Effect of motivational interviewing on preventive strategies for children receiving full-mouth dental rehabilitation under general anesthesia: A randomized controlled trial.

BACKGROUND: Motivational interviewing (MI) is an approach to increase parental compliance to follow up and recall of their children. It has proven to be successful in motivating parents to adopt and maintain preventive child oral health behaviors. AIM: To assess the effectiveness of motivational interviewing on prevention strategies for parents of children who have received full-mouth dental rehabilitation under general anesthesia (GA). DESIGN: This is a parallel-arm randomized controlled trial. Parents in the treatment arm were randomized and received a combination of motivational interviewing, individualized goal setting, visual aids, and verbal education post-GA. Those in the control arm received the same information by verbal and written education. Both groups were evaluated at 2-week follow-up and 3-month recall. Differences in attendance, oral health knowledge, readiness to change, and parental self-efficacy (PSE) were compared between groups and at return visits. RESULTS: Of 74 parents of children randomly allocated in this study, 22 (61%) and 13 (38%) from the intervention group, and 21 (55%) and 16 (46%) from the control group attended the 2-week, and 3-month follow-up, respectively. The average PSE for participants in the intervention group was significantly higher than that of the control group at the follow-up visit (p = .0050). CONCLUSION: Readiness to change dietary habits and average PSE for parents in the intervention group were significantly higher than that of the control group after receiving the modified preventive strategy.

Does crown, root, and bone visualization in a clear aligner virtual setup impact treatment decisions?

INTRODUCTION: Clear aligner technology based on a machine learning algorithm is currently available for orthodontic treatment. Treatment planning on the basis of 3-dimensional crown, root, and bone imaging is claimed to provide accurate diagnosis and better treatment outcomes for adult patients with complex needs. This study aimed to answer the following questions: (1) would practitioners modify their original treatment plan once provided with the crown, root, and bone view? and (2) does practitioner satisfaction regarding treatment outcomes change once the crown, root, and bone view is provided? METHODS: An online questionnaire was emailed to members of the American Association of Orthodontists (n = 2300) and the Virginia Orthodontic Education and Research Foundation (n = 211). The survey consisted of videos of 4 patients shown in 2 presentations: crown-only and crown, root, and bone views, generated by artificial intelligence-driven treatment planning software (3D Predict aligner system; 3D Predict, New York, NY). Respondents were asked to answer treatment-related questions and rate the treatment outcomes using a visual analog scale. Statistical analyses were completed to determine the significance of crown, root, and bone view on treatment planning with clear aligners. RESULTS: A total of 70 orthodontists participated in the survey. There were significant differences in responses when viewing patients in crown-only and crown, root, and bone presentations. Across the 4 patients, 33%-43% of practitioners changed their sentiment toward the treatment plan (P <0.001). When rating satisfaction on the 100-point scale, average ratings changed by 10.6 to 21.0 points; both increases and decreases in satisfaction were seen across the patients (P <0.001). CONCLUSIONS: When given 3-dimensional information on the position of a patient's crowns, root, and bone coverage, orthodontists are likely to change their clear aligner treatment plan. This study showed that a confirmation of dehiscence and fenestrations using the root and bone view resulted in practitioner dissatisfaction despite an initial satisfaction with the crown-only view.

Tribochemical silicoating of amalgam promotes effective amalgam-resin repairs.

The purpose of this study was to determine the most effective method for bonding composite resin to artificially aged amalgam. A spherical amalgam alloy was triturated and condensed by hand into cylindrical plastic molds (6 mm in diameter and 4 mm in height) to create 90 specimens, which were then aged for 2 weeks in closed plastic containers at 23°C. The amalgam surfaces underwent 1 of 3 surface treatments (n = 30 per treatment): (1) air particle abrasion (APA) with 50-µm aluminum oxide particles applied with a force of 45 psi from a 10-mm distance, followed by rinsing with deionized water for 60 seconds; (2) APA following the same protocol with subsequent application of a metal primer (Alloy Primer); or (3) coating with 30-µm silica (CoJet) at a force of 45 psi from a 10-mm distance until the surface turned black. Specimens were then treated with 1 of 3 adhesives (n = 10 per adhesive per surface treatment): (1) 2-step total-etch adhesive (OptiBond Solo Plus), (2) 1-step self-etching adhesive (Scotchbond Universal), or (3) dual-cured resin cement (Panavia F 2.0). Each adhesive was applied to the treated amalgam surfaces following its manufacturer's instructions. The specimens were placed in a bonding clamp, and nanocomposite resin columns, 2.38 mm in diameter and 2.00 mm in height, were photocured (40 seconds, 500 mW/cm2) against the treated amalgam surfaces. The specimens were stored for 24 hours in 37°C deionized water and underwent shear bond strength testing at a crosshead speed of 0.5 mm/min. Data were analyzed using 2-way analysis of variance and post hoc analysis with the Tukey test at 95% confidence. The mean (SD) shear bond strength values ranged from 12.3 (1.2) MPa for aluminum oxide-treated surfaces bonded with OptiBond Solo Plus to 25.9 (4.6) MPa for silicoated surfaces bonded with Panavia F 2.0. All bonding agents produced the highest shear bond strength when the amalgam surface was silicoated. These results indicate that composite can be effectively bonded to amalgam via silicoating.

