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Objectives The current study aims to investigate the aerosol and spatter mitigation quality of 13 dry‐field isolation methods in a simulated setup that replicates real‐life work scenarios encountered in dental practices. Methods A crown preparation on a manikin was performed on tooth number 30 and repeated five times for each setup to simulate a patient under care. Aerosol, environmental, and operator face shield spatter, and sound intensity was measured. Generalized linear mixed models were used, and posthoc pairwise comparisons were performed to compare least‐squares means when appropriate using a Tukey adjustment. Results All tested setups showed some environmental spatter formation; however, these were able to control most (and in some cases all) spatter on the operator face shield. All methods resulted in excellent aerosol mitigation when a second line of high‐volume evacuation (HVE) was added to the device setup. However, in most setups, total sound levels exceeded 85 dB, posing a concern for prolonged noise exposure. Conclusions The Prototype device and four other tested setups with secondary HVE addition completely eliminated aerosol creation as tested. Spatter of the Face Shield was best eliminated using the Prototype device. Clinical Significance Within the limitations of this study, it can be concluded that the dental community has at its disposal equipment that can effectively mitigate aerosol and spatter.

OBJECTIVE The purpose of this study was to test a novel through-the-guide means of irrigation in an in-vitro bovine bone model and to explore the method clinical applicability. MATERIALS AND METHODS Surgical guides were designed to fit over five fresh bovine samples. Control osteotomy sites were compared to experimental sites irrigated through a 3D printed surgical guide with customized channels that direct the coolant toward the interface of the alveolar crest and drill. Temperature was measured during surgery with thermocouples located at 3 and 6 mm from the crestal height of the bone, and with an infrared thermal camera taking direct temperature readings from a window cut into axial wall at 9 mm from the crestal height of the ridge. RESULTS Incorporation of routed irrigation significantly decreased heat generation, keeping temperature consistently below 47°C. A clinical case illustrates the method applicability using standard implant planning software, 3D printing technology, and regular implant armamentarium. CONCLUSIONS The in-vitro analysis shows that this method mitigates temperature increase caused by static surgical guide irrigation blockade at the osteotomy site. This technique can be incorporated in the surgical guide design using commercially available software and 3D printing technology and has immediate applications in practice. CLINICAL SIGNIFICANCE The in-vitro analysis shows that this method can significantly mitigate the temperature increase caused by static surgical guide irrigation blockade at the osteotomy site. This technique also has the advantage that it can be incorporated in the digital surgical guide design using commercially available software and 3D printing technology. The method has immediate applications in practice, and especially in the treatment of edentulism in esthetic zone where use of guided surgery for implant placement is crucial in obtaining consistent results.

Complete-arch digital scans are becoming popular as digital dentistry is adopted for expanded clinical situations such as complete-arch prostheses, removable prostheses, extensive implant-supported treatment, and orthodontic aligners. Whether the scan pattern technique affects the trueness and precision of complete-arch scans and whether differences in accuracy exist among different scanners remain unclear. Furthermore, each manufacturer recommends a different scan pattern, but evidence of the superiority of the manufacturer's recommended pattern is lacking.The purpose of this in vitro study was to determine whether the scan pattern affects the trueness, precision, and speed of complete-arch digital scans performed by using 4 different digital scanning systems.A custom model used as the reference standard was fabricated with teeth having the same refractive index as dentin and enamel to simulate the natural dentition. The scan of the custom typodont was obtained by using an ATOS III Triple Scan 3D optical scanner. This study evaluated the CEREC Omnicam, Planmeca Emerald, Align iTero Element, and 3Shape TRIOS 3. Experimental scans were obtained from each of the 4 different digital scanning systems by using 4 unique scan patterns by experienced clinicians. Four experimental scans were acquired from each of the scanners by using 4 distinct scan patterns for a total of 16 scans for each scanner. Scan patterns 1 to 4 were based on the operator manuals for each different scanner. The scan time was recorded for each scan. All experimental scans were converted to standard tessellation language (STL) format, and a comprehensive metrology program, Geomagic Control X, was used to compare the reference standard scan with the experimental scans.For trueness, the scanner (P.001), scan pattern (P=.001), and their interaction (P.001) were found to be significant. Overall, scan pattern 2 showed the highest average trueness and precision. Likewise, for overall scan pattern precision, the scanner, scan pattern, and their interaction were found to be significant (P.001).Scan pattern affected trueness and precision for some scanners, but not for others. Differences exist in the complete-arch scan speed, trueness, and precision of individual scanners. Scan pattern can play an important role in the success of digital scanning.

