Berna Saglik

Maxillary implant-supported bar overdenture and mandibular implant-retained fixed denture using CAD/CAM technology and 3-D design software: a clinical report.

The implant-supported bar overdenture and the implant-retained fixed complete denture are appropriate treatment choices for patients with inadequate bone volume in the posterior maxilla and mandible, respectively. Computer-aided design/computer-aided manufacturing (CAD/CAM) technology has broadened the scope and application of those treatment options, allowing for prosthodontically-driven implant placement and ideal substructure design for optimal esthetics and biomechanics. This report describes the fabrication of a maxillary implant-supported milled titanium bar with attachments and an overdenture, and a mandibular implant-retained fixed complete denture with milled titanium substructure.

A simple method to duplicate a denture for an implant surgical guide

aClinical Associate Professor, Department of Biologic and Materials Sciences, Division of Prosthodontics. bClinical Assistant Professor, Department of Biologic and Materials Sciences, Division of Prosthodontics. (J Prosthet Dent 2008;99:326-327) A duplicate of an existing prosthesis is often used as a surgical guide to assist in surgical placement of a dental implant. Various duplication methods have been described in the literature.1-5 Generally, the existing denture is evaluated and determined to be adequate for esthetics and function, embedded in an impression material, retrieved, and the space inside the mold is filled with an acrylic resin. These methods, however, require special instruments or materials for the duplication procedure that may not be readily available. Irreversible hydrocolloid material is a widely used impression material because it is accurate, easy to use, and relatively inexpensive.6 This article describes a procedure for duplicating an existing interim removable partial denture (IRPD) using irreversible hydrocolloid impression material and a plastic container. This procedure is simple and employs materials that are commonly used and readily available in a dental laboratory.

Use of a thermoplastic vacuum-formed matrix for secure engagement of an implant surgical template

Oh and Saglik Oh and Saglik Endosseous dental implants should be placed to permit the ideal contour and thickness of the definitive prosthesis.1,2 A diagnostic waxing is developed to plan the optimal position and inclination of the implants to maximize esthetics, facilitate framework design, minimize the cantilever effect, and enhance hygiene access.1-4 The surgical template is fabricated to duplicate the waxing and incorporate plastic or metal tubes to accommodate drills of different sizes for precise implant placement.3,4 However, the surgeon may elect not to use the surgical template if its intraoral placement is not adequately stable or rigid, or if it limits accessibility to the surgical field.5 An interim removable partial denture (IRPD) is a provisional prosthesis fabricated to accommodate the patient’s need and desire for esthetics and function until definitive treatment is rendered.6 The prosthesis may be duplicated in clear acrylic resin and modified to serve as a guide for implant placement.7-9 However, intraorally, the guide may not be secure and stable due to the lack of support provided by the soft tissue of the residual ridge. Reflection of the mucoperiosteum for implant placement further interferes with adequate seating of the guide and restricts accessibility to the surgical field. Engagement of the remaining dentition would assist an accurate orientation and maintain the duplicate IRPD (DRPD) to serve as a surgical template. This paper deUse of a thermoplastic vacuum-formed matrix for secure engagement of an implant surgical template

SPECT/CT Characterization of Oral Activity on Radioiodine Scintigraphy

CONTEXT Oral activity on radioiodine scintigraphy is commonly seen and may cause diagnostic dilemma. Determining the precise mechanism of oral uptake on radioiodine scintigraphy will increase the accuracy and confidence of interpretation and avoid possible misinterpretation. OBJECTIVE To determine the etiology of focal persistent radioiodine oral uptake seen on radioiodine scans. DESIGN Retrospective sequential series at a university clinic and a phantom study experiment. METHODS Preablation iodine-131 planar and single photon emission computed tomography/computed tomography (SPECT/CT) scans of 216 patients after total thyroidectomy were reviewed. Planar images were inspected for the presence of oral activity above the salivary gland background and SPECT/CT was reviewed to determine the location and nature of oral activity. A post-hoc phantom study was designed using typodont stone models fitted with various dental materials, immersed in a diluted iodine-131 solution, and imaged with SPECT/CT to characterize radioiodine uptake by high-attenuation dental materials. RESULTS Oral activity was seen on planar images in 123 of 216 (57%) patients; 12 patients were excluded from analysis because the SPECT/CT field of view did not cover the entire oral cavity. In the remainding 111 patients SPECT/CT images demonstrated focal uptake localizing to high-attenuation dental material on the CT in 95 of 111 (86%) patients. All cases of oral activity on planar imaging were interpreted as benign etiology on SPECT/CT. The phantom study confirmed focal in vitro uptake within high-attenuation dental materials representing a range of commonly used metal alloys. CONCLUSION Focal oral activity on diagnostic radioiodine scans frequently localizes to high-attenuation dental material on SPECT/CT. We postulate that an affinity between negatively charged iodide ions (I(-)) in saliva and positively charged metal ions (eg, Ag(+), Hg(+), Au(2+), Pd(2+)) within the dental materials is at the basis of persistent focal radioiodine uptake in the oral cavity. This represents a new mechanism underlying benign radioiodine activity not previously described in the medical literature.

Tooth reduction guide using silicone registration material along with vacuum-formed thermoplastic matrix

Adequate tooth reduction is a prerequisite for function, esthetics, and longevity of fixed restorations. A tooth reduction guide may be useful for establishing the proper angulation of the tooth and maximizing periodontal health and restorative success. This article describes a simple and versatile technique for an accurate evaluation of tooth reduction for fixed restorations by using a color-contrasting positive guide of a silicone occlusal registration material processed inside a vacuum-formed clear thermoplastic matrix.

The commissure line of the mouth for orienting the occlusal plane.

