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    Jung-Wei Chen

    Purpose. To compare the biocompatibility and antimicrobial effectiveness of the new Fast-Set MTA (FS-MTA) with ProRoot MTA (RS-MTA). Methods. The agar overlay method with neutral red dye was used. L929 mouse fibroblast cells were... more
    Purpose. To compare the biocompatibility and antimicrobial effectiveness of the new Fast-Set MTA (FS-MTA) with ProRoot MTA (RS-MTA). Methods. The agar overlay method with neutral red dye was used. L929 mouse fibroblast cells were cultured. The liquid and oil extracts and solid test material were placed on the agar overlay, four samples for each material. Phenol was used as the positive control and cottonseed oil and MEM extracts were used as negative controls. Cytotoxicity was examined by measuring the zones of decolorization and evaluating cell lysis under an inverted microscope using the established criteria after 24 and 48 hours. The antimicrobial test was performed using the Kirby-Bauer disk-diffusion method against S. mutans, E. faecalis, F. nucleatum, P. gingivalis, and P. intermedia. The size of the zone of inhibition was measured in millimeters. Results. There was no zone of decolorization seen under or around the test materials for FS-MTA and RS-MTA at 24 and 48 hours. The ...
    Purpose: The purpose of this study was to evaluate the cardiopulmonary effects of 2 sedation regimens during treatment: (1) oral meperidine and hydroxyzine with nitrous oxide (N 2 O); and (2) oral diazepam and hydroxyzine, submucosal... more
    Purpose: The purpose of this study was to evaluate the cardiopulmonary effects of 2 sedation regimens during treatment: (1) oral meperidine and hydroxyzine with nitrous oxide (N 2 O); and (2) oral diazepam and hydroxyzine, submucosal meperidine, and N 2 O. Nitrous oxide was tapered to oxygen (O 2 ) only 10 minutes following submucosal meperi- dine administration. Methods: Sixty-two
    Currently more than half of Electronic Health Record (EHR) projects fail. Most of these failures are not due to flawed technology, but rather due to the lack of systematic considerations of human issues. Among the barriers for EHR... more
    Currently more than half of Electronic Health Record (EHR) projects fail. Most of these failures are not due to flawed technology, but rather due to the lack of systematic considerations of human issues. Among the barriers for EHR adoption, function mismatching among users, activities, and systems is a major area that has not been systematically addressed from a human-centered perspective. A theoretical framework called Functional Framework was developed for identifying and reducing functional discrepancies among users, activities, and systems. The Functional Framework is composed of three models – the User Model, the Designer Model, and the Activity Model. The User Model was developed by conducting a survey (N = 32) that identified the functions needed and desired from the user’s perspective. The Designer Model was developed by conducting a systemic review of an Electronic Dental Record (EDR) and its functions. The Activity Model was developed using an ethnographic method called sh...
    This study is a systemic review of coronally positioned flap, coronally positioned flap+chemical root surface conditioning, or coronally positioned flap+enamel matrix derivative (EMD) for the treatment of Miller class I and II gingival... more
    This study is a systemic review of coronally positioned flap, coronally positioned flap+chemical root surface conditioning, or coronally positioned flap+enamel matrix derivative (EMD) for the treatment of Miller class I and II gingival recession. All studies available through the Medline database by the end of October 2005 were used. Each study provided mean clinical attachment level, keratinized tissue, probing pocket depth, gingival recession depth and root coverage percentage before and after treatment with coronally positioned flap alone, coronally positioned flap+chemical root surface conditioning, or coronally positioned flap+EMD. Effectiveness was evaluated by comparing the weighted mean average in gingival recession depth, probing pocket depth, clinical attachment level, keratinized tissue and root coverage percentage achieved with the three treatments. Seven studies for the coronally positioned flap+EMD group, four studies for the coronally positioned flap+chemical root surface conditioning group, and seven studies for the coronally positioned flap group were retrieved for this weighted mean analysis. The results of clinical attachment level, gingival recession depth, and root coverage percentage in the coronally positioned flap+EMD group were statistically significantly better than the changes in the coronally positioned flap and coronally positioned flap+chemical root surface conditioning group at 6 and 12 mo (p<0.001). There was no significant difference at the 6-mo comparison among clinical attachment level, keratinized tissue, probing pocket depth, and gingival recession depth, except in the root coverage percentage for coronally positioned flap and coronally positioned flap+chemical root surface conditioning groups. The results suggest that root coverage by the coronally positioned flap and coronally positioned flap+chemical root surface conditioning procedures were unpredictable but became more predictable when the coronally positioned flap procedure was improved by the modification of adding EMD.