Objective This in vitro study compares the newest generation of intraoral scanners to their older counterparts, and tests whether material substrates affect the trueness and precision of intraoral scanners (IOS). Material and methods A custom model, used as the reference standard, was fabricated with teeth composed of different dental materials. The reference standard scan was obtained using a three-dimensional (3D) optical scanner, the ATOS III. Experimental scans were obtained using eight different IOS, operated by experienced clinicians, using the manufacturer's recommended scanning strategy. A comprehensive metrology program, Geomagic Control X, was used to compare the reference standard scan with the experimental scans. Results For all scanners tested, except Trios3, the substrate does influence the trueness and precision of the scan. Furthermore, differences exist when comparing the same substrate across different scanners with some of the latest generation scanners clearly leaping ahead of the older generation regarding both trueness and precision. Conclusions Substrate type affects the trueness and precision of a scan. Active Triangulation scanners are more sensitive to substrate differences than their parallel confocal counterparts. Some scanners scan certain substrates better, but in general the new generation of scanners outperforms the old, across all substrates. Clinical significance The substrates being scanned play an import role in the trueness and precision of the 3D model. The new generation of scanners is remarkably accurate across all substrates and for complete-arch scanning.

Objectives An impression accuracy study using a cadaver maxilla was performed using both prepared and intact teeth as well as palatal tissue. Materials and methods Three crown preparations were performed on a cadaver maxilla. Seven different digital impression systems along with polyvinylsiloxane impressions were used to create digital models of the maxilla. Three-dimensional (3D) files of the experimental models were compared to a master model. The 3D files were overlaid and analyzed using a comparison software to create color coded figures that were measured for deviations between the master and experimental models. Results For scanning tooth structure, only the Planscan was significantly less accurate than the rest of impression techniques. No significant differences in accuracy were found between models created using digital impressions and those created from traditional vinyl polysiloxane impressions with cross arch deviations ranging from 18 to 39 μm for each. Conclusions Impressions taken using all digital impression systems, save for the Planscan, were able to accurately replicate the tissues of a complete arch human maxilla. Clinical significance Studies examining accuracy of digital impression systems have generally been performed on materials other than dental tissues. Optically, materials such as plastic and metal have properties different from enamel and dentin. This study evaluates accuracy of digital impression systems on human dentin, enamel, and soft tissues.

The novel coronavirus that was first identified in Wuhan, China, in December 2019, created a pandemic that has the potential to change the paradigm of health care delivery. Of interest to the dental community is the presence of SARS-CoV-2 in the saliva of the affected patients that can potentially cause transmission of COVID-19 via droplets. The highly infectious nature of the pathogen has created a sense of urgency and a need for extra caution to prevent the spread of the disease and the potential infection of patients and the entire dental team. Spatter consists of droplets up to 50 µm in size that are effectively stopped by barriers such as gloves, masks, and gowns. Aerosols are defined as droplet particles smaller than 5 µm that can remain airborne for extended periods and that have been reported to be significant in viral respiratory infections. In this study, aerosol represented by particulate matter with a size of 2.5 µm (PM2.5) was measured.Eight dry-field isolation methods were tested in a setup that included a realistic dental manikin and a high-speed handpiece that generated air-water spray. Environmental noise generated by the suction devices, suction flow rate of each setup, and the amount of environmental spatter and aerosols, were measured.The experimental setups showed significant variability in the suction flow rate, but this was not correlated to the level of sound generated. Some experimental setups caused a short-term level of noise that exceeded the NIOSH (National Institute for Occupational Safety and Health) guidelines and were close to the OSHA (Occupational Safety and Health Administration) recommended thresholds. It is also worth noting that the variability in the flow rate is not reflected in the efficacy of the experimental setups to mitigate spatter. All experimental setups, except the IsoVac system, provided statistically significantly better spatter mitigation compared to the control. All experimental setups also were efficient in mitigating aerosols compared with the positive control (P.0001) and most systems yielded results similar to the negative control ambient PM (P.05).Results indicate that spatter reduction was significantly better amongst the setups in which an additional high-volume evacuator (HVE) line was used. All setups were efficient at mitigating PM2.5 aerosols in comparison to the control. The conclusions of this study should be interpreted with caution, and additional mitigation techniques consistent with the Centers for Disease Control and Prevention recommendations must be implemented in dental practices.

Background Chairside systems are becoming more popular for fabricating full-ceramic single restorations, but there is very little knowledge about the effect of the entire workflow process on restoration fit. Therefore, this study aimed to compare the absolute marginal discrepancy (AMD) and the full internal fit (FULL) of all-ceramic crowns made by two chairside systems, Planmeca FIT and CEREC, with detailed and standard mill settings. Methods One upper molar was prepared for an all-ceramic crown in human cadaver maxilla. Full-arch scans were made by Emerald or Omnicam four times each. Twenty-four e.max crowns were designed and milled by the Planmill 30s or 40s or CEREC MCXL mills with either detailed or standard settings. The cadaver tooth was extracted, and each crown was fixed on it and scanned by a high-resolution microCT scanner. The AMD and FULL were measured digitally in mesio-distal and bucco-lingual 2D slices. The actual and predicted times of the milling were also registered. Results No differences were observed between detailed or standard settings in either system. The AMD was significantly higher with CEREC (132 ± 12 μm) than with either Planmill 30s (71 ± 6.9 μm) or 40s (78 ± 7.7 μm). In standard mode, the FULL was significantly higher with CEREC (224 ± 9.6 μm) than with either Planmill 30s (169 ± 8.1 μm) or 40s (178 ± 8.5 μm). There was no difference between actual and predicted time with the two Planmeca models, but with CEREC, the actual time was significantly higher than the predicted time. The 30s had significantly higher actual and predicted times compared to all other models. Across all models, the average milling time was 7.2 min less in standard mode than in detailed mode. Conclusions All fit parameters were in an acceptable range. No differences in fit between Planmeca models suggest no effect of spindle number on accuracy. The detailed setting has no improvement in the marginal or internal fit of the restoration, yet it increases milling time.

