Evaluation of median mandibular flexure values in dentulous and edentulous subjects by using an intraoral digital scanner.

PURPOSE: Mandibular flexure is a crucial phenomenon that may affect the success of rigid bilateral mandibular prosthetic treatment. The aim of this study was to determine the amount of median mandibular flexure (MMF) that occurs during mouth opening from anterior to posterior mandible in seven different regions, in different age and gender groups of both dentulous and edentulous subjects, using an intraoral digital scanner. MATERIALS AND METHODS: In this study, the mandibular arch of 56 dentulous and 35 edentulous individuals were scanned with an intraoral scanner at both the minimum mouth opening (MnMO) and the maximum mouth opening (MxMO). MMF values were calculated by subtracting the distance value at the MxMO from the distance between the reference points at the MnMO at seven different mandibular regions of dentulous and edentulous subjects. In addition, the left and right side MMF values were measured. All data were analyzed statistically (α = .05). RESULTS: MMF value increased linearly from anterior to posterior mandible in both dentulous and edentulous individuals. The differences in MMF values were not statistically significant according to side (left/right), age, or gender (P > .05). No significant differences were found between the mean MMF values of the same region in both dentulous and edentulous individuals (P > .05). CONCLUSION: MMF was seen in different regions of the mandibles of both edentulous and dentulous individuals measured at the MxMO. Mandibular flexure should be considered for the success and prognosis of the long-span and rigid prostheses.

Evaluation of corrosion resistance of Co-Cr alloys fabricated with different metal laser sintering systems.

PURPOSE: The aim of this study was to evaluate the corrosion resistance of the specimens produced by five different commercial metal laser sintering (MLS) systems with their recommended Co-Cr alloy powders. MATERIALS AND METHODS: The MLS machines and the alloy powders used were, ProX 100-ST2724G (St-Pro), Mysint 100-EOS SP2 (SP2-Mys), EOSINT 270-EOS SP2 (SP2-EOS), SLM 100-Starbond CoS (SB-SLM), and MLab Cusing-Remanium® Star (RS-MLab), respectively. Eight specimens from each group were prepared. Open circuit potential (Eocp) and electrochemical impedance spectroscopy (EIS) measurements of polished surfaces of the specimens were conducted in a three-electrode cell using a potentiostat-galvanostat in Fusayama-Meyer artificial saliva (AS). Specimens from each group were immersed in AS and de-ionized water for seven days. Eocp, charge transfer resistance (Rct) values, and released ions (µg/cm2 × 7d) in different solutions were determined. The specimen surfaces were observed with SEM/EDS. Results were analyzed statistically. RESULTS: Eocp values have shifted to potentials that are more positive over time. Steady-state Eocp values were from high to low as follows, SB-SLM, SP2-Mys, SP2-EOS, RS-MLab, and ST-Pro, respectively. After 60 mins, RS-MLab specimens had the highest Rct value, followed by SP2-Mys, SB-SLM, SP2-EOS, and ST-Pro. In all groups, ion release was higher in AS than that in de-ionized water. CONCLUSION: There were small differences among the corrosion resistances of the Co-Cr alloy specimens produced with MLS systems; meanwhile, the corrosion resistances were quite high for all specimens.

Clinical factors affecting the translucency of monolithic Y-TZP ceramics.

The use of monolithic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics in aesthetically critical regions is questionable because of the insufficient translucency and opacity of the restorations. Intrinsic (manufacturing process) and extrinsic factors (laboratory procedures and clinical factors) can affect the translucency of monolithic zirconia. In this narrative review, the clinical factors (thickness, cementation type, colour of the monolithic zirconia, surface finishing methods and wear, dental background, cement colour, low temperature degradation) affecting the translucency of monolithic Y-TZP ceramics were reported.

Factors affecting the translucency of monolithic zirconia ceramics: A review from materials science perspective.

