Proximal Surfaces Research Articles

An evaluation of the relationship between the degree of entheseal changes and the severity of osteodegenerative processes at fibrocartilaginous entheses.

An enthesis refers to the interface at which a tendon or a ligament integrates into the periosteum. Its morphology can be influenced by intrinsic factors such as sex, age, and extrinsic factors such as levels of activity, which will in turn impact on bone remodeling and lead to morphological changes. In bioarcheology, entheseal changes have had a long tradition of being used for the reconstruction of past activities. The literature has shown that in some cases of osteoarthritis, entheseal changes are associated with osteoarthritic manifestations. This work aims to evaluate the relationship between the degree of entheseal changes and the severity of osteodegenerative processes. The studied materials consisted of 30 humeri and 30 femora from the osteological collection at St George's University of London. Intensities of both entheseal changes and osteodegenerative processes were macroscopically assessed and scored. The difference in scores of entheseal changes between osteoarthritic groups and nonosteoarthritic groups is statistically significant at a confidence level of 95% (α=.05) for both the humeri and femora. Results show a positive correlation between the degree of entheseal changes and the severity of osteodegenerative processes in the femora, suggesting that enthesis may play a role in osteoarthritis. Findings from this work supports the proposed hypothesis that the degree of entheseal changes and the severity of osteoarthritic manifestation are related. This work contributes to current knowledge that osteoarthritis is a disease involving the whole joint; the enthesis could potentially be a target for the diagnosis of osteoarthritis.

Gondolatok az egybeöntött vagy szóló koronák alkalmazása közötti választásról

A fogpótlások készítése során többször kell eldönteni, hogy egymás melletti fogakra szóló koronák készüljenek, vagya fogakat foglaljuk merev egységbe a koronákkal. Bizonyos szituációkban szükséges a fogak sínezése, azonban ez problémássá teheti az interdentális tér megfelelő tisztítását. Egybeöntött koronák csak alapos megfontolás után készíthetők, betartva a parodontálhigiéniai szempontokat. Ellenkező esetben a betegek nem képesek az interdentális tér tisztítására, aminek gingivitis, későbbiekben parodontitisz lehet a következménye. A fogak csiszolásakor, a lenyomatvételkor,a mintakészítéskor és a koronák mintázása során is figyelembe kell venni az egyéni fogmorfológiát és ezzel biztosítani az interdentális tér anatomikus kialakítását akár szóló korona, akár egybeöntött koronák készülnek. A szerzők összefoglalják a sínezéskor fontos szempontokat.

Dental Anatomy and Physiology of Human Tooth and the Consequences of Pathogenic Microbiota on the Oral Cavity

Background: Biologically, there are about 700 microbial species found in our oral cavity with a favorable habitat due to nutrients and insulate for the development of a complex ecosystem in the mouth. The bacterial population is a result of dynamic relationship between pathogens and commensal, increases oral diseases and other risk factors. The non-beneficial microbiome have direct link to dental problems created by chemical, acids produced by bacteria and direct contact of tooth surfaces. Ina addition, the human teeth is made of many tissues with different thickness, functions, and types and also similar layers and sets of teeth. Objectives: This article mainly assess the biology of dental anatomy and physiology, impact potential of oral pathogenic microbiota and their consequences on human oral cavity. Methods: Important information’s about dental of human and consequences of pathogenic microbiota from various international published sources, such as researches, reviews, health and biology books, organized and rewrite based on the standard scientific methods. Results and conclusions: Based on human anatomy and physiology, the human teeth is made up of multiple tissues of minerals with varying thickness and rigidity, four types of teeth with different functions, crown and root parts of a teeth with three layers. In addition, similar to other mammals, human beings develop two sets of teeth as “deciduous and permanent” called diphyodont. Moreover, human mouth is the most colonized parts of our bodies that support as important habitats of heterogeneous microbial communities due to nourished nutrients with optimum insulate for development in the mouth, and they can simply bind on tooth surfaces. Therefore, due to exogenous material over tooth surfaces produced chemicals and pathogenic microbiota directly contact to occluding or proximal surfaces cause decaying and eroding of human tooth and other potential impacts like bad smell associated consequences on the oral cavity.