Selective BET inhibitor RVX-208 ameliorates periodontal inflammation and bone loss.

AIM: To determine the effects of RVX-208, a selective bromodomain and extra-terminal domain (BET) inhibitor targeting bromodomain 2 (BD2), on periodontal inflammation and bone loss. MATERIALS AND METHODS: Macrophage-like cells (RAW264.7) and human gingival epithelial cells were challenged by Porphyromonas gingivalis (Pg) with or without RVX-208. Inflammatory gene expression and cytokine production were measured by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. RAW264.7 cells were induced to osteoclast differentiation. After RVX-208 treatment, osteoclast differentiation was evaluated by histology, tartrate-resistant-acid-phosphatase (TRAP) activity and the expression of osteoclast-specific genes. The effect of RVX-208 on osteoclast transcriptome was studied by RNA sequencing. Periodontitis was induced in rats by ligature and local RVX-208 treatment was administered every other day. Alveolar bone loss was measured by micro-computed tomography. RESULTS: RVX-208 inhibited inflammatory gene expression and cytokine production in Pg-infected cells. Osteoclast differentiation was inhibited by RVX-208, as evidenced by reduced osteoclast number, TRAP activity and osteoclast-specific gene expression. RVX-208 displayed a more selective and less profound suppressive impact on transcriptome compared with pan-BET inhibitor, JQ1. RVX-208 administration prevented the alveolar bone loss in vivo. CONCLUSIONS: RVX-208 regulated both upstream (inflammatory cytokine production) and downstream (osteoclast differentiation) events that lead to periodontal tissue destruction, suggesting that it may be a promising 'epi-drug' for the prevention of periodontitis.

Perceived efficacy of extrusion of maxillary lateral incisors with aligners.

INTRODUCTION: This study aimed to assess the perceived efficacy of aligners (Invisalign; Align Technology, Santa Clara, Calif) at performing extrusive movements of maxillary lateral incisors and to evaluate and compare differences in treatment planning protocols and other interventions used when required between orthodontists and general dentists with various degrees of experience. METHODS: An original 18-question survey was sent by mail to a randomized and geographically proportionate selection of orthodontic specialists (N = 400) and general dentists (N = 400) listed as providers on the Invisalign Web site. The data were analyzed using analysis of variance and chi-square tests. RESULTS: One hundred twenty-six providers responded to the survey (15.8% response rate), including 36 general dentists and 90 orthodontists. Overall, the average perceived efficacy was 4.71 out of 10 (95% confidence interval, 4.28-5.14). The threshold for identification of tracking issues was significantly associated with provider type (P = 0.0305). General dentists were significantly more likely to prefer an optimized attachment (P = 0.0001), whereas orthodontists were significantly more likely to prefer a gingivally-beveled horizontal rectangular attachment (P <0.0001). A refinement scan was the most common intervention method, followed by the bootstrap technique. CONCLUSIONS: The average perceived efficacy for extruding maxillary lateral incisors with aligners was 4.71 out of 10. Orthodontists had a lower tolerance than general dentists for tracking issues. A refinement scan was the most common method of intervention. General dentists and orthodontists differed in their treatment planning preferences and timing of intervention.

Adaptations in orthodontics for current and future coronavirus disease 2019 best practices.

