Description

The Journal of Prosthetic Dentistry, now in its 47th year, continues to be a highly respected and trusted resource. With changes made to the Journal in 1997, readers now receive a publication that includes more clinical information and expanded use of color. The Journal is the official publication for 29 leading U.S. and international prosthodontic organizations and is the leading professional journal devoted exclusively to prosthetic and restorative dentistry. It features timely, original articles on the newest techniques, dental materials, and research findings. Color photos illustrate many step-by-step procedures. The Journal serves prosthodontists and dentists in advanced practice. The Journal of Prosthetic Dentistry ranks in the top 17% of the 4,625 scientific journals most frequently cited ( Science Citation Index ).

Publisher details

Elsevier

Publications in this journal

• The influence of upper lip length and lip mobility on maxillary incisal exposure

  Authors: Phillip Roe, Kitichai Rungcharassaeng, Joseph Y K Kan, Rishi D Patel, Wayne V Campagni, James S Brudvik

  Journal of Prosthetic Dentistry.

• Auricular Prosthetic Design and Manufacturing using Computed Tomography, 3D Photogarphic IMaging and Rapid Prototyping

  Authors: Liacouras P, Garnes J, Roman R, Grant GT

  Journal of Prosthetic Dentistry. 105(2):80-82.

• In vitro reproduction of noncarious cervical lesions.

  Authors: John J Dzakovich, Robert R Oslak

  The Journal of prosthetic dentistry. 100(1):1-10.

  STATEMENT OF PROBLEM: A review of the dental literature indicates that noncarious cervical lesions (NCCLs) are formed by erosion, abrasion, and/or abfraction of tooth structure, but their etiologySTATEMENT OF PROBLEM: A review of the dental literature indicates that noncarious cervical lesions (NCCLs) are formed by erosion, abrasion, and/or abfraction of tooth structure, but their etiology remains scientifically unsubstantiated. PURPOSE: The purpose of this study was to reproduce noncarious cervical lesions in vitro. This study was not designed to statistically quantify the amount of lost tooth structure via abrasion, but rather to attempt to create NCCLs in the various shapes and sizes that are clinically observed. MATERIAL AND METHODS: Three pairs of toothbrush types (generic and name-brand) with soft, medium, or firm bristles were tested with 3 different toothpastes of varying abrasive potentials (low, medium, and high) or with water only, on mounted human teeth with and without simulated gingival tissues (6 toothbrushes x 4 brushing solutions (L, M, H, dentifrices, or water only) x 2 gingival mask conditions = 48 test/control groups of 4 teeth each = 192). RESULTS: The control sets, brushed in water only, demonstrated no visible loss of tooth structure. Each set brushed with toothpaste, regardless of the degree of abrasiveness or toothbrush bristle firmness, demonstrated visible wear at the level of the CEJ. CONCLUSIONS: Significant noncarious cervical lesions were created via horizontal brushing with common commercial toothpaste, while brushing with water only did not create these cervical lesions. (J Prosthet Dent 2008;100:1-10).

• Selective laser sintering technology for customized fabrication of facial prostheses.

  Authors: Guofeng Wu, Bing Zhou, Yunpeng Bi, Yimin Zhao

  The Journal of prosthetic dentistry. 100(1):56-60.

  Traditionally, wax or clay sculpted patterns have been used in the development of facial prostheses. New advances in rapid prototyping technologies have demonstrated significant advantages comparedTraditionally, wax or clay sculpted patterns have been used in the development of facial prostheses. New advances in rapid prototyping technologies have demonstrated significant advantages compared to more conventional techniques for fabricating facial prostheses. The use of selective laser sintering technology described in this report is an alternative approach for fabricating a wax pattern for a partial nasal prosthesis. This new approach can generate the wax nasal pattern directly and reduce labor-intensive laboratory procedures. (J Prosthet Dent 2008;100:56-60).

• Diagnostic waxing transfer from diagnostic casts to soft tissue definitive casts.

  Authors: Michel Magne, Inge Magne, Pascal Magne

  The Journal of prosthetic dentistry. 100(1):70-1.

• News from the editorial council.

  Authors: Carol A Lefebvre

  The Journal of prosthetic dentistry. 100(1):A13-4.

• Tensile elastic recovery of elastomeric impression materials.

