Statement of problem The maxillary lateral incisor is often congenitally missing in patients with a cleft palate. The congenital cleft presents the practitioner with challenges including quantity and quality of bone, a surgically managed cleft correction, and limited clinical space. Purpose The purpose of this investigation was to calculate the 5-year success and survival rate of narrow-diameter implants used to restore a missing lateral incisor in patients with a cleft palate. Material and methods Fourteen study participants with a cleft palate and a missing maxillary lateral incisor were enrolled based on established criteria. Seventeen narrow-diameter implants (AstraTech OsseoSpeed 3.0S and OsseoSpeed TX 3.5 mm) were placed using a 2-stage protocol and restored with a custom titanium abutment and a cement-retained crown. Clinical and radiographic examinations were performed annually for 5 years. Four probe depth measurements were measured and evaluated using an analysis of covariance (ANCOVA) with Tukey-Kramer multiple comparisons tests. Radiographic marginal bone loss was measured annually using a digital subtraction technique and evaluated with ANCOVA, and the least square mean was derived. The restoration was evaluated using Pink (PES) and White (WES) Esthetic scores. Results Regarding probing depth measurements, a significant variance was found between the 4 locations (P<.001), and a linear effect of year was also found (P=.005). The multiple comparisons tests showed the mean buccal probe depth was lower compared with the mean at each of the other 3 locations (P≤.039) from baseline to 5-year follow-up. The least square mean ±standard deviation of the marginal bone loss over the 5-year entire study was 0.55 ±0.088 mm. Regarding prosthesis evaluation, the mean score for PES was 6.15 and 6.63 for the WES with a maximum score of 10. The level for clinical acceptance was set at a total score of 6. To meet the criteria for success over the 5-year period, no more than 2.3 mm of total bone loss was acceptable. The number of implants that met the criteria for success at 5 years was 92%. Regarding survival, the number of implants still in place, functional, and asymptomatic at 5 years was 100%. Conclusions Based on the findings, the peri-implant soft tissue probe depths exhibited significant change during the 5-year investigation. Regarding esthetic outcomes, single tooth NDI for replacing a lateral incisor in the cleft patient is a clinically acceptable treatment. Narrow-diameter implants may be a reliable treatment for replacing a missing lateral incisor in patients with a cleft at 5-year follow-up with an implant survival rate of 100% and a success rate of 92%.

Type II dentinogenesis imperfecta is an autosomal dominant condition that affects dentin which increases the complexity of the predictability of restorative treatment. Computer-aided design and computer-aided manufacturing (CAD-CAM) technologies permit the creation of highly accurate devices and dental prostheses that simplify the planning and execution of advanced implant surgery and full-mouth rehabilitation. This clinical report presents the interdisciplinary management of a 20-year-old male with dentinogenesis imperfecta type II. In this article, a combination of analog and CAD-CAM technologies were used to fabricate devices that aided planning, assisted intermaxillary fixation and implant placement, served as interim prostheses, and permitted the accurate establishment of esthetics and occlusion of the definitive full-arch prostheses.

OBJECTIVE The objective of this study was to examine whether bone mineral density (BMD) distribution in the mandibular condyle and facial morphology are associated with temporomandibular joint osteoarthritis (TMJ OA) using clinical cone beam computed tomography (CBCT) images. METHODS CBCT images of 35 adults (16 male and 19 female) were examined to obtain TMJ OA counts, cephalometric analyses, and histograms of gray values that are proportional to BMD. Mean, standard deviation (SD), and low and high gray values at the 5th and 95th percentiles (Low5 and High5) of the histograms were measured. RESULTS The female group had significantly higher values of TMJ OA counts, mean, and SD on the right mandibular condyle, High5 on both sides, and all gray value parameters for total (right + left) than the male group. CONCLUSION Comprehensive analysis of BMD distribution in the mandibular condyle can provide useful information for prognosis of TMJ OA.

