Lauren Oliveira Lima Bohner

Patient outcomes and procedure working time for digital versus conventional impressions: A systematic review

Statement of problem. Limited evidence is available comparing digital versus conventional impressions from the point of view of patient preference. Purpose. The purpose of this systematic review was to identify and summarize the available literature related to patient‐centered outcomes for digital versus conventional impression techniques. Material and methods. The databases Medline, Cochrane, Science Direct, Scopus, and Embase were electronically searched and complemented by hand searches. All published papers available on the databases from 1955 to July 2016 were considered for title and abstract analysis. Results. A total of 2943 articles were initially identified through database searches, of which only 5 met the inclusion criteria for qualitative analysis. Four studies comparing patient‐reported outcome measures (PROMs) between conventional and digital impressions revealed that the digital technique was more comfortable and caused less anxiety and sensation of nausea. Only 1 study reported no difference between the techniques regardless of patient comfort. Two studies reported a shorter procedure for the conventional technique, whereas 3 studies reported a shorter procedure for the digital technique. Conclusions. A lack of clinical studies addressing patient outcomes regarding digital prosthodontic treatments was observed among the included articles. However, current evidence suggests that patients are more likely to prefer the digital workflow than the conventional techniques.

Comparative analysis of imaging techniques for diagnostic accuracy of peri-implant bone defects: a meta-analysis

OBJECTIVE The aim of this study was to systematically review the literature regarding diagnostic accuracy of imaging techniques in detecting peri-implant bone defects. STUDY DESIGN The search was performed in 8 electronic databases from April to May 2016 and updated in September 2016. Studies that assessed imaging techniques to detect peri-implant bone defects were analyzed. RESULTS The search yielded 680 articles published from 1991 to 2016. Of these, 12 studies were considered eligible for this review. The selected studies evaluated the use of cone beam computed tomography (CBCT), intraoral radiography (IR), computed tomography, and panoramic radiography. The sensitivity for CBCT was 59%, whereas the specificity was 67%. For IR, the sensitivity was 60%, and the specificity was 59%. Area under the curve values in receiver operating characteristic (ROC) analysis were 69% for CBCT and 63% for IR. For CBCT, the highest value for positive predictive value was 0.94, negative predictive value was 0.98, positive likelihood ratio was 21.3, and negative likelihood ratio was 1.28. For IR, the highest positive predictive value was 1.0, negative predictive value 1.0, positive likelihood ratio 50.0, and negative likelihood ratio 0.70. The highest diagnostic odds ratio was 80 for CBCT and 4.45 for IR. No conclusion could be drawn for additional techniques. CONCLUSIONS Both CBCT and IR showed a clinically acceptable performance for assessing peri-implant bone defects.

Accuracy of linear measurements around dental implants by means of cone beam computed tomography with different exposure parameters

OBJECTIVES The aim of this study was to determine the accuracy of linear measurements around dental implants when using CBCT unit devices presenting different exposure parameters. METHODS Dental implants (n = 18) were installed in the maxilla of human dry skulls, and images were obtained using two CBCT devices: G1-Care Stream 9300 (70 kVp, 6.3 mA, voxel size 0.18 mm, field of view 8 × 8 cm; Carestream Health, Rochester, NY) and G2-R100 Veraview® (75 kVp, 7.0 mA, voxel size 0.125 mm, field of view 8 × 8 cm; J Morita, Irvine, CA). Measurements of bone thickness were performed at three points located (A) in the most apical portion of the implant, (B) 5 mm above the apical point and (C) in the implant platform. Afterwards, values were compared with real measurements obtained by an optical microscopy [control group (CG)]. Data were statistically analyzed with the significance level of p ≤ 0.05. RESULTS There was no statistical difference for the mean values of bone thickness on Point A (CG: 4.85 ± 2.25 mm, G1: 4.19 ± 1.68 mm, G2: 4.15 ± 1.75 mm), Point B (CG: 1.50 ± 0.84 mm, G1: 1.61 ± 1.27 mm; G2: 1.68 ± 0.82 mm) and Point C (CG: 1.78 ± 1.33 mm, G1: 1.80 ± 1.09 mm; G2: 1.64 ± 1.11 mm). G1 and G2 differed in bone thickness by approximately 0.76 mm for Point A, 0.36 mm for Point B and 0.08 mm for Point C. A lower intraclass variability was identified for CG (Point A = 0.20 ± 0.25; Point B = 0.15 ± 0.20; Point C = 0.06 ± 0.05 mm) in comparison with G1 (Point A = 0.56 ± 0.52; Point B = 0.48 ± 0.50; Point C = 0.47 ± 0.56 mm) and G2 (Point A = 0.57 ± 0.51; Point B = 0.46 ± 0.46; Point C = 0.36 ± 0.31 mm). CONCLUSIONS CBCT devices showed acceptable accuracy for linear measurements around dental implants, despite the exposure parameters used.