This study investigated the positional relation of the commissure line of the mouth to the maxillary first molars. Thirty-five volunteers, 20 to 40 years old, with normal natural dentitions were recruited. Maxillary casts with marks locating the commissure were digitally scanned to measure the vertical distance from the tip to the base of the mesiofacial cusp (CO) and from the tip to the mark (CM). There was no significant difference (t test; P > .05) between the CO (1.61 ± 0.41 mm) and CM (1.14 ± 0.68 mm). The mean distance of the commissure mark from the occlusal plane was 0.78 mm.

Fabrication of a screw-retained restoration avoiding the facial access hole: a clinical report.

Dental implant restorations may be either screw-retained or cemented onto an abutment. While each method has its advantages and disadvantages, cemented restorations are commonly used in the maxillary arch, usually because of esthetic concerns. Available bone in the anterior maxilla dictates the placement of the implant, which may result in a facially positioned screw-access opening. Still, a growing volume of literature states that periimplant soft tissues respond more favorably to screw-retained crowns than cement-retained crowns. This clinical report outlines a treatment with a new method of fabricating a custom abutment-crown combination for a screw-retained restoration. The technique allows the channel for the screw to be placed at an angle other than parallel to the implant body. In this case, the practitioner may choose either a screw-retained or cement-retained implant restoration, where previously only a cemented restoration was possible.

Modified Record Base Featuring Postpalatal Seal Using Silicone Bite Registration Material

This article describes a simple method of fabricating a stable and retentive record base to ensure an accurate registration of the maxillomandibular relationship. A postpalatal seal is established along the posterior end of the record base on the definitive cast using a silicone bite registration material to create a border seal along with the lip/cheek draping actions and to evaluate adequacy of the post dam.

Provisional Prosthetic Management of Mobile Teeth in Conjunction with a Removable Partial Denture Using Orthodontic Wire

Precision attachment-retained removable partial dentures eliminate the use of visible clasps and improve the esthetic appearance of the smile; however, terminal abutment teeth may be subject to unfavorable stresses under function when misused. A provisional prosthetic management technique that incorporates an orthodontic wire to assist cross-arch support and stability of the periodontally weakened abutment teeth is described. This technique is simple, reversible, does not alter the esthetic appearance of the smile, and controls the mobility of the abutment teeth until a definitive treatment plan is established.

Remount cast fabrication for occlusal equilibration against artificial denture teeth

aClinical Associate Professor, Department of Biologic and Materials Sciences, Division of Prosthodontics. bClinical Assistant Professor, Department of Biologic and Materials Sciences, Division of Prosthodontics. (J Prosthet Dent 2009;101:350-351) Establishment of a balanced and harmonious occlusion is a prerequisite for the successful rehabilitation of edentulous patients.1,2 Clinical remounting of the prosthesis simplifies the occlusal equilibration procedure by enhancing the visual detection of occlusal discrepancies, ensuring the accuracy of occlusal adjustments, and minimizing the errors occurring from the viscoelastic nature of the mucosa.1,2 The occlusal relation is evaluated visually by closing the artificial denture teeth against the opposing stone cast, and occlusal contact marks are identified with repeated impact and gliding contacts by means of articulating papers or ribbons placed between the denture teeth and the stone teeth.3,4 Gypsum material is readily accessible, convenient to use, and rigid; however, the stone teeth are not as tough as the artificial denture teeth and are brittle and susceptible to wear and breakage with repeated occlusal contact.3,4 Several methods have been introduced to address the problems of wear, chipping, or fracturing of the stone teeth against the opposing denture teeth. The remount casts are fabricated of low-fusing metal alloy,5 vinyl polysiloxane (VPS) impression material,6 or a combination of VPS, acrylic resin, and dental plaster.7 A cast made of low-fusing metal alloy addresses the problems associated with the weakness of the gypsum materials. It is durable and wear resistant; however, the procedure requires special materials and devices.5 In addition, incorporation of bismuth in the alloy (48-55%) to reduce shrinkage may present health hazards with the inhalation of the fumes developed when burnt out. The method using VPS material facilitates the remounting procedure because it is quick and easy to use and permits the rigid portion of the denture to pass into the undercut area.6,7 The block-out procedure may not be an important consideration because of the resiliency of the silicone material. In addition, the material is resistant to wear or chipping during occlusal adjustment. However, the accuracy of the occlusal contact marks indentified against the silicone tooth is suspect because of the viscoelastic nature of the silicone material. The resiliency of the silicone material may be managed by processing acrylic resin in the incisal or occlusal one third of the silicone tooth.7 This method may provide a stiffer surface against the artificial denture tooth; however, it requires a number of materials and procedures in which dowel pins are inserted into the acrylic resin to connect with the silicone material and dental plaster. The purpose of this article was to describe a simple and accurate procedure of fabricating a remount cast, in which a thin layer of tooth-colored acrylic resin is processed over the gypsum material to present a stiff, wear resistant, and tough surface that can endure the repeated impact and gliding occlusal contacts against the artificial denture teeth. The impression is lined with a thin layer of acrylic resin and poured in dental plaster. Polymerization of the acrylic resin is accelerated with heat from the exothermic reaction of the dental plaster. The acrylic resin shell is secured to the dental plaster by engaging undercuts presented by the tooth and tissue contours. The impression should be stored in a humid environment, and the potential dimensional change of the acrylic resin with polymerization is negligible with the use of a minimal volume of resin. The occlusal contact marks are readily identified on the denture teeth and the tooth-colored acrylic resin surface for an accurate assessment and selective adjustment of occlusion. This procedure can also be extended to fabricate a remount cast for a removable partial denture.