  Authors: Nathaniel C Lawson, John O Burgess, Mark S Litaker

  The Journal of prosthetic dentistry. 100(1):29-33.

  STATEMENT OF PROBLEM: Currently, a standard protocol exists to measure the elastic recovery of impression materials from compressive strain; however, no protocol exists for the measurement of elasticSTATEMENT OF PROBLEM: Currently, a standard protocol exists to measure the elastic recovery of impression materials from compressive strain; however, no protocol exists for the measurement of elastic recovery from tensile strain. PURPOSE: The purpose of this study was to compare elastic recovery from tensile strain test with the ISO elastic recovery test for 5 vinyl polysiloxane materials (Aquasil Ultra, Examix, Genie, Imprint 3, and StandOut) and 1 hybrid material (Senn). MATERIAL AND METHODS: Specimens (n=5) were fabricated in a brass mold and loaded in tension with a crosshead speed of 300 mm/min to 50% or 100% strains. Two hours following specimen elongation, the change in length of the specimens was measured. Additional specimens (n=5) were tested in tension until failure at 200 mm/min. The maximum elongation at failure was recorded. Elastic recovery specimens (n=4) were prepared for each material following ISO standard 4823. The change in dimension of these specimens was measured following a 30% compressive strain. Group means were compared using 1-way ANOVA and Tukey-Kramer HSD test (alpha=.05). Correlation between different tests was evaluated using Pearson's correlation coefficient. RESULTS: Vinyl polysiloxane materials of varying composition demonstrated significantly different elastic recovery, and the hybrid material demonstrated the least elastic recovery in both tests. All materials exceeded a 100% elongation before failure. Significant linear correlation was found between means of the ISO method and those of a 100% tensile strain (r(2)=0.69, P=.039), but not those of a 50% tensile strain (r(2)=0.56, P=.086). CONCLUSIONS: Elastic recovery from compressive strain can only partially predict elastic recovery from tensile strain, suggesting that elastic recovery from tensile strain is a relevant test. (J Prosthet Dent 2008;100:29-33).

• Association between self-reported bruxism activity and occurrence of dental attrition, abfraction, and occlusal pits on natural teeth.

  Authors: Nikolaos Tsiggos, Dimitrios Tortopidis, Andreas Hatzikyriakos, George Menexes

  The Journal of prosthetic dentistry. 100(1):41-6.

  STATEMENT OF PROBLEM: It is unclear whether subjects who report tooth clenching and/or grinding have more noticeable clinical signs of dental attrition, abfractions, and occlusal pits on theirSTATEMENT OF PROBLEM: It is unclear whether subjects who report tooth clenching and/or grinding have more noticeable clinical signs of dental attrition, abfractions, and occlusal pits on their natural teeth than subjects who do not report bruxism activity. PURPOSE: The purpose of this study was to determine whether there was an association between self-reported (or not reported) bruxism activity and occurrence of dental attrition (anterior, posterior), abfractions, and occlusal pits on natural teeth. MATERIAL AND METHODS: One hundred and two volunteer adult Greek subjects (mean age 44.6 +/-5.7 years) were classified into 2 groups (50 self-reported bruxers and 52 nonbruxers) according to 2 inquires regarding grinding and/or clenching of their teeth. Dental attrition (anterior, posterior) was assessed by 2 calibrated experienced examiners on diagnostic casts on a tooth-by-tooth basis, using a previously well established ordinal scale. Abfraction lesions (V-shaped, in the cervical region) and occlusal pits were recorded if these clinical signs were found on at least 2 natural teeth. Statistical comparisons between the 2 groups relative to the distribution of the occurrence of the 4 clinical signs were performed by means of the exact version of the chi-square test. The Fisher's exact test was used for the comparison of percentages. The intra- and interexaminer reliability was assessed by means of the Cohen's kappa coefficient (alpha=.05). RESULTS: The results demonstrated that there was a significant association between self-reported bruxism and occurrence of the 4 clinical signs. Although the 2 groups were significantly different according to the distribution of the 4 clinical signs, the greatest differences occurred for the anterior and posterior attrition signs. CONCLUSIONS: In this study, the occurrence of 4 clinical signs (posterior or anterior dental attrition, abfractions, and occlusal pits) was associated with self-reported bruxers. It is suggested that, primarily, signs of dental attrition may differentiate self-reported bruxers from nonbruxer subjects. (J Prosthet Dent 2008;100:41-46).