Surface roughness of composite resins subjected to hydrochloric acid.

The purpose of this study was to determine the influence of hydrochloric acid on surface roughness of composite resins subjected to brushing. Sixty samples measuring 2 mm thick x 6 mm diameter were prepared and used as experimental units. The study presented a 3x2 factorial design, in which the factors were composite resin (n=20), at 3 levels: microhybrid composite (Z100), nanofilled composite (FiltekTM Supreme), nanohybrid composite (Ice), and acid challenge (n=10) at 2 levels: absence and presence. Acid challenge was performed by immersion of specimens in hydrochloric acid (pH 1.2) for 1 min, 4 times per day for 7 days. The specimens not subjected to acid challenge were stored in 15 mL of artificial saliva at 37 oC. Afterwards, all specimens were submitted to abrasive challenge by a brushing cycle performed with a 200 g weight at a speed of 356 rpm, totaling 17.8 cycles. Surface roughness measurements (Ra) were performed and analyzed by ANOVA and Tukey test (p≤0.05). Surface roughness values were higher in the presence (1.07±0.24) as compared with the absence of hydrochloric acid (0.72±0.04). Surface roughness values were higher for microhybrid (1.01±0.27) compared with nanofilled (0.68 ±0.09) and nanohybrid (0.48±0.15) composites when the specimens were not subjects to acid challenge. In the presence of hydrochloric acid, microhybrid (1.26±0.28) and nanofilled (1.18±0,30) composites presents higher surface roughness values compared with nanohybrid (0.77±0.15). The hydrochloric acid affected the surface roughness of composite resin subjected to brushing.

Computer-aided analysis of digital dental impressions obtained from intraoral and extraoral scanners

Statement of problem The internal and marginal adaptation of a computer‐aided design and computer‐aided manufacturing (CAD‐CAM) prosthesis relies on the quality of the 3‐dimensional image. The quality of imaging systems requires evaluation. Purpose The purpose of this in vitro study was to evaluate and compare the trueness of intraoral and extraoral scanners in scanning prepared teeth. Material and methods Ten acrylic resin teeth to be used as a reference dataset were prepared according to standard guidelines and scanned with an industrial computed tomography system. Data were acquired with 4 scanner devices (n=10): the Trios intraoral scanner (TIS), the D250 extraoral scanner (DES), the Cerec Bluecam intraoral scanner (CBIS), and the Cerec InEosX5 extraoral scanner (CIES). For intraoral scanners, each tooth was digitized individually. Extraoral scanning was obtained from dental casts of each prepared tooth. The discrepancy between each scan and its respective reference model was obtained by deviation analysis (&mgr;m) and volume/area difference (&mgr;m). Statistical analysis was performed using linear models for repeated measurement factors test and 1‐way ANOVA (&agr;=.05). Results No significant differences in deviation values were found among scanners. For CBIS and CIES, the deviation was significantly higher (P<.05) for occlusal and cervical surfaces. With regard to volume differences, no statistically significant differences were found (TIS=340 ±230 &mgr;m; DES=380 ±360 &mgr;m; CBIS=780 ±770 &mgr;m; CIES=340 ±300 &mgr;m). Conclusions Intraoral and extraoral scanners showed similar trueness in scanning prepared teeth. Higher discrepancies are expected to occur in the cervical region and on the occlusal surface.