The use of monolithic [yttria (Y2O3)-stabilized tetragonal zirconia (ZrO2) polycrystalline] (Y-TZP) ceramics to restore teeth is expanding in dentistry. However, there are still some problems about color matching and the translucency of these ceramics. The employment of Y-TZP ceramics in aesthetically critical regions is questionable due to the insufficient translucency and opacity of the restorations. The objective of this review was to assess the factors affecting the translucency of monolithic Y-TZP ceramics for a better understanding the relevant parameters in restorations. The translucency of polycrystalline ceramics is a complex phenomenon. Apprehending the translucency regarding ceramics requires their knowledge of physical, chemical and microstructural characteristics with the light interactions among them.

Comparative radiopacity of conventional and full-contour Y-TZP ceramics.

The purpose of this study was to evaluate the radiopacity of different yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics used in the fabrication of fixed dental prostheses. Disk-shaped specimens (N=120, n=30 per group) were fabricated with thicknesses of 0.3, 0.5, and 1 mm from the following four Y-TZP ceramics: Cercon ht (Degudent) (CZ), Prettau (Zirkonzahn) (ZZ), Alliance (Kuraray Noritake Dental) (NA), and Ice Zirkon (Zirkonzahn) (ICE). The optical densities of each material were measured from radiographic images, and each material (N=1) were characterized by using XRD and SEM. The results were analyzed with oneway analysis of variance and the Tukey-Kramer test (α=0.05). In the case of the ICE and NA specimens, the radiopacity significantly differed with thickness (p<0.05). However, the radiopacities of 0.5- and 0.3-mm-thick CZ and ZZ specimens were not significantly different (p>0.05). Full-contour Y-TZP materials have higher radiopacities than those of the conventional Y-TZP materials in decreased thicknesses.

Effects of surface-finishing protocols on the roughness, color change, and translucency of different ceramic systems.

STATEMENT OF PROBLEM: Surface-finishing protocols have a mechanical impact on ceramic surfaces that could eventually affect surface topography and light scattering. An optimum protocol is needed to avoid damaging the optical properties of ceramics. PURPOSE: The purpose of this study was to determine the effects of different surface-finishing protocols on the surface roughness, color change, and translucency of ceramic and metal ceramic restorations. MATERIAL AND METHODS: Standardized disk-shaped specimens (1.5 × 10 mm, n=128) were fabricated from 3 different ceramic core materials (aluminum oxide [Al2O3]-AL, zirconium oxide [ZrO2]-ZR, lithium disilicate [Li2Si2O5]-LIT), veneered (V) with dentin ceramics (n=32 per group), and placed in the following groups: ALV, ZRV, and LITV. The metal ceramic group acted as the control (n=32). Four different surface-finishing methods were tested. Airborne-particle abrasion with 50 µm Al2O3, polishing with adjustment kit, polishing with adjustment kit plus diamond polishing paste, and autoglazing (n=8 subgroup) were applied on the veneering ceramics. The specimens were analyzed with a profilometer for surface roughness, and color change and translucency were measured with a clinical spectrophotometer. Statistical analyses were performed with 1-way ANOVA and the Tukey honest significant difference tests (α=.05). RESULTS: Specimens treated with the airborne particle abrasion method showed significantly higher mean profilometer for surface roughness values in all groups (P<.05). The polishing with adjustment kit and autoglazing methods revealed statistically similar surface roughness values in all groups (P>.05). With the diamond polishing paste method, lower surface roughness values were achieved in the ZRV and metal ceramic groups acted as the control groups. Different surface-finishing methods affected the color change of the ceramic systems, except for ZRV. Surface-finishing protocols significantly affected the translucency values of the ALV, LITV, and metal ceramic groups (P<.05). CONCLUSIONS: No single surface-finishing protocol can be recommended to obtain the smoothest surface and the least color change without affecting translucency for the ceramics tested. The airborne-particle abrasion protocol created rougher surfaces and decreased translucency, and color change in zirconia was not affected by the finishing protocols.

