PURPOSE: The objective of this study was to evaluate the influence of various cement types on the stress distribution in monolithic zirconia crowns under maximum bite force using the finite element analysis. MATERIALS AND METHODS: The models of the prepared #46 crown (deep chamfer margin) were scanned and solid models composed of the monolithic zirconia crown, cement layer, and prepared tooth were produced using the computer-aided design technology and were subsequently translated into 3-dimensional finite element models. Four models were prepared according to different cement types (zinc phosphate, polycarboxylate, glass ionomer, and resin). A load of 700 N was applied vertically on the crowns (8 loading points). Maximum principal stress was determined. RESULTS: Zinc phosphate cement had a greater stress concentration in the cement layer, while polycarboxylate cement had a greater stress concentration on the distal surface of the monolithic zirconia crown and abutment tooth. Resin cement and glass ionomer cement showed similar patterns, but resin cement showed a lower stress distribution on the lingual and mesial surface of the cement layer. CONCLUSION: The test results indicate that the use of different luting agents that have various elastic moduli has an impact on the stress distribution of the monolithic zirconia crowns, cement layers, and abutment tooth. Resin cement is recommended for the luting agent of the monolithic zirconia crowns.
Bite Force ; Computer-Aided Design ; Crowns* ; Dental Cements ; Dental Stress Analysis ; Finite Element Analysis* ; Glass ; Glass Ionomer Cements ; Polycarboxylate Cement ; Resin Cements ; Tooth ; Zinc Phosphate Cement ; Zirconium

PURPOSE: The purpose of this study was to investigate the diametral tensile strength of polymer-based temporary crown and fixed partial denture (FPD) materials, and the change of the diametral tensile strength with time. MATERIAL AND METHODS: One monomethacrylate-based temporary crown and FPD material (Trim) and three dimethacrylate-based ones (Protemp 3 Garant, Temphase, Luxtemp) were investigated. 20 specimens (the empty set 4 mm x 6 mm) were fabricated and randomly divided into two groups (Group I: Immediately, Group II: 1 hour) according to the measurement time after completion of mixing. Universal Testing Machine was used to load the specimens at a cross-head speed of 0.5 mm/min. The data were analyzed using one-way ANOVA, the multiple comparison Scheffe test and independent sample t test (alpha = 0.05). RESULTS: Trim showed severe permanent deformation without an obvious fracture during loading at both times. There were statistically significant differences among the dimethacrylate-based materials. The dimethacrylate-based materials presented an increase in strength from 5 minutes to 1 hour and were as follows: Protemp 3 Garant (23.16 - 37.6 MPa), Temphase (22.27 - 28.08 MPa), Luxatemp (14.46 - 20.59 MPa). Protemp 3 Garant showed the highest value. CONCLUSION: The dimethacrylate-based temporary materials tested were stronger in diametral tensile strength than the monomethacrylate-based one. The diametral tensile strength of the materials investigated increased with time.
Acrylic Resins ; Bisphenol A-Glycidyl Methacrylate ; Collodion ; Composite Resins ; Crowns ; Denture, Partial, Fixed ; Methacrylates ; Polymethacrylic Acids ; Tensile Strength

Implant treatment, which was first attempted in fully edentulous patients, is now widely used in partially edentulous, and a single tooth missing patients. Moreover, implant treatment has become an essential treatment modality in modern dentistry. The material of fabricating implant prostheses has also become more diverse than before, one of which is the use of high-performance polymers. The frequency of using high-performance polymers, which have been used in the medical field, is also increased in the dental field compared to the past. In the first case, a PEKK abutment and a PFG crown (cement-screw-retaining type) were fabricated in the lower left second premolar, and in the second case, a PEKK abutment and a monolithic zirconia crown (cement-screw-retaining type) were fabricated in the missing upper left first molar, and in the third case two PEKK abutments and a splinted PFM crowns (cement-screw-retaining type) were fabricated and connected to the upper right first and second molar implants. Through these procedures the patients obtained esthetically and functionally satisfactory results after 4 years of follow-up.

In the case of excessively worn dentition, there is often insufficient space for the prosthesis, and if physiologically acceptable, the prosthesis can be fabricated by increasing the vertical dimension of occlusion. Various methods have been introduced to determine the vertical dimension of occlusion. Clinicians have to choose a method that can comfort the patient among several methods. A removable appliance can be used as a reversible method to ensure that the determined vertical dimension of occlusion does not cause physiological problems. When making impressions of many teeth, it is often difficult to make accurate impressions at once. In this case, after making an accurate impression of the individual teeth, a transfer coping was made and a pickup impression was taken in the oral cavity to create a master cast. In this case, a fixed partial denture was fabricated and full mouth rehabilitation was performed by increasing the vertical dimension of occlusion in a patient with excessively worn dentition and lack of space for restoration. As a result of follow-up of the patient for 7 years, satisfactory results were obtained both esthetically and functionally.