• An impression technique for implant-retained orbital prostheses.

  Authors: Secil Karakoca, Cemal Aydin, Handan Yilmaz, Turan Korkmaz

  The Journal of prosthetic dentistry. 100(1):52-5.

  This article describes an impression technique to transfer implant positions to the definitive cast using magnetic attachments splinted with acrylic resin for an implant-retained orbital prosthesis.This article describes an impression technique to transfer implant positions to the definitive cast using magnetic attachments splinted with acrylic resin for an implant-retained orbital prosthesis. The acrylic resin transfer device that incorporated the magnets was also used as the acrylic resin magnet substructure for the silicone orbital prosthesis. (J Prosthet Dent 2008;100:52-55).

• Cast-based guided implant placement: A novel technique.

  Authors: Lambert J Stumpel

  The Journal of prosthetic dentistry. 100(1):61-9.

  One of the most challenging aspects of implant placement is the correct spatial positioning of the dental implant in the bone. Surgical guides of various configurations have been proposed to aidOne of the most challenging aspects of implant placement is the correct spatial positioning of the dental implant in the bone. Surgical guides of various configurations have been proposed to aid implant placement. If a fully limiting surgical guide is used, the encoded information should be reliable, as deviations are not possible during surgery. This article describes a combination of analog techniques, including bone sounding and periapical radiographs used to study the available bone volume. A simplified casting protocol is proposed, and the implant platform position of the implant analog is transferred to a surgical guide composed of a stiff vinyl polysiloxane material. This surgical guide is used in a conventional flapless guided implant surgery protocol. This combination of techniques allows precise placement of a dental implant, abutment, and provisional restoration in a minimally invasive manner. (J Prosthet Dent 2008;100:61-69).

• A procedure for relieving an existing prosthesis to fit implant abutments.

  Authors: Yung-Tsung Hsu

  The Journal of prosthetic dentistry. 100(1):72-3.

• Color distribution of a shade guide in the value, chroma, and hue scale.

  Authors: Jin-Soo Ahn, Yong-Keun Lee

  The Journal of prosthetic dentistry. 100(1):18-28.

  STATEMENT OF PROBLEM: Shade tabs in a shade guide are matched to teeth in the order of value, hue, and chroma; therefore, information on the distribution of shade tabs is essential for clinicalSTATEMENT OF PROBLEM: Shade tabs in a shade guide are matched to teeth in the order of value, hue, and chroma; therefore, information on the distribution of shade tabs is essential for clinical application of a shade guide. However, there is limited information on the color distribution as sorted by these 3 parameters of a recently introduced shade guide. PURPOSE: The purposes of this study were to determine the color distributions of tabs from a shade guide in the value (CIE L*), chroma (C*(ab)), and hue scale, and to determine the distribution of step intervals between adjacent tabs by value and chroma. MATERIAL AND METHODS: The color of shade tabs (n=29) from a shade guide (Vitapan 3D-Master) was measured to determine the distribution of shade tabs by the value, chroma, hue angle, and CIE a* and b* values. The distribution of the ratios of the value and the chroma of each tab, when compared with the lowest value tab or the lowest chroma tab, was also determined. The data for each color parameter were analyzed by a 3-way ANOVA with the factors of value, chroma, and hue designations of the tabs (alpha=.05). RESULTS: The value, chroma, hue angle, and CIE a* and b* values were influenced by the value, chroma, and hue designations of shade tabs (P<.001). The distributions of the chroma of the tabs within the same value group were relatively ordered, but the values of different value groups overlapped in several instances. Distributions for the CIE a* and b* values reflected the chroma designations in each value group. In the same value group, L, M, and R hue designations corresponded with the manufacturer's stated hue, such as a yellow hue for the L designation and a red hue for the R designation. The distance in the value and chroma scales between adjacent tabs was not uniform. CONCLUSIONS: The color distribution of the Vitapan 3D-Master shade guide was more ordered than previously reported color distributions of other, traditional shade guides. However, the interval in the color parameters between adjacent tabs was not uniform; therefore, shade tabs spaced equally, according to the color parameters, should be studied based on the observer's response data. (J Prosthet Dent 2008;100:18-28).