    ABSTRACT
    The purpose of this study was to measure the fluoride concentrations in ready-to-eat infant food, and to determine if significant differences exist among flavors and brands. One hundred fifty samples of 5 infant food flavors from an... more
    The purpose of this study was to measure the fluoride concentrations in ready-to-eat infant food, and to determine if significant differences exist among flavors and brands. One hundred fifty samples of 5 infant food flavors from an organic infant food manufacturer and the largest infant food manufacturer were compared using the Taves microdiffusion method. Total fluoride ingestion per serving was calculated based on average amounts consumed and container size of individual products. Fluoride concentrations ranged from 0.01 to 0.60 ppm (mean = 0.170 +/- 0.125 [SD] ppm) for all samples, with both the highest and lowest fluoride concentrations found in processed banana infant food (Gerber, mean = 0320 +/- 0.167 ppm; Earth's Best, mean = 0.030 +/- 0.013 ppm). Significant differences were noted when comparing the 2 infant food manufacturers for all flavors. The fluoride concentrations in ready-to-eat infant food varied among the 5 flavors tested. All infant foods tested were found to provide less fluoride than the Institute of Medicine tolerable upper daily intake. No trends in fluoride concentrations for different flavors or brands were noted. Fluoride in infant foods should be considered when determining total fluoride intake.
    This study assessed the association of caries, plaque accumulation, gingival health, and antiretroviral therapy (AT) with oral lesion prevalence in human immunodeficiency virus (HIV)-infected Romanian children. A convenience sample of... more
    This study assessed the association of caries, plaque accumulation, gingival health, and antiretroviral therapy (AT) with oral lesion prevalence in human immunodeficiency virus (HIV)-infected Romanian children. A convenience sample of HIV-infected children who received dental care in 2 hospitals were evaluated for oral lesions, caries (dfs+DFS/total teeth present), plaque (PI, Silness and Löe), and gingival indices (GI, Löe and Silness). Oral lesions were grouped as: (1) extraoral herpetic infections; (2) parotid gland swelling; (3) oral ulcerative lesions; and (4) fungal infections. A standardized operator performed the examinations and photographed the oral lesions for confirmation. Age, gender, and use of AT were documented. Data were analyzed by logistic and multiple regression, Pearson correlation and t test (P<.05). One hundred four children (mean age=11.7 years) were evaluated. Fungal infections were associated with increased caries rate (P=.002; OR=2.5) and increased GI (...
    This study compared the effectiveness of topical benzocaine 20% versus a combination of lidocaine, tetracaine, and phenylephrine in providing sufficient analgesia for the placement of orthodontic temporary anchorage devices (TADs). The 2... more
    This study compared the effectiveness of topical benzocaine 20% versus a combination of lidocaine, tetracaine, and phenylephrine in providing sufficient analgesia for the placement of orthodontic temporary anchorage devices (TADs). The 2 topical anesthetics were tested against each other bilaterally using a randomized, double-blind, crossover design. The agents were left in place for the amount of time prescribed by the manufacturer. The TAD was then placed, and each subject rated the degree of pain on a Heft-Parker visual analogue scale. A pulse oximeter was used to record the preoperative and postoperative pulse rates. Statistically significant differences in perceived pain (P < .05) and success rate (P < .01) between drugs were seen, but no significant difference in pulse rate change between the topical anesthetics was observed (P > .05). It was concluded that when the efficacy of topical benzocaine and of a combination product was compared as the sole anesthetic to faci...