INTRODUCTION: This study aimed to determine adaptations orthodontists made during the coronavirus disease 2019 pandemic to maintain safety and determine which adaptations will remain after the pandemic. METHODS: An original 34-question survey was sent by mail to a randomized selection of practicing orthodontic specialists (n = 1000). Questions included the changes made during the pandemic in 4 categories (infection control, social distancing, appliance type, and teleorthodontics) and whether those changes will remain postpandemic. RESULTS: The use of personal protective equipment increased during the pandemic, with a significant decrease anticipated after the pandemic. The most common aerosol modification during the pandemic and predicted after the pandemic was using an assistant with high-volume suction (61% and 49%, respectively; P = 0.0013). Ninety-six percent of orthodontists changed their waiting room protocol during the pandemic, but only 23% plan to continue that practice (P <0.0001). Forty-two percent of orthodontists increased clear aligners during the pandemic in response to patient demand (91%). The use of teleorthodontics increased from 8% to 68% during the pandemic and is expected to decrease significantly postpandemic. Virtual appointments are anticipated to be used for screening and consultations of new patients and monitoring active patients in clear aligners but not fixed appliances. CONCLUSIONS: The specialty recommended patient safety modifications during the coronavirus disease 2019 pandemic. Postpandemic, enhanced personal protective equipment is expected to decrease, and high-volume suction will likely be continued for aerosol-producing procedures. Teleorthodontics will likely remain in limited use.

The effect of crowding on the accuracy of 3-dimensional printing.

INTRODUCTION: The purpose of this study was to evaluate the accuracy of 3-dimensional (3D) printed aligners compared to conventional vacuum-formed thermoplastic aligners with varying levels of dental crowding. METHODS: Digital intraoral scans of 10 cases were assigned to their respective groups (n = 10, each, 30 total) as follows: no crowding (control), moderate crowding, and severe crowding. Digital images of these models were created in standard tessellation language (STL) file format using 3Shape software and randomly 3D printed. The STL files of each case were also sent to a dental laboratory to fabricate vacuum-formed samples, the current technology used for manufacturing aligners. The intaglio surfaces of fabricated aligners in both groups were scanned using cone beam computed tomography to create STL files, which were then compared to the original STL files of the cases using Geomagic Control X software. Absolute deviations from the original file and root mean square values were recorded. A Kruskal-Wallis test was conducted to analyze the difference in average deviation, and a t-test was repeated for the RMS measure. The significance level was set at 0.05. RESULTS: The crowding did not affect the trueness of aligners manufactured using 3D printing or conventional vacuum-forming techniques (P = 0.79). 3D-printed aligners showed less deviation than the vacuum-formed samples (0.1125 mm vs 0.1312 mm; P <0.01). Aligners manufactured with the vacuum-forming technique had significantly higher variation than those with the 3D printing process (P = 0.04). CONCLUSIONS: 3D aligners printed directly from an STL file exhibited better precision and trueness than those fabricated using the conventional vacuum-forming technique. Since accuracy is defined as a combination of precision and trueness, it is concluded that direct printing from an STL file can be used to manufacture aligners.

Clear aligner therapy in the mixed dentition: Indications and practitioner perspectives.

INTRODUCTION: This study evaluated current trends and perspectives among orthodontists regarding clear aligner therapy in the mixed dentition (CAMD), including insights into perceived indications, compliance, oral hygiene, and other factors. METHODS: An original, 22-item survey was mailed to a randomized, nationally representative sample of practicing orthodontists (n = 800) and a specific, randomized subsample of high-aligner-prescribing orthodontists (n = 200). Questions assessed respondents' demographic information, experience with clear aligner therapy, and perceived advantages and disadvantages of CAMD compared with fixed appliances (FAs). Responses were compared using McNemar's chi-square and paired t tests to assess CAMD vs FAs. RESULTS: One thousand orthodontists were surveyed, and 181 (18.1%) responded over 12 weeks. CAMD use was less common than mixed dentition FAs, but most respondents predicted an increase in their future CAMD use (57.9%). Among respondents using CAMD, the number of patients with mixed dentition treated with clear aligners was significantly lower than the number of total patients with clear aligners (23.7% vs 43.8%; P <0.0001). Fewer respondents considered skeletal expansion, growth modification, sagittal correction, and habit cessation feasible indications for CAMD compared with FAs (P <0.0001). Perceived compliance was similar for CAMD and FAs (P = 0.5841), but perceived oral hygiene was significantly better with CAMD (P <0.0001). CONCLUSIONS: CAMD is an increasingly common treatment modality for children. Most surveyed orthodontists reported limited indications for CAMD compared with FAs but perceived noticeable benefits for oral hygiene with CAMD.