• Flexural and fatigue strengths of denture base resin.

  Authors: Ana M Diaz-Arnold, Marcos A Vargas, Kenneth L Shaull, John E Laffoon, Fang Qian

  The Journal of prosthetic dentistry. 100(1):47-51.

  STATEMENT OF PROBLEM: Mechanical properties of denture acrylic resins are important for the clinical success of multiple types of prostheses. Acrylic resins must be strong and resilient so as toSTATEMENT OF PROBLEM: Mechanical properties of denture acrylic resins are important for the clinical success of multiple types of prostheses. Acrylic resins must be strong and resilient so as to withstand impact. Few studies utilize cyclic loads to characterize material response to repeated stress. PURPOSE: The purpose of this study was to evaluate static and dynamic flexure properties of a variety of acrylic resins utilized in the fabrication of prostheses: (1) heat-polymerized polymethyl methacrylate (PMMA), powder-liquid type, and (2) a newly introduced, visible light-polymerized urethane dimethacrylate dough type. MATERIAL AND METHODS: Twenty rectangular bars each of 4 PMMA acrylic resin materials (Diamond D, Fricke HI-I, Lucitone 199, Nature-Cryl Hi-Plus) and 1 urethane dimethacrylate (Eclipse) were fabricated and stored in 100% humidity for 30 days. Half of the specimens for each group were submitted to a static 3-point flexure test. The other half was submitted to cycling loading at 5 Hz for 10(4) cycles. Data were analyzed using 1-way ANOVA and 2-way ANOVA, followed by Tukey HSD or Bonferroni post hoc tests when necessary (alpha=.05). RESULTS: Mean static flexure strength (SDs) in MPa were: Eclipse, 127.11 (5.83); Diamond D, 84.92 (5.10); Lucitone 199, 83.96 (11.96); HI-I, 79.54 (5.84); and Nature-Cryl Hi-Plus, 75.82 (6.96). Mean flexural strengths (SDs) in MPa postcycling were: Eclipse, 113.36 (31.29); Diamond D, 88.26 (5.46); Nature-Cryl Hi-Plus, 81.86 (4.93); HI-I, 79.18 (6.60); and Lucitone 199, 74.34 (4.95). CONCLUSIONS: The visible light-polymerized urethane dimethacrylate resin (Eclipse) showed greater flexure strength than all PMMA heat-polymerized resins for both static and cycled groups (P<.001). Yet the Eclipse material had lower load limits, and demonstrated brittle-type behavior and greater standard deviations. The heat-polymerized PMMA materials did not significantly differ from each other after static or cyclic testing. (J Prosthet Dent 2008;100:47-51).

• Corrosion behavior of as-received and previously cast high noble alloy.

  Authors: Mohamed F Ayad, Stanley G Vermilyea, Stephen F Rosenstiel

  The Journal of prosthetic dentistry. 100(1):34-40.

  STATEMENT OF PROBLEM: The rationale for using high noble alloys is based largely upon their alleged ability to resist corrosion. However, combining previously cast metal with new alloy might have aSTATEMENT OF PROBLEM: The rationale for using high noble alloys is based largely upon their alleged ability to resist corrosion. However, combining previously cast metal with new alloy might have a detrimental effect on the corrosion behavior of a high noble alloy. PURPOSE: The purpose of this study was to characterize the elemental composition of an as-received and recast high noble alloy and to examine the in vitro corrosion behavior in 2 media, using a potentiodynamic polarization technique. MATERIAL AND METHODS: Disk-shaped specimens, 6 mm in diameter and 3 mm thick, were prepared from a high noble alloy (Ney-Oro-B2) under 3 casting protocols, according to the proportion of as-received and recast gold alloy (n=26); the groups included an as-received (100% as-received metal) group, 50% to 50% group (50 wt% new metal, 50 wt% once-recast metal), and recast group (100% once-recast metal). The surface structures of 20 specimens from each group were examined under scanning electron microscopy (SEM), the elemental compositions were determined using x-ray energy-dispersive spectroscopy at 3 sites on the specimen, and the data were averaged. Further, the potentiodynamic cyclic polarization between -1000 and +1000 mV (SCE, or saturated calomel electrode) was performed for 6 specimens from each casting protocol in 0.09% NaCl solution (n=3) and Fusayama artificial saliva (n=3) at 37 degrees C. Zero-current potential and corrosion current density were determined. The data were analyzed with 1-way and 2-way analysis of variance and the Ryan-Einot-Gabriel-Welsch multiple-range t test (alpha=.05). RESULTS: Elemental composition was significantly different among the casting groups (P<.001). The mean weight percentage values were 72.7% to 75.7% Au, 4.5 to 7.0% Pd, 10.7% to 11.1% Ag, 7.8% to 8.4% Cu, and 1.0% to 1.4% Zn. The mean values for zero-current potential (ZCP) and corrosion current density (I(CORR)) for all the casting protocols were not significant (P=.67 and P=.51, respectively). Moreover, the mean values were not significant for corrosion current density with the electrolyte effect (P=.45). Only zero-current potential had a significant electrolyte effect (P<.001). Furthermore, the interaction between casting protocols and electrolyte were not significant among all corrosion parameters. CONCLUSIONS: High noble alloy in all casting protocols evaluated retained passivity under electrochemical conditions similar to the oral environment. (J Prosthet Dent 2008;100:34-40).

