Dimensional Space Analysis for Fabrication of Implant Prosthesis Substructures : A Guide to Better Laboratory Communication

Dual cure resin cements polymerize in the self-cure mode when light cannot pass through. Purpose: Measure bond strength of 4 dual cure resin cements to dentin/enamel in self – cure mode. Method: Pretreated e.max rods were cemented to molars ground to flat dentin/enamel using 4 adhesive/cement combinations under force (100g) for 8 minutes. The experiment repeated with specimens in incubator (37°C) for 10minutes. Samples debonded after 24 hours storage in incubator using a universal testing device. Statistical analysis was performed. Conclusions: Temperature increase improved bond strength with highest bond strength for Panavia V5. 90. Maxillary Arch Size and Obstructive Sleep Apnea: A Case Report and Review of the Literature Ali H. Ramadhan, BDS Second Year Prosthodontic Resident Marquette University Few reports have described the relationship between obstructive sleep apnea and maxilla arch size. Certain syndromes with a constricted maxillary arch have manifest obstructive sleep apnea syndrome (OSAS). This case report describes a 27 year-old female patient with a skeletal class III discrepancy and a narrow maxilla arch. The patient’s major concern was the esthetic appearance of her anterior teeth. Comprehensive clinical examination revealed congenitally missing teeth, bilateral posterior cross bite, and symptoms strongly correlating with sleep apnea. Further investigation will include ENT consultation and genetics study with regards to oligodontia, enlarged adenoid tissue, and the constricted maxilla. Polysomnography study is required to confirm OSAS. The dental treatment after OSAS evaluation should involve orthodontic and orthognathic consultation, then followed by a prosthodontic treatment plan. 91. Comparison of Internal Fit of Restorations Milled from Different Materials Bryan P. Rasmussen, DDS Third Year Prosthodontic Resident Naval Postgraduate Dental School Bethesda MD The aim of the poster presentation is to evaluate the internal fit of different materials manufactured by the same computer aided milling manufacturer. polymethyl methacrylate, lithium disilicate, zirconia, and cad-wax materials will be used. The same die will be scanned and restorations from each material made, seated, and cemented on identical dies. The restorations will then be sectioned and evaluated to compare internal fit. 92. 3D Printing: An Innovative Approach to Nasoalveolar Molding Samantha B. Rawdin, DMD Third Year Prosthodontic Resident Montefiore Medical Center Of the many new technologies in the dental field, 3D printing is gaining a lot of attention and popularity. Although the full potential of 3D printing is not yet known, its application in both the laboratory and clinical settings is proving to be very promising. 3D printing in craniofacial reconstruction has been utilized, but has had limited involvement thus far with Nasoalveolar Molding (NAM). Rather than manually fabricating and adjusting a NAM appliance, we propose a series of 3D printed aligners that incrementally approximate the alveolus. This technique could help save time and money and increase patient compliance. 93. The Effect of Core Material on Color of Pressed E-Max with Varying Thicknesses Priscila Schaefer, DDS Third Year Prosthodontic Resident University of Michigan The purpose of this study will be to assess the effect of underlying core material and the thickness of ceramic on the color of pressed E-max restorations. Thirty heat pressed E-max disks will be separated into three groups of a different thickness. The color of each disk will be evaluated using a colorimenter against a standard white tile for a control, and four different core material specimens, each simulating a clinically relevant core material. The color difference (ΔE*ab) values between the standard and the specimen tested will be calculated and recorded. 94. Full-Mouth Restoration of a Patient Presenting with Compromised Restorative Space Stuart R. Schelkopf, DDS Second Year Prosthodontic Resident University of Illinois at Chicago With the evolution of implant designs and the advent of new materials in full-arch restorations, thorough diagnosis and treatment planning is critical in comprehensively treating complex restorative cases. In the presented case, a 60 year old female presents with an edentulous atrophic mandible and a severely compromised fixed complete denture supported by 6 original Brånemark Nobel-Biocare external hex implants in the maxilla with sub-optimal restorative space. With consideration of implant utilization, restorative materials, vertical dimension of occlusion and smile design, treatment was carefully planned and rendered to achieve a satisfactory result. 