Effect of clear aligner attachment design on extrusion of maxillary lateral incisors: A multicenter, single-blind randomized clinical trial.

INTRODUCTION: Extrusion of maxillary lateral incisors during aligner treatment is a difficult movement to achieve accurately. Despite recommendations regarding attachment design, few studies and no prospective trials compare predictability among attachments. This study aimed to compare the efficacy between optimized and horizontal attachment designs for achieving maxillary lateral incisor extrusion during clear aligner treatment. METHODS: The study included maxillary lateral incisors in 3 orthodontic practices requiring at least 0.3 mm of extrusion during the first series of 20-25 aligners in patients aged ≥16 years who were scheduled to begin clear aligner treatment (Invisalign; Align Technology, San Jose, Calif). Teeth were randomly assigned to receive optimized (O), rectangular horizontal nonbeveled (H), rectangular horizontal incisally-beveled (HIB), or rectangular horizontal gingivally-beveled (HGB) attachments. After the first series, a blinded evaluator measured extrusion using superimpositions with initial and predicted models. Linear models determined the difference in the predicted extrusion percentage achieved on the basis of attachment design. Other covariates were patient age, sex, number of trays, and self-reported compliance. RESULTS: Forty patients (74 teeth) were enrolled, and 38 patients (71 teeth) completed the study. Intraexaminer and interexaminer reliability for extrusion measurements was high (intraclass correlation coefficient, 0.985 and 0.991, respectively). The achieved extrusion was significantly less than predicted (mean, 73%; P <0.0001). The average achieved extrusion was 62%, 79%, 78%, and 78% for O, H, HIB, and HGB attachments, respectively, with H significantly more effective than O (P = 0.0403). Horizontal attachments (H, HIB, and HGB combined) were significantly more effective than O attachments (P = 0.0060), with an average difference in achieved extrusion of 14% of the predicted amount (95% confidence interval, 4-23; estimated 76% vs 62%). Horizontal attachments were an estimated 22% more effective than O attachments for extruding maxillary lateral incisors. CONCLUSIONS: Horizontal attachments are more effective than O attachments for predicted maxillary lateral incisor extrusion between 0.3 and 2.5 mm. The 3 horizontal attachment designs evaluated performed similarly for achieving predicted extrusion. TRIAL REGISTRATION: This randomized clinical trial was registered and reported at clinicaltrials.gov (NCT04968353). PROTOCOL: The protocol was not published before trial commencement. FUNDING: This study was funded in part by the Alexander Fellowship of the Virginia Commonwealth University School of Dentistry, the Southern Association of Orthodontists, and the Virginia Orthodontic Education and Research Foundation. No funding source influenced the study design, the collection, analysis or interpretation of data, writing of the report, or the decision to submit the article for publication.

The In Vitro Effect of Laser Irradiation (Er:YAG and CO2) and Chemical Reagents (Hydrogen Peroxide, Sodium Hypochlorite, Chlorhexidine, or Sodium Fluoride) Alone or in Combination on Reducing Root Caries Bacteria.

(1) Lasers have been used for the treatment of dentinal hypersensitivity and bacterial reductions in periodontology. The purpose of this in vitro study was to evaluate the effect of Carbon Dioxide (CO2) and Erbium-doped Yttrium Aluminum Garnet (Er:YAG) lasers with chlorhexidine (CHX), hydrogen peroxide (H2O2), sodium hypochlorite (NaOCl), or sodium fluoride (NaF) on the viability of oral bacteria associated with root caries. (2) Streptococcus mutans, Streptococcus sanguinis, and Enterococcus faecalis were grown in Brain Heart Infusion (BHI) broth, diluted to an OD660 of 0.5, and treated with antiseptics with or without simultaneous irradiation with the Er:YAG and CO2 lasers for 30 s repeated three times. The treatment groups consisted of 1: no treatment, 2: 0.5% H2O2 alone, 3: 0.5% NaOCl alone, 4: 0.12% CHX alone, 5: 2% NaF alone, 6: laser alone, 7: laser with 0.5% H2O2, 8: laser with 0.5% NaOCl, 9: laser with 0.12% CHX, and 10: laser with 2% NaF for both lasers. The microbial viability was determined through plating and viable colonies were counted, converted into CFU/mL, and transformed into log form. The statistical analysis was performed using a two-tailed paired t-test. (3) The use of CO2 and Er:YAG lasers alone failed to show statistically significant antibacterial activity against any of the bacteria. The only effective monotreatment was CHX for S. mutans. The combined treatment of 0.5% NaOCl with Er:YAG produced the greatest reduction in overall viability. (4) The combination of the Er:YAG laser with 0.5% NaOCl resulted in the largest reduction in bacterial survival when compared to monotherapies with antimicrobial solutions or lasers.