    Graphic User Interface (GUI) is commonly considered to be superior to Text-based User Interface (TUI). This study compares GUI and TUI in an electronic dental record system. Several usability analysis techniques compared the relative... more
    Graphic User Interface (GUI) is commonly considered to be superior to Text-based User Interface (TUI). This study compares GUI and TUI in an electronic dental record system. Several usability analysis techniques compared the relative effectiveness of a GUI and a TUI. Expert users and novice users were evaluated in time required and steps needed to complete the task. A within-subject design was used to evaluate if the experience with either interface will affect task performance. The results show that the GUI interface was not better than the TUI for expert users. GUI interface was better for novice users. For novice users there was a learning transfer effect from TUI to GUI. This means a user interface is user-friendly or not depending on the mapping between the user interface and tasks. GUI by itself may or may not be better than TUI.
    A work domain ontology (WDO) was developed by constructing and integrating three models inverted exclamation markXuser, system, and activity models. The user model was built on results of a user need survey. The activity model was built... more
    A work domain ontology (WDO) was developed by constructing and integrating three models inverted exclamation markXuser, system, and activity models. The user model was built on results of a user need survey. The activity model was built by shadowing the workflow. The system model was developed by analyzing an Electronic Dental Records (EDR) system. The WDO reflects the objects, activities, constraints and should serve as the reference and baseline for the design and evaluation of EDR systems.
    The purpose of this study was to evaluate the color of primary teeth. A Vita Easyshade intraoral spectrophotometer was used to determine the color of primary teeth: (1) maxillary central incisors, canines, and first molars; and (2)... more
    The purpose of this study was to evaluate the color of primary teeth. A Vita Easyshade intraoral spectrophotometer was used to determine the color of primary teeth: (1) maxillary central incisors, canines, and first molars; and (2) mandibular central incisors, canines, and first molars. A total of 604 teeth were measured. Color difference was compared to DeltaE*=2.7 (mean=50:50 replacement point). Coverage error (DeltaE*cov) was calculated. Mean L*a*b*C*ho values for primary teeth were 82.5, 0.2, 18.3, 18.4, and 89.4 respectively. The most frequently chosen shades were A1 (46%), A2 (25%), and B2 (11%). Canines had the highest lightness. Maxillary canines had the lowest a* values, whereas mandibular primary incisors had the highest a* values. Molars were the most chromatic (having the highest b* values), followed by canines and primary incisors in decreasing order. Coverage error (DeltaEcov*) of Vitapan Classical was 4.2 (+/-1.9 SD). Among primary teeth, the widest ranges, in order, ...
    This project was comparing the accuracy of capturing the oral pathology diagnoses among different coding systems. 55 diagnoses were selected for comparison among 5 coding systems. The results of accuracy in capturing oral diagnoses are:... more
    This project was comparing the accuracy of capturing the oral pathology diagnoses among different coding systems. 55 diagnoses were selected for comparison among 5 coding systems. The results of accuracy in capturing oral diagnoses are: AFIP (96.4%), followed by Read 99 (85.5%), SNOMED 98 (74.5%), ICD-9 (43.6%), and CDT-3 (14.5%). It shows that the currently used coding systems, ICD-9 and CDT-3, were inadequate, whereas the AFIP coding system captured the majority of oral diagnoses. In conclusion, the most commonly used medical and dental coding systems lack terms for the diagnosis of oral and dental conditions.