Accuracy of digital technologies for the scanning of facial, skeletal, and intraoral tissues: A systematic review

Statement of problem. The accuracy of the virtual images used in digital dentistry is essential to the success of oral rehabilitation. Purpose. The purpose of this systematic review was to estimate the mean accuracy of digital technologies used to scan facial, skeletal, and intraoral tissues. Material and methods. A search strategy was applied in 4 databases and in the non–peer‐reviewed literature from April through June 2017 and was updated in July 2017. Studies evaluating the dimensional accuracy of 3‐dimensional images acquired by the scanning of hard and soft tissues were included. Results. A total of 2093 studies were identified by the search strategy, of which 183 were initially screened for full‐text reading and 34 were considered eligible for this review. The scanning of facial tissues showed deviation values ranging between 140 and 1330 &mgr;m, whereas the 3D reconstruction of the jaw bone ranged between 106 and 760 &mgr;m. The scanning of a dentate arch by intraoral and laboratorial scanners varied from 17 &mgr;m to 378 &mgr;m. For edentulous arches, the scanners showed a trueness ranging between 44.1 and 591 &mgr;m and between 19.32 and 112 &mgr;m for dental implant digital scanning. Conclusions. The current digital technologies are reported to be accurate for specific applications. However, the scanning of edentulous arches still represents a challenge.

Association between Oral Health-Related Quality of Life in People with Rare Diseases and Their Satisfaction with Dental Care in the Health System of the Federal Republic of Germany

Background: The aim of this study was to examine the current dental care situation in Germany from the perspective of those affected by a rare disease, especially concerning their satisfaction with the German dental health care system, and thus assess the relationship between their perspective and their oral health-related quality of life (OHRQoL). Methods: A questionnaire regarding their experiences with the dental assistance and the health care system, such as the OHIP-14, was sent to the member associations of the organization of self-help groups for rare diseases ACHSE e.V. The correlation between OHIP-14 values and patient’s perspective was statistically analyzed by the non-parametric Tau de Kendall test (p < 0.05). Results: There was a statistically significant correlation between the OHIP score and the patient’s perspective regarding dental assistance and health care system (p < 0.05). For those surveyed who were satisfied with the support of the health care system, an average OHIP score of 8.54 ± 10.45 points (range: 0–48) was determined. The group that did not feel sufficiently supported by the health care system had an average OHIP score of 16.07 ± 13.43 points (range: 0–56). Discussion: The majority of respondents with rare diseases are dissatisfied with the German health care system and its support with regard to dental care.

Oral Health-Related Quality of Life in People with Rare Hereditary Connective Tissue Disorders: Marfan Syndrome

Background: The aim of this study was to analyze data on oral health-related quality of life (OHRQoL) in people with Marfan syndrome and to obtain information on the diagnosis period, orthodontic treatment, and oral symptoms. Methods: A questionnaire was developed consisting of open questions and the standardized German version of the OHIP-14 (Oral Health Impact Profile) questionnaire for the evaluation of OHRQoL. The age of diagnosis, time period from the first signs of the disease to diagnosis, and OHIP-values were compared between male and female participants. Additionally, the OHIP-values between participants who were orthodontically treated and those who were not treated were assessed. The statistical analysis was performed using the Mann–Whitney test with a significance level at p = 0.05. Results: A total of 51 questionnaires were evaluated, which included 34 female and 17 male participants. Overall, 84% of respondents reported oral symptoms. Male respondents tended to diagnose the disease earlier (p = 0.00), with a smaller period between the first symptom and the diagnosis (p = 0.04). The OHIP-14 score was gender-neutral at 13.65 ± 13.53 points. Conclusion: In Marfan syndrome, many years (12.01 ± 11.61) elapse between the onset of first symptoms and correct diagnosis of the disease. People with Marfan syndrome have a worse OHRQoL than do the general population.

