Evaluating Streptococcus mutans Colonization on 3D-Printed, Milled, and Conventional Acrylic Resin Materials: An In Vitro Study.

Purpose: To compare surface roughness and bacterial colonization of Streptococcus mutans to 3D printed (3DP), milled (M), and conventional (CV) acrylic resin. Methods: Thirty-six discs (n equals 12 per group) were fabricated from 3DP, M, and CV materials. One surface of sample was polished (Po); the opposite surface was left unpolished (UPo). Surface roughness (µm) was assessed using a contact profilometer. The specimens were placed in S. mutans suspension and incubated at 37 degrees Celsius overnight. The attached colonies were separated using a sonicator, and the resulting solution was diluted to 10-3 to assess colony-forming units per milliliter (CFU/ml) after 48 hours. The colonies were categorized into a quantitative S. mutans (QS) index. Data were analyzed using one-way ANOVA, chi-squares, and multivariate analysis of variance analysis with the least significant difference (LSD) post-hoc test (P<0.05). Results: Roughness average (Ra) values of CV were higher than 3DP and M for UPo surfaces (P<0.001; 3DP=0.10; M=0.13; CV=0.26 µm, respectively). For Po and UPo surfaces, the CV harbored more S. mutans colonies than M and 3DP (P<0.001; 3DP=5.2x10 6 ; M=4.7x10 6 ; CV=1.49x10 7 CFU/ml, respectively). M group had the lowest range of QS scores, while CV had the highest range (P<0.001). Conclusions: Digitally manufactured material provides smoother surfaces than the conventional group, resulting in fewer Streptococcus mutans colonies. However, all the material groups must still be adequately polished to prevent the colonization of S. mutans, regardless of the manufacturing methods, as higher S. mutans counts were observed with an increase in surface roughness values.

Wear Resistance Comparison of Prefabricated Primary Crowns Using a Novel 3D Computed Tomography Method.

PURPOSE: The purpose of this study was to compare the wear resistance of stainless steel crowns, (SSCs), zirconia crowns (ZRCs), and nanohybrid crowns (NHCs) using a 3D tomography method. METHODS: Prefabricated SSCs, ZRCs, and NHCs (n equals 80) were worn for 400,000 cycles, equivalent to three years of simulated clinical wear, at 50 N and 1.2 Hz using the Leinfelder-Suzuki wear tester. Wear volume, maximum wear depth, and wear surface area were computed using a 3D superimposition method and 2D imaging software. Data were statistically analyzed using one-way analysis of variance with the least significant difference post hoc test (P<0.05). RESULTS: After a wear simulation of three years, NHCs had a 45 percent failure rate; NHCs also had the greatest wear volume loss (0.71 mm³), maximum wear depth (0.22 mm), and wear surface area (4.45 mm²). SSCs (0.23 mm³ , 0.12 mm, 2.63 mm²) and ZRCs (0.03 mm³ , 0.08 mm, 0.20 mm ²) had less wear volume, area, and depth (P<0.001). ZRCs were the most abrasive to their antagonists (P<0.001). The NHC (against SSC wearing group) had the greatest total wear facet surface area (4.43 mm²). CONCLUSIONS: Stainless steel crowns and zirconia crowns were the most wear-resistant materials. Based on these laboratory findings, in the primary dentition, nanohybrid crowns are not recommended as long-term restorations beyond 12 months (P=0.001).

A MicroCT Study on Mineral Change over Time Associated with Demineralisation in Primary Teeth.

OBJECTIVE: To evaluate the change in demineralisation depth (DD)and mineral density (MD) over time in primary teeth exposed to a demineralisation protocol with microcomputed tomography (microCT). METHODS: Caries lesions were artificially induced on the labial surfaces of 9 primary incisors by way of a demineralisation protocol using 0.1 M lactic acid with 10% methylcellulose gel for 7 and 14 days. The specimens were scanned with microCT and CTAn software (Bruker, Billerica, MA, USA) was used to analyse the changes in DD and MD. Statistical analyses were performed using SPSS software (IBM, Armonk, NY, USA). Repeated analysis of variance (ANOVA) test and Pearson bivariate correlation were used and the level of significance was set at P < 0.05. RESULTS: The DD ranged from 0.00 to 0.99 µm (mean ± standard deviation [SD] 0.70 ± 0.43 µm) at baseline, 11.18 to 29.5 µm (18.15 ± 5.23 µm) at 7 days and 18.00 to 55.30 µm (34.20 ± 8.70 µm) at 14 days. The MD for all specimens (n = 9) ranged from 1.48 to 1.76 g/cm3 (1.65 ± 0.08 g/cm3) at baseline, from 1.47 to 1.74 g/cm3 (1.62 ± 0.08 g/cm3) at 7 days demineralisation and 1.33 to 1.72 g/cm3 (1.54 ± 0.13 g/cm3) at 14 days. There were statistically significant differences in DD (P < 0.001) and MD (P = 0.016) between different durations of demineralisation. CONCLUSION: DD and MD change with time after being exposed to demineralising solution. MicroCT is a nondestructive method that allows repeated MD evaluations of the same sample.