Influence of different maintenance times of torque application on the removal torque values to loosen the prosthetic abutment screws of external hexagon implants.

PURPOSE: To analyze the torque application on prosthetic abutment screws using different maintenance times, to determine an influence on the removal torque values. MATERIALS AND METHODS: A total of 40 external hexagon implants, 40 titanium screws, and 40 customized abutments were used. In group 1, the screws received a torque of 30 N·cm by instant torque application; in groups 2, 3, and 4, torque of 30 N·cm was applied and maintained for 10, 20, and 30 seconds, respectively. Removal torque was performed 10 minutes after torque application. Data were statistically analyzed using 1-way ANOVA and Tukey HSD test (α = 0.05). RESULTS: The mean and standard deviation (±SD) of removal torque values found were 11.61 ± 1.43 N·cm for group 1; 18.64 ± 1.71 N·cm for group 2; 21.62 ± 0.97 N·cm for group 3; and 21.48 ± 1.55 N·cm for group 4. Groups 3 and 4 exhibited statistically higher values than group 2, which demonstrated significantly higher values than group 1 (P < 0.05). CONCLUSIONS: A torque of 30 N·cm applied for 20 seconds seemed to be the best option when considering the removal torque values of external hexagon implants.

Does rinsing following particle deposition methods have a negative effect on adhesion to titanium?

PURPOSE: This study evaluated whether air blasting or rinsing particle remnants with water would impair adhesion of resin composite to metal. MATERIALS AND METHODS: Commercially pure titanium plates (1 mm x 25 mm x 50 mm) were wet polished down to 1200-grit silicone carbide abrasive and ultrasonically cleaned. They were then embedded in auto-polymerizing acrylic with the bonding surfaces exposed. Specimens were randomly assigned to one of the following particle deposition protocols (N = 60, n = 10 per group): group 1: particle deposition with aluminum trioxide (50 µm Al2O3) (AL) + air blasting + silane (ESPE-Sil); group 2: particle deposition with 30 µm SiO2 (CoJet) (CSC) + air blasting + silane; group 3: particle deposition with Rocatec Pre 110 µm Al2O3+Rocatec Plus 110 µm SiO2 (LSC) + air blasting + silane. In groups 4 (AL-W), 5 (CSC-W) and 6 (LSC-W), the same protocols were used, but instead of air blasting only, particle-deposited specimen surfaces were rinsed with water and air blasted. Adhesive resin (VisioBond) was applied and resin composite (Quadrant Posterior, Cavex) was bonded using polyethylene molds and photopolymerized. The specimens were then submitted to thermocycling (6000 cycles, 5°C-55°C, dwell time: 30 s, transfer time: 5 s). Pre-test failures during thermocycling were assigned a value of 0 MPa. Failure modes were identified using an optical microscope. SEM images of particles were obtained. Bond strength data (MPa) were statistically analyzed using two-way ANOVA and Tukey's post-hoc tests (a = 0.05). RESULTS: Particle type significantly affected the bond results (p < 0.001). AL groups presented significantly lower results (air blasting: 4.3 ± 3.3, rinsing: 11.8 ± 6.5) compared to those of CSC (air blasting: 27.7 ± 6.6, rinsing: 30.4 ± 9.3) and LSC (air blasting: 31.4 ± 8.7, rinsing: 28.7 ± 7.0). AL groups presented 5 spontaneous debondings during thermocycling in the air-blasted group. Rinsing with water as opposed to air blasting only did not decrease the results with any of the particle types (p > 0.05). While AL groups showed exclusively adhesive failure between the resin composite and the substrate, the incidence of cohesive failures in the composite was more frequent in groups CSC and LSC after either air blasting or rinsing. SEM images of particles showed sharp morphology of the particles in AL compared to CSC and LSC. CONCLUSION: Rinsing and air blasting following particle deposition methods did not impair adhesion of resin composite to titanium. Particle deposition with silica particles provided better adhesion of resin composite to this substrate compared to the use of alumina particles.