Survival rate after endodontic treatment in general dentistry for cracked teeth with different coronal restorations

Objective The aim of this study was to analyse the survival rate of cracked teeth after endodontic treatment. The secondary aim was to compare the survival rate of cracked teeth restored with composite filling/crown and those restored with a full crown. Materials and methods The study was conducted retrospectively from three general dental clinics in Stockholm, which are all part of the national dental service organisation. Two-hundred patients with teeth receiving endodontic treatment due to symptomatic cracks were included. The patient data range from year 2001 to 2016. Results The mean age of the patients was 48 years (range 29–69). Fifty-five per cent had cracks located above the pulpal cavity, 11% within the pulpal cavity and 3% located in the root canal. The cracks were located most commonly on the proximal surfaces. The survival rate for teeth with cracks was 68% and 54% after 5 and 10 years, respectively. The survival rate was significantly higher (97%) for cracked teeth receiving a full crown after endodontic treatment compared to teeth restored with either a composite filling or composite crown. Conclusion The overall survival rate for cracked teeth was 68% after 5 years, while it was significantly higher for cracked teeth restored with a full crown. The results suggest within the limitations of this study that cracked teeth should be restored with a full crown after endodontic treatment.

An Intraoral OCT Probe to Enhanced Detection of Approximal Carious Lesions and Assessment of Restorations.

Caries, the world’s most common chronic disease, remains a major cause of invasive restorative dental treatment. To take advantage of the diagnostic potential of optical coherence tomography (OCT) in contemporary dental prevention and treatment, an intraorally applicable spectral-domain OCT probe has been developed based on an OCT hand-held scanner equipped with a rigid 90°-optics endoscope. The probe was verified in vitro. In vivo, all tooth surfaces could be imaged with the OCT probe, except the vestibular surfaces of third molars and the proximal surface sections of molars within a "blind spot" at a distance greater than 2.5 mm from the tooth surface. Proximal surfaces of 64 posterior teeth of four volunteers were assessed by intraoral OCT, visual-tactile inspection, bitewing radiography and fiber-optic transillumination. The agreement in detecting healthy and carious surfaces varied greatly between OCT and established methods (18.2–94.7%), whereby the established methods could always be supplemented by OCT. Direct and indirect composite and ceramic restorations with inherent imperfections and failures of the tooth-restoration bond were imaged and qualitatively evaluated. The intraoral OCT probe proved to be a powerful technological approach for the non-invasive imaging of healthy and carious hard tooth tissues and gingiva as well as tooth-colored restorations.

3D imaging of proximal caries in posterior teeth using optical coherence tomography

Optical coherence tomography (OCT) can create cross-sectional images of tooth without X-ray exposure. This study aimed to investigate the diagnostic accuracy of 3D imaging of OCT for proximal caries in posterior teeth. Thirty-six human molar teeth with 51 proximal surfaces visibly 6 intact, 16 slightly demineralized, and 29 distinct carious changes were mounted to take digital radiographs and 3D OCT images. The sensitivity, specificity and area under the receiver operating characteristic curve (AUC) for the diagnosis of enamel caries and dentin caries were calculated to quantify the diagnostic ability of 3D OCT in comparison with digital radiography. Diagnostic accuracy was evaluated by the agreement with histology using weighted Kappa. OCT showed significantly higher sensitivity, AUC and Kappa values than radiography. OCT can be a safer option for the diagnosis of proximal caries in posterior teeth that can be applied to the patients without X-ray exposure.

Accurate Detection of Non-Cavitated Proximal Caries in Posterior Permanent Teeth: An in vivo Study.