Backgrounds Intraoral scanner (IOS) accuracy is commonly evaluated using full-arch surface comparison, which fails to take into consideration the starting position of the scanning (scan origin). Previously a novel method was developed, which takes into account the scan origin and calculates the deviation of predefined identical points between references and test models. This method may reveal the error caused by stitching individual images during intraoral scan. This study aimed to validate the novel method by comparing the trueness of seven IOSs (Element 1, Element 2, Emerald, Omnicam, Planscan, Trios 3, CS 3600) to a physical impression digitized by laboratory scanner which lacks linear stitching problems. Methods Digital test models of a dentate human cadaver maxilla were made by IOSs and by laboratory scanner after polyvinylsiloxane impression. All scans started on the occlusal surface of the tooth #15 (universal notation, scan origin) and finished at tooth #2. The reference model and test models were superimposed at the scan origin in GOM Inspect software. Deviations were measured between identical points on three different axes, and the complex 3D deviation was calculated. The effect of scanners, tooth, and axis was statistically analyzed by the generalized linear mixed model. Results The deviation gradually increased as the distance from scan origin increased for the IOSs but not for the physical impression. The highest deviation occurred mostly at the apico-coronal axis for the IOSs. The mean deviation of the physical impression (53 ± 2 μm) was not significantly different from the Trios 3 (156 ± 8 μm) and CS 3600 (365 ± 29 μm), but it was significantly lower than the values of Element 1 (531 ± 26 μm), Element 2 (246 ± 11 μm), Emerald (317 ± 13 μm), Omnicam (174 ± 11 μm), Planscan (903 ± 49 μm). Conclusions The physical impression was superior compared to the IOSs on dentate full-arch of human cadaver. The novel method could reveal the stitching error of IOSs, which may partly be caused by the difficulties in depth measurement.

The intraoral scanning of the edentulous arch might be challenging for an inexperienced operator because of the large mucosal area and the use of scan bodies.The purpose of this ex vivo study was to compare the trueness of 5 intraoral scanners in replicating implant scan bodies and soft tissues in an edentulous maxilla and to investigate the effects of operator experience.The maxilla was resected from a fresh cadaver, 5 implants placed, and a reference scan made. Eight scans were made by experienced operators and 8 by an inexperienced operator with each scanner (iTero Element 2, Medit i500, Primescan, TRIOS 3, TRIOS 4). The implant platform deviation was measured after complete surface alignment and after scan body alignment. Deviation data were analyzed with a generalized linear mixed model (α=.05).After complete surface alignment, the mean ±standard deviation implant platform deviation was higher for the inexperienced operator (421 ±25 μm) than for experienced ones (191 ±12 μm, P.001) for all scanners. After scan body alignment, no significant differences were found between operators for Element 2, Primescan, and TRIOS 3. The experienced operators produced a lower deviation for TRIOS 4 (35 ±3.3 μm versus 54 ±3.1 μm, P.001), but higher deviation for i500 (68 ±4.1 μm versus 57 ±3.6 μm, P.05). The scanner ranking was Element 2 (63 ±4.1 μm), i500 (57 ±3.6 μm, P=.443), TRIOS 4 (54 ±3.1 μm, P=.591), TRIOS 3 (40 ±3.1 μm, P.01), Primescan (27 ±1.6 μm, P.001) for the inexperienced operator and i500 (68 ±4.1 μm), Element 2 (58 ±4.0 μm, P=.141), TRIOS 3 (41 ±2.8 μm, P.001), TRIOS 4 (35 ±3.3 μm, P=.205), Primescan (28 ±1.8 μm, P=.141) for the experienced operators.Mucosal alignment greatly overestimated the platform deviation. The intraoral scanners showed different trueness during the complete-arch implant scanning. The operator experience improved the trueness of the edentulous mucosa but not implant platform deviation.

Objective Clinicians have been slow to adopt digital impression technologies due possibly to perceived technique sensitivities involved in data acquisition. This research has two aims: determine whether scan pattern and sequence affects the accuracy of the three-dimensional (3D) model created from this digital impression and to compare the 5 imaging systems with regards to their scanning accuracy for sextant impressions. Materials and methods Six digital intraoral impression systems were used to scan a typodont sextant with optical properties similar to natural teeth. The impressions were taken using five different scan patterns and the resulting digital models were overlayed on a master digital model to determine the accuracy of each scanner performing each scan pattern. Furthermore, regardless of scan pattern, each digital impression system was evaluated for accuracy to the other systems in this same manner. Results No differences of significance were noted in the accuracy of 3D models created using six distinct scan patterns with one exception involving the CEREC Omnicam. Planmeca Planscan was determined to be the truest scanner while 3Shape Trios was determined to be the most precise for sextant impression making. Conclusions Scan pattern does not significantly affect the accuracy of the resulting digital model for sextant scanning. Clinical significance Companies who make digital impression systems often recommend a scan pattern specific for their system. However, every clinical scanning scenario is different and may require a different approach. Knowing how important scan pattern is with regards to accuracy would be helpful for guiding a growing number of practitioners who are utilizing this technology.