95. The Comparison of Tensile Strength Among Different Surfaces of Implant Custom Abutments Sae-Eun Schlottke, DDS Third Year Prosthodontic Resident University of Minnesota The retention of anterior implant crowns is an important factor especially when the crown is cemented with temporary cement. Different mechanical and chemical surface treatment methods are commercially available for better retention and esthetic results. This in-vitro study is designed from a real clinical case that investigates how those changes on abutment surface result in different tensile strength between a CAD/CAM E.max crown and different custom abutment designs; titanium, titanium with retention features, titanium gold anodized, and zirconia. The maximum tensile strength of each combination was measured using the Universal Machine until the interface fails. 96. Two-Body Wear Performance of Zirconia Opposing e.Max Ceramic Christina Schiltz, DDS Second Year Prosthodontic Resident University of Illinois at Chicago The usage of different opposing all-ceramic materials has increased clinically. However, the wear characteristics of opposing different all-ceramic materials have not been studied. The aim of this study is to examine the two-body wear resistance of opposing e.max and zirconia with 2 different surface treatments. A ball-on-disc tribometer will be utilized to evaluate the effect of Glazed (G) and Glazed-and-Polished (GP) Zirconia balls on the wear characteristics of e.max (G) and (GP) discs as assessed by interferometry and SEM. The volume loss and coefficient of friction will be analyzed. Results: Research in progress 97. Long Term Resin Bonded Fixed Provisional Restoration (RBFPD) During Ridge Augmentation and Prior to Final Implant Restoration: A Clinical Report Karnik Shah, BDS Third Year Prosthodontic Resident The Ohio State University In contemporary implant practice, consistent results can be predictably achieved utilizing state-of-theart surgical and prosthetic techniques. These provide desirable solutions for the social and business needs of the prospective patient. Clinical situations where immediate implant placement and loading is not recommended, a fixed provisional restoration will provide for an optimal outcome, with minimal patient discomfort. This clinical report describes the provisionalization of partially edentulous anterior maxillae utilizing a long spanned RBFPD (winged metal ceramic fixed partial denture). This alternative method was useful for shaping and preserving the gingival soft tissues, while restoring function, esthetics, and patient comfort without violating any surgical or prosthodontic principles. 98. Oral Rehabilitation of a Patient with Ectodermal Dysplasia: A Clinical Report Azadeh Shojaei, DDS, MSc Third Year Prosthodontic Resident University of British Columbia Ectodermal dysplasia (ED) is a hereditary disorder that occurs as a result of defects in the development of 2 or more tissues derived from embryonic ectoderm. Usually the ED patients suffer from both reduced number of teeth and underdeveloped alveolar ridges, therefore the oral rehabilitation of these cases is often challenging. This case report illustrates the prosthetic rehabilitation of an 11year-old girl with severe hypodontia. Oral rehabilitation was accomplished with complete upper and lower partial removable acrylic prostheses. After the treatment, patient’s facial esthetics, masticatory function, speech and self-esteem improved significantly. 99. Diagnosis and Treatment Modality for Linear IgA Disease: A Case Report Jose Sierra, DDS Second Year Prosthodontic Resident Marquette University School of Dentistry Linear IgA Disease (LAD) is a rare acquired autoimmune bullous disorder, characterized by linear deposition of IgA along the dermoepidermal basement membrane zone. The clinical presentation of LAD consists of vesiculobullous lesions affecting skin and mucosal surfaces. However, there are few reported cases of involvement of the mouth as the sole manifestation. A 60 year old female presented with stomatodynia, dysphagia, and widespread erosions affecting the palate, buccal mucosa, maxillary and mandibular alveolar ridges. Furthermore, patient is interested in conventional maxillary and mandibular dentures. The use of Clobestol, in an adhesive denture paste is an effective drug for symptomatic oral vesiculo-erosive lesions. The selective pressure technique (Boucher’s technique) with relief holes in the tray, and light bodied polyvinyl siloxane is a suitable final impression technique. 