Ediz Kale

Effect of feldspathic porcelain layering on the marginal fit of zirconia and titanium complete-arch fixed implant-supported frameworks

Statement of problem. Veneering with porcelain may adversely affect the marginal fit of long‐span computer‐aided design and computer‐aided manufacturing (CAD‐CAM) implant‐supported fixed prostheses. Moreover, data regarding the precision of fit of CAD‐CAM–fabricated implant‐supported complete zirconia fixed dental prostheses (FDPs) before and after porcelain layering are limited. Purpose. The purpose of this in vitro study was to evaluate the effect of porcelain layering on the marginal fit of CAD‐CAM–fabricated complete‐arch implant‐supported, screw‐retained FDPs with presintered zirconia frameworks compared with titanium. Material and methods. An autopolymerizing acrylic resin–fixed complete denture framework prototype was fabricated on an edentulous typodont master model (all‐on‐4 concept; Nobel Biocare) with 2 straight in the anterior and 2 distally tilted internal‐hexagon dental implants in the posterior with multiunit abutments bilaterally in canine and first molar locations. A 3‐dimensional (3D) laser scanner (S600 ARTI; Zirkonzahn) was used to digitize the prototype and the master model by using scan bodies to generate a virtual 3D CAD framework. Five presintered zirconia (ICE Zirkon Translucent ‐ 95H16; Zirkonzahn) and 5 titanium (Titan 5 ‐ 95H14; Zirkonzahn) frameworks were fabricated using the CAM milling unit (M1 Wet Heavy Metal Milling Unit; Zirkonzahn).The 1‐screw test was applied by fixing the frameworks at the location of the maxillary left first molar abutment, and an industrial computed tomography (CT) scanner (XT H 225 ‐ Basic Configuration; Nikon) was used to scan the framework‐model complex to evaluate the passive fit of the frameworks on the master model. The scanned data were transported in standard tessellation language (STL) from Volume Graphics analysis software to PolyWorks analysis software by using the maximum‐fit algorithm to fit scanned planes in order to mimic the mating surfaces in the best way. 3D virtual assessment of the marginal fit was performed at the abutment‐framework interface at the maxillary right canine (gap 3) and right first molar (gap 4) abutments without prosthetic screws. The facial or buccal aspects of the teeth on frameworks were layered with corresponding porcelain (Initial Dental Ceramic System; GC) and CT‐scanned again using the same protocol. Marginal fit measurements were made for 4 groups: titanium (Ti) (control), porcelain‐layered titanium (Ti‐P) (control), zirconia (Zir), and porcelain‐layered zirconia (Zir‐P). 3D discrepancy mean values were computed and calculated, and the results were analyzed with a repeated measures 3‐way ANOVA using the maximum likelihood estimation method and Bonferroni adjustments for selected pairwise comparison t‐tests (&agr;=.05). Results. The 3D fit was measured at gap 3 and gap 4. Statistically significant differences in mean 3D discrepancies were observed between Zir‐P (175 &mgr;m) and Zir (89 &mgr;m) and between Zir‐P and Ti‐P (71 &mgr;m) (P<.001). Conclusions. Porcelain layering had a significant effect on the marginal fit of CAD‐CAM–fabricated complete‐arch implant‐supported, screw‐retained FDPs with partially sintered zirconia frameworks. 3D marginal discrepancy mean values for all groups were within clinically acceptable limits (<120 &mgr;m), except for the layered zirconia framework.

Effect of fabrication stages and cementation on the marginal fit of CAD-CAM monolithic zirconia crowns

Statement of problem Monolithic zirconia crowns fabricated using computer‐aided design and computer‐aided manufacturing (CAD‐CAM) technology have recently become an alternative dental prosthetic treatment. The marginal fit of monolithic zirconia crown may be affected by different stages of the fabrication procedures in the laboratory and cementation. Information regarding the accuracy of fit of monolithic zirconia crowns at different stages of fabrication and cementation is limited. Purpose The purpose of this in vitro study was to evaluate the effect of different stages of fabrication and cementation on the vertical marginal discrepancy (VMD) of CAD‐CAM fabricated monolithic zirconia crowns. Material and methods Six ivorine right maxillary first molar typodont teeth with standardized anatomic preparations for complete coverage ceramic crowns were scanned with a 3‐dimensional laboratory scanner. Crowns were designed using CAD software and milled from presintered monolithic zirconia blocks in a 5‐axis dental milling machine. A cement space of 25 &mgr;m for the margins and a 50‐&mgr;m space starting 1 mm above the finish lines of the teeth were virtually set in the CAD software. A total of 144 measurements were performed on 6 specimens with 8 measurement locations in 3 different stages using stereoscopic zoom microscopy; after initial production of the crowns (post‐sintering group), after glazing (post‐glazing group), and after cementation (post‐cementation group). The VMD values were statistically analyzed with 1‐way repeated measures ANOVA and the Holm‐Sidak method (&agr;=.05). Results Different stages of fabrication and cementation significantly affected the VMD of tested crowns (P=.003). The mean VMD was 38 &mgr;m for post‐sintering group, 38 &mgr;m for post‐glazing group, and 60 &mgr;m for post‐cementation group, with statistical differences between the post‐sintering group, the post‐cementation group (P<.002), and the post‐glazing group and post‐cementation group (P<.003); there were no statistical differences between the post‐sintering group and the post‐glazing group (P=.966). Conclusions Within the limitations of this in vitro study, glazing did not significantly change the VMD of CAD‐CAM monolithic zirconia crowns. Cementation significantly increased the VMD values.