Existing root-analog dental implant systems have no standardized protocols regarding retentive design, surface manipulation, or prosthetic attachment design relative to the site's unique anatomy. Historically, existing systems made those design choices arbitrarily. For this report, strategies were developed that deliberately reference the adjacent anatomy, implant and restorable path of draw, and bone density for implant and retentive design. For proof of concept, dentate arches from human cadavers were scanned using cone-beam computed tomography and then digitally modeled. Teeth of interest were virtually extracted and manipulated via computer-aided design to generate root-analog implants from zirconium. We created a stepwise protocol for analyzing and developing the implant sites, implant design and retention, and prosthetic emergence and connection all from the pre-op cone-beam data. Root-analog implants were placed at the time of extraction and examined radiographically and mechanically concerning ideal fit and stability. This study provides proof of concept that retentive root-analog implants can be produced from cone-beam data while improving fit, retention, safety, esthetics, and restorability when compared to the existing protocols. These advancements may provide the critical steps necessary for clinical relevance and success of immediately placed root-analog implants. Additional studies are necessary to validate the model prior to clinical trial.

Objective To investigate the effect of poly-acrylic acid (PAA) copper iodide (CuI) adhesives on bond degradation, tensile strength, and biocompatibility. Methods PAA-CuI particles were incorporated into Optibond XTR, Optibond Solo and XP Bond in 0.1 and 0.5 mg/ml. Clearfil SE Protect, an MDPB-containing adhesive, was used as control. The adhesives were applied to human dentin, polymerized and restored with composite in 2 mm-increments. Resin–dentin beams (0.9 ± 0.1 mm 2 ) were evaluated for micro-tensile bond strength after 24 h, 6 months and 1 year. Hourglass specimens (10 × 2 × 1 mm) were evaluated for ultimate tensile strength (UTS). Cell metabolic function of human gingival fibroblast cells exposed to adhesive discs (8 × 1 mm) was assessed with MTT assay. Copper release from adhesive discs (5 × 1 mm) was evaluated with UV–vis spectrophotometer after immersion in 0.9% NaCl for 1, 3, 5, 7, 10, 14, 21 and 30 days. SEM, EDX and XRF were conducted for microstructure characterization. Results XTR and Solo did not show degradation when modified with PAA-CuI regardless of the concentration. The UTS for adhesives containing PAA-CuI remained unaltered relative to the controls. The percent viable cells were reduced for Solo 0.5 mg/ml and XP 0.1 or 0.5 mg/ml PAA-CuI. XP demonstrated the highest ion release. For all groups, the highest release was observed at days 1 and 14. Significance PAA-CuI particles prevented the bond degradation of XTR and Solo after 1 year without an effect on the UTS for any adhesive. Cell viability was affected for some adhesives. A similar pattern of copper release was demonstrated for all adhesives.

Objective When using a completely digital workflow on larger prosthetic cases it is often difficult to communicate to the laboratory or chairside Computer Aided Design and Computer Aided Manufacturing system the provisional prosthetic information. The problem arises when common hard tissue data points are limited or non-existent such as in complete arch cases in which the 3D model of the complete arch provisional restorations must be aligned perfectly with the 3D model of the complete arch preparations. In these instances, soft tissue is not enough to ensure an accurate automatic or manual alignment due to a lack of well-defined reference points. A new technique is proposed for the proper digital alignment of the 3D virtual model of the provisional prosthetic to the 3D virtual model of the prepared teeth in cases where common and coincident hard tissue data points are limited. Clinical considerations: A technique is described in which fiducial composite resin dots are temporarily placed on the intraoral keratinized tissue in strategic locations prior to final impressions. These fiducial dots provide coincident and clear 3D data points that when scanned into a digital impression allow superimposition of the 3D models. Conclusions Composite resin dots on keratinized tissue were successful at allowing accurate merging of provisional restoration and post-preparation 3D models for the purpose of using the provisional restorations as a guide for final CLINICAL SIGNIFICANCE Composite resin dots placed temporarily on attached tissue were successful at allowing accurate merging of the provisional restoration 3D models to the preparation 3D models for the purposes of using the provisional restorations as a guide for final restoration design and manufacturing. In this case, they allowed precise superimposition of the 3D models made in the absence of any other hard tissue reference points, resulting in the fabrication of ideal final restorations.