PurposeThis study aimed to compare the sensitivity and specificity of DIAGNOdent versus bitewing radiographs in detecting non-cavitated proximal caries.Patients and MethodsThis observational prospective study included 120 proximal surfaces, without obvious cavitation, on permanent mandibular and maxillary posterior teeth in patients over 16 years old. The DIAGNOdent test was performed, and digital bitewing radiographs were obtained; these were compared with a standard reference method, which comprised a clinical assessment of the proximal surfaces following the application of an orthodontic separator between the teeth for 7 days. Each test was performed by a different investigator blinded to the assessment results of the other examiners.ResultsThe DIAGNOdent device exhibited a higher sensitivity in detecting enamel proximal caries (95%) than digital bitewing radiographs (64%), and the specificity of DIAGNOdent (89%) was greater than that of bitewing radiographs (77%). Regarding the detection of dentin caries, the sensitivities of DIAGNOdent and bitewing radiographs were similar (both 62%); however, the specificity of DIAGNOdent was higher (98% versus 88%). The results of the Kruskal–Wallis test revealed a significant difference in DIAGNOdent scores across the three diagnoses (sound tooth surfaces, enamel caries, dentin caries) (p-value <0.001).ConclusionThe diagnostic accuracy of DIAGNOdent in detecting enamel caries is significantly higher than that of digital bitewing radiography. The routine use of DIAGNOdent can facilitate an accurate diagnosis of early carious lesions and inform the implementation of preventive treatment.

In vitro comparison of two types of digital X-ray sensors for proximal caries detection validated by micro-computed tomography.

We aimed to compare the diagnostic accuracy of two intraoral digital X-ray sensors-the charged-coupled device (CCD) and complementary metal-oxide-semiconductor (CMOS)-for proximal caries detection in permanent molar and premolar teeth. Micro-CT served as the reference standard. 250 samples were mounted in three-dimensional (3D)-printed phantoms, and their proximal surfaces were evaluated by ICDAS criteria directly to create a balanced sample. Bitewing radiography was conducted using 3D-constructed X-ray phantoms with a CCD sensor at a 0.08 s and a CMOS sensor at 0.12 and 0.16 s exposure time. Two examiners determined the diagnostic decisions twice at appropriate intervals. Three diagnostic thresholds for sound surfaces and enamel and dentin caries were defined and presented in a cross-table. Sensitivity and specificity values and overall accuracy were calculated, and receiver operating curves were generated and compared. Reliability assessment was performed using linear weighted κ statistics. The overall accuracies between the reference standard and different sensors and exposure times were 63.1% (CCD), 67.1% (CMOS sensor at 0.12 s) and 70.7% (CMOS sensor at 0.08 s). High specificity but low sensitivity values were found for all examination conditions at all thresholds. The area under the curve comparison values revealed no significant difference between sensor types and exposure times. Linear-weighted κ analysis revealed almost perfect agreement for all assessments. No significant difference was found for diagnostic performance of proximal caries detection between the different sensors and exposure times. The increased exposure time did not lead to a significant diagnostic benefit.

Feasibility of 3-Dimensional Visual Guides for Preparing Pediatric Zirconia Crowns: An In Vitro Study.

This study evaluated the feasibility of a tooth preparation guide for prefabricated zirconia crowns (PZCs). Three-dimensional surface data for PZCs of the left maxillary primary first molar and left mandibular primary second molar were obtained using a model scanner. The tooth preparation data were digitally designed to harmonize with the adjacent teeth on the mixed dentition model and visualized using a color-coded map, which presents the required amount of tooth reduction. Twenty participants were recruited for preparing teeth with and without using the tooth preparation guide. The following three parameters were evaluated: tooth preparation time, harmony score, and amount of tooth reduction. The preparation time when using the guide was significantly reduced (p < 0.05), and a significant difference was observed in the harmony scores for the maxillary primary first molar preparation. Furthermore, the amount of tooth reduction was significantly different for both maxillary and mandibular primary molars (p < 0.05) in terms of the occlusal distal surface and buccal line angle in the maxillary primary first molars, and the smooth surfaces, proximal surfaces, and mesial line angles in the mandibular primary second molars. Thus, the results suggest that a tooth preparation guide could facilitate better tooth preparation for PZCs.

Otolith and Scale morphology of Endemic fish Cyprinion macrostomum in Tigris–Euphrates Basin

The present study aims to determine the otolith and scale morphology of Cyprinion macrostomum in the Tigris–Euphrates Basin. A total of 50 specimens are evaluated, and total length and body weight values of samples are ranged 6.7–10.4 cm, and 2.7–10.9 g, respectively. The asteriscus and lapillus pairs are examined, and also the scales from the six body regions of juvenile and adult C. macrostomum samples are investigated. The otolith characters such as shape, size, proximal and distal surfaces, antirostrum and rostrum types and the scale morphological characters such as type, size, shape, focus position, circuli appearance, radii type, and rostral and caudal margin shapes are the distinguishable characters for the C. macrostomum samples. Whereas asteriscus pairs shape is discoidal, lapillus pairs shape is kidney-shaped for C. macrostomum samples. When the scales in six different body regions of C. macrostomum are compared, there are differences between the scale shapes obtained from six different regions.