Patients with ectodermal dysplasia have abnormalities of 2 or more structures that originate from the ectoderm. The oral manifestations often include the congenital absence of teeth and malformed teeth. This clinical report describes the interdisciplinary care from childhood through the definitive dental rehabilitation completed at skeletal maturation to replace the missing teeth in a patient with ectodermal dysplasia. Treatment began at 9 years of age with an implant-assisted mandibular overdenture to improve function and replace the missing mandibular teeth. Orthodontic treatment for the consolidation of space, composite resin restorations, and interim removable dental prostheses were provided to improve esthetics and replace the missing maxillary teeth. Skeletal growth was monitored, and orthognathic surgery was performed at the cessation of growth. The definitive rehabilitation consisted of a mandibular fixed dental prosthesis supported by dental implants and a maxillary removable dental prosthesis to restore the patient to esthetics and function.

Statement of problem. The fracture or dislodgement of an interim prosthesis may result in additional appointments and could negatively affect the outcome of a fixed prosthodontic procedure. Purpose. The purpose of this study was to evaluate the flexural strength (FS), flexural modulus (FM), work-of-fracture (WOF), and Weibull parameters of 4 bis-acryl (Protemp Plus, Integrity, Turbo Temp 2, Temphase Fast-set) and 2 urethane (NuForm and Tuff-Temp) interim resins after being stored in distilled water for 1 hour and 24 hours. Material and methods. Rectangular beam specimens (25 x 2 x 2 mm) of each resin (n=23) were prepared and stored in distilled water at 37 degrees C. Then 3-point bending tests were performed on 1-hour and 24-hour (wet) and 24-hour (dry and wet) specimens in a universal testing machine at a cross-head speed of 1.0 mm/min. Stress/strain curves were generated and flexural strength, flexural modulus, and WOF values were calculated. Data were subjected to 3-way ANOVA and the Tukey-Kramer pairwise comparison test (alpha=.05). FS data were also subjected to a 2-parameter Weibull analysis. Results. The 24-hour (wet) mean flexural strength and flexural modulus values were significantly higher than 1-hour values. The urethane Tuff-Temp, chemically and dual-polymerized, showed significantly higher (P<.05) 1-hour FS and FM, while the bis-acryl Protemp Plus showed significantly greater flexural strength and work-of-fracture than the other resins after 24 hours of wet storage. Protemp Plus, NuForm, and Turbo Temp 2 did not decrease in flexural strength and flexural modulus after 24 hours in dry and wet storage conditions. The Weibull modulus values of the flexural strengths of the interim resins at 1 hour and 24 hours ranged from 8.4 to 26.8. Conclusions. Postgelation polymerization plays an important role in the substantial increase in the flexural strength and flexural moduli of the interim resins between 1 and 24 hours. A wide variation in the mechanical properties of the interim resin materials was noted but was, for the most part, not category specific.

STATEMENT OF PROBLEM:Fracture of the interim partial denture may cause patient discomfort and result in unplanned appointments and expense. At present, limited information is available concerning the fracture toughness of bis-acryl interim resins, especially immediately following fabrication. PURPOSE:The purpose of this investigation was to evaluate the relative fracture toughness and Weibull parameters of 4 commercial chemically polymerized (Protemp Garant 3, Perfectemp II, Integrity, Temphase) and 1 dual polymerizing (Luxatemp Solar) bis-acryl interim resin materials with various filler loading after 1 hour and 24 hours. MATERIAL AND METHODS:Disk-shaped, mini-compact test specimens (8.20 × 1.85 mm thick, n=18) with introduced pre-cracks were prepared in a pre-heated split-mold and maintained at 37°C for 5 minutes during polymerization to simulate clinical conditions. Polymerization temperature was measured using an infrared digital thermometer. Specimens were stored in distilled water at 37°C after which the peak load to fracture was recorded at 1 and 24 hours and the fracture toughness (K(1c)) was calculated. An overall Weibull analysis of the fracture toughness was performed incorporating the fracture toughness data with factors polymerization method, time of testing and filler load of the resin. Weibull analysis was performed at (α =.05). Fracture surfaces of representative specimens were examined using scanning electron microscopy. RESULTS:The overall Weibull analysis results showed significant differences (P<.001) in fracture toughness between the times of testing (1 and 24 hours), polymerization method, and as a function of filler loading. The results of the individual Weibull survival analyses showed a significant increase in Weibull Characteristic Strength (σo) values between 1 and 24 hours for all materials. The Weibull moduli (m) for the interim resins ranged between 5.8 and 10.3. SEM analysis of fractured surfaces revealed that crack propagation occurred primarily through the resin matrix between filler particles. CONCLUSIONS:Post-gelation polymerization has an important role in determining the fracture properties of both chemical and dual-polymerized bis-acryl interim materials within the first 24 hours. For the materials tested, the higher the filler load, the lower the fracture toughness.