Comparison of the Masking Ability and Translucency of Different Tooth-Colored Restorative Materials.

PURPOSE: The purpose of this study was to evaluate the masking of simulated silver diamine fluoride (SDF) carious tooth discoloration using tooth-colored restorative materials. METHODS: Eighty disc specimens (N equals 10 disc specimens per group) were prepared using pink opaquer (PO), pink opaquer with composite resin (DUAL), opaque-shade composite resin (OSC), and resin-modified glass ionomer (RMGI) of one-mm and two-mm thicknesses. Three backgrounds were prepared: white, dark dentin shade (C4D), and black tile. Vita Easyshade® spectrophotometer was used to determine the color values of each disc specimen against each background. Color difference (E) and translucency parameter (TP) were analyzed. RESULTS: There was a significant difference in material masking black background (one-way analysis of variance; P<0.001) in the following order: PO (TP 5.47) and DUAL (TP 3.89) are similar in masking ability but much higher than RMGI (TP 11.03) and OSC (TP 17.81). For masking the dark background, the result was similar. The material thickness makes a significant difference in color masking, with two mm superior to one mm for all four tooth-colored materials (multivariate analysis of variance; P<0.001). Both PO and DUAL two mm were clinically acceptable in masking dark and black backgrounds (E less than 2.7). CONCLUSION: Pink opaquer and pink opaquer with composite resin restorative materials were found to be the best masking materials for simulated silver diamine fluoride-arrested carious lesions.

Comparison of Different Clinical Decision Support Tools in Aiding Dental and Medical Professionals in Managing Primary Dentition Traumatic Injuries.

BACKGROUND: Many patients are taken to the emergency room for dental trauma treatment, but studies reveal that medical professionals do not feel confident in diagnosing and treating children with traumatic dental injuries. The purpose of this study was to determine if a clinical decision support tool (CDST) would improve dental trauma knowledge of primary teeth in medical students and pediatric dentists. Another purpose was assessing effectiveness of print and mobile app CDSTs. METHODS: Medical students (n = 100) and pediatric dentists (n = 49) were given a pretest to assess baseline dental trauma knowledge. All subjects were randomly assigned to 1 of 3 groups for the posttest: no CDST, print CDST, and mobile app CDST. Test scores and total time spent on each test were recorded and analyzed. RESULTS: Compared with medical students, pediatric dentists scored significantly higher in both pretest (8.57 ± 0.96 vs 4.20 ± 1.58; P < 0.001) and posttest (8.37 ± 1.09 vs 4.96 ± 1.99; P < 0.001). There was no significant difference in time spent to complete the 2 tests between both groups. Medical students and pediatric dentists who utilized the mobile app CDST had scored highest (P = 0.028) but took the longest time (P < 0.001) on the posttest. CONCLUSIONS: Both print and mobile app CDSTs improved diagnosing and managing traumatic dental injuries in primary dentition significantly compared with those without aid. Medical students with CDSTs showed significant improvement in managing primary dental trauma; therefore, it is recommended for better, more accurate diagnosis and treatment in patients.

Incisor liability and its effects among East Asian children.

BACKGROUND/PURPOSE: Incisor liability is the discrepancy in the sum of the mesiodistal crown width between the primary and permanent incisors. Incisor liability affects the integrity and eruption of the permanent incisors during the transition from the primary to permanent dentition. This study investigated the incisor liability in the primary dentition of Taiwanese children. METHODS: The digital periapical films of 203 upper arches of 105 boys and 98 girls and 195 lower arches of 119 boys and 76 girls aged between 3 and 6 years were selected in this retrospective study. The mesiodistal crown widths of the primary and permanent incisors were measured using the medical imaging software for both arches. Differences in incisor liability values were statistically analyzed. RESULTS: The mean ± standard deviation of the incisor liability values were 8.32 ± 1.88 and 6.91 ± 1.13 mm for the upper and lower arches, respectively, in all children. The incisor liability was closely related with the total crown widths of the permanent incisors for upper and lower arches. The incisor liability values were higher among boys than girls for the upper but not lower arch. CONCLUSION: Incisor liability differs depending on ethnicity. In Taiwanese children, incisor liability was closely related with the crown widths of the permanent incisors. The incisor liability values of boys were higher than those of girls in the upper arch but not the lower arch.