    ABSTRACT
    To elucidate the aetiology of periodontitis, this study focused on the adenosine receptor (AR) expression profiles (A1AR, A2AAR, A2BAR and A3AR) in periodontal diseased tissues. Adenosine receptor gene expression levels in human gingiva... more
    To elucidate the aetiology of periodontitis, this study focused on the adenosine receptor (AR) expression profiles (A1AR, A2AAR, A2BAR and A3AR) in periodontal diseased tissues. Adenosine receptor gene expression levels in human gingiva from 15 patients with healthy gingival tissues (control group) and 15 patients who exhibited severe chronic periodontitis (test group) were measured using quantitative reverse transcription-polymerase chain reaction (RT-PCR). The mRNA expression pattern changed in human chronic periodontitis: the A1AR decreased 20%, A2AAR increased 2.5-fold, A2BAR increased 3.7-fold and A3AR decreased 70% as compared with that of healthy gingiva. Inflammation of the gingival tissue is associated with (1) an unchanged expression of A1AR, (2) an increased expression of A2AAR and A2BAR, and (3) a decreased expression of A3AR. Logistic regression analysis indicated that the change in the expression patterns can be used to diagnose/predict periodontitis. This finding indi...
    ABSTRACT
    This study compared the incidence of adverse sedation-related events occurring with two different multiagent oral sedation regimens in pediatric dental patients. Forty healthy patients (three to six years old), received either a sedation... more
    This study compared the incidence of adverse sedation-related events occurring with two different multiagent oral sedation regimens in pediatric dental patients. Forty healthy patients (three to six years old), received either a sedation regimen of chloral hydrate, meperidine, and hydroxyzine with nitrous oxide (CH/M/H/N2O; N=19) or a regimen of midazolam, meperidine, and hydroxyzine with nitrous oxide (MZ/M/H/N2O; N=21). The two treating dentists answered a questionnaire regarding the perioperative period. Parents received two phone interviews at eight and 24 hours after sedation. Statistical analysis included chi-square, Pearson correlation coefficient, and t-test (P<.05). Children sedated with MZ/M/H/N2O showed a significant increase in hyperactivity during dental treatment, slurring/difficulty speaking, and difficulty walking postoperatively within eight hours after discharge. Children sedated with CH/M/H/N2O showed a significant increase in frequency of sleeping, talking les...
    The purpose of this study was to determine if cone beam computed tomography (CBCT) is more effective than traditional radiography (TR) in diagnosing pediatric dental clinical cases involving impacted and supernumerary teeth. Surveys were... more
    The purpose of this study was to determine if cone beam computed tomography (CBCT) is more effective than traditional radiography (TR) in diagnosing pediatric dental clinical cases involving impacted and supernumerary teeth. Surveys were given to 10 pediatric dental faculty and 10 pediatric dental residents after viewing 8 clinical cases in either CBCT or TR in which the patient presented with pathology (impaction or supernumerary) in the anterior maxilla. The surveys asked for pathology diagnosis, location, and identification of root resorption, as well as questions about the usefulness of the radiographic mode in treatment planning. A statistically significant difference in CBCT vs. TR viewed cases was found with CBCT statistically better (P<0.05) for pathology location, determining root resorption, usefulness, adequacy in treatment planning, and was the overall recommended mode. More faculty were able to correctly identify the pathology location (P=0.034), while more residents...
    The capacity to locate, access, and appraise information is an important skill required for success in dental school and beyond. An interdisciplinary course was implemented to teach first-year dental students at the University of Texas... more
    The capacity to locate, access, and appraise information is an important skill required for success in dental school and beyond. An interdisciplinary course was implemented to teach first-year dental students at the University of Texas Health Science Center at Houston Dental Branch about evidence-based dentistry, search strategies, critical appraisal of the literature, and dental informatics. Students learned to develop a clinical question, conduct a search to find answers to that question, and critically appraise one of the retrieved resources. Over a period of four years, a total of 259 dental students completed a questionnaire that requested their assessment of this course. Seventy-five percent of the respondents agreed or strongly agreed that they learned to effectively search databases such as the Cochrane Collaboration and PubMed and to critically appraise websites and journal articles and that the information on evidence-based dentistry and critical thinking skills was valuab...