• An occlusal guard for preventing and treating self-inflicted tongue trauma in a comatose patient: a clinical report.

  Authors: Sudarat Kiat-Amnuay, Sheila H Koh, David J Powner

  The Journal of prosthetic dentistry. 99(6):421-4.

  This clinical report describes the treatment of a 48-year-old patient who demonstrated neuropathologic and reflex mastication of her tongue after an intracerebral hemorrhage. Standard medicalThis clinical report describes the treatment of a 48-year-old patient who demonstrated neuropathologic and reflex mastication of her tongue after an intracerebral hemorrhage. Standard medical interventions failed to address the oral condition, and the attending neurosurgeon consulted the dental team. A provisional soft occlusal guard was initially placed, followed by fabrication of a heat-polymerized, acrylic resin occlusal guard. The tongue injury improved after placement of the oral device and administration of systemic hydrocortisone.

• Evaluation of the wear resistance of new nanocomposite resin restorative materials.

  Authors: Zeynep Duymus Yesil, Satish Alapati, William Johnston, Robert R Seghi

  The Journal of prosthetic dentistry. 99(6):435-43.

  STATEMENT OF PROBLEM: The use of composite resins for the restoration of posterior teeth is popular because of the improved performance and appearance of these materials. Wear resistance continues toSTATEMENT OF PROBLEM: The use of composite resins for the restoration of posterior teeth is popular because of the improved performance and appearance of these materials. Wear resistance continues to be of particular importance when restoring large occlusal areas in posterior teeth. PURPOSE: The purpose of this study was to evaluate the relative wear characteristics of 2 recently introduced nanofiller-based composite resins (Filtek Supreme, Premise) and compare them to the more traditional microhybrid (Point 4) and microfill (Heliomolar RO) materials that have been used for many years. MATERIAL AND METHODS: Six specimens (2 mm thick and 15 mm in diameter) of each material were subjected to 3-body wear tests using the Oregon Health Sciences University Oral Wear Simulator to produce abrasive wear and attrition for all specimens using human enamel as the opposing cusp. Profilometric tracings of the worn surfaces were used to determine the relative abrasive wear, attrition wear, and roughness (Ra) of the composite resin substrate. The mean diameter of the antagonist enamel wear facets was determined under a measuring microscope. Qualitative SEM analysis was also used to assess the surface appearance of the resulting enamel and composite resin wear facets. The data were analyzed by 1-way ANOVA and Tukey's multiple range post hoc test (alpha=.05). RESULTS: The results indicated that the composite resin type did not significantly affect the amount of measured attrition (P=.15) but did significantly affect abrasive wear (P=.02). The conventional microfill composite resin (Heliomolar RO) exhibited significantly less abrasive wear than the nanohybrid material (Premise). There was no significant difference in the average size of the opposing enamel wear facet generated by the different composite resin materials. Heliomolar RO resulted in a significantly rougher surface within the wear track than either nanohybrid composite resin (Premise) or microhybrid composite resin (Point 4) but was not significantly different than nanofilled composite resin (Filtek Supreme). CONCLUSIONS: The incorporation of nanofillers in 2 of the composite resin materials tested did not significantly improve their wear resistance or the amount of opposing cusp wear when compared to the traditional materials tested.