Implant dentistry is going through a digital revolution. Through the development of new equipment and their corresponding workflows, the diagnosis and treatment of our patients are becoming simpler and more efficient. This review examines the workflows and techniques that apply digital technology to the pre-operative planning stages, the surgical placement, and the prosthetic phases of implant treatment. With the current influx of new hardware and software into the market, dental technology has the potential to infiltrate every area of clinical implant dentistry. Its use generally begins with the diagnostic scanning by means of an intra-oral scanner and cone beam computed tomography. These modalities, in conjunction with implant planning software, allow for the planning and the guided surgical execution of dental implants. Technology can further be used with the prosthetic design and manufacturing of the interim and final restorations of the implants allowing all areas of clinical diagnosis and care to have the opportunity to apply digital dentistry. These tools can allow for more predictable, profitable, and pleasant treatment for our patients. As our clinical landscape changes with the influx of digital tools, the uses, workflows, and clinical protocols associated with implant dentistry can be learned and applied in our daily clinical practice allowing for the streamlining and simplification of patient care.

Objective This study aimed to determine how the accuracy of digital impressions was affected by four common dental substrates using seven prevalent IOS systems to scan the complete arch of a human maxilla. Setting and sample population The Department of Oral Rehabilitation at the Medical University of South Carolina. A single cadaver maxilla. Materials and methods Seven digital intraoral impression systems were used to scan a freshly harvested human maxilla. The maxilla contained several teeth restored with amalgam and composite, as well as unrestored teeth characterized by enamel. Also, three teeth were prepared for full coverage restorations to expose natural dentin. An industrial grade metrology software program that allowed 3D overlay and dimensional computation compared deviations of the complete arch and its substrates on the test model from the reference model. Results Substrates were significantly different from each other when considering scan data as a whole, as well as when comparing IOS devices individually. Only PlanScan failed to reveal trueness differences between the different substrates, while only Emerald revealed precision differences between the substrates. Conclusions Substrate type does impact the overall accuracy of intraoral scans with dentin being the most accurate and enamel being the least accurate. The four substrates scanned impacted the trueness of all IOS devices.

Rapid advancements in computer-aided design and computer-aided manufacturing (CAD-CAM) have opened new pathways in the fabrication of removable partial dentures (RPDs) through additive and subtractive processes. Questions remain whether the digital pathway is an acceptable one compared with conventional analog or combined analog and digital pathways.The purpose of this clinical study was to determine the quality of RPD frameworks fabricated using 3 different fabrication methods: analog, combined analog-digital, and digital.Three RPD frameworks were fabricated for each of the 9 participants using each of the 3 techniques. Of the 9 participants enrolled, 4 were of Kennedy class I, 3 were of Kennedy class II, and 2 were of Kennedy class III. The first technique was completely analog: a physical impression was made using polyvinyl siloxane, stone casts were made, a survey was performed, and a laboratory technician waxed and cast the RPD framework. The combined analog-digital workflow had the analog steps, but the stone cast was scanned with a laboratory scanner to generate a digital cast. The 3Shape CAD software was then used to design a digital RPD, which was fabricated from a cobalt-chroumum alloy by selective laser melting. The third technique was completely digital: an intraoral digital scanner was used to make a definitive scan, which was sent to the 3Shape software for digitally designing the RPD framework and subsequent selective laser melting for fabrication. For all frameworks in the same participant, the same design was used for consistency. The evaluation consisted of a yes/no survey with 7 framework-related parameters and was completed by 5 clinicians. For statistics, an overall P value was calculated using a chi-squared test to determine any difference among the groups (α=.05).Seven of the 9 participants received the framework fabricated using the digital pathway as their definitive prosthesis. The completely digital method was significantly better than the traditional method of analog fabrication (P.001). Intraoral scanning was also significantly better than the combined method of fabrication (P.001). The completely analog method was better than the combined method of framework fabrication (P=.008).Within the limitations of this clinical study, it was concluded that the combined analog-digital pathway of RPD fabrication was the least clinically acceptable one as determined by 5 calibrated clinicians using a yes/no questionnaire, whereas the completely digital method of fabrication was found to be the best.

Purpose This study evaluated the marginal gap of crowns fabricated using two new chairside computer-aided design/computer-aided manufacturing systems on preparations completed by clinicians with varying levels of expertise to identify whether common preparation errors affect marginal fit. The null hypothesis is that there is no difference in the mean marginal gaps of restorations of varying qualities and no difference in the mean marginal gap size between restorations fabricated using the PlanScan (D4D, Richardson, TX, USA) and the CEREC Omnicam (Sirona, Bensheim, Germany). Material and Methods The fit of 80 lithium disilicate crowns fabricated with the E4D PlanScan or CEREC Omnicam systems on preparations of varying quality were examined for marginal fit by using the replica technique. These same preparations were then visually examined against common criteria for anterior all-ceramic restorations and placed in one of four categories: excellent, good, fair, and poor. Linear mixed modeling was used to evaluate associations between marginal gap, tooth preparation rating, and fabrication machine. Results The fit was not significantly different between both systems across all qualities of preparation. The average fit was 104 μm for poor-quality preparations, 87.6 μm for fair preparations, 67.2 μm for good preparations, and 36.6 μm for excellent preparations. Conclusion The null hypothesis is rejected. It can be concluded that preparation quality has a significant impact on marginal gap regardless of which system is used. However, no significant difference was found when comparing the systems to each other. Clinical Significance Within the limitations of this in vitro study, it can be concluded that crown preparation quality has a significant effect on marginal gap of the restoration when the clinician uses either CEREC Omnicam or E4D PlansScan.