Effect of surface conditioning modalities on the repair bond strength of resin composite to the zirconia core / veneering ceramic complex.

PURPOSE: This study evaluated the effect of different surface conditioning protocols on the repair strength of resin composite to the zirconia core / veneering ceramic complex, simulating the clinical chipping phenomenon. MATERIALS AND METHODS: Forty disk-shaped zirconia core (Lava Zirconia, 3M ESPE) (diameter: 3 mm) specimens were veneered circumferentially with a feldspathic veneering ceramic (VM7, Vita Zahnfabrik) (thickness: 2 mm) using a split metal mold. They were then embedded in autopolymerizing acrylic with the bonding surfaces exposed. Specimens were randomly assigned to one of the following surface conditioning protocols (n = 10 per group): group 1, veneer: 4% hydrofluoric acid (HF) (Porcelain Etch) + core: aluminum trioxide (50-µm Al2O3) + core + veneer: silane (ESPE-Sil); group 2: core: Al2O3 (50 µm) + veneer: HF + core + veneer: silane; group 3: veneer: HF + core: 30 µm aluminum trioxide particles coated with silica (30 µm SiO2) + core + veneer: silane; group 4: core: 30 µm SiO2 + veneer: HF + core + veneer: silane. Core and veneer ceramic were conditioned individually but no attempt was made to avoid cross contamination of conditioning, simulating the clinical intraoral repair situation. Adhesive resin (VisioBond) was applied to both the core and the veneer ceramic, and resin composite (Quadrant Posterior) was bonded onto both substrates using polyethylene molds and photopolymerized. After thermocycling (6000 cycles, 5°C-55°C), the specimens were subjected to shear bond testing using a universal testing machine (1 mm/min). Failure modes were identified using an optical microscope, and scanning electron microscope images were obtained. Bond strength data (MPa) were analyzed statistically using the non-parametric Kruskal-Wallis test followed by the Wilcoxon rank-sum test and the Bonferroni Holm correction (α = 0.05). RESULTS: Group 3 demonstrated significantly higher values (MPa) (8.6 ± 2.7) than those of the other groups (3.2 ± 3.1, 3.2 ± 3, and 3.1 ± 3.5 for groups 1, 2, and 4, respectively) (p < 0.001). All groups showed exclusively adhesive failure between the repair resin and the core zirconia. The incidence of cohesive failure in the ceramic was highest in group 3 (8 out of 10) compared to the other groups (0/10, 2/10, and 2/10, in groups 1, 2, and 4, respectively). SEM images showed that air abrasion on the zirconia core only also impinged on the veneering ceramic where the etching pattern was affected. CONCLUSION: Etching the veneer ceramic with HF gel and silica coating of the zirconia core followed by silanization of both substrates could be advised for the repair of the zirconia core / veneering ceramic complex.

Radiopacity of different shades of resin-based restorative materials compared to human and bovine teeth.

This study evaluated the radiopacity of different shades of resin-based restorative materials and compared the results to human and bovine dental hard tissues. Disk specimens 6 mm in diameter and 1 mm thick (N = 220, n = 10) were prepared from the following restorative materials: · eight shades of nanofilled composite (Aelite Aesthetic Enamel), · seven shades of nanohybrid composite (Grandio Universal), · six shades of photopolymerized polyacid modified compomer (Glasiosite), and · one shade of hybrid composite (X-tra fil U). Human canine dentin (n = 10), bovine enamel (n = 10), and an aluminum (Al) step wedge were used as references. The optical density values of each material were measured from radiographic images using a transmission densitometer. Al step wedge thickness and optical density values were plotted, and equivalent Al thickness (eq Al) values were determined for radiopacity measurements of each material. The data were analyzed using a non-parametric one-way ANOVA (Kruskal-Wallis), and multiple comparisons were made with a Student-Newman-Keuls post hoc test (a = 0.05). Different shades of resin-based restorative materials tested did not reveal statistically significant differences within each material group (p > 0.05). Radiopacity values of the resin-based restorative materials investigated varied depending on their types; however, within different shades of one material type, radiopacity values were comparable. Every shade of nanocomposite material other than Aelite Aesthetic Enamel Incisal LT Gray showed comparable radiopacity to human dentin. Other materials tested demonstrated higher radiopacity compared to human dentin and bovine enamel.