Bacteriologic status of non-cavitated proximal enamel caries lesions. A histologic and histobacteriologic study

ObjectivesThis histologic and histobacteriologic study evaluated non-cavitated interproximal white spot lesions in human teeth for the 1) presence and morphology of bacterial aggregations at the enamel-dentinal junction (EDJ), and 2) reactions in the subjacent pulp tissue. MethodsThe material comprised 16 third molars diagnosed with early interproximal caries lesions obtained consecutively in a single clinical practice. Four third molars with clinically intact proximal surfaces served as controls. Caries activity was categorized as active or arrested. Teeth were prepared for histologic and histobacteriologic analyses. ResultsControl teeth exhibited normal tissue conditions with no bacteria. Macroscopic discoloration of the superficial dentin occurred in 14/16 teeth with early caries lesions. Bacterial aggregations resembling biofilms were observed in 10/16 teeth (six with active and four with arrested lesions). Bacterial cells were observed superficially in some of the underlying dentinal tubules, while in a few cases a deeper penetration was evident. Pathologic changes of varying degrees were observed in the pulps of all 16 teeth, regardless of the caries activity (active or arrested). Pulp reactions varied from disruption of the odontoblast layer, with loss of odontoblasts, to formation of tertiary dentin. ConclusionsBacterial biofilms associated with white-spot caries lesions may traverse the enamel and reach the underlying dentin in both active and arrested lesions. In all teeth with early lesions, the pulps showed changes in response to the very superficial biofilm challenge. Clinical significanceIn non-cavitated, active or arrested, enamel caries lesions, bacteria traverse the enamel and may establish structured biofilms at the enamel-dentinal junction, causing early pulp changes. These new findings may stimulate clinicians to rethink the rationale for treatment methods that are based on the assumption that bacteria are absent in white-spot lesions.

Evaluation of proximal bone loss around 2 commercial brands of SLA-surfaced implants and investigating possible effective factors

Introduction: The long term clinical success of dental implants depends on the stability of crestal bone level. Different dental implantation systems focus on micro-and macro-design to reduce late bone resorption. The purpose of this study was to evaluate bone loss at the proximal (mesial and distal) surfaces of SLA implants from 2 different companies. Materials and Methods: This retrospective cross-sectional study was done on 48 patients receiving 161 SLA-surfaced (Straumann and Dentium) dental implants. The marginal bone loss was measured at mesial &amp; distal sides of the implants on peri-apical X-ray images. The effective factors considered in this study were patients age, implant brand, time passed from fixture placement, preprosthetic surgery and type of prosthetic treatment that were obtained from patient records &amp; interviews. Results: Average mesial and distal bone loss was 1.50±1.359 and 1.517±1.3465 respectively. Pearson correlation coefficient indicates that 1) time passed from fixture placement, 2) commercial brand, 3) history of pre-prosthetic surgery and 4) age affected the amount of bone loss. Conclusion: SLA-surfaced dental implants showed an acceptable amount of bone resorption and no statistically significant difference was observed between commercial brands.