• The effect of metal ceramic restoration framework design on tooth color.

  Authors: Vanessa L Swain, Igor J Pesun, James S Hodges

  The Journal of prosthetic dentistry. 99(6):468-76.

  STATEMENT OF PROBLEM: The opacity of the metal framework in metal ceramic restorations results in reduced light transmission through the tooth that diminishes the esthetics of the tooth. PURPOSE: TheSTATEMENT OF PROBLEM: The opacity of the metal framework in metal ceramic restorations results in reduced light transmission through the tooth that diminishes the esthetics of the tooth. PURPOSE: The purpose of this study was to investigate the color change that occurs apically to a metal ceramic restoration as a result of altering the metal framework design. MATERIAL AND METHODS: Color change relative to the unprepared tooth (DeltaE) between various metal ceramic restorations was determined using computer imaging and CIELAB coordinates and compared to previously determined levels of clinical acceptability. Color change was evaluated by examining 2 conditions (the metal copings and the completed metal ceramic restorations), 4 framework designs (metal collar and porcelain margins with 0-mm, 1-mm, or 2-mm cutbacks), and 2 locations on the tooth apical to the margin of the restoration, using an imaging system developed at the Minnesota Dental Research Center for Biomaterials and Biomechanics. The data were analyzed statistically using repeated measures analysis of variance (P=.05). RESULTS: For metal ceramic restorations there exists a significant (P=.001) color change (DeltaE) between all framework designs except for the 0-mm and 1-mm cutbacks. Color change (DeltaE) in the location above the cemento-enamel junction was significantly greater (P=.004) than below the cemento-enamel junction. CONCLUSIONS: The framework design for metal ceramic restorations can affect the esthetics of the adjacent natural tooth. A minimum 2-mm facial cutback of the metal framework is necessary for there to be a significant difference in color change.

• Obtaining maxillomandibular records and definitive impressions in a single visit for a completely edentulous patient with a history of combination syndrome.

  Authors: Tony Daher, Setrag Dermendjian, Steven M Morgano

  The Journal of prosthetic dentistry. 99(6):489-91.

  Any attempt to reduce the number of dental visits for the fabrication of complete dentures is appreciated by both the dentist and the patient. This article illustrates clinical and laboratoryAny attempt to reduce the number of dental visits for the fabrication of complete dentures is appreciated by both the dentist and the patient. This article illustrates clinical and laboratory procedures for making a 2-stage definitive impression combined with the recording of maxillomandibular relations in the same visit for a completely edentulous patient with maxillary anterior mobile soft tissues.

• Modification of interim removable partial denture using thermoplastic vacuum-formed matrix.

  Authors: Won-Suk Oh, Seung-Eun Kim

  The Journal of prosthetic dentistry. 99(6):494-6.

• The management of a completely edentulous patient using simultaneous maxillary and mandibular CAD/CAM-guided immediately loaded definitive implant-supported prostheses: a clinical report.

  Authors: Neo Tee-Khin, Ansgar C Cheng, Helena Lee, Alvin G Wee, Elvin W J Leong

  The Journal of prosthetic dentistry. 99(6):416-20.

  Functional rehabilitation of a completely edentulous patient with removable prostheses is a clinical challenge. A patient with an edentulous maxilla and mandible received 6 endosseous implants in theFunctional rehabilitation of a completely edentulous patient with removable prostheses is a clinical challenge. A patient with an edentulous maxilla and mandible received 6 endosseous implants in the maxilla and 5 implants in the mandible using CAD/CAM surgical templates. Definitive maxillary and mandibular implant-supported fixed complete dentures were connected immediately after implant placement using a CAD/CAM-guided implant surgical placement protocol.

• Initial stability measurement of dental implants placed in different anatomical regions of fresh human cadaver jawbone.

  Authors: Wook-Jin Seong, James E Holte, James R Holtan, Paul S Olin, James S Hodges, Ching-Chang Ko

  The Journal of prosthetic dentistry. 99(6):425-34.