Edentulous patients with severe alveolar bone resorption have trouble with using traditional complete denture. In order to overcome these problems, implant-retained overdenture was developed. SFI-bar(R) system can save time and cost compared to other existing bar systems which need complicated laboratory procedures because it can be adjusted directly in a patient's mouth. A 55-year-old male, who had experienced a fractured lower old implant-retained overdenture, wanted a durable and painless denture. The fractured Locator(R) attachments were removed and edentulous mandible was restored with SFI-bar(R). A 77-year-old female with a medical history of the Parkinson's disease and severely absorbed alveolar bone of mandible, wanted to wear a retentive mandibular denture without pain. After placing two implants in front of mental foramen, two adaptors were connected to two implants and a tube bar was connected to the adaptors. A female part fitted to the bar was attached to the new denture. These clinical reports describe two-implant-retained overdenture using the SFI-bar(R) system in mandibular edentulous patients. Since the patients were satisfied esthetically and functionally during 2 years' observation, we would like to report cases.
Aged ; Bone Resorption ; Dental Implants ; Denture, Complete ; Denture, Overlay* ; Dentures ; Female ; Humans ; Male ; Mandible ; Middle Aged ; Mouth ; Parkinson Disease

Purpose: The purpose of present study was to evaluate the effect of changing structural stability of wax disc on the fit of prosthesis when the milling proceeded in order. Materials and methods: Prepared maxillary left first molar was used to fabricate a Ni-Cr alloy reference model. This was scanned to design crown and then wax pattern was milled, invested and cast to fabricate prosthesis. The wax patterns located in a row centrally within a single wax disc were set into a total of five groups ranging from WM1 group that was first milled to WM5 group that was last milled and the number of each group was set as 10. Silicone replica technique was used to measure the marginal gap, axial internal gap, line angle internal gap, occlusal internal gap. Data was evaluated with one-way ANOVA with significance level set at α = .05 and then Tukey HSD test was conducted for post analysis. Results: Marginal gap measured in each group, it was 40.41 ± 2.15 µm in WM1group, 40.44 ± 2.23 µm in WM2 group, 39.96 ± 2.25 µm in WM3 group, 39.96 ± 2.48 µm in WM4 group, and 40.57 ± 2.53 µm in WM5 group. No significant difference was found between groups. The significant difference between the groups was also not found in the axial internal gap, line angle internal gap, and occlusal internal gap. Conclusion Internal and marginal fit of single crown to the sequential order of milling processing in the single machinable wax disc did not seem to be affected by the sequence.

In cases where a palatal defect resulting from oral cancer surgery is reconstructed using a free flap, dentures placed on the grafted site, lacking bone support, may experience stability problems due to insufficient support. This case report presents a 41-year-old male patient who underwent a sinus resection due to maxillary sinus carcinoma. The defect was reconstructed using a lateral thigh free flap.After a three-month interim prosthesis phase, a conventional removable partial denture was fabricated. Considering the condition of the remaining teeth and the patient’s age, natural tooth alteration was performed and lingual undercuts of the right posterior teeth were incorporated into the design to compensate for the lack of bone support. Digital occlusal analysis devices and 3D facial scanning were utilized to evaluate changes in occlusion and facial form, and the visualized results were presented to the patient to enhance understanding.

In cases where a palatal defect resulting from oral cancer surgery is reconstructed using a free flap, dentures placed on the grafted site, lacking bone support, may experience stability problems due to insufficient support. This case report presents a 41-year-old male patient who underwent a sinus resection due to maxillary sinus carcinoma. The defect was reconstructed using a lateral thigh free flap.After a three-month interim prosthesis phase, a conventional removable partial denture was fabricated. Considering the condition of the remaining teeth and the patient’s age, natural tooth alteration was performed and lingual undercuts of the right posterior teeth were incorporated into the design to compensate for the lack of bone support. Digital occlusal analysis devices and 3D facial scanning were utilized to evaluate changes in occlusion and facial form, and the visualized results were presented to the patient to enhance understanding.

In cases where a palatal defect resulting from oral cancer surgery is reconstructed using a free flap, dentures placed on the grafted site, lacking bone support, may experience stability problems due to insufficient support. This case report presents a 41-year-old male patient who underwent a sinus resection due to maxillary sinus carcinoma. The defect was reconstructed using a lateral thigh free flap.After a three-month interim prosthesis phase, a conventional removable partial denture was fabricated. Considering the condition of the remaining teeth and the patient’s age, natural tooth alteration was performed and lingual undercuts of the right posterior teeth were incorporated into the design to compensate for the lack of bone support. Digital occlusal analysis devices and 3D facial scanning were utilized to evaluate changes in occlusion and facial form, and the visualized results were presented to the patient to enhance understanding.

In cases where a palatal defect resulting from oral cancer surgery is reconstructed using a free flap, dentures placed on the grafted site, lacking bone support, may experience stability problems due to insufficient support. This case report presents a 41-year-old male patient who underwent a sinus resection due to maxillary sinus carcinoma. The defect was reconstructed using a lateral thigh free flap.After a three-month interim prosthesis phase, a conventional removable partial denture was fabricated. Considering the condition of the remaining teeth and the patient’s age, natural tooth alteration was performed and lingual undercuts of the right posterior teeth were incorporated into the design to compensate for the lack of bone support. Digital occlusal analysis devices and 3D facial scanning were utilized to evaluate changes in occlusion and facial form, and the visualized results were presented to the patient to enhance understanding.