Effect of print angulation on the accuracy and precision of 3D-printed orthodontic retainers.

INTRODUCTION: The study aimed to (1) compare the accuracy and precision of 3-dimensional (3D) printed retainers at various angulations and (2) evaluate the effect of angulation on printing time and the amount of resin consumed. METHODS: Using a stereolithography 3D printer, 60 clear retainers were printed at 5 angulations (n = 12, each): 15°, 30°, 45°, 60°, and 90°. Samples for each group were randomly printed in a batch of 6 retainers at all print angulations as print 1 and print 2 cycles. Digital images of the original and printed samples were superimposed. Discrepancies on 8 landmarks were measured by 2 independent examiners, and 0.25 mm was set as the clinically acceptable threshold to determine the accuracy of the retainers. RESULTS: Deviations ranged from 0.074 mm to 0.225 mm from the reference retainer at the cusp tips and incisal edges at all angulations, falling within the threshold of clinical acceptance. However, smooth surface measurements with deviations up to 0.480 mm were deemed clinically not acceptable. Three-dimensional printing at 15° was estimated to be the most time-efficient, whereas 3D printing at 45° was shown to be the most cost-effective setting. CONCLUSIONS: Three-dimensional printed retainers, using a stereolithography printer, were found to be accurate within 0.25 mm at all print angulations at the cusp tips and incisal edges compared with the digital reference file. Smooth facial surfaces did not meet clinical acceptability. Print angulations were shown to affect the cost and amount of resin used.

Comparison of Accuracy and Time for Four Implant Placement Techniques Supporting Fixed-Partial Denture.

Various guiding methods are used to place implants. This ex vivo pilot study used a convenience sample to examine time and accuracy for placement of 2 dental implants supporting a 3-unit fixed prosthesis on a simulation model using freehand and 3 guided placement techniques. Four operators with no prior implant placement experiences were randomly assigned placement of 2 maxillary or mandibular implants for a fixed prosthesis. Techniques included dynamic navigation (DN), static guide (SG), template-based guide (TBG), and freehand placement (FH). Preoperative and operative times were recorded. Discrepancies between the planned and placed implant positions were assessed by superimposing preoperative and postoperative cone beam computerized tomography scans. Data were analyzed with repeated-measures regression with Tukey's adjusted pairwise comparisons (α = 0.05). Dynamic navigation was associated with the longest operative time (13.5 minutes vs 5-10.2, P = .0001) but overall fastest when incorporating preoperative time (32.1 minutes vs 143-181.5, P < .0001). All deviation measures were significantly associated with the placement method (P < .05) except apex vertical deviation (P = .3925). Implants placed by SG had significantly lower entry 2-dimensional deviation than the other methods, particularly on the mandible. The DN and SG methods had significantly lower Apex 3D and overall angle deviations, again particularly on the mandible. The mandible had significantly higher deviations than maxilla. Within limitations of this study, implant placement by novice operators is more accurate when using dynamic and static guidance compared to freehand and template-based techniques.

In Vitro Comparison of Time and Accuracy of Implant Placement Using Trephine and Conventional Drilling Techniques Under Dynamic Navigation.

The aim of this randomized in vitro study was to compare the time and accuracy of implant-site preparation and implant placement using a trephine drill versus a conventional drilling technique under dynamic navigation. In total, 42 implants were placed in simulation jaw models with the 2 drilling techniques by 2 operators who had previous experience with dynamic navigation. The timing of each implant placement was recorded, and horizontal, vertical, and angulation discrepancies between the planned and placed implants were compared. There was no significant difference in time or accuracy between the trephine and conventional drilling techniques. Implant-site preparation with a single trephine drill using dynamic navigation was as accurate under in vitro experimental conditions as a conventional drilling sequence.