Using the Timmer Scale to Standardize Pediatric Dentistry Residents' Scientific Appraisal Skills.

Introduction: There is no consensus on the best methodology to apply evidence-based practice principles to develop a systematic approach to improve critical appraisal or research design evaluation skills in advanced education journal clubs. Methods: We implemented a tool-based approach for our pediatric dentistry residents' journal club centered on the use of a study quality assessment tool, the Timmer scale. The tool consisted of 19 standard questions that evaluated the research methodology, data collection, statistical analysis, and reporting of the findings of each article. Learners first underwent a 4-hour training session on study quality assessment. They were then assigned to read articles from monthly issues of core journals and appraised the quality of each article using the Timmer scale and submitted their scores in advance of the group session. Then, during a 1-hour journal club, the group came to a consensus on the Timmer scale score, and group and individual scores were compared to the course director's scores as prompts for feedback and further discussion. Results: Over 3 years, 24 pediatric dentistry residents participated in the course. A noticeable improvement in the pediatric dentistry residents' performance was noticed, with the discrepancy between their scores and group scores improving over time. Discussion: Using a quality assessment tool in journal clubs appeared to improve the residents' ability to critically assess articles in a systematic way. Additionally, the tool was useful for assessing residents' performance over time.

An Investigation of the Long and Short Term Behavioral Effects of General Anesthesia on Pediatric Dental Patients With Autism.

Purpose: The purpose of this study was to compare the incidence of short and long term adverse behavioral effects of general anesthesia (GA) in healthy vs. moderate to severe autistic (ASD) children. Methods: Forty healthy and 37 ASD children, aged 3-17 years, undergoing GA for dental surgery participated in this study. Their anesthesia records were reviewed, and their parents answered telephone surveys to assess activity level, sleep disturbances, gastrointestinal disturbances, central nervous system effects, and respiratory depression. Three follow-up surveys were taken 8 h, 24 h, and 3 months post-surgery. Results: Four hundred fifty-five incidences of adverse behavioral effects occurred within 8 h post-surgery. Significantly more ASD patients had difficulty walking (P = 0.016) and nausea (P = 0.030), while more healthy children snored in the car ride home (P = 0.036) and talked about the dental surgery (P = 0.027). Three months post-discharge, sixASD patients acted in a way that concerned caregivers compared to 0 healthy patients, (P = 0.008). Incidence of adverse behavioral effects significantly decreased from 8 to 24 h overall. Conclusions: Most behavioral effects occur within 8 h post-surgery. There are potential long term adverse behavioral effects in ASD children from GA, but the chance is low and generally not long lasting.

Comparison of Microbial Activity Among Infants With or Without Using Presurgical Nasoalveolar Molding Appliance.

PURPOSE: The aim of the current study is as follows: (1) to study whether wearing the presurgical nasoalveolar molding appliance (PNAM) had facilitated the establishment of Streptococcus mutans and Lactobacillus (LB) and to determine other factors including pH and caries susceptibility associated with wearing the PNAM. METHODS: Saliva samples of 61 infants (4.5 ± 2.06 months old) were collected from the following 3 groups: PNAM (n = 23), healthy (n = 30), and cleft lip and palate (CLP) without any treatment (n = 8). Saliva samples were assessed using selective agar to enumerate total LB and S mutans and subjected to adenosine triphosphate (ATP)-driven bioluminescence determinations using a luciferin-based assay system, and pH level was evaluated. One-way analysis of variance with least significant difference post hoc test (P < .05) and Pearson correlation were used to evaluate S mutans, LB, pH, and ATP levels. RESULTS: A total of 63 patients (30 healthy patients, 23 patients with cleft lip/palate who had PNAM appliance and 8 patients with cleft lip/palate who did not use the appliance) were seen in this study. There is a significant difference in pH (P = .012), LB Caries Risk Test (P < .001), LB colony count (P < .001), S mutans Caries Risk Test (P < .001), and S mutans colony count (P < .001) among the 3 groups (PNAM > CLP > healthy). The ATP level was not significantly different among the 3 groups. CONCLUSION: Higher bacterial count and lower pH were found in the PNAM group. Cleft lip and/or palate patients wearing the PNAM appliance are at higher risk for dental caries.

Dens evaginatus: Current treatment options.