    The purpose of this study was to investigate the occurrence and clinical parameters that are associated with halitosis in pediatric dental patients and compare these findings with those found for the patients' mother. Children aged 5... more
    The purpose of this study was to investigate the occurrence and clinical parameters that are associated with halitosis in pediatric dental patients and compare these findings with those found for the patients' mother. Children aged 5 to 12 years old were evaluated with mothers present during a dental visit. Each mother completed the child's medical history and a breath odor questionnaire. The mother and an oral breath judge (OBJ) evaluated the child's oral breath using organoleptic methods. A commercial breath analyzer (CBA) measured the oral and nasal levels of volatile sulfur compounds (VSCs) for child and mother before and after tongue debridement. A number of oral parameters were recorded for the children. Thirty children (mean age=8.8 years) and 18 mothers participated. Halitosis (VSC>100 parts per billion, or ppb) was found in 23% of children and 11% of mothers, but was not significantly correlated. In contrast, 61% of mothers reported halitosis in themselves an...
    The purpose of this study was to examine the relationship between the specific types of medication, length of use, frequency of use, and dosing time of day on the dental caries of children diagnosed with asthma. Using a patient list from... more
    The purpose of this study was to examine the relationship between the specific types of medication, length of use, frequency of use, and dosing time of day on the dental caries of children diagnosed with asthma. Using a patient list from a previous study, surveys were mailed to the parents of 179 asthmatic children. The survey itself consisted of a table that asked 4 questions: (1) What combination of asthma medications was used by the subject? (2) How long were the medications used? (3) How often were the medications used? (4) What time of day were the medications used? Of the 179 surveys that were mailed out, 156 were returned. Children who used their medication greater than twice daily were significantly more likely to experience dental disease in both the primary (odds ratio [OR]=2.56, 95% confidence interval [CI]=1.45-6.29) and mixed dentitions (OR=3.56, 95% CI 2.45-5.94). Increased frequency of asthma medication use was associated with increased likelihood of caries experience...
    The purpose of this study was to measure the fluoride concentration in the most commonly consumed, commercially available infant fruit juices and to determine if a significant difference existed among various juice flavors and brands.... more
    The purpose of this study was to measure the fluoride concentration in the most commonly consumed, commercially available infant fruit juices and to determine if a significant difference existed among various juice flavors and brands. Ninety samples of different flavors from three infant juice manufacturing companies were analyzed using the Taves microdiffusion method. The fluoride content in one serving juice container was calculated and compared to the recommended optimal daily fluoride intake. Fluoride concentrations ranged from 0.11 to 1.81 ppm (mean=0.75+0.45 ppm) for all samples. A statistically significant difference in fluoride concentration among different manufacturers (P<.001) was found. Gerber juices contained higher fluoride amounts (mean=1.1+0.22 ppm) than Beechnut juices (mean=0.43+0.42 ppm) and Earth's Best juices (mean=0.34+0.13 ppm). Fluoride was found in all tested infant juice samples, and concentrations varied among manufacturers and flavors assessed. Flu...
    The authors conducted a systematic review and meta-analysis to compare the long-term clinical and radiographic success of using mineral trioxide aggregate (MTA) and formocresol (FC) as a pulp-dressing material in pulpotomy treatment in... more
    The authors conducted a systematic review and meta-analysis to compare the long-term clinical and radiographic success of using mineral trioxide aggregate (MTA) and formocresol (FC) as a pulp-dressing material in pulpotomy treatment in primary molars. The authors searched MEDLINE, Thomson Reuters Web of Science and the Cochrane Central Register of Controlled Trials for randomized controlled trials (RCTs) published from Jan. 1, 1990, to May 9, 2013. For an RCT to be included, the authors required that the primary molars treated with a pulpotomy procedure must have received stainless steel crowns as a final restoration and that rubber dam isolation was used during treatment; that the pulp must have been vital as determined clinically by means of hemorrhage control with a cotton pellet; and that the RCT must have included a follow-up period of at least two years. For each included RCT, two authors assessed the risk of bias independently. The authors identified 20 trials and included fi...