100. Wear and Corrosion at the Titanium-Zirconia Implant Abutment Interface Craig L. Sikora, DMD Third Year Prosthodontic Resident University of Illinois at Chicago Under masticatory activity, micromotion occurs at the dental implant-abutment interface. Recently, there has been a lot of attention given to the material degradation occurring at this junction. This study investigates the wear and corrosion effects between implant and abutment materials. Utilizing a simulated oral tribocorrosive environment, both titanium (TiV) and zirconia (Zr) balls were slid under free potential against TiV and Roxolid discs for 25K cycles. The volume loss was calculated, and surface characterization was performed using interferometry and SEM. Overall, volume loss rankings from highest to lowest were (Ball/Disk): TiV/TiV > TiV/Roxolid > Zr/TiV > Zr/Roxolid 102. A Review of the Literature Regarding the Tooth-Implant-Supported Prosthesis (TISP) Naif G. Sinada, DMD Second Year Prosthodontic Resident University of Maryland Using Tooth-Implant-Supported-Prostheses (TISPs) has been a historically widely debated issue. Inherently, implants do not feature the same anatomical and physiological aspects of teeth. The natural tooth is provided with PDL that functions as a hydraulic system. Implants do not feature any PDL, and are directly connected with the surrounding bone. This literature review discusses (1) recommended techniques for utilizing TISPs to overcome the mobility differences between teeth and implants, (2) advantages/disadvantages of utilizing TISPs, and (3) techniques to prevent intrusion/complications. Ultimately, these guidelines are reviewed in order to reassess a previously stigmatized treatment modality. 103. One Step Triad Custom Tray Impression Technique for Fixed Detachable Prosthesis Robert A. Sparks, DMD Third Year Prosthodontic Resident Georgia Regents University One of the most popular trends in dentistry is attempting to decrease the treatment time for all involved. Fixed-detachable prosthesis require multiple steps and appointments that requires clinical time and lab fees. The impression for such a prosthesis has historically required an initial impression, followed by fabrication of a verification jig, and a second impression appointment. We have successfully utilized triad to replace the verification jig and 2 impression appointment. The lower shrinkage of triad and its rigidity appear to make it a material suitable for splinting impression copings and making the final impression without a second impression appointment. 104. Maxillectomy and Midfacial Defects: Lost in Classifications? Akanksha Srivastava, BDS, MSc First Year Prosthodontic Resident University of Connecticut Surgical defects from maxillary and midfacial resections are often compound and involve many anatomic structures. Surgically driven classifications for such defects are based on the nature of the surgical procedure or by the resultant tissue loss without incorporation of any prosthetic considerations. Conversely, prosthodontic classifications group these defects from a prosthetic management perspective. A classification system that is consistent with both surgical and prosthodontic needs is lacking. This poster will highlight a critical appraisal of 14 classification systems identified from the available literature and present a recently published novel method of a criteria-based universal description of maxillectomy and midfacial defects. 105. Influence of Milling Tools on Marginal Integrity and Accuracy of Zirconia Crowns Patricia H. Swanson, DDS First Year Prosthodontic Resident Stony Brook University While much attention is given to restorative materials, focus should also be on the milling tools used in fabrication. This poster compares the effect of diamond versus ceramic coated milling tools on zirconia restorations. Four different milling tools will be compared on two different machines (VHF and Roland), using the same design software and CAM software for standardization. To ensure transparency, milling tool life is reported by hours of use. Optical analysis of crown margins is performed, and the relationship between milling tool usage and marginal integrity and accuracy is evaluated for each drill and milling machine. 