Accuracy of direct digital radiography for detecting occlusal caries in primary teeth compared with conventional radiography and visual inspection: an in vitro study

Objectives: The diagnosis of caries lesions is still a matter of concern in dentistry. The diagnosis of dental caries by digital radiography has a number of advantages over conventional radiography; however, this method has not been explored fully in the field of paediatric dentistry. This in vitro research evaluated the accuracy of direct digital radiography compared with visual inspection and conventional radiography in the diagnosis of occlusal caries lesions in primary molars. Methods: 50 molars were selected and evaluated under standardized conditions by 2 previously calibrated examiners according to 3 diagnostic methods (visual inspection, conventional radiography and direct digital radiography). Direct digital radiographs were obtained with the Dixi3 system (Planmeca, Helsinki, Finland) and the conventional radiographs with InSight film (Kodak Eastman Co., Rochester, NY). The images were scored and a reference standard was obtained histologically. The interexaminer reliability was calculated using Cohen`s kappa test and the specificity, sensitivity and accuracy of the methods were calculated. Results: Examiner reliability was good. For lesions limited to the enamel, visual inspection showed significantly higher sensitivity and accuracy than both radiographic methods, but no significant difference was found in specificity. For teeth with dentinal caries, no significant differences were found for any parameter when comparing visual and radiographic evaluation. Conclusions: Although less accurate than the visual method for detecting caries lesions confined to the enamel, the direct digital radiographic method is as effective as conventional radiographic examination and visual inspection of primary teeth with occlusal caries when the dentine is involved. Dentomaxillofacial Radiology (2010) 39, 362-367. doi: 10.1259/dmfr/22865872

Slow crack growth and reliability of dental ceramics

Objective. To determine the slow crack growth (SCG) and Weibull parameters of five dental ceramics: a vitreous porcelain (V), a leucite-based porcelain (D), a leucite-based glass-ceramic (E1), a lithium disilicate glass-ceramic (E2) and a glass-infiltrated alumina composite (IC). Methods. Eighty disks (empty set 12mm x 1.1mm thick) of each material were constructed according to manufacturers` recommendations and polished. The stress corrosion susceptibility coefficient (n) was obtained by dynamic fatigue test, and specimens were tested in biaxial flexure at five stress rates immersed in artificial saliva at 37 degrees C. Weibull parameters were calculated for the 30 specimens tested at 1MPa/s in artificial saliva at 37 degrees C. The 80 specimens were distributed as follows: 10 for each stress rate (10(-2), 10(-1), 10(1), 10(2) MPa/s), 10 for inert strength (10(2) MPa/s, silicon oil) and 30 for 10(0) MPa/s. Fractographic analysis was also performed to investigate the fracture origin. Results. E2 showed the lowest slow crack growth susceptibility coefficient (17.2), followed by D (20.4) and V (26.3). E1 and IC presented the highest n values (30.1 and 31.1, respectively). Porcelain V presented the lowest Weibull modulus (5.2). All other materials showed similar Weibull modulus values, ranging from 9.4 to 11.7. Fractographic analysis indicated that for porcelain D, glass-ceramics E1 and E2, and composite IC crack deflection was the main toughening mechanism. Significance. This study provides a detailed microstructural and slow crack growth characterization of widely used dental ceramics. This is important from a clinical standpoint to assist the clinician in choosing the best ceramic material for each situation as well as predicting its clinical longevity. It also can be helpful in developing new materials for dental prostheses. (c) 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Clinical, Histological, and Microbiological Findings in Peri-Implant Disease: A Pilot Study