Objectives: This in vitro comparative study evaluated the effect of different stone mixing methods on material properties of four dental stones. Two ADA type IV stones (Silky-Rock and Snap-Stone), one type V high expansion stone (Die Keen), and one recently introduced type V specialty stone (HandiMix) were chosen for this study.Methods: Forty cylindrical specimens (25 mm x 12.5 mm) were cast for each of the nine stone sub-groups and bench dried at 23 +/- 2 C for 1 and 24 h. Specimens were they, tested in an Instron in tensile and compression modes at crosshead speeds of 0.5 and 1.0 mm/min, respectively. Four rectangular-shaped specimens (30 mm x 15 mm x 15 mm) of each stone type were cast and bench dried for 48 h. Knoop microhardness measurements were obtained from defined areas on each specimen for surface hardness testing using 200 g load and 20 s dwell time. A 12.6 mm(2) area was then delimited in the center of two sides of each specimen and photographed under low power magnification (40x). The average pore number per area was then determined for each specimen for surface porosity testing. The setting tine and setting expansion for each stone type was recorded as well.Results: ANOVA (P < 0.001) and Ryan-Einot-Gabriel-Welsh test (P < 0.05) showed significant differences between diametral tensile strengths and pore numbers for both stone types and mixing methods.Conclusion: Within the limitations of this study, the newly introduced mixing method did not appear to have an effect on the physical properties of HandiMix stone. (C) 2008 Elsevier Ltd. All rights reserved.

OBJECTIVES:New aliphatic and aromatic urethane dimethacrylate monomers containing pendant phenyl methoxy or ethyl substituents were synthesized in order to reduce the water sorption and solubility of urethane dimethacrylate systems. Selected properties including flexural strength, flexural modulus, water sorption and solubility, and water contact angle were evaluated. Hoy's solubility parameters were also calculated to rank copolymer hydrophilicity. METHODS:Filled (20%) composite resins were formulated with each of the newly synthesized dimethacrylates as well as the commercially available urethane dimethacrylate monomer, UDMA. Flexural strength, flexural modulus, water sorption and solubility of the urethane composites were evaluated after light-cured specimens were immersed in water for seven days. Water contact angles were measured on the surface of each material. Data were analyzed using ANOVA and Ryan-Einot-Gabriel-Welsch multiple range tests (alpha=0.05). RESULTS:A significant reduction of nearly 30% and 40% in water uptake was observed with composite polymers containing pendant ethyl and phenyl methoxy groups, respectively, compared to UDMA (p<0.05). Urethane copolymers containing pendant ethyl groups also showed a significant reduction in water solubility (p<0.05). A positive correlation was found between contact angle and water sorption as well as Hoy's delta(h) for hydrogen bonding forces. SIGNIFICANCE:The results of this study indicate that the incorporation of pendant hydrophobic substituents within the monomer backbone may be an effective method in reducing the water sorption and water solubility of urethane based dimethacrylate systems. The use of Hoy's solubility parameters to determine the relative hydrophilicity of a polymer may be limited by its three-dimensional chemical structure.