106. Novel Technique Using 3Shape to Digitally Fabricate and 3D Print Prosthetic Splint for Protecting Soft Tissue Grafts Around Implants Marko Y. Tadros, DMD Second Year Prosthodontic Resident Georgia Regents University Dentists frequently encounter situations in which the patient has several implants placed with inadequate keratinized tissue. In order to augment this soft tissue deficiency, the patient has to undergo a soft tissue graft that has to be held with wire fixations beneath the mandible. The external wire insertion sites frequently cause significant infection and discomfort. The technique in this poster shows an easy and comfortable approach using 3shape and 3D printing technology to digitally fabricate implant supported surgical guide cover to hold a full arch soft tissue graft. 107. Prosthodontic Treatment of a Reconstructed Partial Mandibulectomy Patient Using TitaniumZirconia-Resin Fixed Implant Prosthesis Tyler Thomas, DMD Second Year Prosthodontic Resident University of Connecticut Metal resin fixed prostheses has traditionally been used to treat mandibulectomy patients seeking a fixed prosthesis. This prosthesis has a finite time limit to event-free survival and is susceptible to significant wear and fracture. To mitigate this problem, newer prosthetic designs have evolved with a unique combination of biomaterials. One such emerging design is a CAD CAM milled titanium bar with cemented individual zirconia crowns, finished with denture base resin for gingival contours and esthetics. This poster describes the outcome of such treatment in a patient who received prosthetic treatment after having previously received a partial mandibulectomy reconstruction. 108. Intra-Oral Scanners: Are They Created Equal? Joshua C. Treesh, DMD Third Year Prosthodontic Resident Navy Post Graduate Dental School, Bethesda, MD Currently there are approximately 15 intraoral scanners on the market. All commercially available scanners claim a high degree of accuracy. The available literature shows that differences do exist concerning the overall accuracy of the scanners. Most studies have looked at ‘the big four’ scanners in their evaluation: Cerec, Bluecam; COS Lava, iTero, and E4D. This table clinic will evaluate the resolution and accuracy of three intraoral scanners in which little to no scientific data is available: Cerec Omnicam, Trios, and Carestream. Specifically the table clinic will analyze the scanning accuracy of a prepared tooth mounted in a plaster mold. The STL files generated from the scans will be compared against a reference scan of the same model using an industrial strength laboratory scanner. The scans will be evaluated using Geomatics 3D software using a ‘best fit’ algorithm. These scans will also be evaluated for degree of resolution (# of triangles per unit area). This information may help guide the clinician in choosing which intraoral scanner to employ in their clinical practice. Although this table clinic will focus on a single prepared tooth, differences in accuracy may have a significant impact on utilization of the scanner in full mouth reconstruction. 109. Fatigue Behavior of CAD/CAM Ceramic Abutments as a Function of Design and Ceramics Processing Konstantinos Vazouras, DDS, MPhil Third Year Prosthodontic Resident University of Connecticut Purpose: Testing of four CAD/CAM abutments using a modified ISO implant fatigue protocol to determine performance as a function of design and processing. Materials-Methods: Two full-zirconia and two hybrid abutments were tested wet at a variety of loads to failure. Data was combined for lifetime analysis from accelerated to clinical conditions. Results: Two different failure modes were found for both abutment types. Under accelerated conditions performance differed significantly depending on manufacturer. Performance was not related to rotational fit tolerances. Conclusion: Our modified ISO protocol produced failures seen clinically. Manufacturer matters; differences in design and fabrication cannot be discerned clinically. 111. Pros and Cons of the Fixed Detachable Prosthesis William M. Wahle, DDS, BS Third Year Prosthodontic Resident University of Maryland The fixed detachable acrylic metal hybrid prosthesis, otherwise known as the hybrid, and fixed complete denture, has recently been a popularized treatment option that provides a fixed solution to edentulous or soon to be edentulous patients. Surgical and prosthetic obstacles will be presented from a clinical aspect for the fixed complete denture with overall pros and cons of the treatment presented. 