Objectives: This study is intended to verify the correlation among clinical indices of the peri-implant soft tissues, the histological condition and the presence of 3 pathogens commonly associated with peri-implant diseases (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia). Materials: Four clinical indices, Gingival Index (GI), Sulcus Bleeding Index, GI modified by Mombelli, and Plaque Index modified by Mombelli (mPI) were evaluated around I dental implant of each subject (n = 10). Subgingival plaque was collected for bacterial analysis (polymerase chain reaction) and a biopsy of peri-implant soft tissues for histological analysis was harvested. The clinical indices and detected pathogens correlated with a developed histological index (HI). Results: There was no statistically significant relationship between the clinical indices (GI, Sulcus Bleeding Index, and GI modified by Mombelli) and the HI, except for the mPI on the central area of lingual aspects (r = 0.85, P = 0.0029). There was a tendency for a positive correlation between the mPI on the central area of buccal aspects and the HI (r = 0.63, P = 0.0544). The counting of lymphocytes and plasmocytes correlated positively with 111, thus suggesting the index reliability. The prevalence of A. actinomycetemcomitans, P. gingivalis, and T. forsythia did not present a significant relationship with the HI. Conclusion: Despite the small number of samples and the poor statistical significance, the mPI seems to be useful for evaluation of inflammatory severity on soft tissue around dental implants as demonstrated by its relationship with the HI. Further studies are necessary to elucidate this subject. (Implant Dent 2009;18:334-344)

Dynamic processes in the contingent valuation of an endangered mammal species

Reports experimental results involving 204 members of the public who were asked their willingness to pay for the conservation of the mahogany glider Petaurus gracilis on three occasions: prior to information being provided to them about the glider and other wildlife species; after such information was provided, and after participants had an opportunity to see live specimens of this endangered species. Variations in the mean willingness to pay are analysed. Concerns arise about whether information provision and experience reveal ‘true’ contingent valuations of public goods and about the choice of the relevant contingent valuation measure.

Auditory steady state response in pediatric audiology

The main issue regarding pediatric audiology diagnosis is determining procedures to configure reliable results which can be used to predict frequency-specific hearing thresholds. Aim: To investigate the correlation between auditory steady-state response (ASSR) with other tests in children with sensorineural hearing loss. Methods: Prospective cross-sectional contemporary cohort study. Twenty-three children (ages 1 to 7; mean, 3 years old) were submitted to ASSR, behavioral audiometry, click audiometry brain stem response (ABR), tone burst ABR, and predicting hearing level from the acoustic reflex. Results: the correlation between behavioral thresholds and ASSR was (0.70- 0.93), for the ABR tone burst it was (0.73 -0.93), for the ABR click it was (0.83-0.89) only at 2k and 4 kHz. The match between the ASSR and the hearing threshold prediction rule was considered moderate. Conclusion: there was a significant correlation between the ASSR and audiometry, as well as between ABR click (2k and 4 kHz) and for the ABR tone burst. The acoustic reflex can be used to add information to diagnosis in children.

Telehealth in audiology: The need and potential to reach underserved communities

Permanent hearing loss is a leading global health care burden, with 1 in 10 people affected to a mild or greater degree. A shortage of trained healthcare professionals and associated infrastructure and resource limitations mean that hearing health services are unavailable to the majority of the world population. Utilizing information and communication technology in hearing health care, or tele-audiology, combined with automation offer unique opportunities for improved clinical care, widespread access to services, and more cost-effective and sustainable hearing health care. Tele-audiology demonstrates significant potential in areas such as education and training of hearing health care professionals, paraprofessionals, parents, and adults with hearing disorders; screening for auditory disorders; diagnosis of hearing loss; and intervention services. Global connectivity is rapidly growing with increasingly widespread distribution into underserved communities where audiological services may be facilitated through telehealth models. Although many questions related to aspects such as quality control, licensure, jurisdictional responsibility, certification and reimbursement still need to be addressed; no alternative strategy can currently offer the same potential reach for impacting the global burden of hearing loss in the near and foreseeable future.