Recognition of the Asymmetrical Smile: A Comparison of Orthodontists, Oral and Maxillofacial Surgeons, and Laypersons.

PURPOSE: Studies have shown that an asymmetrical smile is a relatively common problem. Yet, many patients are unaware of having this condition. Because having an asymmetrical smile can affect the final esthetic result of orthodontic therapy or orthognathic surgery, such patients need to be aware of the problem. The purpose of this study was to determine what amount of smile asymmetry is clinically evident to orthodontists, oral and maxillofacial surgeons (OMSs), and the lay public. MATERIALS AND METHODS: A total of 56 OMSs, 117 orthodontists, and 123 laypersons participated in the study. They were asked to view a randomly arranged series of computer-generated male and female facial photographs with the smile symmetrical or altered in 0.5-mm increments from 1 to 4 mm and to indicate whether the person had an asymmetrical smile. RESULTS: The OMSs and orthodontists were able to recognize relatively smaller amounts of asymmetry than the laypersons (2 mm vs 3 to 3.5 mm). CONCLUSIONS: Although the clinicians performed better than the laypersons, both groups were able to recognize relatively small amounts of asymmetry. Because such a condition is generally not correctable and can affect the esthetic result, patients undergoing orthodontic therapy or orthognathic surgery need to be made aware of the situation before treatment.

Accuracy and precision of 3D-printed implant surgical guides with different implant systems: An in vitro study.

STATEMENT OF PROBLEM: Implant guided surgery systems promise implant placement accuracy and precision beyond straightforward nonguided surgery. Recently introduced in-office stereolithography systems allow clinicians to produce implant surgical guides themselves. However, different implant designs and osteotomy preparation protocols may produce accuracy and precision differences among the different implant systems. PURPOSE: The purpose of this in vitro study was to measure the accuracy and precision of 3 implant systems, Tapered Internal implant system (BioHorizons) (BH), NobelReplace Conical (Nobel Biocare) (NB), and Tapered Screw-Vent (Zimmer Biomet) (ZB) when in-office fabricated surgical guides were used. MATERIAL AND METHODS: A cone beam computed tomography (CBCT) data set of an unidentified patient missing a maxillary right central incisor and intraoral scans of the same patient were used as a model. A software program (3Shape Implant Studio) was used to plan the implant treatment with the 3 implant systems. Three implant surgical guides were fabricated by using a 3D printer (Form 2), and 30 casts were printed. A total of 10 implants for each system were placed in the dental casts by using the manufacturer's recommended guided surgery protocols. After implant placement, postoperative CBCT images were made. The CBCT cast and implant images were superimposed onto the treatment-planning image. The implant positions, mesiodistal, labiopalatal, and vertical, as well as implant angulations were measured in the labiolingual and mesiodistal planes. The displacements from the planning in each dimension were recorded. ANOVA with the Tukey adjusted post hoc pairwise comparisons were used to examine the accuracy and precision of the 3 implant systems (α=.05). RESULTS: The overall implant displacements were -0.02 ±0.13 mm mesially (M), 0.07 ±0.14 mm distally (D), 0.43 ±0.57 mm labially (L), and 1.26 ±0.80 mm palatally (P); 1.20 ±3.01 mm vertically in the mesiodistal dimension (VMD); 0.69 ±2.03 mm vertically in the labiopalatal dimension (VLP); 1.69 ±1.02 degrees in mesiodistal angulation (AMD); and 1.56 ±0.92 degrees in labiopalatal angulation (ALP). Statistically significant differences (ANOVA) were found in M (P=.026), P (P=.001), VMD (P=.009), AMD (P=.001), and ALP (P=.001). ZB showed the most displacements in the M and vertical dimensions and the least displacements in the P angulation (P<.05), suggesting statistically significant differences among the M, VMD, VLP, AMD, and ALP. NB had the most M variation. ZB had the least P deviation. NB had the fewest vertical dimension variations but the most angulation variations. CONCLUSIONS: Dimensional and angulation displacements of guided implant systems by in-office 3D-printed fabrication were within clinically acceptable limits: <0.1 mm in M-D, 0.5 to 1 mm in L-P, and 1 to 2 degrees in angulation. However, the vertical displacement can be as much as 2 to 3 mm. Different implant guided surgery systems have strengths and weaknesses as revealed in the dimensional and angulation implant displacements.

Orthodontists' and parents' perception of finished occlusion and willingness to extend treatment time.