Load-bearing capacity of indirect inlay-retained fixed dental prostheses made of particulate filler composite alone or reinforced with E-glass fibers impregnated with various monomers.

The load-bearing capacity and failure types of indirect inlay-retained fixed dental prostheses (FDP), made of particulate filler composite (PFC) (Estenia) alone or reinforced with E-glass fibers impregnated with various monomers were evaluated. Indirect inlay-retained FDPs were made between first premolars and first molars (N=30, 10/per group). The inlay parts of the specimens were silica coated and silanized and the specimens were cemented with dual-polymerized resin cement under ultrasonic vibrations. The experimental groups were as follows: Group 1: FRC1 (BR-100, UTMA) + PFC; Group 2: FRC2 (everStick C&B, Bis-GMA/PMMA) + PFC; Group 3: PFC only. The specimens were kept in distilled water at 37 °C for one month and then subjected to fracture strength test. No significant difference was found between the Group 1 and Group 2 FDPs (1357±301 N and 1213±316 N, respectively) (p>0.05) (ANOVA). Group 3 (856±299 N) showed significantly lower results than those of FRC reinforced groups (p<0.05). Failure analyses revealed no debonding of any of the FDPs from the inlay cavities. FDPs made of PFC only showed mainly catastrophic fracture of the pontic. In the FRC reinforced groups, predominantly delamination of the veneering was observed. The use of silica coating and silanization in combination with the dual-polymerized resin cement used; under ultrasonic cementation procedure provided sufficient adhesion to withstand static loading forces at the cementation interface, since the failures were predominantly delamination of the veneering in the FRC reinforced groups.

Radiopacity of different resin-based and conventional luting cements compared to human and bovine teeth.

This study evaluated the radiopacity of different resin-based luting materials and compared the results to human and bovine dental hard tissues. Disc specimens (N=130, n=10 per group) (diameter: 6 mm, thickness: 1 mm) were prepared from 10 resin-based and 3 conventional luting cements. Human canine dentin (n=10), bovine enamel (n=10), bovine dentin (n=10) and Aluminium (Al) step wedge were used as references. The optical density values of each material were measured from radiographic images using a transmission densitometer. Al step wedge thickness and optical density values were plotted and equivalent Al thickness values were determined for radiopacity measurements of each material. The radiopacity values of conventional cements and two resin luting materials (Rely X Unicem and Variolink II), were significantly higher than that of bovine enamel that could be preferred for restorations cemented on enamel. Since all examined resin-based luting materials showed radiopacity values equivalent to or greater than that of human and bovine dentin, they could be considered suitable for the restorations cemented on dentin.

Comparative radiopacity of bone graft materials.

The aim of this study was to investigate the radiopacity of bone graft materials (BGMs) in comparison with bovine mandibular cortical bone and human dentine. Eight samples of each material (8 mm in diameter and 3 mm in thickness) were prepared from Dexabone(®) (DB), Bio - Oss(®) (BO), 4BONE SBS (4B), KASIOS(®) TCP (KA), S.C. PONETI (PO), and Apatite-Wollastonite (AW). The optical densities of each material, along with one tooth section (human canine tooth 1 mm slice), bovine mandibular cortical bone (BC) samples, and an aluminum step wedge, were measured from radiographic images using a transmission densitometer. The data were analyzed by nonparametric one-way ANOVA (Kruskal-Wallis) and Duncan's multiple range tests for post hoc comparison (α = 0.05). BC and AW had statistically lower optical density values than BO, 4B and human dentine (p < 0.05). Among BGMs, AW (3.681 ± 0.409 mm eq Al) had the highest radiopacity values whereas BO (1.925 ± 0.176 mm eq Al) had the lowest one. The radiopacity values of DB and KA did not reveal a statistically significant difference when compared with other materials (p > 0.05). The radiopacity of all BGMs investigated seemed to be too low to be detected radiographically when placed in the mandibular cortical bone.