  STATEMENT OF PROBLEM: Initial implant stability has been used as an indicator for future osseointegration and whether an immediate/early loading protocol should be applied. However, differences inSTATEMENT OF PROBLEM: Initial implant stability has been used as an indicator for future osseointegration and whether an immediate/early loading protocol should be applied. However, differences in initial stability in relation to anatomical regions of jawbone have not been studied extensively because of the risks involved with stability measurements. PURPOSE: The purpose of this study was to determine whether initial implant stability varies with anatomical regions of the jawbone. MATERIAL AND METHODS: Four pairs of edentulous maxillae and mandibles were retrieved from fresh human cadavers. Six implants (Biomet 3i) per pair were placed in different anatomical regions (maxillary anterior, right and left maxillary posterior, mandibular anterior, right and left mandibular posterior). Immediately after implant placement, initial implant stability was measured with a custom-made resonance frequency analyzer, a commercial resonance frequency analysis device (Osstell), and a mechanical tapping device (Periotest). All implant surgeries and initial stability measurements were performed within 72 hours of death to simulate a clinical setting. Repeated measures ANOVA (alpha=.05) and univariate correlation analyses were used to analyze the data. RESULTS: Mandibular implants had significantly higher initial stability than maxillary implants. Posterior maxillary implants were least stable. Stability was less buccolingually than mesiodistally. The measurements from 3 stability measuring devices were strongly associated with each other. CONCLUSIONS: Initial implant stability varied among anatomical regions of jawbone. Rank of Periotest value and implant stability quotient (Osstell) had the highest correlation (r=-0.852).

• Influence of airborne-particle abrasion on mechanical properties and bond strength of carbon/epoxy and glass/bis-gma fiber-reinforced resin posts.

  Authors: Carlos Jose Soares, Fernanda Ribeiro Santana, Janaina Carla Pereira, Tatiana Santos Araujo, Murilo Souza Menezes

  The Journal of prosthetic dentistry. 99(6):444-54.

  STATEMENT OF PROBLEM: Controversy exists concerning the use of fiber-reinforced posts to improve bond strength to resin cement because some precementation treatments can compromise the mechanicalSTATEMENT OF PROBLEM: Controversy exists concerning the use of fiber-reinforced posts to improve bond strength to resin cement because some precementation treatments can compromise the mechanical properties of the posts. PURPOSE: The purpose of this study was to analyze the influence of airborne-particle abrasion on the mechanical properties and microtensile bond strength (MTBS) of carbon/epoxy and glass/bis-GMA fiber-reinforced resin posts. MATERIAL AND METHODS: Flexural strength (delta(f)), flexural modulus (E(f)), and stiffness (S) were assessed using a 3-point bending test for glass fiber-reinforced and carbon fiber-reinforced resin posts submitted to airborne-particle abrasion (AB) with 50-microm Al(2)O(3), and for posts without any surface treatment (controls) (n=10). Forty glass fiber (GF) and 40 carbon fiber (CF) posts were submitted to 1 of 4 surface treatments (n=10) prior to MTBS testing: silane (S); silane and adhesive (SA); airborne-particle abrasion with 50-microm Al(2)O(3) and silane (ABS); airborne-particle abrasion, silane, and adhesive (ABSA). Two composite resin restorations (Filtek Z250) with rounded depressions in the lateral face were bilaterally fixed to the post with resin cement (RelyX ARC). Next, the specimen was sectioned with a precision saw running perpendicular to the bonded surface to obtain 10 bonded beam specimens with a cross-sectional area of 1 mm(2). Each beam specimen was tested in a mechanical testing machine (EMIC 2,000 DL), under stress, at a crosshead speed of 0.5 mm/min until failure. Data were analyzed by 2-way ANOVA followed by Tukey HSD test (alpha=.05). Failure patterns of tested specimens were analyzed using scanning electron microscopy (SEM). RESULTS: The 3-point bending test demonstrated significant differences among groups only for the post type factor for flexural strength, flexural modulus, and stiffness. The carbon fiber posts exhibited significantly higher mean flexural strength (P=.001), flexural modulus (P=.003), and stiffness (P=.001) values when compared with glass fiber posts, irrespective of surface treatment. An alteration in the superficial structure of the posts could be observed by SEM after airborne-particle abrasion. MTBS testing showed no significant effect for the surface treatment type; however, significant effects for post system factor and for interaction between the 2 factors were observed. For the carbon fiber post, the ABSA surface treatment resulted in values significantly lower than the S surface treatment. SEM analysis of MTBS-tested specimens demonstrated adhesive and cohesive failures. CONCLUSIONS: Airborne-particle abrasion did not influence the mechanical properties of the post; however, it produced undesirable surface changes, which could reduce the bond strength to resin cement. For the surface treatments studied, if silane is applied, the adhesive system and airborne-particle abrasion are not necessary.