Accuracy of self-perforating impression tray for maxillary dental implant

| Objectives: To analyze the accuracy of a pre-fabricated self-perforating tray for implant impression in an edentulous maxilla. Methods: Four implants (13, 16, 23, 26) were placed in an acrylic resin model of an edentulous maxilla. Implant impressions (n = 7) were taken using a customized open tray (Control Group) and a pre-fabricated selfperforating tray (Test Group). A metal bar was fabricated and screw-retained on implant 13 and the vestibular gap between the framework and implants was measured by stereomicroscopy on implants 16, 23, and 26. Data were analyzed by ANOVA repeated measures and Tukey tests with a significance level (α) of 0.05. Results: There was no statistical difference between self-perforating and customized open tray groups. Control group showed a gap of 73.31± 26.01 for I1; 149.16± 53.90 for I2; and 115.46± 73.34 for I3. Whereas Test Group showed a gap of 154.41± 74.64 for I1; 159.45± 87.64 for I2; and 109.28± 49.18 for I3. Conclusion: The pre-fabricated self-perforating and custom trays showed a similar accuracy for implant impression of edentulous maxilla. DESCRIPTORS | Impression Technique; Dental Implants; Dimensional Measurement Accuracy. RESUMO | Precisão de moldeira autoperfurante para impressão de implante dentário maxilar • Objetivos: Analisar a precisão de uma moldeira autoperfurante de impressão pré-fabricada para implantes na maxila edêntula. Métodos: Quatro implantes (13, 16, 23, 26) foram colocados em um modelo de resina acrílica de uma maxila edêntula. As impressões dos implantes (n = 7) foram tiradas com uma moldeira aberta customizada (Grupo Controle) e uma moldeira autoperfurante pré-fabricada (Grupo Teste). Uma barra de metal foi fabricada e aparafusada no implante 13, e o gap vestibular entre a estrutura e os implantes foi medido por estereomicroscopia nos implantes 16, 23 e 26. Os dados foram analisados por Anova de medidas repetidas e teste de Tukey, com um nível de significância (α) de 0,05. Resultados: Não houve diferença estatística entre os grupos de moldeiras, tanto autoperfurante quanto aberta customizada. O grupo controle apresentou gaps de 73,31 ± 26,01 para I1; 149,16 ± 53,90 no I2; e 115,46 ± 73,34 para o I3. Ao passo que o Grupo Teste apresentou gaps de 154,41 ± 74,64 no I1; 159,45 ± 87,64 no I2; e 109,28 ± 49,18 para o I3. Conclusão: A moldeira autoperfurante pré-fabricada e a moldeira customizada apresentaram precisão similar na impressão de implantes da maxila edêntula. DESCRITORES | Técnica de Impressão; Implantes Dentários; Precisão da Medição Dimensional. CORRESPONDING AUTHOR | • Lauren Oliveira Lima Bohner Department of Prosthodontics, School of Dentistry, University of São Paulo • Av. Prof. Lineu Prestes, 2227 São Paulo, SP, Brazil • 05508-000 E-mail: lauren@usp.br • Received Aug 11, 2017 • Accepted Dec 20, 2017 • DOI http://dx.doi.org/10.11606/issn.2357-8041.clrd.2018.135626 Accuracy of self-perforating impression tray for maxillary dental implant 2 ● Clin Lab Res Den 2017: 1-7 INTRODUCTION Passive fit of an implant-supported dental prosthesis is determinant to provide the long-term success of oral rehabilitation, since a misfit may lead to mechanical complications such as screw loosening, screw fracture or the induction of an internal load on the prosthesis, implants, and bone. Furthermore, biological events have been reported due to the increase in plaque accumulation, resulting in implant failure.1-5 The accuracy of an implant impression is one of the most important factors to determine the fit of restorations, provided that the implant position in the patient̀ s mouth is entirely reproduced in the cast model.6,7,8 Therefore, obtaining an adequate implant impression is an important step to avoid misfit of the implant-supported prosthesis.1,3,5,6,9,10 Currently, the pick-up technique offers the most accurate implant positioning reproduction when the impression is taken of 3 or more implants.11,12 The main disadvantage of the pick-up technique is the large tray holes and long guide screws, which make them difficult to use in mouths with opening restrictions and in the posterior areas.13,14 However, a tray design was developed to make it faster and easier to take impressions of dental implants. The self-perforating tray holds a thin plastic film on the occlusal surface, allowing it to be perforated by the transfers during tray positioning. This feature leads to a clean and precise impression, without excess material on abutments.15 Despite all its advantages, the accuracy of impressions obtained with the self-perforating tray is still controversial.15 Furthermore, there are no reports evaluating the use of this new technology for maxillary impressions. Several studies reported the influence of impression technique and implant position on the accuracy of dental casts.16-23 With this regard, gap measurements are commonly used to evaluate the fit of implants; hence, most studies use the gap width to evaluate the marginal discrepancy.1,9,24,25 Thus, the aim of this study was to evaluate the accuracy of the self-perforating tray for taking an implant impression of the edentulous maxilla when compared with the conventional pick-up technique. The