Traditionally, evaluating student work in preclinical courses has relied on the judgment of experienced clinicians utilizing visual inspection. However, research has shown significant disagreement between different evaluators (interrater reliability) and between results from the same evaluator at different times (intrarater reliability). This study evaluated a new experimental software (E4D Compare) to compare 66 student-produced tooth wax-ups at one U.S. dental school to an ideal standard after both had been digitally scanned. Using 3D surface-mapping technology, a numerical evaluation was generated by calculating the surface area of the student's work that was within a set range of the ideal. The aims of the study were to compare the reliability of faculty and software grades and to determine the ideal tolerance value for the software. The investigators hypothesized that the software would provide more consistent feedback than visual grading and that a tolerance value could be determined that closely correlated with the faculty grade. The results showed that a tolerance level of 450 μm provided 96% agreement of grades compared with only 53% agreement for faculty. The results suggest that this software could be used by faculty members as a mechanism to evaluate student work and for students to use as a self-assessment tool.

Objectives This study aimed to investigate incorporation of polyacrylic acid (PAA) coated copper iodide (CuI) nanoparticles into dental adhesives, and to evaluate for the first time, their antibacterial properties, bond strength and cytotoxicity. Methods PAA-CuI nanoparticles were synthesized and incorporated into commercially available adhesives Optibond XTR (1.0 mg/ml) and XP Bond (0.5 and 1.0 mg/ml). The antibacterial properties of experimental and control specimens were evaluated ( n = 8), after ageing for 18 h or 1 year, against Streptococcus mutans (1 × 10 8 cells/ml). Bond strength to human dentine of the control and experimental adhesives was evaluated by shear bond strength ( n = 10). For cytotoxicity evaluation, HGF cells were cultured with gingival fibroblast media and exposed to control and experimental adhesive blends ( n = 3). An MTT cell viability assay was used to assess cell metabolic function. A one-way analysis of variance followed by Tukey's test was used for data analysis. Results Significantly greater antibacterial properties were demonstrated for PAA-CuI containing adhesives after ageing for 18 h or 1 year relative to all control groups. A reduction in Streptococcus mutans viable cell count of 99.99%, 99.99% and 79.65% was shown for XP Bond – 0.5 mg/ml, XP Bond – 1.0 mg/ml and Optibond XTR – 1.0 mg/ml PAA-CuI after ageing for 18 h, and 99.99% for both XP Bond – 0.5 mg/ml and XP Bond – 1.0 mg/ml PAA-CuI after ageing for 1 year. No significant variations in shear bond strength or cytotoxicity were detected between the experimental resins and their corresponding controls. Conclusions PAA-CuI nanoparticles are an effective additive to adhesive blends as it renders them antibacterial without adversely affecting their bond strength or cytotoxicity. Clinical significance The incorporation of PAA-coated copper iodide particles into adhesive resins renders the adhesive antibacterial to S. mutans for at least 1 year in vitro . This may prevent or delay bacterial invasion and the consequent development of caries lesions if the adhesive interface becomes defective.

The aim of this study was to evaluate dental students' opinions regarding the utilization of a new grading software program for student self-assessment and a faculty-grading tool in a preclinical course. Using surface mapping technology, this program, called E4D Compare, yields a digital model of a student's preparation that is color-coded to show deficient areas. The program has now been used for two years at the James B. Edwards College of Dental Medicine at the Medical University of South Carolina, and the students previously assessed with E4D Compare have now entered into the dental clinics. For this study, students were asked to complete an anonymous survey for the investigators to evaluate students' attitudes and opinions on the effectiveness of this software in their preclinical courses to determine if this type of feedback helped them develop clinical skills. The survey also sought to collect students' opinions on the traditional objective criteria-based grading system. The survey was distributed to all members of the Classes of 2014 and 2015; it yielded a 59 percent response rate for the two classes, with a total of eighty-one students responding. Overall, the majority of students preferred the E4D Compare grading system over traditional hand-grading methods. The grading system provided instant, objective, and visual feedback that allowed students to easily see where their deficiencies were and encouraged them to work towards an ideal final product.