INTRODUCTION: Patients and parents want shorter treatment times, but it is unclear whether they would compromise outcome quality to shorten treatment. The purpose of this study was to compare orthodontists' and parents' perceptions of finished occlusion and their willingness to extend treatment time to achieve improved outcomes. The effects of elapsed treatment time and patient compliance were also investigated. METHODS: Parallel surveys for orthodontists (n = 1000) and parents (n = 750) displayed simulated treatment outcomes of well-aligned teeth with occlusions in 1 mm increments from 3 mm Class III to 3 mm Class II. Participants rated their preferences on a visual analogue scale (VAS; 0-100) and specified whether they would extend treatment, and for how long, to improve the occlusion. RESULTS: Two hundred thirty-three orthodontists (23%) and 243 parents (32%) responded. Despite differences between the scores given (P < 0.0001), both groups rated Class I occlusion most acceptable (mean VAS = 93.9 and 80.7, respectively) and 3 mm Class III malocclusion least acceptable (mean VAS = 25.9 and 40.9, respectively). Parents were willing to extend treatment more often and for a greater time than orthodontists to improve results (P < 0.0001). In addition, parents were less willing to terminate treatment early (P < 0.05). Both groups perceived existing outcomes as more acceptable if the patient was noncompliant (P < 0.05), but elapsed time in treatment had no significant effect on ratings. CONCLUSIONS: For outcomes with well-aligned teeth, orthodontists and parents agreed on what the most and least acceptable occlusal relationships were. To achieve better outcomes, parents were willing to extend treatment duration more often and for a greater time than were orthodontists. In addition, parents were less willing than orthodontists to terminate treatment early.

Influence of Tooth Preparation Design and Scan Angulations on the Accuracy of Two Intraoral Digital Scanners: An in Vitro Study Based on 3-Dimensional Comparisons.

PURPOSE: To evaluate the accuracy of two intraoral scanners (IOS) in terms of different preparation designs and scan angulation limitation due to the presence of adjacent teeth. MATERIALS AND METHODS: Eight different complete coverage (CC) and partial coverage (PC) tooth preparations were scanned by two IOS, the 3Shape TRIOS (TRI) and the 3M True Definition (TRU). All teeth preparations were scanned in the presence and absence of adjacent teeth. Four groups were established for each IOS; Group 1: PC preparations with adjacent teeth. Group 2: CC preparations with adjacent teeth. Group 3: PC preparations without adjacent teeth. Group 4: CC preparations without adjacent teeth. 3D analysis was performed to examine average absolute discrepancy (AAD) and maximum absolute discrepancy (MAD). A Two-way ANOVA was performed followed by a post-hoc Tukey's test HSD to evaluate the effect of adjacent teeth, preparation design, and the type of IOS used. RESULTS: For TRI, AAD for groups 1, 2, 3, and 4 were 20 ± 1.8 µm, 19.6 ± 2.4 µm, 15.5 ± 2.7 µm, and 12.9 ± 1.4 µm, respectively, whereas MAD for groups 1, 2, 3, and 4 were 109.7 ± 13.5 µm, 93.2 ± 28.9 µm, 85.6 ± 16.1 µm, and 66 ± 20.1 µm, respectively. For TRU IOS, AAD for groups 1, 2, 3, and 4 were 22.0 ± 3.6 µm, 17.9 ± 2 µm, 20 ± 5.9 µm, and 14.9 ± 1.7 µm, respectively, whereas the MAD for groups 1, 2, 3, and 4 were 151.4 ± 38.4 µm, 92.2 ± 17. µm, 92.6 ± 23.6 µm, and 71.4 ± 11.9 µm, respectively. Two-way ANOVA showed statistically significant differences between the AAD and MAD of TRI and TRU (p < 0.001). There were also statistically significant differences for presence or absence of adjacent teeth (p < 0.001), and preparation design (p < 0.001). CONCLUSIONS: PC preparation scans revealed lower accuracy than CC. The presence of adjacent teeth decreased the accuracy of both IOS. TRI gave higher accuracy than TRU for PC, but both IOS showed comparable accuracy for CC groups.

How Important Are Letters of Recommendation? A Survey of Oral and Maxillofacial Surgery Residency Program Directors.