• Condylar guidance: correlation between articular morphology and panoramic radiographic images in dry human skulls.

  Authors: Ilan Gilboa, Harold S Cardash, Israel Kaffe, Martin D Gross

  The Journal of prosthetic dentistry. 99(6):477-82.

  STATEMENT OF PROBLEM: Several studies have shown the unreliability of recording and reproducing the condylar guidance in semiadjustable articulators. PURPOSE: The purpose of this study was toSTATEMENT OF PROBLEM: Several studies have shown the unreliability of recording and reproducing the condylar guidance in semiadjustable articulators. PURPOSE: The purpose of this study was to determine the correlation between the anatomic shape of the articular eminence and the corresponding panoramic radiographic image in dry skulls. MATERIAL AND METHODS: Two metal wires were adapted and fixed to the inner and outer surfaces of the articular eminences in 25 human skulls. The inner (thicker) wire was fixed to the middle of the most concave aspect of the articular eminence in an anterior-posterior direction. The outer (thinner) wire was attached to the inferior aspect of the zygomatic arch adjacent to the articular eminence. Panoramic radiographic images were recorded by the same operator at the same time and with the same panoramic radiographic unit (Orthoralix SD). Impressions were made of the condylar fossae in 25 human dry skulls. Tracings of the incline of the articular eminence on the panoramic radiographs and the impression sections were compared. Each measurement was repeated twice by 2 operators. The results were subjected to the Pearson correlation statistical analysis (alpha=.05). RESULTS: The outline of the articular eminence in a panoramic radiographic image was identified as a thinner superior radio-opaque line above a thicker radio-opaque outline of the inferior-lateral aspect of the zygomatic arch. A significant correlation was found between the sagittal inclination of the anatomic articular eminence outline and the corresponding panoramic radiographic image for both right (R=0.802; P=.001) and left (R=0.561; P=.004) sides. A significant correlation was found between articular eminences on left and right sides in the same skull (P=.025). CONCLUSIONS: The panoramic radiographic image of the sagittal inclination of the articular eminence consistently replicated the eminence inclinations in the 25 human skulls evaluated.

• Method for fabrication of a custom occlusal template.

  Authors: Philip S Baker, Jimmy Londono

  The Journal of prosthetic dentistry. 99(6):492-3.

• Translucency of newly extracted maxillary central incisors at nine locations.

  Authors: Fang Xiong, Yonglie Chao, Zhimin Zhu

  The Journal of prosthetic dentistry. 100(1):11-7.

  STATEMENT OF PROBLEM: In addition to color, translucency is one of the primary factors influencing the esthetics of a dental prosthesis. Due to difficulties in measuring the translucency of naturalSTATEMENT OF PROBLEM: In addition to color, translucency is one of the primary factors influencing the esthetics of a dental prosthesis. Due to difficulties in measuring the translucency of natural teeth, minimal data are available. PURPOSE: The purpose of this study was to measure the translucency of newly extracted maxillary central incisors and analyze the relationship between translucency, anatomic location, and age. MATERIAL AND METHODS: The translucency of 32 newly extracted maxillary central incisors was measured with a spectrocolorimeter (PR-650) at 9 locations on the tooth crown. These locations were identified by dividing the tooth incisally to cervically and medially to laterally in equal dimensions. The relationships between transmittance, locations, and age were analyzed by univariate analysis of variance (alpha=.05). RESULTS: The transmittance of maxillary central incisors ranged from 0.13% to 0.65%, which decreased from incisal to cervical (P<.05). Age also affected transmittance in certain locations of the crown; older teeth demonstrated higher transmittance (P<.05). CONCLUSIONS: Transmittance of the maxillary central incisor was variable at different locations of the crown and was positively correlated with age. (J Prosthet Dent 2008;100:11-17).

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