Medicine and Health Sciences Commons^™

Finite Element Analysis Of A One-Piece Zirconia Implant In Anterior Single Tooth Implant Applications, Georgi Talmazov, Nathan Veilleux, Aous Abdulmajeed, Sompop Bencharit

General Practice Publications

This study evaluated the von Mises stress (MPa) and equivalent strain occurring around monolithic yttria-zirconia (Zir) implant using three clinically simulated finite element analysis (FEA) models for a missing maxillary central incisor. Two unidentified patients’ cone-beam computed tomography (CBCT) datasets with and without right maxillary central incisor were used to create the FEA models. Three different FEA models were made with bone structures that represent a healed socket (HS), reduced bone width edentulous site (RB), and immediate extraction socket with graft (EG). A one-piece abutment-implant fixture mimicking Straumann Standard Plus tissue level RN 4.1 X 11.8mm, for titanium alloy (Ti) …

Using Er:Yag Laser To Remove Lithium Disilicate Crowns From Zirconia Implant Abutments: An In Vitro Study, Janina Golob Deeb, Sompop Bencharit, Nishchal Dalal, Aous Abdulmajeed, Kinga Grzech-Leśniak

Periodontics Publications

Background
When implants are restored with cement-retained restorations, prosthetic retrievability can be difficult and often requires sectioning using rotary instruments. Sometimes repeated removals of a cement-retained implant crown are needed such as for treatment of peri-implantitis or immediate implant provisionalization. The purpose of this study was to evaluate the effect of erbium-doped yttrium aluminum garnet (Er:YAG) laser as a non-invasive treatment modality to remove lithium disilicate crowns from zirconia implant abutments following long-term cementation, repetitive debonding and re-cementation, and short-term retrieval.

Material and methods
Twenty identical lithium disilicate crowns were cemented onto zirconia prefabricated abutments using composite resin cement. Ten …

Treatment Decisions Involving Teeth With Intrapulpal Cracks: A Survey Of Endodontists, Sheldon M. Sealey

Theses and Dissertations

There is no universal protocol for diagnosing, treating and managing cracked teeth. The purpose of this survey was to investigate the use of traditional methods of crack detection and to explore how treatment decisions were made using an intrapulpal crack classification. The electronic survey was sent to 1115 active members of the American Association of Endodontists (AAE) and The Digital Office (TDO^™) community. Comparisons were assessed using logistic or repeated-measures regression. The most often used diagnostic method was probing. When the crack involved one wall, 85% of respondents would complete root canal therapy > 50% of the time or …

Restorative Characteristics Of Intrapulpally Cracked Teeth, Charles M. Beavers

Theses and Dissertations

Cracked teeth have long presented a diagnostic challenge. Previous investigators have considered possible predictive factors, many of which revolve around the tooth’s restorative characteristics. Few have investigated the restorative status of teeth with cracks extending into the pulp chamber. The purpose of this investigation was to determine the prevalence of the different types of restorations present in intrapulpally cracked teeth and determine any other restorative factors that may aid in predicting the presence or extent of an intrapulpal crack. Intrapulpally cracked molars requiring endodontic therapy at the VCU Graduate Endodontic Practice were included in this study. For each tooth, the …

A Justification For The Trend Towards Indirect Pulp Therapy, Marissa Kuhnen

Theses and Dissertations

Purpose: The purpose of this retrospective chart review was to determine how primary molars needing vital pulp therapy have been treated in the past four years at Virginia Commonwealth University (VCU) and to determine which treatments: indirect pulp therapy (IPT), formocresol pulpotomy, and ferric sulfate pulpotomy have been successful. Methods: AxiUm records that contained the procedure codes D3120 (Pulp Cap – Indirect) or D3220 (Therapeutic Pulpotomy) were totaled by year. Visit records were queried again to identify treatment failures i.e. extractions or pulpectomy. Results: In 2010, 52% of vital pulp therapies were ferric sulfate pulpotomies and in …

Esthetic Posterior Stainless Steel Crowns And Their Relative Shear Strengths, Lonny Dale Carmichael

Theses and Dissertations

Purpose: The purpose of this study was to evaluate esthetic posterior stainless steel crowns (EP-SSC) and compare their relative shear strengths.Methods: Sixty EP-SSC were compared. 15 crowns from NuSmile® Primary Crowns, Kinder Krowns, and Dental Innovators 1UP and EC Crowns were studied. The crowns were cemented to a typodont tooth then thermally cycled in water baths to simulate oral conditions. Shear strengths were evaluated by subjecting these crowns to simulated forces of occlusion.Results: The force required to cause shearing of the esthetic facings was statistically significant. With the 1UP crown being significantly weaker than the other crowns tested. Conclusion: The …

Concurrent Whitening And Orthodontic Treatment, Jason Thomas Gladwell

Theses and Dissertations

The aim was to evaluate whether a whitening system, when used during the final stages of orthodontics, would yield results comparable to whitening alone. Patients were assigned to either the control (n=20) or experimental (n=26) groups. At T1, patients were given a ten day supply of Trèswhite™ by Opalescence®, instructions on use, and initial shade determination was made and photographs were taken. At T2 and T3, shade determination was accomplished and updated photographs were taken. Whitening of the teeth occurred in both groups on average, but significantly more whitening was experienced in the experimental group (p < 0.004). An average of 87% of teeth whitened during orthodontic treatment compared to 97% of control teeth (p < 0.01) were judged to be uniform in appearance. In conclusion, the data do not contraindicate the concurrent accomplishment of teeth whitening during orthodontic treatment.