STATEMENT OF PROBLEM: One of the common problems of provisional crown and fixed partial denture materials is that when they are subjected to constant loads for a long period of time, they exhibit a dimensional change (creep). PURPOSE: The aim of this study was to investigate the viscoelastic behaviour of polymer-based provisional crown and fixed partial denture materials with time at constant compressive load. MATERIAL AND METHODS: Three dimethacrylate-based materials (Protemp 3 Garant, Temphase, Luxatemp) and one monomethacrylate-based material (Trim) were selected. Dimensional changes of the specimens were recorded by a LVDT to evaluate their viscoelastic behavior and creep strain. For all specimens, two loading procedures were used. At first, static compressive stress of 4 MPa was applied for 30 minutes and followed by 1 hour of strain recovery. Then, after 24 hours of water storage, the specimens were loaded again. The creep values between materials were statistically analyzed using one-way ANOVA and multiple comparison Scheffe'test. Independent samples t-test was also used to identify the difference of creep strain between first and secondary loading conditions at the significance level of 0.05. RESULTS: Following application of the first loading, Trim showed the highest maximum creep strain (32.7%) followed by Luxatemp, Protemp 3 Garant and Temphase, with values of 3.78%, 2.86% and 1.77%, respectively. Trim was significantly different from other materials (P<0.05), while there were no significant differences among Luxatemp, Protemp 3 Garant and Temphase (P>0.05). The highest recovery and permanent set of Trim, were significantly different from those of others (P<0.05). At the secondary loading of the dimethacrylate-based materials, creep deformation, recovery and permanent set decreased and the percentage of recovery increased, while in Trim, all values of the measurements increased. This result showed that the secondary loading at 24 hours produced a significant creep magnitude. CONCLUSION: The dimethacrylate-based provisional crown and fixed partial denture materials showed significantly higher creep resistance and lower deformation than the monomethacrylate-based material. Thus, monomethacrylate-based materials should not be used in long-term stress-bearing situations.
Crowns* ; Denture, Partial, Fixed* ; Water

STATEMENT OF PROBLEM: Fracture of the tooth-colored superstructure material is one of the main prosthetic complications in implant-supported prostheses. PURPOSE: The purpose of this in vitro study was to compare the fracture strength between the cement-retained implant-supported metal-ceramic crowns and the indirect composite resinveneered metal crowns under the vertical compressive load. MATERIAL AND METHODS: Standard implants of external type (AVANA IFR 415 Pre-mount; Osstem Co., Busan, Korea) were embedded in stainless steel blocks perpendicular to their long axis. Customized abutments were fabricated using plastic UCLA abutments (Esthetic plastic cylinder; Osstem Co., Busan, Korea). Thirty standardized copings were cast with non-precious metal (Rexillium III, Pentron, Walling ford, Conn., USA). Copings were divided into two groups of 15 specimens each (n = 15). For Group I specimens, metal-ceramic crowns were fabricated. For Group II specimens, composite resin-veneered (Sinfony, 3M-ESPE, St. Paul, MN, USA) metal crowns (Sinfony-veneered crowns) were fabricated according to manufacturer's instructions. All crowns were temporary cemented and vertically loaded with an Instron universal testing machine (Instron 3366, Instron Corp., Norwood, MA, USA). The maximum load value (N) at the moment of complete failure was recorded and all data were statistically analyzed by independent sample t-test at the significance level of 0.05. The modes of failure were also investigated with visual analysis. RESULTS: The fracture strength of Sinfony-veneered crowns (2292.7 +/- 576.0 N) was significantly greater than that of metal-ceramic crowns (1150.6 +/- 268.2 N) (P < 0.05). With regard to the failure mode, Sinfony-veneered crowns exhibited adhesive failure, while metal-ceramic crowns tended to fracture in a manner that resulted in combined failure. CONCLUSION: Sinfony-veneered crowns demonstrated a significantly higher fracture strength than that of metal-ceramic crowns in cement-retained implant-supported prostheses.
Adhesives ; Axis, Cervical Vertebra ; Busan ; Crowns* ; Plastics ; Prostheses and Implants ; Stainless Steel

When wearing complete dentures, patients want to function naturally within a physiologically stable range. To do this, recovery of esthetics, biologically stable arrangement and contour, and occlusal contacts with denture stability are necessary. In this case report, a complete denture patient of adverse conditions was presented. To increase stability of the dentures, functional impression was made by border molding using the neutral zone. The dentures were checked for physiological centric relations and stable occlusion. The clinical results showed satisfactory results on function and esthetics.
Centric Relation ; Denture Retention ; Denture, Complete ; Dentures ; Esthetics ; Fungi ; Humans