419 Clinical characteristics and quality of life burden in aquagenic pruritus: A global questionnaire-based study

Aquagenic pruritus (AP) is a rare pruritic dermatosis characterized by intense itching following water exposure and often results in patients avoiding water contact. Limited epidemiologic studies describe the characteristics of AP and its impact on quality of life. Our objective was to characterize the demographics, itch, and quality of life of AP patients using a descriptive cross-sectional study design. An anonymous, online Qualtrics survey was developed and delivered to 1,829 patients via a Facebook AP support group in July 2019. The survey assessed symptoms associated with AP, but also utilized established quality of life measures including the Dermatology Life Quality Index (DLQI), the 5-D pruritus scale and the Pittsburgh Sleep Quality Index (PSQI). A total of 106 respondents from 16 countries completed the survey. The mean (SD) age of respondents was 41.4 (14.2) years with the majority being female (79.3%), and Caucasian (82.1%); 45.3% of respondents were Fitzpatrick skin type 3 and 31.1% were type 2. Itch was symmetrically distributed with the greatest prevalence reported on proximal ventral surfaces, including the thighs (90%, n = 99) and upper arms (80%, n=90). The top five triggers associated with itch onset included bathing, sweating, humidity, rain, and friction over the skin. Prickling was the most common sensation felt along with itch (n=80, 75.5%). AP patients had a mean (SD) DLQI of 11.1 (7.0), 5D pruritus score of 13.9 (2.8) and a PSQI of 8.4 (3.6). Compared to mean DLQI scores of psoriasis patients, the mean DLQI score in this study suggests that AP patients have a significantly decreased quality of life. With a better understanding of AP itch distribution, severity, and quality of life, physicians can provide tailored care for this subset of itch patients.

The efficacy of the novel zinc-containing desensitizer CAREDYNE Shield on dentin hypersensitivity: a study protocol for a pilot randomized controlled trial

BackgroundDentin hypersensitivity (DH) is a condition characterized by short and sharp episodes of pain which will arise in response to tactile, chemical, thermal, evaporative or osmotic stimuli. The painful symptoms cause discomfort in patients and reduce their quality of life. Recently, the novel zinc-containing desensitizer CAREDYNE Shield has been developed as a new type of desensitizer that acts by inducing chemical occlusion of dentinal tubules, and releasing zinc ion for root caries prevention. However, the clinical effectiveness of CAREDYNE Shield on DH remains unclear. Therefore, the aim of this study is to evaluate the effectiveness of CAREDYNE Shield on DH by comparing with that of another desensitizer, Nanoseal, commonly used in Japan.Methods/designThis study protocol is a two-arm, parallel, pilot randomized controlled trial. Forty DH patients will be randomly allocated to two groups. Participants in the intervention group will be treated with CAREDYNE Shield, while those in the control group will be treated with Nanoseal. The primary outcome is the reduction of pain intensity in response to air stimuli measured with a 5-point verbal response scale from baseline to 4 weeks after the intervention, and Fisher’s exact test will be used for analyses.DiscussionCAREDYNE Shield can be casually applied to subgingival areas and proximal surfaces because it reacts with only tooth substance. Furthermore, zinc has been reported to reduce the demineralization of enamel and dentin and inhibit biofilm formation, plaque growth and dentin-collagen degradation. Therefore, CAREDYNE Shield may be expected to be a useful novel desensitizer that acts not only as a desensitizer but also as a root caries inhibitor.Trial registrationUMIN Clinical Trials Registry (UMIN-CTR), ID: UMIN000038072. Registered on 21 September 2019.Trial statusThis study (protocol version number: version 1.4.0; approved on 22 October 2019) is ongoing. The recruitment of participants began in December 2019 and will be continued until November 2020 (Hanke, Am Dent Assoc 27:1379–1393, 1940).

Impact of interdental brush shape on interpapillary cleaning efficacy \u2013\xa0a clinical trial

This study aimed to investigate whether interdental brush shape influences cleaning efficacy, by comparing a waist-shaped interdental brush (W-IDB) with a cylindrical IDB (C-IDB); both provided with the same bristle texture. Cleaning efficacy of differently shaped IDBs was measured in proximal surfaces of teeth in a split-mouth cross-over design. Twenty-eight patients abolished oral hygiene for 4 d. Line angle plaque area was scanned with an intraoral camera after use of disclosing dye in baseline and after IDB application and analyzed planimetrically. Additionally, bacterial load in the IDBs was analyzed after usage by colony forming units (cfu). A Wilcoxon signed-rank test with continuity correction was used to compare the results of the waist-shaped and the cylindrically-shaped IDBs. The waist-shaped IDBs cleaned significantly better than their cylindrically-shaped counterparts (area cleaned: 23.1% vs. 18.3%), when applied at same interdental spaces (p < 0.001). However, no significant differences were found in comparison of bacterial load on the IDBs (median cfu counts: 2.3E9 vs. 2.7E9, p = 0.93). Irrespective of bristle texture or size, IDB shape have impact on cleaning efficacy. Waist-shaped IDBs are more effective in cleaning of the line angle area than cylindrically-shaped IDBs.