Reliability and Failure Modes of Implant-Supported Y-TZP and MCR Three-Unit Bridges

Purpose: Chipping within veneering porcelain has resulted in high clinical failure rates for implant-supported zirconia (yttria-tetragonal zirconia polycrystals [Y-TZP]) bridges. This study evaluated the reliability and failure modes of mouth-motion step-stress fatigued implant-supported Y-TZP versus palladium-silver alloy (PdAg) three-unit bridges. Materials and Methods: Implant-abutment replicas were embedded in polymethylmethacrylate resin. Y-TZP and PdAg frameworks, of similar design (n = 21 each), were fabricated, veneered, cemented (n = 3 each), and Hertzian contact-tested to obtain ultimate failure load. In each framework group, 18 specimens were distributed across three step-stress profiles and mouth-motion cyclically loaded according to the profile on the lingual slope of the buccal cusp of the pontic. Results: PdAg failures included competing flexural cracking at abutment and/or connector area and chipping, whereas Y-TZP presented predominantly cohesive failure within veneering porcelain. Including all failure modes, the reliability (two-sided at 90% confidence intervals) for a ""mission"" of 50,000 and 100,000 cycles at 300 N load was determined (Alta Pro, Reliasoft, Tucson, AZ, USA). No difference in reliability was observed between groups for a mission of 50,000. Reliability remained unchanged for a mission of 100,000 for PdAg, but significantly decreased for Y-TZP. Conclusions: Higher reliability was found for PdAg for a mission of 100,000 cycles at 300 N. Failure modes differed between materials.

Palpation of the lateral pterygoid area in the myofascial pain diagnosis

Objectives. To evaluate the diagnostic value of intraoral palpation at the lateral pterygoid (LP) area as part of the physical examination to detect myofascial pain, according to modified research diagnostic criteria for temporomandibular disorders. Study design. Fouty-four women composed the myofascial pain group, and 33 symptom-free age-matched were the control group. One examiner calibrated and blinded to group distribution performed 2 intraoral bilateral palpations of the lateral pterygoid. Results. The LP area palpation showed sensitivity and specificity values of 79.55% and 77.27%, respectively, and positive and negative likelihood ratios of 3.50 and 0.26, respectively. Conclusions. Palpation at the LP area did not reach acceptable values of specificity, and care must be taken when judging positive response to this procedure.

Analytical solution and numerical model for the interface in a stratified long wave system

For a two layered long wave propagation, linearized governing equations, which were derived earlier from the Euler equations of mass and momentum assuming negligible friction and interfacial mixing are solved analytically using Fourier transform. For the solution, variations of upper layer water level is assumed to be sinosoidal having known amplitude and variations of interface level is solved. As the governing equations are too complex to solve it analytically, density of upper layer fluid is assumed as very close to the density of lower layer fluid to simplify the lower layer equation. A numerical model is developed using the staggered leap-forg scheme for computation of water level and discharge in one dimensional propagation having known amplitude for the variations of upper layer water level and interface level to be solved. For the numerical model, water levels (upper layer and interface) at both the boundaries are assumed to be known from analytical solution. Results of numerical model are verified by comparing with the analytical solutions for different time period. Good agreements between analytical solution and numerical model are found for the stated boundary condition. The reliability of the developed numerical model is discussed, using it for different a (ratio of density of fluid in the upper layer to that in the lower layer) and p (ratio of water depth in the lower layer to that in the upper layer) values. It is found that as ‘CX’ increases amplification of interface also increases for same upper layer amplitude. Again for a constant lower layer depth, as ‘p’ increases amplification of interface. also increases for same upper layer amplitude.

Monolithic CAD/CAM Lithium Disilicate Versus Veneered Y-TZP Crowns: Comparison of Failure Modes and Reliability After Fatigue