STATEMENT OF PROBLEM: Composite resin-veneered metal restorations can be used as an alternative to porcelain-fused-metal restorations. But, because of the relatively low bond strength of veneering composite to metal framework, various surface treatment methods have been introduced to improve the bond strength. PURPOSE: The object of this study was to compare the shear bond strength of different combinations of each of the two bonding systems and each of the two composite veneering resins to cp-Ti / Co-Cr alloy. MATERIAL AND METHODS: Two resin bonding systems (metal conditioner containing MEPS monomer, tribochemical silicoating system) and two composite resins (Gradia, Sinfony) were tested on cp-Ti and Co-Cr alloy. Then, according to manufacturers' instructions, resin bonding systems and composite resins were applied. All test specimens were divided into four groups for each alloy; I) sandblast + Metal Primer II+ Gradia (MG), II) sandblast + Metal Primer II + Sinfony (MS), III) Rocatec + Gradia (RG), IV) Rocatec + Sinfony (RS). The shear bond strength was determined using a universal testing machine and all data were statistically analyzed with Mann-Whitney test and Kruskal-Wallis test at the significance level of 0.05. RESULTS: The mean (standard deviations) of shear bond strength according to the combinations of two bonding systems and two composite resins to cp-Ti arranged from 16.44 MPa to 17.07 MPa and the shear bond strength to Co-Cr alloy ranged from 16.26 MPa to 17.70 MPa. The result shows that the difference were not statistically significant. CONCLUSION: The shear bond strengths of composite resins to both cast cp-Ti and Co-Cr alloy were not significantly different between the metal conditioner and the tribochemical silicoating system. And no differences in bond strength were found between cp-Ti and Co-Cr alloy.
Alloys* ; Composite Resins*

With the introduction of dental implants, restoration of missing teeth with conventional fixed or removable partial dentures is being replaced with implants. Especially, with young patients, not only longevity but also esthetic factors need to be considered. Implant restorations provide long-term success functionally but, esthetic complications such as, marginal exposure due to gingival recession, loss of the papilla and dark color of metal abutments may occur. Recently, zirconia restorations with CAD/CAM technology provide functional, biocompatible and esthetic restorations possible. All-ceramic restorations using the pressed ceramic technique show better fracture toughness values than those of the conventional porcelain veneering technique. Pressed ceramic technique creates the veneer design in wax and the lost wax technique is used to create the restoration. The final contour of the restoration may be controlled during wax-up. A 22-year old female patient was restored with dental implants and zirconia restorations using the pressed ceramic technique presenting short-term but optimistic prognosis.
Ceramics ; Dental Implants ; Dental Porcelain ; Denture, Partial, Removable ; Female ; Gingival Recession ; Humans ; Longevity ; Prognosis ; Tooth ; Zirconium

Traumatic defects are mostly accompanied by hard and soft tissue loss. This report describes the surgical and prosthetic treatment of a patient with post-traumatic mandibular defect. A split-thickness skin graft was performed prior to implant placement and prefabricated acrylic stent was placed to hold the graft in place. The esthetic and functional demands of the patient were fulfilled by implant-supported screw-retained fixed prosthesis using CAD-CAM technology.
Computer-Aided Design ; Dental Implants ; Humans ; Hypogonadism ; Mitochondrial Diseases ; Ophthalmoplegia ; Prostheses and Implants ; Skin ; Skin Transplantation ; Stents ; Transplants ; Zirconium

Data collection including checking the problem list and analyzing the etiology cannot be overemphasized in full mouth rehabilitation cases. It is well reported that favorable prognosis of prosthodontic treatment depends on accurate diagnosis. Seventy seven year old female patient presented with chief complaints of chewing pain on maxillary and mandibular left premolars and unesthetic existing prosthesis. Clinical evaluation, radiographic examination and cast analysis were performed to gather comprehensive data and problem lists. Treatment planning was based on collected data and related articles. Abutment evaluation, prognosis depending on various types of prosthesis, and maintenance were considered as well. Occlusal vertical dimension was increased to solve esthetic dissatisfaction and insufficient interocclusal space. Patient adaptation was verified with provisional restorations followed by diagnostic wax up. Function, esthetics and occlusal stability were verified during 8 week follow-up period. Prosthodontic reconstruction based on systemic analysis, diagnosis, and treatment plan led to satisfactory result after delivery of definitive prosthesis.
Bicuspid ; Data Collection ; Esthetics ; Female ; Follow-Up Studies ; Humans ; Mastication ; Mouth Rehabilitation ; Mouth* ; Prognosis ; Prostheses and Implants ; Prosthodontics ; Vertical Dimension