Amelogenesis Imperfecta: Rehabilitation and Brainstorming on the Treatment Outcome after the First Year

Amelogenesis imperfecta (AI) affects enamel on primary and permanent dentition. This hereditary disorder is characterized by loss of enamel, poor esthetics, and hypersensitivity. Functional and cosmetic rehabilitation is challenging with variety of treatment options. This report presents the treatment of an AI patient using conventional fixed dentures and discusses issues related to posttreatment complications and prosthetic treatment outcome after 1 year of follow-up. A 19-year-old male AI patient with impaired self-esteem presented with hypersensitive, discolored, and mutilated teeth. Clinical examination revealed compromised occlusion and anterior open-bite. After hygiene maintenance full-coverage porcelain-fused-to-metal fixed restorations were indicated and applied. At the end of the treatment acceptable functional and esthetic results could be achieved. However, nearly a year after treatment a gingival inflammation in the esthetic zone complicated the outcome. Insufficient oral hygiene was to be blamed. Tooth sensitivity present from early childhood in these patients may prevent oral hygiene from becoming a habit. The relaxation due to relieve of hypersensitivity after treatment makes oral hygiene learning difficult. Continuous oral hygiene maintenance motivation may be crucial for the success of the treatment of AI patients. Treatment of AI patients should be carefully planned and an acceptable risk-benefit balance should be established.

Marginal discrepancy of CAD-CAM complete-arch fixed implant-supported frameworks

Statement of problem. Computer‐aided design and computer‐aided manufacturing (CAD‐CAM) high‐density polymers (HDPs) have recently been marketed for the fabrication of long‐term interim implant‐supported fixed prostheses. However, information regarding the precision of fit of CAD‐CAM HDP implant‐supported complete‐arch screw‐retained prostheses is scarce. Purpose. The purpose of this in vitro study was to evaluate the marginal discrepancy of CAD‐CAM HDP complete‐arch implant‐supported screw‐retained fixed prosthesis frameworks and compare them with conventional titanium (Ti) and zirconia (Zir) frameworks. Material and methods. A screw‐retained complete‐arch acrylic resin prototype with multiunit abutments was fabricated on a typodont model with 2 straight implants in the anterior region and 2 implants with a 30‐degree distal tilt in the posterior region. A 3‐dimensional (3D) laboratory laser scanner was used to digitize the typodont model with scan bodies and the resin prototype to generate a virtual 3D CAD framework. A CAM milling unit was used to fabricate 5 frameworks from HDP, Ti, and Zir blocks. The 1‐screw test was performed by tightening the prosthetic screw in the maxillary left first molar abutment (terminal location) when the frameworks were on the typodont model, and the marginal discrepancy of frameworks was evaluated using an industrial computed tomographic scanner and a 3D volumetric software. The 3D marginal discrepancy at the abutment‐framework interface of the maxillary left canine (L1), right canine (L2), and right first molar (L3) sites was measured. The mean values for 3D marginal discrepancy were calculated for each location in a group with 95% confidence limits. The results were analyzed by repeated‐measures 2‐way ANOVA using the restricted maximum likelihood estimation and the Satterthwaite degrees of freedom methods, which do not require normality and homoscedasticity in the data. The between‐subjects factor was material, the within‐subjects factor was location, and the interaction was included in the model. Tukey tests were applied to resolve any statistically significant source of variation (overall &agr;=.05). Results. The 3D marginal discrepancy measurement was possible only for L2 and L3 because the L1 values were too small to detect. The mean discrepancy values at L2 were 60 &mgr;m for HDP, 74 &mgr;m for Ti, and 84 &mgr;m for Zir. At the L3 location, the mean discrepancy values were 55 &mgr;m for HDP, 102 &mgr;m for Ti, and 94 &mgr;m for Zir. The ANOVA did not find a statistically significant overall effect for implant location (P=.072) or a statistically significant interaction of location and material (P=.078), but it did find a statistically significant overall effect of material (P=.019). Statistical differences were found overall between HDP and the other 2 materials (P≤.037). Conclusions. When the tested materials were used with the CAD‐CAM system, the 3D marginal discrepancy of CAD‐CAM HDP frameworks was smaller than that of titanium or zirconia frameworks.