Saddle nose deformity, palatal perforation and truncus arteriosus in a patient with Crohn's disease.

Crohn's disease (CD) is a chronic granulomatous inflammatory bowel disease which may also involve the extraintestinal organs such as joints, liver, skin and perianal tissue. Involvement of the nasal cavity is quite rare in CD. This case report presents a 28-year-old girl with CD and saddle nose deformity, alar collapse and palatal perforation as extraintestinal manifestations of the disease in addition to persistent truncus arteriosus-type 4.

Comparative radiopacity of ceramics and metals with human and bovine dental tissues.

STATEMENT OF PROBLEM: Ceramics should be radiopaque enough to be seen on radiographs and to be distinguishable from tooth structures. Information on the radiopacity of different ceramics used in restorative dentistry is limited. PURPOSE: The purpose of this study was to investigate the radiopacity of ceramics in comparison with human and bovine dental hard tissues and metals. MATERIAL AND METHODS: A total of 128 disk-shaped specimens, 6 × 1 mm (n=8), were prepared from dental ceramic materials and metals. The optical densities of each material, along with 2 tooth sections (canine and molar teeth), bovine dentin and enamel specimens, and 2 different aluminum step wedges, were measured from radiographic images using a transmission densitometer. The optical densities of the specimens were used to determine the equivalent aluminum thicknesses. The data were analyzed by nonparametric 1-way ANOVA (Kruskal-Wallis) and Student-Newman-Keuls multiple range tests for post hoc comparison (α=.05). RESULTS: Among ceramic materials, Cercon Zirconia had the highest and the Cergo Pressable Ceramic had the lowest radiopacity values. Cergo Pressable Ceramic, Noritake Super Porcelain EX3 dentin, IPS Empress e.max Press, Cercon Kiss dentin, IPS Empress 2, Cercon Ceram dentin, bovine dentin, human canine, and molar tooth dentin radiopacity measurements were not significantly different. The radiopacity measurements of In-Ceram Alumina, In-Ceram Spinell, Celay Alumina, Titanium alloy (Ti-6Al-4V), Celay Zirconia, In-Ceram Zirconia, NiCr alloy, Wieland Zirconia, Cercon Zirconia, and 22-carat gold were significantly higher than that of bovine enamel (P<.05). CONCLUSIONS: Significant differences in radiopacity were found among ceramic materials, when compared to metals, bovine enamel and human and bovine dentin. Cercon and Wieland Zirconia had high radiopacity values, which were similar to metals.

Treatment of a tardive dyskinesia patient with temporomandibular disorder: a case report.

This case report presents a patient with tardive dyskinesia who also suffered from masticatory muscle pain and temporomandibular joint osteoarthrosis. The patient was treated with clozapine in gradually increasing doses and two injections of botulinum toxin type A one year apart. Involuntary movements of mandibular clenching and bruxing disappeared and pain was relieved to a great extent. Reappearances of dyskinetic movements and pain were observed during the follow-up period of 1.5 years.

Prosthetic rehabilitation of velopharyngeal insufficiency: pharyngeal obturator prostheses with different retention mechanisms.