PURPOSE: Letters of recommendation are currently part of the application process for residencies in oral and maxillofacial surgery. However, the value placed on the information contained in such letters by program directors is unclear. The purpose of this study was to determine what role letters of recommendation play in the decision-making process. MATERIALS AND METHODS: In this cross-sectional study, a questionnaire was sent to 122 current and former program directors asking them to rate the importance they gave to letters of recommendation compared with other application attributes through a visual analog scale that ranged from 0 ("not important") to 100 ("very important"). Respondents also specified the format in which they would prefer recommendations be sent and, if they preferred letters, to state why. Responses were summarized with descriptive statistics (counts and percentages). The average perceived importance of applicant attributes and components of recommendations was compared using random-effects models to adjust for multiple responses from the same respondent. Post hoc pairwise comparisons were performed using Tukey adjustment. RESULTS: Of the 122 questionnaires sent, 14 were not deliverable. Forty-one of the 108 remaining program directors answered, for a response rate of 38%. Only 10% of respondents indicated that they do not consider letters of recommendation. However, they rated class rank, comprehensive basic science score, and leadership qualities more important than letters of recommendation. They preferred letters of recommendation from a faculty member rather than from a dean or non-oral surgeon and favored letters over a standard recommendation form, which they believed provided information not found in supporting documents. CONCLUSIONS: Despite some deficiencies found with letters of recommendation, and the varying importance given to the information they contain, program directors still find that they provide some useful information.

Evaluation of fit for 3D-printed retainers compared with thermoform retainers.

INTRODUCTION: In the literature, there is little information available on 3D-printed orthodontic retainers. This study examined the accuracy of 3D-printed retainers compared with conventional vacuum-formed and commercially available vacuum-formed retainers. METHODS: Three reference models (models 1, 2, and 3) were used to fabricate traditional vacuum-formed, commercially available vacuum-formed, and 3D-printed retainers. For each model, retainers were made using the 3 methods (a total of 27 retainers). To determine the trueness, ie, closeness of a model to a true model, the distance between the retainer and its digital model at reference points were calculated with the use of engineering software. The measurements were reported as average absolute observed values and compared with those of the conventional vacuum-formed retainers. RESULTS: Average differences of the conventional vacuum-formed retainers ranged from 0.10 to 0.20 mm. The commercially available and 3D-printed retainers had ranges of 0.10 to 0.30 mm and 0.10 to 0.40 mm, respectively. CONCLUSIONS: The conventional vacuum-formed retainers showed the least amount of deviation from the original reference models and the 3D-printed retainers showed the greatest deviation. However, all 3 methods yielded measurements within 0.5 mm, which has previously been accepted to be clinically sufficient.

Exploring training dental implant placement using computer-guided implant navigation system for predoctoral students: A pilot study.

INTRODUCTION: Recent computer-guided dynamic navigation systems promise a novel training approach for implant surgery. This study aimed to examine learning progress in placement of dental implants among dental students using dynamic navigation on a simulation model. MATERIALS AND METHODS: Senior students with no implant placement experience were randomly assigned five implant placement attempts involving either three maxillary or four mandibular implants distributed in the anterior/posterior, and left/right segments. Implant placement was planned using a Navident Dynamic Guidance system. Surgical time was recorded. Horizontal, vertical and angulation discrepancies between the planned and placed implant positions were measured using superimposed CBCT scans. Data were analysed with repeated measures regression with Tukey's adjusted pairwise comparisons (α = 0.05). RESULTS: Fourteen students participated, with a mean age of 26.1 years and equal males and females. Mean time for implant placement was associated with attempt number (P < 0.001), implant site (P = 0.010) and marginally related to gender (P = 0.061). Students had a significant reduction in time from their first attempt to their second (10.6 vs 7.6 minutes; adjusted P < 0.001) then plateaued. Overall 3D angulation (P < 0.001) and 2D vertical apex deviation (P = 0.014) improved with each attempt, but changes in lateral 2D (P = 0.513) and overall 3D apex deviations (P = 0.784) were not statistically significant. Implant sites were associated with lateral 2D, 2D vertical and overall 3D apex deviation (P < 0.001). DISCUSSION: Males were marginally faster than females, had slightly lower overall 3D angulation, and reported higher proficiency with video games. Novice operators improved significantly in speed and angulation deviation within the first three attempts of placing implants using dynamic navigation. CONCLUSION: Computer-aided dynamic implant navigation systems can improve implant surgical training in novice population.