    The purpose of this study was to compare the efficacy of the pulverization and sterile paper point techniques for sampling root canals using 5.25% NaOCl/17% EDTA and 1.3% NaOCl/MTAD (Dentsply, Tulsa, OK) as irrigation regimens.... more
    The purpose of this study was to compare the efficacy of the pulverization and sterile paper point techniques for sampling root canals using 5.25% NaOCl/17% EDTA and 1.3% NaOCl/MTAD (Dentsply, Tulsa, OK) as irrigation regimens. Single-canal extracted human teeth were decoronated and infected with Enterococcus faecalis. Roots were randomly assigned to 2 irrigation regimens: group A with 5.25% NaOCl/17% EDTA (n = 30) and group B with 1.3% NaOCl/MTAD (n = 30). After chemomechanical debridement, bacterial samplings were taken using sterile paper points and pulverized powder of the apical 5 mm root ends. The sterile paper point technique did not show growth in any samples. The pulverization technique showed growth in 24 of the 60 samples. The Fisher exact test showed significant differences between sampling techniques (P < .001). The sterile paper point technique showed no difference between irrigation regimens. However, 17 of the 30 roots in group A and 7 of the 30 roots in group B resulted in growth as detected by pulverization technique. Data showed a significant difference between irrigation regimens (P = .03) in pulverization technique. The pulverization technique was more efficacious in detecting viable bacteria. Furthermore, this technique showed that 1.3% NaOCl/MTAD regimen was more effective in disinfecting root canals.
    This laboratory study evaluated an experimental 1-second initial partial polymerization (IPP) technique using Fuji II LC vs the manufacturer's standard placement (control), both with and without Fuji Coat, relative to... more
    This laboratory study evaluated an experimental 1-second initial partial polymerization (IPP) technique using Fuji II LC vs the manufacturer's standard placement (control), both with and without Fuji Coat, relative to microleakage. Class V restorative preparations were placed on the buccal and lingual aspects of 30 permanent, caries-free and restoration-free, third molar teeth. Fuji II LC restorations were placed either following manufacturer-specified guidelines or IPP for 1 second prior to contouring and full light curing. Half of the restorations were placed using the IPP experimental technique and half of the teeth were finished using Fuji Coat LC. Following thermocycling, specimens were sectioned and dye penetration was measured. SPSS 16 was used for statistical analysis (p<0.05). Mean microleakage results: experimental/varnish (0.08 ± 0.15 mm), control/varnish (0.17 ± 0.35 mm), experimental/nonvarnish (0.33 ± 0.33 mm), and control/nonvarnish (0.58 ± 0.47 mm). Univariate analysis of variance demonstrated significantly less microleakage for the experimental technique (p<0.001), use of finishing varnish (p<0.001), and the combination of experimental/varnish (p=0.013). The initial partial polymerization technique of Fuji II LC placement significantly reduces microleakage. Fuji Coat LC results in further diminished microleakage.
    The authors conducted a study to determine concentrations of fluoride in infant formulas, and to estimate fluoride intake in infants consuming predominantly formula. The authors compared estimated fluoride ingestion with the tolerable... more
    The authors conducted a study to determine concentrations of fluoride in infant formulas, and to estimate fluoride intake in infants consuming predominantly formula. The authors compared estimated fluoride ingestion with the tolerable upper limit and adequate intake level for fluoride recommended by the Institute of Medicine (IOM). The authors analyzed fluoride concentrations of powdered and liquid formula concentrates and ready-to-feed formulas. They estimated the total fluoride ingested by infants by considering the fluoride content measured in both the infant formula and various concentrations of fluoridated water. They based consumption volumes on published recommendations. The authors compared estimates for fluoride ingestion with the upper tolerable limit and adequate intake level, which they calculated by using published infant growth charts. Fluoride concentrations of the different formulas were low and, if reconstituted with low-fluoride water, would not result in ingestion of fluoride at levels exceeding the IOM's upper tolerable limit. Some infants aged between birth and 6 months who consume powdered and liquid concentrate formulas reconstituted with water containing 1.0 part per million fluoride likely will exceed the upper tolerable limit of fluoride. When powdered or liquid concentrate infant formulas are the primary source of nutrition, some infants are likely to exceed the recommended fluoride upper limit if the formula is reconstituted with water containing 1.0 ppm fluoride. On the other hand, when the fluoride concentration in water used to reconstitute infant formulas is below 0.4 ppm, it is likely that infants between 6 and 12 months of age will be exposed to fluoride at levels below IOM's recommended adequate intake level.