Pharyngeal obturator prostheses restore the congenital or acquired defects of the soft palate and allow adequate closure of palatopharyngeal sphincter. Two patients with soft palate defect and subsequent velopharyngeal insufficiency were rehabilitated using pharyngeal obturator prostheses which had different retention mechanisms. Since it is necessary for swallowing and intelligible speech, the patients were examined in terms of adequate velopharyngeal closure after prosthetic treatment. The results were satisfying for both the patients and physicians.

Comparative audiometric evaluation of temporomandibular disorder patients with otological symptoms.

OBJECTIVES: The purpose of this study was to assess the audiological status of temporomandibular disorder (TMD) patients with otological symptoms and to make comparisons with that of a control group of subjects without TMD and otological symptoms. METHODS: 25 TMD patients with otological symptoms and 20 age and gender matched controls, 45 subjects in total, were included in the study. All subjects underwent a series of audiological tests that included pure-tone audiometry, impedance test and reflex tympanometry. The audiological parameters recorded in the two groups were compared statistically by means of unpaired t tests and corrected according to Bonferroni in the case of repeated tests. RESULTS: The pure-tone thresholds at frequencies 125, 250, 500Hz, and 6kHz showed significant differences between the TMD patients and control subjects after the Bonferroni correction (p<0.007). Compliance peaks demonstrated significant differences when the TMD and control groups were compared (p<0.05). CONCLUSIONS: The findings indicate that TMD patients with otological complaints have hearing impairment at low frequencies and also perhaps, at high frequencies.

Evaluation of shear and tensile bond strength between dentin and ceramics using dual-polymerizing resin cements.

STATEMENT OF PROBLEM: The applications of dual-polymerizing resin cements for all-ceramic restorations have considerably increased. For a successful clinical outcome, the luting agent should have high bond strength, not only to the ceramic surface, but also to the tooth surface. PURPOSE: The purpose of this study was to examine shear (S) and tensile (T) bond strengths between 2 all-ceramic systems and human dentin using 3 dual-polymerizing resin cements. MATERIAL AND METHODS: The buccal surfaces of 120 freshly extracted human third molars were ground flat, parallel to the long axis. Sixty specimens were prepared from each of 2 all-ceramic systems (IPS Empress 2 (E) and Cergo Pressable Ceramic (C)). Twenty specimens were luted with each of the following resin cements: Nexus 2 (N) with Self-Etch Primer, Duo-Link (D), and Variolink II (V), with their respective bonding systems. All specimens were immersed in water at 37 degrees C for 1 week, before being thermal cycled for 500 cycles in 5 degrees C and 55 degrees C water. Shear (S) and tensile (T) bond strength tests were applied to 10 specimens from each group. Fractured surfaces were inspected by scanning electron microscopy (SEM). Statistical analyses were performed using nonparametric 1-way ANOVA (Kruskal-Wallis) followed by Duncan's multiple range tests for post hoc comparison and Mann-Whitney U test for 2 ceramic systems (alpha=.05). RESULTS: Significant differences were observed in shear and tensile bond strength values of the adhesive systems used (P<.05). Duo-Link showed the highest mean bond strength values, whereas Nexus 2 revealed lower shear and tensile bond strength values. Fracture modes were hybrid at the dentin interface and/or cohesive in dentin. CONCLUSIONS: Cementing agents/adhesive systems may influence the bond to dental hard tissues. Dual-polymerizing activators may have a negative effect on polymerization of the bonding agent.

Rehabilitation of an edentulous cleft lip and palate patient with a soft palate defect using a bar-retained, implant-supported speech-aid prosthesis: a clinical report.

Prosthetic rehabilitation of an edentulous cleft lip and palate patient with a combined hard and soft palate defect is a great challenge, due to the lack of retention of the obturator prosthesis as a result of its weight and the inability to obtain a border seal. Dental implants improve the retention, stability, and occlusal function of prostheses when used in carefully selected cleft lip and palate cases. This clinical report presents an edentulous unilateral cleft lip and palate patient who has hard and soft palate defects and an atrophied maxilla, treated with an implant-supported speech-aid prosthesis.