Matilda Dhima

Practice-based clinical evaluation of ceramic single crowns after at least five years.

STATEMENT OF PROBLEM Long-term practice-based clinical evaluations of various contemporary ceramic crown restorations from multiple practitioners are limited. PURPOSE The aims of this study were to evaluate the clinical performance of ceramic single crowns and to identify factors that influence their clinical performance. MATERIAL AND METHODS Ceramic single crowns that had been placed at the Mayo Clinic and in function since 2005 were identified and included in the study. The restorations were examined clinically, radiographically, and with photographs. Modified United States Public Health Services criteria were used for the clinical evaluation. The ceramic systems evaluated were bilayer and monolayer. RESULTS Fifty-nine patients (41 women, 18 men) with 226 single teeth and implants restored with single ceramic crowns were identified. The mean duration from insertion date to study examination date was 6.1 years. Thirteen restorations (6%) were replaced at a mean 3.3 years after insertion date (range, 0.1-6.1 years). Estimated replacement-free survival rates (95% confidence interval [CI]; number of teeth/implants still at risk) at 5 years after insertion date were 95.1% (95% CI, 92.2-98.1; 153) and at 10 years were 92.8% (95% CI, 89.1-96.8; 8). The most common reason for replacement was fracture to the core of posterior layered ceramic crowns. The most commonly used luting agent was resin-modified ionomer cement. Most restorations exhibited clinically acceptable marginal integrity, shade, no caries recurrence, and no periapical pathology. CONCLUSIONS The clinical performance of ceramic single crowns at 5 and 10 years supports their application in all areas of the mouth. With the majority of fractures to the core occurring early in the lifetime of layered ceramic posterior crowns, consideration of other monolithic ceramic systems for posterior crowns is advised.

Evaluation of Fracture Resistance in Aqueous Environment of Four Restorative Systems for Posterior Applications. Part 1

PURPOSE The goals of this study were to: (1) establish a range of the performance of four restorative systems for posterior single-tooth crowns under single load to fracture submerged in an aqueous environment, (2) identify restorative system(s) of interest to be examined in the second study phase under sliding contact step-stress fatigue as full-contour anatomically appropriate single posterior tooth restoration(s), (3) establish a range for loading/testing for phase 2. MATERIALS AND METHODS Forty specimens (n = 10/group) of 2 mm uniform thickness were tested. Group 1: monolithic lithium disilicate IPS e.max Press; group 2: IPS e.max ZirPress, 0.8 mm zirconia core with 1.2 mm pressed veneering porcelain; group 3: IPS e.max ZirPress, 0.4 mm zirconia core with 1.6 mm pressed veneering porcelain; group 4: IPS InLine PoM. Specimens were bonded to a block of polycast acrylic resin on a 30° sloped surface with resin cement. Specimens were axially single loaded to failure while submerged under water. RESULTS There was a statistically significant difference (p < 0.001) in failure load among the four restorative systems. Lithium disilicate showed a mean failure load similar to mean maximum posterior bite forces (743.1 ± 114.3 N). IPS e.max Zirpress with a 0.4 mm zirconia core exhibited the lowest mean failure load (371.4 ± 123.0 N). CONCLUSION Fracture resistance of monolithic lithium disilicate in an aqueous environment is promising and requires second phase testing to evaluate the potential of various thicknesses appropriate for posterior single tooth applications. Doubling the IPS e.max Zirpress zirconia core from 0.4 mm to 0.8 mm increased the fracture resistance of this restorative system threefold.

A retrospective analysis of mandibular bone height changes associated with 81 screw-retained implant-supported prostheses with distal cantilevers: a long-term follow-up analysis.

PURPOSE The aims of this study were (1) to evaluate long-term changes in bone height beneath mandibular screw-retained implant-supported prostheses with distal cantilevers and (2) to determine whether the reversal of residual ridge resorption in the posterior mandible is temporary or continues over the long term. MATERIALS AND METHODS Panoramic radiographs, obtained at surgery and at two follow-up visits, of 81 patients rehabilitated with mandibular screw-retained implant-supported prostheses with distal cantilevers supported by four, five, or six implants were followed for 5 to 19 years (overall mean follow-up, 9.00 years. Changes and trends in bone height adjacent to the most distal implant were evaluated between each follow up visit as well as from time of surgery (baseline) to the final visit using two-way analysis of variance, a two-sample t test, and piecewise linear regression. RESULTS Average bone height distal to the distal most implant at placement was 10.34 ± 6.87 mm. From baseline to the first follow-up exam, a mean bone gain of 0.68 mm was noticed, and a mean gain of 0.26 mm was observed from baseline to the second follow-up exam. A statistically significant bone gain (0.92 mm) was noticed in women (n = 49) between the first and second exams, compared to 0.33 mm in men (n = 32). Individuals experienced both bone gain and loss during the study, with an overall gain. Patients with lower initial bone height experienced greater growth, but this was not statistically significant. CONCLUSION Bone growth is associated with mandibular screw-retained implant-supported prostheses with distal cantilevers, and both bone loss and bone growth may occur in the same patient over time. Within the diverse population of this study, women experienced 2.5 times more gain in bone height than men. No correlation could be established between initial bone height and overall bone height changes.

Development of stable peri-implant soft tissue and mentolabial sulcus depth with an implant-retained soft tissue conformer after osteocutaneous flap reconstruction.