    Abstract AbstractThe objective of this ex vivo cadaver study was to determine the accuracy of cone beam computed tomography(CBCT) and 3D stereolithographic(STL) model in identifying and measuring the anterior loop length(ANLL) of the... more
    Abstract AbstractThe objective of this ex vivo cadaver study was to determine the accuracy of cone beam computed tomography(CBCT) and 3D stereolithographic(STL) model in identifying and measuring the anterior loop length(ANLL) of the mental nerve. A total of 12 cadavers (24 mental nerve plexus) were used for this study. Standardized CBCT scans of each mandible were obtained both with and without radiographic contrast tracer injected into the mental nerve plexus. STL models of the two acquired CBCT images were made. ANLL were measured using CBCT, STL and anatomy. The measurements obtained from the CBCT images and STL models were then analyzed and compared with the direct anatomic measurements. Paired sample t-test was used. P values less than .05 was considered statistically significant. The mean difference between CBCT and anatomic measurement was 0.04mm and not statistically significant (p= .332) while the mean difference between STL and anatomic measurement was 0.4mm and statistically significant (p=.042). There was also a statistical significant difference between CBCT and STL (p=.048) with the mean difference of 0.35mm. Therefore, CBCT is an accurate and reliable method in determining and measuring the ANLL while the STL over or underestimated the ANLL by as much as 1.51mm and 1.83mm respectively.
    The objective of this ex vivo cadaver study was to determine the accuracy of cone beam computerized tomography (CBCT) and a 3-dimensional stereolithographic (STL) model in identifying and measuring the anterior loop length (ANLL) of the... more
    The objective of this ex vivo cadaver study was to determine the accuracy of cone beam computerized tomography (CBCT) and a 3-dimensional stereolithographic (STL) model in identifying and measuring the anterior loop length (ANLL) of the mental nerve. A total of 12 cadavers (24 mental nerve plexus) were used for this study. Standardized CBCT scans of each mandible were obtained both with and without radiographic contrast tracer injected into the mental nerve plexus, and STL models of the two acquired CBCT images were made. The ANLL were measured using CBCT, STL model, and anatomy. The measurements obtained from the CBCT images and STL models were then analyzed and compared with the direct anatomic measurements. A paired sample t test was used, and P values less than .05 were considered statistically significant. The mean difference between CBCT and anatomic measurement was 0.04 mm and was not statistically significant (P = .332), whereas the mean difference between STL models and anatomic measurement was 0.4 mm and was statistically significant (P = .042). There was also a statistical significant difference between CBCT and the STL model (P = .048) with the mean difference of 0.35 mm. Therefore, CBCT is an accurate and reliable method in determining and measuring the ANLL but the STL model over- or underestimated the ANLL by as much as 1.51 mm and 1.83 mm, respectively.
    The purpose of this study was to determine if crimping the lingual aspect of commercially available, preveneered, anterior stainless steel primary crowns affects the fracture resistance of the veneer facings. Twenty-six anterior NuSmile... more
    The purpose of this study was to determine if crimping the lingual aspect of commercially available, preveneered, anterior stainless steel primary crowns affects the fracture resistance of the veneer facings. Twenty-six anterior NuSmile crowns (size A1) were divided into 2 groups: group 1 served as the control, and group 2 was manually crimped evenly on the lingual cervical portion. All crowns were cemented onto a screw-mounted resin core duplicated from a manually prepared Kilgore tooth and tested under compression. Recorded were fracture resistance, percent of veneer facing loss, and fracture to the gingival margin. Differences between the control and experimental groups were analyzed by independent t test and chi-square (alpha=0.05). The mean shear force required to fracture the veneers of the noncrimped crowns was 510.11 N (+/-79.66 SD), and 511.02 N (+/-62.37) for the crimped crowns. The mean percentage of veneer facing removed in the noncrimped crowns was 33% (+/-12.18), and 4...