Purpose: The aim of this research was to evaluate the fatigue behavior and reliability of monolithic computer-aided design/computer-assisted manufacture (CAD/CAM) lithium disilicate and hand-layer-veneered zirconia all-ceramic crowns. Materials and Methods: A CAD-based mandibular molar crown preparation, fabricated using rapid prototyping, served as the master die. Fully anatomically shaped monolithic lithium disilicate crowns (IPS e.max CAD, n = 19) and hand-layer-veneered zirconia-based crowns (IPS e.max ZirCAD/Ceram, n = 21) were designed and milled using a CAD/CAM system. Crowns were cemented on aged dentinlike composite dies with resin cement. Crowns were exposed to mouth-motion fatigue by sliding a WC-indenter (r = 3.18 mm) 0.7 mm lingually down the distobuccal cusp using three different step-stress profiles until failure occurred. Failure was designated as a large chip or fracture through the crown. If no failures occurred at high loads (> 900 N), the test method was changed to staircase r ratio fatigue. Stress level probability curves and reliability were calculated. Results: Hand-layer-veneered zirconia crowns revealed veneer chipping and had a reliability of < 0.01 (0.03 to 0.00, two-sided 90% confidence bounds) for a mission of 100,000 cycles and a 200-N load. None of the fully anatomically shaped CAD/CAM-fabricated monolithic lithium disilicate crowns failed during step-stress mouth-motion fatigue (180,000 cycles, 900 N). CAD/CAM lithium disilicate crowns also survived r ratio fatigue (1,000,000 cycles, 100 to 1,000 N). There appears to be a threshold for damage/bulk fracture for the lithium disilicate ceramic in the range of 1,100 to 1,200 N. Conclusion: Based on present fatigue findings, the application of CAD/CAM lithium disilicate ceramic in a monolithic/fully anatomical configuration resulted in fatigue-resistant crowns, whereas hand-layer-veneered zirconia crowns revealed a high susceptibility to mouth-motion cyclic loading with early veneer failures. Int J Prosthodont 2010; 23: 434-442.

Microtensile vs Microshear Bond Strength of All-in-One Adhesives to Unground Enamel

Purpose To determine the bond strength to unground enamel of all in one adhesives in comparison with an etch and rinse system and to compare the reliability of microtensile and microshear methods in providing such measurements Materials and Methods The bonding procedure was performed on enamel of 64 extracted molars The tested all in one adhesives were Bond Force (Tokuyama), AdheSE One (Ivoclar Vivadent) and Xeno V (Dentsply) Prime&Bond NT (Dentsply) served as control Microtensile specimens were obtained from 4 teeth per group Twelve teeth per group were used for microshear testing Microtensile specimens that failed prior to testing were included in statistical calculations, they were assigned the lowest value measured in the respective group Failure modes were observed under light microscope and classified (cohesive within substrates, adhesive mixed) Statistically significant differences in bond strength were assessed among the adhesives within each testing method and between microshear and microtensile data for each adhesive Failure mode distributions were compared using the chi square test Results All in-one adhesives had similar microshear and microtensile bond strengths In both testing methods, the etch and rinse system achieved the strongest bond For all adhesives significantly higher bond strengths were measured with the microshear test In microtensile testing specimens bonded with the etch and rinse adhesive exhibited a significantly different distribution of failure modes The coefficients of variation were extremely high for microtensile bond strength data, particularly of all in one adhesives Conclusion The adhesive potential to intact enamel of recently introduced all in-one adhesives was inferior to that of an etch and rinse system When testing bond strength to enamel of all in one adhesives, microshear testing may be a more accurate method than microtensile

Reliability of Metalloceramic and Zirconia-based Ceramic Crowns

Despite the increasing utilization of all-ceramic crown systems, their mechanical performance relative to that of metal ceramic restorations (MCR) has yet to be determined. This investigation tested the hypothesis that MCR present higher reliability over two Y-TZP all-ceramic crown systems under mouth-motion fatigue conditions. A CAD-based tooth preparation with the average dimensions of a mandibular first molar was used as a master die to fabricate all restorations. One 0.5-mm Pd-Ag and two Y-TZP system cores were veneered with 1.5 mm porcelain. Crowns were cemented onto aged (60 days in water) composite (Z100, 3M/ESPE) reproductions of the die. Mouth-motion fatigue was performed, and use level probability Weibull curves were determined. Failure modes of all systems included chipping or fracture of the porcelain veneer initiating at the indentation site. Fatigue was an acceleration factor for all-ceramic systems, but not for the MCR system. The latter presented significantly higher reliability under mouth-motion cyclic mechanical testing.

