a duplicate master cast, and a vacuum adaptor is needed.     

Precise Reproduction of Soft Tissue Structure around the Pontic Area Using Computer‐Aided Design and Manufacturing

Reproducing soft tissue contours around a pontic area is important for the fabrication of an esthetic prosthesis, especially in the anterior area. A gingival model that precisely replicates the soft tissue structure around the pontic area can be easily obtained by taking a pick‐up impression of an interim fixed dental prosthesis. After a working cast is fabricated using the customary technique, the pick‐up model is superimposed onto the working model for the pontic area using computer‐aided design and manufacturing (CAD/CAM). A definitive restoration using this technique would be well adapted to the pontic base, which is formed by the interim prosthesis.     

应用"L"型硅胶假体与膨体聚四氟乙烯补片修复单侧唇裂鼻畸形17例报道

目的:探讨应用“L”型硅胶假体与膨体聚四氟乙烯(ePTFE)补片修复单侧唇裂鼻畸形的方法及效果。方法:在纠正错位软骨的基础上,在“L”型硅胶假体上的鼻尖部附加一(ePTFE)薄片,用5-0尼龙线将两者缝合固定,对单侧唇裂鼻畸形患者进行鼻背、鼻尖、鼻翼、鼻小柱的加固和塑形。结果:“L”型硅胶假体与(ePTFE)补片联用,可使扁平的鼻梁、鼻尖及塌陷的鼻翼抬起,使鼻小柱挺立,大大改善了鼻的外观,效果满意,优良11例,改善6例。结论:应用“L”型硅胶假体与ePTFE修复单侧唇裂鼻畸形,是一种简便有效的方法。