A Volumetric Assessment of External Cervical Resorption Cases and Its Correlation to Classification, Treatment Planning, and Expected Prognosis

IntroductionExternal cervical resorption (ECR) is a relatively uncommon type of external resorption; its treatment planning and prognosis are largely dependent on the clinician’s subjective assessment. This study aimed to provide a volumetric assessment of ECR cases while correlating them to the Heithersay classification, treatment decision, and prognosis determined by 3 calibrated, independent evaluators. MethodsA total of 168 ECR cases with corresponding periapical radiographs and cone-beam computed tomographic (CBCT) imaging were included in this study. An oral and maxillofacial radiologist calculated the volume occupied by the resorptive defects in root structures on CBCT imaging using Amira software (Thermo Scientific, Waltham, MA). Also, 3 board-certified endodontists evaluated anonymized and randomized periapical radiographs and corresponding CBCT images in separate sessions. Examiners were asked to provide a Heithersay classification, whether they would surgically repair the ECR lesion, and the expected prognosis of each case. ResultsThe percentage of radicular volume affected by ECR ranged from 0.5%–58% with a median of 12%. The volumetric quantification of ECR best correlated with classification and prognosis assigned by the independent examiners using CBCT evaluation. The greatest variation in agreement was observed on whether to surgically repair the ECR. However, examiners agreed more uniformly on not to treat when the resorptive port of entry was found on either the lingual or proximal surfaces of the tooth. ConclusionsFor the first time, the volumetric quantification of resorptive defects was calculated in vivo and correlated to the Heithersay classification and prognosis. Because the longevity of teeth affected with ECR depends on the integrity of the remaining root, the findings of this study provide important information to help clinicians decide on treatment planning and inform their patients of the expected prognosis. Future studies should focus on automating volumetric assessments of ECR to aid in unbiased chairside treatment planning decisions.

Application of panoramic radiography with a multilayer imaging program for detecting proximal caries: a preliminary clinical study.

The aim of this study is to introduce a novel program of panoramic radiography that shows 41 multilayer images from the buccal to lingual aspects in a region of interest, and to evaluate the effectiveness of this program for detecting proximal caries. In total, 480 premolars and molars on 30 panoramic radiographs taken with the multilayer imaging program were included in this study. The presence or absence of caries in 960 proximal surfaces was assessed by three experienced oral and maxillofacial radiologists as a consensus-based gold-standard. Two general dentists evaluated and scored proximal caries on 980 surfaces on panoramic radiographs with and without the multilayer imaging program. The two general dentists' scores were compared with the gold-standard, and were analyzed for sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic (ROC) curve with and without using the program. The area under the ROC curve was analyzed using STATA/SE 13.1. When the multilayer imaging program was used for panoramic radiography, the inter- and intraobserver agreement of the two general dentists improved. All values, including the area under the ROC curve, were higher when the multilayer imaging program was used than when it was not used. The area under the ROC curve showed a statistically significant improvement only in Observer 1, whose diagnostic ability was poorer than that of Observer 2. This multilayer imaging program might help the inexperienced dentist to improve the diagnostic accuracy of proximal caries. If further studies would be performed in various clinical application, it could be useful when intraoral radiography taking is difficult for reasons such as mouth-opening limitations and the gag reflex of the patients.

Predicting Knee Joint Instability Using a Tibio-Femoral Statistical Shape Model.