Excessive soft tissue bulk, movement, chronic inflammation, and hypertrophy in periimplant areas pose challenges for long-term management of peri-implant soft tissues surrounding osteocutaneous flap reconstructions. A case history report is presented on the predictable establishment of stable peri-implant soft tissue and improved mentolabial sulcus depth in a patient treated for high-grade osteosarcoma of the mandible. Following surgical resection, reconstruction with osteocutaneous fibula free flap, and endosseous implant placement, a combined surgical and prosthetic approach was used through a lip switch vestibuloplasty and an implant-retained soft tissue conformer.

Rehabilitation of medically complex ectodermal dysplasia with novel surgical and prosthodontic protocols

The functional and aesthetic needs of a 17-year-old patient afflicted with ectodermal dysplasia, chronic long-term immunosuppression, cleft palate, velopharyngeal insufficiency, hypernasality, maxillary hypoplasia, and oligodontia were met with a multidisciplinary team approach. Predictable functional and aesthetic outcomes were obtained with a combination of injection augmentation of the soft palate and nasopharynx and rigid fixation maxillary external distraction with immediate placement and immediate load protocols. No biological or prosthetic complications were noted after definitive rehabilitation with a mandibular implant-retained fixed prosthesis and a maxillary implant-retained detachable prosthesis.

Virtual surgical planning for treatment of severe mandibular retrognathia with collapsed occlusion using contemporary surgical and prosthodontic protocols.

PURPOSE To meet functional and esthetic needs in an older adult for treatment of complex skeletal and dentoalveolar deformities using contemporary surgical and prosthodontic protocols. METHODS An older adult with dentoalveolar complex and skeletal deformity (mandibular retrognathia) was treated by a combination of virtual planning and current surgical and prosthodontic protocols. Treatment planning steps and sequencing are presented. RESULTS Skeletal, soft tissue, and dental harmonies were attained without biological or mechanical complications. Definitive oral rehabilitation was completed with a maxillary complete denture and a mandibular metal ceramic fixed implant-retained prosthesis. CONCLUSIONS A surgical and prosthodontic team approach in combination with technologic advances can predictably optimize esthetic and functional outcomes for patients with complex skeletal and dentoalveolar deformities.

Novel Oncologic, Surgical, and Prosthetic Treatment of High-Grade Surface Osteosarcoma, Osteoblastic Mandible Type

An accurate diagnosis of osteosarcoma of the jaws (OS) is determined by proper documentation and interpretation of clinical symptoms, radiologic findings, meticulous histologic survey, and a characteristic growth pattern. The characteristics of high-grade OS include a chief complaint of swelling/pain, a ‘‘fluffy’’ radiologic appearance with or without corticomedullary involvement, osteoblasts as the predominant cell type on histologic examination, and a highly aggressive growth pattern arising from the periosteal tissue. OSs of the mandible and maxilla are collectively known as gnathic osteosarcomas (GOSs) and usually exhibit long-standing pain or swelling. Emphasis on multidisciplinary oncologic, surgical, and prosthetic treatment planning of GOSs improves the treatment outcome and long-term prognosis. The treatment of GOSs, especially in the mandible, requires careful consideration of adjacent bone, soft tissue, surrounding perioral musculature, teeth, interocclusal relationships, and facial aesthetics. Integration of oncologic therapy is of predictive value in the treatment of GOSs. Neoadjuvant chemotherapy assesses the responsiveness of the tumor to chemotherapy and minimizes the potential for the presence of distant micrometastasis. The benefits of adjuvant and neoadjuvant chemotherapy protocols have continued to be evaluated, with a reported local recurrence risk of 1.1% to 13.5%. It has been reported

Elective edentulation after 7 episodes of infective endocarditis: a clinical report.

aResident, Prosthodontics & Maxillofacial Prosthetics, Division of Prosthetic and Esthetic Dentistry. bAssociate Professor, College of Medicine, Division of Prosthetic and Esthetic Dentistry. cProfessor, College of Medicine, Chair, Division of Prosthetic and Esthetic Dentistry. (J Prosthet Dent 2011;106:1-5) A 3-year clinical follow-up is presented of a patient who underwent elective extraction of the remaining natural dentition, followed by rehabilitation with maxillary and mandibular complete dentures after 7 documented episodes of infective endocarditis. The patient was diagnosed with congenital ventricular septal and valvular defect and was treated in 1984 with a prosthetic aortic valve replacement secondary to idiopathic infective endocarditis due to Haemophilus influenzae. From 1984 to 2007, the patient experienced 7 episodes of infective endocarditis associated with various microorganisms, all of oral flora origin. In the 3 years after elective extraction of the remaining natural dentition, the patient had not experienced any episodes of infective endocarditis. In light of recent changes and controversy in the recommendations for the prevention of bacterial endocarditis, the question arises as to whether the efforts of dental providers to maintain the dentition of high risk patients outweighs the associated increased risks of morbidity and mortality. While the guidelines attempt to assist health care providers in clinical decision making, there are certain instances where a patient-centered approach necessitates alternative options.

A Contemporary Framework and Suprastructure Ceramic Design for Posterior Implant Fixed Partial Denture: Contemporary Framework for Posterior Implant FPD

Bone and soft tissue deformities in long-standing partial edentulism are commonly treated with implant therapy. The various ceramic restorative systems available and digital technology allow for customization of design and material selection. A substructure design that mimics tooth preparation in a custom zirconia framework with a lithium disilicate suprastructure is presented as an effort to address the functional and esthetic challenges posed by long-standing posterior partial edentulism. The aim is to present several contemporary elements of design to address the functional, esthetic, and maintenance needs.

A tooth-stabilized surgical template for alveolectomy

The supraeruption of teeth and bone in patients with long-standing partial edentulism often results in compromised interarch distance. A method is presented for the fabrication and predictable use of a tooth-stabilized surgical template for alveolectomy in instances where teeth are present.