Statement of problem As digital impressions become more common and more digital impression systems are released onto the market, it is essential to systematically and objectively evaluate their accuracy. Purpose The purpose of this in vitro study was to evaluate and compare the trueness and precision of 6 intraoral scanners and 1 laboratory scanner in both sextant and complete-arch scenarios. Furthermore, time of scanning was evaluated and correlated with trueness and precision. Material and methods A custom complete-arch model was fabricated with a refractive index similar to that of tooth structure. Seven digital impression systems were used to scan the custom model for both posterior sextant and complete arch scenarios. Analysis was performed using 3-dimensional metrology software to measure discrepancies between the master model and experimental casts. Results Of the intraoral scanners, the Planscan was found to have the best trueness and precision while the 3Shape Trios was found to have the poorest for sextant scanning ( P iTero >3Shape TRIOS 3 >Carestream 3500 >Planscan >CEREC Omnicam >CEREC Bluecam. The order of precision for complete-arch scanning was as follows: CS3500 >iTero >3Shape D800 >3Shape TRIOS 3 >CEREC Omnicam >Planscan >CEREC Bluecam. For the secondary outcome evaluating the effect time has on trueness and precision, the complete- arch scan time was highly correlated with both trueness (r=0.771) and precision (r=0.771). Conclusions For sextant scanning, the Planscan was found to be the most precise and true scanner. For complete-arch scanning, the 3Shape Trios was found to have the best balance of speed and accuracy.

Statement of problem Confusion exists as to what constitutes an ideal ceramic crown preparation and whether certain deviations from the ideal can affect the marginal fit of the milled restoration. Purpose This study evaluated the marginal gap of E4D crowns fabricated on preparations completed by clinicians with varying levels of expertise to identify whether common errors affect marginal fit. Material and methods The fit of 75 crowns fabricated with the E4D system on preparations of varying quality were examined for marginal fit by using the replica technique. These same preparations were then visually examined for common criteria for ceramic restorations and placed in one of 3 categories: excellent, fair, or poor. These visual examinations sought the presence of common preparation errors, particularly those involving the finish line. The average marginal gap values and standard deviations were calculated for each category, and the Kruskal-Wallis test was used to determine significance. Results The results showed a statistically significant correlation between the marginal fit of a CAD/CAM fabricated crown and the quality of the preparation. The mean marginal gap of the crowns fabricated on ideal preparations was 38.5 µm, those considered fair had a mean marginal gap of 58.3 µm, while those categorized as poor averaged 90.1 µm. The fit differences among all 3 groups were statistically significant ( P Conclusions Within the limitations of this in vitro study, it can be concluded that preparation quality has a significant impact on marginal gap on crowns fabricated with a CAD/CAM system.

The traditional method of evaluating student tooth preparations in preclinical courses has relied on the judgment of experienced clinicians primarily utilizing visual inspection. At times, certain aids such as reduction matrices or reduction instruments of known dimension are used to assist the evaluator in determining the grade. Despite the skill and experience of the evaluator, there is still a significant element of uncertainty and inconsistency in these methods. Students may perceive this inconsistency as a form of subjective, arbitrary, and empirical evaluation, which often results in students’ focusing more on the grade than the actual learning or developing skills necessary to accomplish the preparation properly. Perceptions of favoritism, discrimination, and unfairness (whether verbalized or not) may interfere with the learning process. This study reports the use of a new experimental scanning and evaluation software program (E4D Compare) that can consistently and reliably scan a student’s tooth preparation and compare it to a known (faculty-determined) standardized preparation. An actual numerical evaluation is generated by the E4D Compare software, thereby making subjective judgments by the faculty unnecessary. In this study, the computer-generated result was found to be more precise than the hand-graded method.

Desiring to better encourage students' thinking and conceptual development, a fourth-grade teacher examines classroom discourse and written work during her students' analysis and description of basic geometric shapes.

The use of predictive factors allows a more effective use of available therapies by enabling clinicians to distinguish patients likely to obtain substantial benefit from treatment from those for whom the same therapy is less likely to be effective. A most relevant aspect of clinical research is thus to develop alternative therapeutic approaches which are more efficacious for this latter group, particularly important since treatment effects are likely to be small. In the preoperative setting several predictors of response were identified. They include: diameter of the lesion (larger lesions respond less than smaller lesions), MIB-1 increased expression associated with increased response to chemotherapy, and estrogen receptor (ER) and progesterone receptor (PgR) expression in the tumor typically associated with increased response to endocrine therapies. Other factors include HER-2/neu overexpression, which is a target for treatment with the humanized monoclonal antibody against its extracellular domain, is hypothesized to increase response to anthracycline combination chemotherapy and to lead to an improved response to some endocrine agents (e.g. letrozole) rather than to others. Although primary endocrine therapy demonstrated activity and low profile of side effects in selected populations of older patients, it is infrequently used. On the other hand, chemotherapy remains the mainstay of treatment being considered to be a more active and better documented option. Experience at the European Institute of Oncology on 399 patients with large or locally advanced breast cancer (cT2-T4, N0-2, M0) treated with primary chemotherapy, indicated that a proper selection of primary treatment should be based on tumor characteristics such as ER and PgR status. In particular, patients with tumors with no ER and PgR expression (endocrine-unresponsive disease) at the baseline core-biopsy had a significantly higher response rate to chemotherapy if compared with tumors with some ER/PgR expression. In fact, the absence of ER and PgR expression was the strongest predictors of pCR at the multivariate analysis (P

How can and do teachers create equal access within everyday classroom lessons and establish opportunities for girls to participate fully? What contexts contribute to equity? In contrast to classrooms where boys receive more attention, encouragement, and content-area instruction, Ms. Jeffreys conducts whole class lessons in her fourth grade classroom where girls participate equally and successfully with boys during mathematics. To ascertain what contributes to the equal participation, I use interactional analysis to closely examine two mathematics lessons. Part of Ms. Jeffreys’ success lies in altering normative classroom discourse and in the assertive context created and sustained by the math, science, and technology magnet school setting. However, another layer of complexity is introduced: to teach her students at their instructional level, Ms. Jeffreys groups her students by their ability to pass timed multiplication tests. By instituting a form of tracking, Ms. Jeffreys also legitimates girls a...