Craniocervical posture and hyoid bone position in children with mild and moderate asthma and mouth breathing

Introduction The objective of the present study was to assess the craniocervical posture and the positioning of the hyoid bone in children with asthma who are mouth breathers compared to non-asthma controls. Methods The study was conducted on 56 children, 28 of them with mild (n = 15) and moderate (n = 13) asthma (14 girls aged 10 79 +/- 1 31 years and 14 boys aged 9 79 +/- 1.12 years), matched for sex, height, weight and age with 28 non-asthma children who are not mouth breathers The sample size was calculated considering a confidence interval of 95% and a prevalence of 4% of asthma in Latin America. Eighteen variables were analyzed in two radiographs (latero-lateral teleradiography and lateral cervical spine radiography), both obtained with the head in a natural position The independent t-test was used to compare means values and the chi-square test to compare percentage values (p < 0 05) Intraclass correlation coefficient (ICC) was used to verify reliability. Results. The Craniovertebral Angle (CVA) was found to be significantly smaller in asthma than in control children (106.38 +/- 766 vs. 111 21 +/- 7.40. p = 0 02) and the frequency of asthma children with an absent or inverted hyoid triangle was found to be significantly higher compared to non-asthma children (36% vs 7%, p = 0.0001). The values of the inclination angles of the superior cervical spine in relation to the horizontal plane were significantly higher in moderate than in mild asthma children (CVT/Hor 85 10 +/- 725 vs. 90 92 +/- 6.69, p = 0 04 and C1/Hor. 80 93 +/- 5.56 vs 85 00 +/- 4 20, p = 0 04) Conclusions These findings revealed that asthma children presented higher head extension and a higher frequency of changes in hyoid bone position compared to non-asthma children and that greater the asthma severity greater the extension of the upper cervical spine. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Mid-thoracic tenderness: a comparison of pressure pain threshold between spinal regions, in asymptomatic subjects

Palpation for tenderness forms an important part of the manual therapy assessment for musculoskeletal dysfunction, In conjunction with other testing procedures it assists in establishing the clinical diagnosis. Tenderness in the thoracic spine has been reported in the literature as a clinical feature in musculoskeletal conditions where pain and dysfunction are located primarily in the upper quadrant. This study aimed to establish whether pressure pain thresholds (PPTs) of the mid-thoracic region of asymptomatic subjects were naturally lower than those of the cervical and lumbar areas. A within-subject study design was used to examine PPT at four spinal levels C6, T4, T6, and L4 in 50 asymptomatic volunteers. Results showed significant (P < 0.001) regional differences. PPT values increased in a caudal direction. The cervical region had the lowest PPT scores, that is was the most tender. Values increased in the thoracic region and were highest in the lumbar region. This study contributes to the normative data on spinal PPT values and demonstrates that mid-thoracic tenderness relative to the cervical spine is not a normal finding in asymptomatic subjects. (C) 2001 Harcourt Publishers Ltd.

Development, reliability, and concurrent validity of the modified inventory of potential reconstructive needs

Documentation of burn sequelae can be a difficult and time-consuming task. To date a reliable and systematic format for recording postburn trauma is lacking. The purpose of this research was two-fold: first, to develop a Modified Inventory of Potential Reconstructive Needs from the original Inventory of Potential Reconstructive Needs to allow methodical documentation of functional and cosmetic burn sequelae in all body surface areas of children with burns and, second, to establish interrater reliability and concurrent validity of the instrument, thus allowing its clinical application. Two raters scored the Modified Inventory of Potential Reconstructive Needs on 41 children with a range of burns types and severity. Excellent interrater reliability was demonstrated for both total (intraclass correlation coefficient = 0.996) and subsection inventory scores. Concurrent validity was also established with total scores showing strong positive correlations (0.73-0.76) with three indicators of burn severity. These findings provide initial support for the tool's clinical applicability, particularly in relation to rehabilitative planning and documentation.