null hypothesis was that there would be no difference in accuracy between the two types of trays for maxillary implant impressions. MATERIAL AND METHODS Sample preparation An acrylic resin master model representing an edentulous maxilla was used in this study. Perforations were made in the region of the canine and first molar (13,16,23,26), in which 4 implants (Straumann, Basel, Switzerland) were fixed with utility wax (Epoxiglass, Diadema, Brazil), as shown in Figure 1. The implant on tooth 13 was kept as reference (IR) for screw tightening and the remaining implants were evaluated (Tooth 16= I1, 23= I2, and 26= I3). Figure 1 | Master model. Bohner L • Marques ADA • Keedi CB • Steagall W • Tortamano Neto P • Clin Lab Res Den 2017: 1-7 ● 3 A cobalt-chromium bar was fabricated using a wax pattern (S-U-Flexible Wax; Schuler-Dental) and cast in cobalt chromium alloy (Remanium 2000; Dentaurum J.P. Winkelstroeter KG). Posteriorly, the bar was screw-retained onto the implants. Toensure an optimal fit, the implants were firstly removed from the model to be individually fixed to the bar. After that, the whole set was fixed to the model using acrylic resin. Subsequently, the entire set was repositioned in the perforations and the implants were fixed to the master model with acrylic resin.15 Impression procedures Two types of impression trays were evaluated (n = 7): Customized open impression trays (G1 Control group) and pre-fabricated selfperforating impression trays (G2 Test group). For the conventional open tray group, individual trays with perforations at the site of the impression copings were fabricated with acrylic resin (Jet, Clássico, São Paulo, Brazil). One tray was used to each impression. Likewise, for the self-perforating group, as the film was perforated after use, a new tray was obtained (Miratray Implant, Hager and Werken GmbH) to each impression (Figure 2). Figure 2 | Self-perforating tray. Firstly, the impression copings (Square transfer, 4.5, Conexão, São Paulo, Brazil) were positioned on the implants and an adhesive (Universal Tray Adhesive, Zhermack, Rome, Italy) was applied to the trays. For both groups, impressions were taken with polyvinyl siloxane (Express, 3M ESPE, St. Paul, USA), manipulated according to the manufacturer’s instructions. After impressiontaking, implant analogs were positioned on the transfer components and dental stone (Type IV, Durone, Dentsply, Petrópolis, Brazil) was poured, after being mixed in accordance with the manufacturer̀ s instructions. Dental casts were stored at 37 °C for 2 weeks. Accuracy analysis For both groups, the metal bar was adapted to each cast model, to analyze the fit accuracy Accuracy of self-perforating impression tray for maxillary dental implant 4 ● Clin Lab Res Den 2017: 1-7 between the bar and the implants. The bar was tightened on implant IR with a torque of 30 Ncm, and the vertical distance between the implant and the bar was measured in implants I1, I2, and I3. The gap was evaluated with a stereomicroscope (40x magnification, Zeiss SV11, Carl Zeiss, Jena, Germany). Measurements were taken in the entire gap and the mean value was calculated and determined as the value of the gap (Figure 3). For each implant, measurements were performed 3 times by the same examiner at intervals of one week. The final gap was defined as the average value of these measurements. The effects of “Tray type” and “Position of implants” were assessed by ANOVA repeated measures and Tukey tests. The T-test was used to evaluate the effect of “Tray type” for each implant. Statistical analysis was performed with the software SPSS 20 (IBM Corp., Chicago, USA) at a level of significance p = 0.05. Figure 3 | Measurement area to determine the mean gap value. RESULTS All data presented variance normality and homogeneity, and were described as mean value ± standard deviation (Table 1, Figure 4). The tray type presented no statistically significant difference (p = 0.192), and no relationship was found between the tray and the implant position (p = 0.224). However, when analyzing the factor “Tray type” individually, implant I1 showed a lower gap value for G1 compared with G2 (p = 0.019). Table 1 | Mean± Standard Deviation (SD) and Confidence of Interval 95% (IC 95%) of the mean gap for customized (G1) and self-perforating (G2) trays according to the different implant locations (I1, I2, I3). I1 I2 I3 p Mean±SD IC 95% Mean±SD IC 95% Mean±SD IC95% G1 73.31±26.01* 49.26; 97.37 149.16±53.90 99.30; 199.02 115.46±73.34 41.63;183.30 >0.05 G2 154.41±74.64 85.37; 223.44 159.45±87.64 78.39; 240.51 109.28±49.18 61.28;155.26 >0.05

Group 5 ITI Consensus Report: Digital technologies

OBJECTIVES Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer-aided implant surgery (s-CAIS) and patient-related outcome measurements when using s-CAIS were addressed. MATERIALS AND METHODS The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. RESULTS Static computer-aided surgery (s-CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s-CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. CONCLUSIONS Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s-CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s-CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care.