Nanomechanical Comparison of Commonly Used Dental Crown Cements to a Newly Developed One

Nanomechanical Comparison of Commonly Used Dental Crown Cements to a Newly Developed One E. Kale, Z. Arslanoğlu, H. Altan, F. Bilgiç, M. Tuzlali, A. Köroğlua,e,∗ and S. Özarslan Mustafa Kemal University, Faculty of Dentistry, Department of Prosthodontics, Hatay, Turkey Mustafa Kemal University, Faculty of Dentistry, Department of Paediatric Dentistry, Hatay, Turkey Gaziosmanpaşa University, Faculty of Dentistry, Department of Paediatric Dentistry, Tokat, Turkey Mustafa Kemal University, Faculty of Dentistry, Department of Orthodontics, Hatay, Turkey Mustafa Kemal University, Faculty of Dentistry, Department of Periodontology, Hatay, Turkey Mustafa Kemal University, Department of Physics, Hatay, Turkey

Retrospective study on the 7.5-year survival of resin-bonded dental prostheses in single missing second premolar cases.

Purpose: The purpose of this study is to report retrospectively the clinical results of cast metal slot-retained resin-bonded fixed dental prostheses (RBFDPs) used in the restoration of single missing second premolar teeth, as this kind of prostheses provides acceptable clinical outcomes in a minimally invasive and esthetic treatment for the average patient requiring cheaper and faster treatment alternative for a single missing posterior tooth. However, the data present in the literature are scarce. Materials and Methods: Clinical follow-up was reported up to 7.5 years in nine different cast metal slot-retained RBFDPs patients of both genders between 21 and 49 years of age. Routine clinical controls were performed 6 and 12 months after treatment, followed by regular intervals every year afterward. The Kaplan–Meier survival estimation method was used to determine the overall and functional survival rates and times of the RBFDPs at the end of the observation period. Results: At the end of the follow-up, all of the RBFDPs were still functional with a mean follow-up of 6.7 years. The Kaplan–Meier estimation for the overall survival was calculated as 89% for up to 7.5 years with one failure due to debonding. The functional survival rate was 100% with the lowest and highest observation periods being 5.8 and 7.5 years, respectively. Conclusions: Within the limitations of this retrospective clinical study, it seems that the design and cementation regimen used for the RBFDPs presented can guarantee clinical success in the restoration of single missing second premolar teeth.

Evaluation of patient with Holt-Oram syndrome in terms of oral and maxillofacial findings

The Holt-Oram syndrome (HOS) is a genetic disorder with autosomal dominant inheritance associated with anomalies in upper extremities and heart and affects one out of every 100,000 live births. Maxillofacial development is also affected by these skeletal abnormalities. Although there are many studies about the HOS in the literature, the data about the development of oral and maxillofacial development are very few. In this study, evaluation of a child with the HOS is made in terms of dental and gingival health, oral and maxillofacial formation, and cephalometric analysis measurements are made for the 1 st time in the literature and identified findings are discussed in company with the literature.

The effects of idiopathic hypoparathyroidism on dental development

Hypoparathyroidism cases without etiology diagnosed in the first 10 years of life are called as idiopathic hypoparathyroidism (IHP). IHP is a rare endocrinological disorder among hypoparathyroidism cases, and the anomalies accompanying it are infrequently observed. Ca ++ metabolism disorders occurring during the formation of tooth germs may cause enamel defects in teeth, enamel hypoplasia, enlarged pulp chambers, short roots, late eruptions, and missing teeth. The case presented in this article is a good example in terms of demonstrating how tooth damage ends with the commencement of treatment. Within this article, the results of a 9-year-old male IHP patient are discussed based on the literature. The said patient could not be diagnosed until the age of 18 months so developed enamel hypoplasia as well as enamel defects in this period due to abnormal mineralization, and no problems were observed in his dental tissue that formed after the ionic equilibrium was ensured following the diagnosis.