The traditional method of evaluating student tooth preparations in preclinical courses has relied on the judgment of experienced clinicians primarily utilizing visual inspection. At times, certain aids such as reduction matrices or reduction instruments of known dimension are used to assist the evaluator in determining the grade. Despite the skill and experience of the evaluator, there is still a significant element of uncertainty and inconsistency in these methods. Students may perceive this inconsistency as a form of subjective, arbitrary, and empirical evaluation, which often results in students’ focusing more on the grade than the actual learning or developing skills necessary to accomplish the preparation properly. Perceptions of favoritism, discrimination, and unfairness (whether verbalized or not) may interfere with the learning process. This study reports the use of a new experimental scanning and evaluation software program (E4D Compare) that can consistently and reliably scan a student’s tooth preparation and compare it to a known (faculty-determined) standardized preparation. An actual numerical evaluation is generated by the E4D Compare software, thereby making subjective judgments by the faculty unnecessary. In this study, the computer-generated result was found to be more precise than the hand-graded method.

1. Tsuo Y, Yoshida K, Atsuta M. Effects of alumina-blasting and adhesive primers on bonding between resin luting agent and zirconia ceramics. Dent Mater J 2006;25:66974. 2. Wolfart M, Lehmann F, Wolfart S, Kern M. Durability of the resin bond strength to zirconia ceramic after using different surface conditioning methods. Dent Mater 2007;23:45-50. 3. Kern M, Wegner SM. Bonding to zirconia ceramic: adhesion methods and their durability. Dent Mater 1998;14:64-71. 4. Kern M, Barloi A, Yang B. Surface conditioning influences zirconia ceramic bonding. J Dent Res 2009;88:817-22. 5. Derand T, Molin M, Kvam K. Bond strength of composite luting cement to zirconia ceramic surfaces. Dent Mater 2005;21:115862. 6. Aboushelib MN, Kleverlaan CJ, Feilzer AJ. Selective infiltration-etching technique for a strong and durable bond of resin cements to zirconia-based materials. J Prosthet Dent 2007;98:379-88. 7. Phark JH, Duarte S Jr, Blatz M, Sadan A. An in vitro evaluation of the long-term resin bond to a new densely sintered high-purity zirconium-oxide ceramic surface. J Prosthet Dent 2009;101:29-38. 8. Yang B, Wolfart S, Scharnberg M, Ludwig K, Adelung R, Kern M. Influence of contamination on zirconia ceramic bonding. J Dent Res 2007;86:749-53. Corresponding author: Dr Matthias Kern Department of Prosthodontics, Propaedeutics and Dental Materials School of Dentistry, Christian-Albrechts University at Kiel Arnold-Heller Strasse 16 24105 Kiel GERMANY Fax: +49 431 597 2860 E-mail: mkern@proth.uni-kiel.de

Fibroepithelial polyps are the most frequently observed mesenchymal tumors of the renal pelvis. We report on one case of fibroepithelial polyp of the renal pelvis with unusual CT findings of totally cystic structure with septations.

Thoracic splenosis is a rare event, and fine needle aspiration (FNA) of a pleural implant of splenic tissue can be a pitfall when previous anamnestic data are ignored.A 53-year-old male underwent FNA of a left thoracic subpleural nodule highly suggestive of a metastatic lesion. The presence of a population of small and medium-sized lymphocytes suggested the possibility of lymphoproliferative disease; frozen sections confirmed this possibility. The final diagnosis was normal splenic tissue. Twenty-five years earlier the patient sustained a gunshot wound in the left side of the upper abdomen followed by splenectomy and drainage of the left pleural cavity because of mild, concomitant hemothorax.A left pleural thoracic nodule in subjects with a previous history of traumatic rupture of the spleen must be considered highly suggestive of thoracic splenosis. Scintigraphy with Tc 99 m and magnetic resonance imaging are diagnostic, while FNA, especially in the absence of anamnestic data, can create a pitfall that can induce inappropriate removal of ectopic, normally functioning splenic tissue.

(2001). Sentinel Node Biopsy in Male Breast Cancer: Future Standard Treatment? The European Journal of Surgery: Vol. 167, No. 6, pp. 461-462.

A review of cases treated in 1978-82 revealed 1 case of lipid cell carcinoma of the breast out of 310 mammary carcinomas. Given the rarity of this histological type and the generally poorer than average prognosis, it seems likely that it should be considered separately from the other cases.