STATEMENT OF PROBLEM: Poor wettability of denture relining materials may lead to retention problems and patient discomfort. PURPOSE: Purpose of this study is to compare and evaluate wettability of nine denture relining materials using contact angle measurements under air and water storage over time. MATERIAL AND METHODS: Nine denture relining materials were investigated in this study. Two heat-curing polymethyl-methacrylate (PMMA) denture base materials: Vertex RS, Lang, one self-curing polyethyl-methacrylate (PEMA) chairside reline resin: Rebase II, six silicone relining materials: Mucopren soft, Mucosoft, Mollosil(R) plus, Sofreliner Touch, GC Reline(TM) Ultrasoft, Silagum automix comfort were used in this experiment. Contact angles were measured using high-resolution drop shape analysis system (DSA 10-MK2, KRUESS, Germany) under three conditions (in air after setting, 1 hour water storage, and 24 hours water storage). Nine materials were classified into three groups according to material composition (Group 1: PMMA, Group 2: PEMA, Group 3: Silicone). Mean values of contact angles were compared using independent samples t-test and one-way ANOVA, followed by a Scheffe's post hoc analysis (alpha= 0.01). RESULTS: Contact angles of materials tested after air and water storage increased in the following order: Group 1 (PMMA), Group 2 (PEMA), Group 3 (Silicone). Heat-cured acrylic denture base resins had more wettability than silicone relining materials. Lang had the highest wettability after 24 hours of water storage. Silicone relining materials had lower wettability due to their hydrophobicity. Wettability of all denture relining materials, except Rebase II and Mollosil(R) plus, increased after 24 hours of water storage. CONCLUSIONS: Conventional heat-cured resin showed the highest wettability, therefore, it can be suggested that heat-cured acrylic resin is material of choice for denture relining materials.
Denture Bases ; Denture Rebasing ; Dentures ; Humans ; Hydrophobic and Hydrophilic Interactions ; Polymethyl Methacrylate ; Retention (Psychology) ; Silicones ; Water ; Wettability

PURPOSE: The accuracy of denture bases was compared among injection molding, milling, and rapid prototyping (RP) fabricating method. MATERIALS AND METHODS: The maxillary edentulous master cast was fabricated and round shaped four notches were formed. The cast was duplicated to ten casts and scanned. In the injection molding method, designed denture bases were milled from a wax block and fabricated using SR Ivocap injection system. Denture bases were milled from a pre-polymerized block in the milling method. In the RP method, denture bases were printed and post-cured. The intaglio surface of the base was scanned and surface matching software was used to measure inaccuracy. Measurements were performed between four notches and two points in the mid-palatal suture to evaluate inaccuracy. The palatine rugae resolution was evaluated. One-way analysis of variance was used for statistical analysis at α=.05. RESULTS: No statistically significant differences in distances among four notches (P>.05). The accuracy of the injection molding method was lower than those of the other methods in two points of the mid-palatal suture significantly (P < .05). The degree of palatine rugae resolution was significantly higher in the injection molding method than that in other methods (P < .05). CONCLUSION: The overall accuracy of the denture base is higher in milling and RP method than the injection molding method. The degree of fine reproducibility is higher in the injection molding method than the milling or RP method.
Denture Bases ; Dentures ; Fungi ; Methods ; Printing, Three-Dimensional ; Sutures

Background: This study aimed to analyze the clinical outcome and complications of narrow-diameter dental implants (NDIs) (diameter ≤3.5 mm). Methods: The 274 NDIs that met the selection criteria from 2013 to 2018 were included in the retrospective study, and the survival rates (SVR) were compared. Mechanical complications included screw loosening and fractures of the implant components, such as the implant fixture, abutment, and prosthesis. In addition, marginal bone loss (MBL) was measured immediately after surgery and 1 year after loading. Results: The 3-year cumulative SVR was 92.4%. Nineteen fixtures failed during the follow-up. The failure rate was sig‑ nificantly higher (OR=4.573, p<0.05) in smokers and was significantly higher in osteoporosis patients (OR=3.420, p<0.05). The vertical and horizontal values of MBL were 0.33±0.32 mm and 0.18±0.17 mm, respectively. Mechanical complications included screw loosening (5.5%) and porcelain fracture (2.2%), but no fractures of the fixture or com‑ ponents were observed. The choice of titanium and zirconium (TiZr) alloy implant was significantly more frequent in the posterior region. Bone graft was significantly more frequently done in the anterior region. Conclusions According to the high SVR and stability of NDIs, the findings of the study suggest that NDIs may be a replacement for regular diameter dental implants (RDIs) and the use of TiZr alloy could extend the indication of NDIs. In the esthetic area, contour augmentation may be a reason for increasing the frequency of bone grafts