Statistical shape models (SSMs) are a well established computational technique to represent the morphological variability spread in a set of matching surfaces by means of compact descriptive quantities, traditionally called “modes of variation” (MoVs). SSMs of bony surfaces have been proposed in biomechanics and orthopedic clinics to investigate the relation between bone shape and joint biomechanics. In this work, an SSM of the tibio-femoral joint has been developed to elucidate the relation between MoVs and bone angular deformities causing knee instability. The SSM was built using 99 bony shapes (distal femur and proximal tibia surfaces obtained from segmented CT scans) of osteoarthritic patients. Hip-knee-ankle (HKA) angle, femoral varus-valgus (FVV) angle, internal-external femoral rotation (IER), tibial varus-valgus (TVV) angles, and tibial slope (TS) were available across the patient set. Discriminant analysis (DA) and logistic regression (LR) classifiers were adopted to underline specific MoVs accounting for knee instability. First, it was found that thirty-four MoVs were enough to describe 95% of the shape variability in the dataset. The most relevant MoVs were the one encoding the height of the femoral and tibial shafts (MoV #2) and the one representing variations of the axial section of the femoral shaft and its bending in the frontal plane (MoV #5). Second, using quadratic DA, the sensitivity results of the classification were very accurate, being all >0.85 (HKA: 0.96, FVV: 0.99, IER: 0.88, TVV: 1, TS: 0.87). The results of the LR classifier were mostly in agreement with DA, confirming statistical significance for MoV #2 (p = 0.02) in correspondence to IER and MoV #5 in correspondence to HKA (p = 0.0001), FVV (p = 0.001), and TS (p = 0.02). We can argue that the SSM successfully identified specific MoVs encoding ranges of alignment variability between distal femur and proximal tibia. This discloses the opportunity to use the SSM to predict potential misalignment in the knee for a new patient by processing the bone shapes, removing the need for measuring clinical landmarks as the rotation centers and mechanical axes.

Microtensile Bond Strength Evaluation of Composite Resin to Discolored Dentin After Amalgam Removal

BackgroundTo obtain prolonged clinical success with composite restorations, better bonding of resin to the tooth substrate is crucial.AimThe study was aimed to evaluate the microtensile bond strength (µTBS) of bulk-fill composite resin restorations when bonded to a cavity previously restored with amalgam, comparing with that of freshly prepared dentin.Materials and methodMesio-occlusal cavity preparations were done on 80 extracted human mandibular molars with a buccolingual width of 4 mm and a 1.5 mm axial depth by placing the gingival seat 0.5 mm coronal to the cementoenamel junction (CEJ) and were restored with fine-grain amalgam alloy. After thermocycling, the amalgam restorations were removed. Disto-occlusal cavities with similar dimensions of mesial cavities were prepared, and both the proximal surfaces were filled with bulk-fill composite using either etch-and-rinse or self-etch adhesives. Following thermomechanical cyclic loading, all the teeth were sectioned for µTBS testing. Bond strength data expressed in megapascals (MPa) were subjected to statistical analyses using analysis of variance (ANOVA) and Tukey’s multiple post-hoc tests.ResultsThe total-etch adhesive exhibited statistically higher bond strength values to both dentin substrates compared to self-etch adhesives (p<0.05). Failure mode analysis reported more of adhesive failures.ConclusionThe µTBS of bulk-fill composite resin restorations bonded to a cavity previously restored with amalgam was significantly lower than that of freshly prepared dentin. Total-etch adhesives bond strength was higher than self-etch adhesives to both the substrates tested.

The role of stationary intraoral tomosynthesis in reducing proximal overlap in bitewing radiography.

This study examined the utility of stationary intraoral tomosynthesis (s-IOT) in opening proximal contacts in bitewing radiography. 11 DENTSPLY Rinn Dental X-ray Teaching and Training Replica mannequins (Model #546002, Elgin, Ill) were imaged with a prototype s-IOT device (Surround Medical Systems, Morrisville, NC) and standard bitewing (SBW) technique. Premolar and molar bitewings were acquired with each system. Image receptor holders were used to position receptors and aid in the alignment of the position indicating devices. An expert operator (having more than 5 years of experience in intraoral radiography) acquired the images with the s-IOT prototype and standard intraoral X-ray devices. Images were assessed to analyze percentage overlap of the proximal surfaces using the tools available in ImageJ (NIH, Bethesda Maryland). 253-paired surfaces were included in the analysis. The difference in overlap was statistically significant with standard bitewing (SBW) images resulting in a median overlap of 13%, a minimum of 0%, a maximum of 100% and an interquartile range of 40%. s-IOT resulted in a median overlap of 1%, a minimum of 0%, a maximum of 37% and an interquartile range of 0%. The s-IOT prototype substantially reduced proximal surface overlap compared to conventional bitewing radiography. The use of s-IOT reduced proximal contact overlap compared to standard bitewing radiography for an experienced radiographer. Stationary intraoral tomosynthesis may be a potential alternative to SBW radiography, reducing the number of retakes due to closed contacts.