Statement of problem. One-bottle self-etching adhesives have been introduced that combine the etchant, primer, and adhesive into a single bottle in an effort to reduce the number of bonding steps. Limited research has been conducted comparing the efficacy of 1-bottle and 2-bottle self-etching adhesives.Purpose. This investigation evaluated the microtensile bond strength (MTBS) of 3 one-step self-etching adhesives, 2 two-step self-etching adhesives, and a total-etch adhesive. A secondary objective was to evaluate the effect of an intermediary layer of elastic resin on the MTBS of 2 of the self-etching adhesives.Material and methods. The MTBS of 3 one-step self-etching adhesives (G-Bond, iBond, and Clearfil S-3),2 two-step self-etching adhesives (Clearfil SE and Optibond Solo Plus Self-Etch), and a total-etch adhesive (Prime & Bond NT) was evaluated. Microtensile bond strength (MPa) was determined using composite resin (Herculite XRV) cylinders bonded to the dentin surface of human third molars (n=24) using 6 bonding agents. Each bonded tooth specimen was longitudinally sectioned to produce bar-shaped specimens with a square cross-sectional nominal bond area of 1.4 mm(2) (n=20). Bonded specimens were stored in distilled water at 37 degrees C +/- 2 degrees C for 72 hours, during which time they were subjected to thermal cycling (1500 cycles, in water baths of 5 degrees C and 55 degrees C, for a dwell time of 30 seconds). Testing was performed on a universal testing machine at a crosshead speed of 1.0 mm/min. One-way ANOVA, Ryan-Einot-Gabriel-Welsh multiple range test, and Wald chi square test, each using an overall alpha=.05, were performed on all data. Low-power (X20) microscopic examination of the bond failure was observed for each specimen.Results. The 1-way ANOVA (P <.001) and Ryan-Einot-Gabriel-Welsh multiple range test (P <.05) showed significant differences between the mean MTBS values for several of the bonding agents tested. The Wald chi square test of the Weibull distribution showed significant differences between adhesives (P <.001).Conclusion. Of the bonding agents tested, significantly higher MTBS was obtained with the total-etch 2-stage adhesive. The results of this stud), suggest that there are similar bond strengths between the 1- and 2-bottle self-etch adhesives.

PURPOSE:This study evaluated the wear of human enamel opposing 5 low-fusing dental porcelains and a traditional feldspathic control. In a second experiment, the repeatability of the test method and the effect of ceramic overfiring on enamel wear were also evaluated.MATERIALS AND METHODS:Five low-fusing dental porcelains--Finesse (FI), Rhapsody (RP), IPS d.Sign (DS), Omega 900 (OM), and Duceram LFC (LFC)--and 1 traditional feldspathic porcelain--VMK 68 (VMK)--were formed into disks (n = 10) and used as substrate for the wear test. Enamel was harvested from extracted human molars and machined into cusps with a 5-mm spherical radius (n = 60). The Oregon Health Sciences University oral wear simulator was used to simulate chewing and the size of the resulting enamel wear facets (in mm(2)) were evaluated after a specified number of chewing cycles. A portion of the experiment was duplicated to assess the repeatability of the data and determine the effects of overfiring on enamel wear. Data were subjected to analysis of variance and post hoc tests to determine significant differences. After wear testing, scanning electron micrographs were made using representative ceramic samples from each group.RESULTS:The results indicate that none of the low-fusing ceramics resulted in significantly less wear than the VMK control. In fact, 3 of the low-fusing porcelains (OM, RP, LFC) resulted in significantly greater enamel wear than VMK. Enamel wear was not significantly affected (p = 0.29) by the increased ceramic firing temperature. Wear data were repeatable, with no significant difference (p = 0.56) between the enamel wear from 2 separate experiments. The results from both experiments indicated that ceramic material significantly affected enamel wear (p <0.001). There was significantly less enamel wear opposite DS than LFC.CONCLUSIONS:This work suggests that variations in ceramic composition and microstructure may affect the opposing enamel wear, but that low-fusing temperatures do not necessarily guarantee low enamel wear. Although the clinical relevance of this testing apparatus may be questioned, the testing method was repeatable.

PURPOSE:This study evaluated the wear area of human enamel opposing 2 conventional and 2 low-fusing dental porcelains, as well as abrasive wear, attrition, surface hardness, and fracture toughness for the 4 porcelain substrates.MATERIALS AND METHODS:Two low-fusing and 2 conventional metal-ceramic porcelains were used to form 15-mm-diameter disks (n = 10), which were fired according to manufacturer's recommendations. Enamel cusps (n = 40) were formed from extracted third molars. All ceramic and enamel specimens were finished to a 1000-grit silicon carbide surface. The Oregon Health Sciences University (Portland, OR) oral wear simulator was used to deliver a 20-N load from the cusps to the ceramic substrates through a food-like slurry. The sliding action of the cusps over an 8-mm linear path produced abrasive wear. A static 70-N load was applied at the end of the path to create attrition. This sequence was repeated at 1.0 Hz for 50,000 cycles. Ceramic wear was measured with a profilometer (+/-2 micrometers), and enamel wear was evaluated using optical scanning methods. After wear testing, the hardness and fracture toughness of the ceramic surfaces were determined, and scanning electron photomicrographs were made using representative ceramic and enamel specimens from each group. Enamel wear areas, abrasion and attrition depths, hardness, and fracture toughness values were subjected to analysis of variance and Tukey-Kramer post hoc tests to determine significant differences.RESULTS:Enamel wear was not significantly different for low-fusing and conventional porcelains (p =.29). The wear of conventional and low-fusing ceramic substrates was also not significantly different (p =.79). However, depth of porcelain wear caused by attrition was in general significantly greater than abrasive wear (p =.0004). Although no significant differences were found in the measured porcelain hardness values (p =.08), 1 conventional porcelain exhibited fracture toughness significantly greater than 1 low-fusing porcelain (p <.01).CONCLUSIONS:No differences in wear patterns were noted among low-fusing compared with conventional metal-ceramic porcelains, but static loading resulted in significantly greater attrition compared with the observed sliding abrasive wear. J Prosthodont 2001;10:8-15.