BACKGROUND: Teeth with dens evaginatus (DE) are more commonly observed in Western countries than previously. This is due to the increase in populations of patients of Asian origin, in whom DE is more common than in people of European origin. The interest in DE has also increased with the introduction of a procedure called regenerative endodontics. CASE DESCRIPTION: A narrative review of treatment options for teeth with DE is presented, based on pulpal conditions and maturity of the teeth. PRACTICAL IMPLICATIONS: Early recognition of teeth with DE allows for treatment choices that generally lead to good outcomes and can aid in preserving developing teeth in young patients.

Evaluating the re-identification risk of a clinical study report anonymized under EMA Policy 0070 and Health Canada Regulations.

BACKGROUND: Regulatory agencies, such as the European Medicines Agency and Health Canada, are requiring the public sharing of clinical trial reports that are used to make drug approval decisions. Both agencies have provided guidance for the quantitative anonymization of these clinical reports before they are shared. There is limited empirical information on the effectiveness of this approach in protecting patient privacy for clinical trial data. METHODS: In this paper we empirically test the hypothesis that when these guidelines are implemented in practice, they provide adequate privacy protection to patients. An anonymized clinical study report for a trial on a non-steroidal anti-inflammatory drug that is sold as a prescription eye drop was subjected to re-identification. The target was 500 patients in the USA. Only suspected matches to real identities were reported. RESULTS: Six suspected matches with low confidence scores were identified. Each suspected match took 24.2 h of effort. Social media and death records provided the most useful information for getting the suspected matches. CONCLUSIONS: These results suggest that the anonymization guidance from these agencies can provide adequate privacy protection for patients, and the modes of attack can inform further refinements of the methodologies they recommend in their guidance for manufacturers.

Effect of Crown Preparation Height on Retention of a Prefabricated Primary Posterior Zirconia Crown.

Purpose: The purpose of this study was to evaluate the retention strength of prefabricated zirconia crowns for primary teeth with various crown preparation heights. Methods: Seventy-five extracted human teeth were prepared to have remaining occluso-cervical heights (OCH) of one mm, two mm, three mm, and four mm. Prefabricated posterior zirconia crowns (EZCrown) were cemented with glass ionomer cement. All groups were thermocycled, except for the nonthermocycled control group, which had three mm OCH. Instron E3000 was used for the pullout test. One-way analysis of variance (ANOVA) with Least Significant Difference post hoc test (P<0.05) were performed. Results: The means for the one-mm, two-mm, three-mm, and four-mm thermocycled groups were 1.7±1.0 MPa, 2.9±1.4 MPa, 3.1±0.7 MPa, and 3.3.0±0.6 MPa, respectively. The mean for the nonthermocycled control three-mm group was 2.7±0.8MPa. A significant difference in retention within the four thermocycled groups was observed (one-way ANOVA, P<0.001). Conclusions: The zirconia crown retention force is closely related to occluso-cervical heights. Two millimeters OCH is crucial for prefabricated zirconia crown retention. (Pediatr Dent 2019;41(3):229-33) Received November 14, 2018 | Last Revision February 25, 2019 | Accepted March 5, 2019.

Pharmacologic management for pediatric dental patients in the 21st century.

Most children are able to cooperate during conventional, in-office dental treatment using traditional, communicative behavior guidance techniques that are carefully selected and applied to the developmental needs of a particular child. Children who are unable to cooperate during conventional treatment due to a lack of psychological or emotional maturity and/or the existence of a mental, physical, or medical disability may require pharmacologic techniques such as procedural sedation or general anesthesia to complete rehabilitative dental treatment. Patient safety dictates that careful preparation and robust case selection processes guide clinical decision-making related to pharmacologic behavior guidance. Before using these techniques, the sedation provider must demonstrate an adequate understanding of these techniques, from definitions and best practices to case selection and patient safety. This article presents essential information-with an emphasis on best practices and patient safety-for dentists who are considering pharmacologic behavior guidance for the children they treat.

Early Childhood Caries-Related Knowledge, Attitude, and Practice: Discordance between Pediatricians and Dentists toward Medical Office-Based Prevention in Taiwan.

The aim of this study was to assess the knowledge, attitude, and practice regarding early childhood caries (ECC) prevention and implementation of medical setting-based caries prevention among pediatricians and dentists in Taiwan. Data were collected from currently practicing pediatricians and general and pediatric dentists using self-administered questionnaires. A total of 301 questionnaires were completed by the pediatricians (n = 105), general dentists (n = 117), and pediatric dentists (n = 79). The pediatric dentists obtained significantly higher knowledge and practice scores than the general dentists and pediatricians (p < 0.0001). The pediatricians' attitude score related to engaging physicians in medical office-based caries prevention was significantly higher than the attitude scores of the general and pediatric dentists (p < 0.05). A Spearman rank correlation analysis indicated a significant positive correlation between knowledge and practice among the general dentists (rs = 0.271, p < 0.01) and pediatricians (rs = 0.262, p < 0.01). The correlation between knowledge and attitude among the pediatricians was significantly positive (rs = 0.242, p < 0.05). Attitude and practice among the pediatricians were significantly positively correlated (rs = 0.271, p < 0.01). Pediatricians lacked ECC-related knowledge; however, they had a more positive attitude toward medical office-based prevention when they had a higher level of knowledge. Oral health-related education for pediatricians is necessary if such medical office-based caries prevention programs are to be implemented in Taiwan.