112. Full-Mouth Rehabilitation of an Edentulous Patient with Dental Implants: A Digital Approach Kan Wongkamhaeng, DDS Third Year Prosthodontic Resident University of Iowa The use of dental implants in the management of completely edentulous patients provides improved quality of life with predictable treatment outcomes. This case report presents oral rehabilitation for a completely edentulous patient using monolithic zirconia implant-supported (maxillary arch) and metalresin implant fixed complete denture (mandibular arch). Digital technologies were applied for treatment planning and designing surgical guide and definitive implant restorations. The treatment described here significantly improved the patient’s functional, esthetic, oral health and self-esteem. 113. Maxillary Fixed Implant Immediate Rehabilitation of a Microstomic Patient with Systemic Scleroderma Roberta A. Wright, DMD Third Year Prosthodontic Resident University of Connecticut Scleroderma is an autoimmune rheumatic disease that affects the connective tissues. Oral manifestations include progressive limitation of mouth opening, microstomia, tongue rigidity, osseous resorption of the mandible, and radiographic widening of periodontal ligament space. Complete-arch fixed implant immediate rehabilitation in patients with systemic scleroderma present a number of unique challenges. The use of tilted implants is mechanically favorable; however, the placement of them can be difficult due to severely restricted mouth opening and steep angulation during implant placement. Furthermore, the positioning of angled abutments, and the subsequent fabrication of a conversion prosthesis prove to be complicated. This case report describes unique challenges faced surgically and prosthetically in treating a patient with systemic scleroderma, and offers advantages and tips for treating scleroderma patients with the All-on-Four concept. 114. A Modified Fabrication Technique of a Closed-Hollow Bulb Obturator for the Rehabilitation of an Acquired Maxillectomy Defect Hui Wen Yu, DDS Second Year Prosthodontic Resident Stony Brook School of Dental Medicine An 85-year-old male patient presented with a history of surgical excision of carcinoma of the maxillary arch. This resulted in an Aramany Class IV defect. Patient’s existing obturator lost retention after tooth # 14 was extracted. To reduce the weight and enhance the retention, a closed-hollow bulb obturator was fabricated. This poster describes a modified technique in fabricating a closed-hollow bulb oburator, in which the repositioning pins were used to index the hollow portion of the obturator. The obturator design characteristics as well as the comparison between a closedand an open-hollow bulb obturators are discussed. 115. Evaluation of Flexural Strength of Milled Cubic Zirconia After Accelerated Aging of 3, 6 and 9 Years Omar M. Alaryani, BDS Third Year Prosthodontic Resident Columbia University College of Dental Medicine Recent introduction of cubic zirconia into the dental market claims improved translucency and a flexural strength of 650-700 mpa. The authors recently evaluated the flexural strength of milled polycrystalline zirconia (PCZ) and found the flexural strength to be closer to 850-900 mpa as compared to the manufacturers claim of 1300 mpa. Cubic zirconia presents a different crystal structure than PCZ. The authors seek to determine if milled cubic zirconia undergoes a significant decrease in flexural strength similar to PCZ. Specimens will also undergo accelerated aging of 3, 6 and 9 years to determine if aging affects the flexural strength of milled cubic zirconia. 116. The Wear Characteristics of Opposing CAD/CAM Materials Alec D. Zurek, DDS Third Year Prosthodontic Resident University of Illinois at Chicago With the improvement of CAD/CAM technology in its application to dentistry, there has been an increase in use of milled, all-ceramic restorations. This study evaluates wear characteristic between two CAD/CAM materials with different surface textures as a function of time. Utilizing a ball-on-disc tribometer and artificial saliva, glazed (G) and glazed then polished (GP) samples of Zirconia and e.Max were tested. Surface characterization was performed using interferometry and SEM. The volume loss and coefficient of friction were analyzed. GP Zirconia showed less volume loss than the G Zirconia, in contrast, GP e.Max showed more volume loss than the G e.Max. 117. One-Appointment Fabrication of a Removable Prosthesis: A Systematic Review Elahe Behrooz Fourth Year Dental Student University of Toronto (Ontario, Canada) Purpose: This study aimed to systematically review the published literature on removable prostheses fabricated in a single appointment. Materials and Methods: Electronic and manual search of literature published up to July 2015 was