PURPOSE:This study compared denture base resin shear bond strengths to silicoated Au-Pd, Au-Pd-Ag, Au-Ag-Pd-Cu, high-Pd, and Ni-Cr-Be alloys used to fabricate frameworks for hybrid implant prostheses. Microleakage between alloy and resin was also compared among groups after specimen fracture.MATERIALS AND METHODS:Twelve cylindrical specimens were cast for each alloy. Each specimen was made from a ring-shaped pattern (diameter [d] = 12 mm and height = 4 mm) and machined to achieve uniform hollow centers (d = 6.5 mm). Castings were abraded with 250-micron aluminum oxide and ultrasonically cleaned in distilled water before silicoating. Denture base resin was processed to the internal surfaces of the silicoated specimens. All specimens were thermocycled (1,000 cycles) between 4 degrees C and 50 degrees C, and placed in basic fuchsin dye for a week. A punch (d = 3.8 mm) driven at a cross-head speed of 0.5 mm/min was used to push out the resin specimens. The force required to cause failure was converted to the nominal shear bond strength for each specimen, and mean shear bond strengths for the 5 groups of specimens (N = 12) were compared using one-way analysis of variance and the Tukey-Kramer HSD multiple range test (alpha = 0.05). Six of the 12 debonded resin samples for each alloy were selected at random and evaluated for dye penetration. Using an 80-square grid, the percentage of dye penetration was evaluated with an optical microscope (x25) to determine the percentage of grid area penetrated by the dye. One-way analysis of variance was used to compare the degree of microleakage among groups.RESULTS:The mean resin-alloy shear bond strengths for the Au-Pd (9.6 +/- 3.7 MPa) and Au-Ag-Pd-Cu (9.2 +/- 1.5 MPa) alloys were significantly greater than mean resin-alloy shear bond strength for the Au-Pd-Ag alloy (5.6 +/- 1.9 MPa). No other significant differences in resin-alloy shear bond strengths were noted among the alloy groups. No significant differences were noted for dye penetration into the resin specimens bonded to any of the 5 alloys. The mean grid area penetrated by the dye was 25% when results for the alloys were pooled.CONCLUSIONS:Alloy type influences the shear bond strength of a denture base resin to silicoated alloys, but no difference in bond strength was found between Au-Pd, Au-Ag-Pd-Cu, high-Pd, and Ni-Cr-Be alloys. In addition, under the conditions of this study, all groups showed a similar degree of microleakage, which penetrated approximately 25% of the bonded specimen surface area.

This study evaluated the shear bond strength of Rexillium III (Jeneric Pentron, Wallingford, CT) to enamel using various resin composite luting systems. Cast alloy cylinders (3.9 mm x 6.0 mm) were bonded with each cement to human molar buccal enamel surfaces (n = 8). The enamel was etched using a 35% phosphoric acid solution for 30 seconds. Bonded specimens were stored in distilled water for 7 days at 37 degrees C and thermocycled (1,500 cycles) in 5 degrees C and 55 degrees C water baths (1-minute dwell time). Specimens were randomly tested in shear using a crosshead speed of 0.5 mm per minute. Use of a one-way analysis of variance (P < .001) and the Ryan-Einot-Gabriel-Welsh multiple range test showed significant differences between several of the resin cements. Panavia exhibited a significantly higher shear bond strength than any of the other cements tested (P < .05).