Use of a clinical decision support tool for the management of traumatic dental injuries in the primary dentition by novice and expert clinicians.

BACKGROUND/AIM: Studies reveal many dental students and general dentists have inadequate knowledge about treating children who sustain traumatic dental injuries. The aims of this study were to assess dental trauma knowledge among novice clinicians and expert pediatric dentists and determine the effectiveness of a clinical decision support tool (CDST) for the management of trauma scenarios. A secondary purpose was to compare the effects of a print and mobile app format of the CDST. METHODS: A print and mobile app CDST was developed based upon current AAPD and IADT clinical guidelines. Baseline knowledge for dental students (n = 84) and pediatric dentists (n = 60) was assessed using a multiple-choice Pre-test. A Post-test was used to evaluate changes in the knowledge level following the random assignment of participants into 3 groups: Group A (control) had no CDST provided; Group B (print CDST) had access to the print paper pamphlet; and Group C (mobile app CDST) had access to the mobile app on a handheld device for use during the Post-test. Test scores and time required to complete each test were recorded. RESULTS: Pediatric dentists scored significantly higher and required less time on both the Pre-test (P < .001) and Post-test (P < .05) compared to dental students. Dental students and pediatric dentists who had access to the mobile app CDST scored significantly higher (P < .05) in the Post-test compared to the control and the print CDST groups. Post-test time for the dental students in the mobile app group was significantly longer (P < .001) compared to the control and print format. CONCLUSION: Expert pediatric dentists demonstrated greater knowledge of dental trauma compared to novice clinicians. The mobile app clinical decision support tool was a more effective means of improving the diagnosis and management of traumatic dental injuries by both dental students and pediatric dentists than the print CDST.

Changes of Surface Properties of Composite Preveneered Stainless Steel Crowns After Prophy Polishing to Remove Stains.

PURPOSE: The purpose of this study was to assess the effect of fine-, medium-, and coarse-grit prophy paste used to polish grape juice-stained preveneered stainless steel crowns (PvSSCs). METHODS: Forty-five maxillary central incisor PvSSCs were immersed in grape juice for 30 days and randomly assigned to three groups (n equals 15) using fine-, medium-, and coarse-grit prophy paste for polishing. Color measurement (L*a*b*), surface roughness (Ra), and scanning electron microscopy imaging were performed at prestain, poststain, and postpolish periods. The significance level was P<.05. RESULTS: From prestain to poststain, the change in color (ΔE) was 5.4; poststain to postpolish it was 4.7. The overall ΔE value from prestain to postpolish was 1.7, meaning that there was no overall perceivable color change. There was no significant color difference among the three grit groups. The Ra value of prestain (0.047 µm) and poststain (0.050 µm) were significantly lower than postpolish (0.209 µm; P<.001). After polishing, the mean Ra value of the fine-grit polish was 0.164 µm; for the medium-grit polish, it was 0.229 µm; and for the coarse-grit polish, it was 0.232 µm. CONCLUSION: The composite facings were susceptible to grape juice stains, and all three grit prophy pastes removed stains equally effectively. A fine-grit prophy paste is preferred over medium- and coarse-grit to minimize the amount of surface roughness change.

Cytotoxicity and Antimicrobial Effects of a New Fast-Set MTA.

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 antimicrobial test demonstrated no inhibitory effect of FS-MTA or RS-MTA on any bacterial species after 24 and 48 hours. Conclusions. There was no cytotoxicity or bacterial inhibition observed by the new Fast-Set MTA when compared to the ProRoot MTA after setting.

Pre-Eruptive Intracoronal Resorption (PEIR): Literature Review and Case Report.

Pre-eruptive intracoronal resorption (PEIR) are lesions that are often located in the occlusal portion of the crown in unerupted teeth. The etiology and pathology of these lesions remain unclear and most go undetected until later stages of development. Prognosis is dependent on early detection, and conservative treatment is recommended. This report reviews the etiology, prevalence, diagnosis and treatment of PEIR and describes a case of a permanent second molar with PEIR diagnosed in an 11-year-old patient.