Mean Coronal Deviation Research Articles

Transfer accuracy of 3D printed versus CAD/CAM milled surgical guides for temporary orthodontic implants: A preclinical micro CT study

ObjectivesTemporary anchorage devices (TADs) have become an integral part of comprehensive orthodontic treatments. This study evaluated the transfer accuracy of three-dimensional (3D) printed and computer-aided design/computer-aided manufacturing (CAD/CAM) milled surgical guides for orthodontic TADs using micro-computed tomography (CT) imaging in a preclinical trial. MethodsOverall, 30 surgical guides were used to place TADs into typodonts; 3D printing and CAD/CAM milling were used to produce the guides. The virtual target positions of the TADs were compared to the real positions in terms of spatial and angular deviations using digital superimposition. Micro-CT imaging was used to detect the positions. To evaluate reliability, two investigators collected the measurements twice. Intra-rater and inter-rater correlations were tested. ResultsIn total, 60 palatal TADs were evaluated. The mean coronal deviations in the print group ranged from 0.15 ± 0.20 mm to 0.71 ± 0.22 mm, whereas in the mill group, they ranged from 0.09 ± 0.15 mm to 0.83 ± 0.23 mm. At the apical tip, the overall deviations in the print group ranged from 0.14 ± 0.56 mm to 1.27 ± 0.66 mm, whereas in the mill group, they ranged from 0.15 ± 0.57 mm to 1.09 ± 0.44 mm. The mean intra-class and inter-class correlation coefficients ranged from 0.904 to 0.987. No statistically significant differences were found between the groups. ConclusionsCAD/CAM milled guides yielded spatial and angular accuracies comparable to those of 3D printed guides with notable deviations in the vertical positioning of TADs. Clinical significanceDigital planning of orthodontic temporary implants combines clinical predictability and the safety of surrounding tissue. Therefore, the transfer accuracy of the guides is crucial. This preclinical study was the first to evaluate CAD/CAM milling for orthodontic guides and found its accuracy comparable to that of the current "gold standard".

Accuracy Comparison between Robot-Assisted Dental Implant Placement and Static/Dynamic Computer-Assisted Implant Surgery: A Systematic Review and Meta-Analysis of In Vitro Studies.

Background and Objectives: The present systematic review and meta-analysis undertake a comparison of studies that examine the accuracy of robot-assisted dental implant placement in relation to static computer-assisted implant surgery (SCAIS), dynamic computer-assisted implant surgery (DCAIS), and freehand procedures. This study aims to provide a comprehensive understanding of the precision of robot-assisted dental implant placement and its comparative efficacy in relation to other placement techniques. Methods: The guidelines recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were used to organize and compose this review. Four electronic databases (PubMed, Web of Science, Scopus, and Cochrane) were systematically searched for pertinent articles. Articles were selected following the inclusion and exclusion criteria. Qualitative and quantitative analyses of the selected articles were performed. Results: The initial electronic search resulted in 1087 hits. Based on the inclusion and exclusion criteria, five articles were selected for qualitative analysis, out of which three were considered for quantitative analysis. Three parameters were considered for accuracy evaluation (angular, coronal, and apical deviation). The mean angular deviation was -1.22 degrees (95% CI, -1.06--1.39), the mean coronal deviation was -0.15 mm (95% CI, -0.24--0.07), and the mean apical deviation was -0.19 mm (95% CI, -0.27--0.10). Conclusions: The robotic implant system was found to have significantly lower angular deviations and insignificantly lower coronal and apical deviations compared to DCAIS. Within the limitations of this review, it can be concluded that robot-assisted implant placement in resin models permits higher accuracy compared to DCAIS and SCAIS systems. However, due to the limited number of comparative studies with high heterogeneity, the findings of this review should be interpreted with caution. Further research is necessary to confirm the clinical application of robotics in implant surgery.

Accuracy of Computer-Guided Implantology with Pilot Drill Surgical Guide: Retrospective 3D Radiologic Investigation in Partially Edentulous Patients.

Background and Objectives: Implant placement with static navigation enables the reaching of a correct position of implants from an anatomical and prosthetic point of view. Different approaches of static navigation are described in the scientific literature, and the pilot-guided approach is one of the least investigated. The aim of the present study is the evaluation of the accuracy of implant insertion using a pilot drill template. Materials and Methods: Fifteen partially edentulous patients, requiring an implant rehabilitation of at least one implant, were enrolled. Pre- and post-operative low-dose CTs were acquired to measure the differences between final positions of implants and virtually planned ones. Three linear discrepancies (coronal, apical, and depth), two angular ones (bucco-lingual and mesio-distal), and the imprecision area were evaluated. Correlations between accuracy and rehabilitated jaws, sectors, and implant length and diameters were also analyzed. Results: Forty implants were inserted in fifteen patients using pilot drill templates. Mean coronal deviation was 1.08 mm, mean apical deviation was 1.77 mm, mean depth deviation was -0.48 mm, mean bucco-lingual angular deviation was 4.75°, and mean mesio-distal one was 5.22°. The accuracy was statistically influenced only by the rehabilitated jaw for coronal discrepancy and sectors and implant diameter for bucco-lingual angular deviations. Conclusions: The pilot drill template could represent a predictable solution to obtain a correct implant placement. Nonetheless, a safety margin of at least 2 mm should be respected during implant planning to prevent damages to anatomical structures. Therefore, the tool is helpful in order to prosthetically drive the implants; still, great attention must be paid in fully relying on this procedure when approaching dangerous structures such as nerves and vessels.

Cone Beam Computed Tomography-Based Evaluation of the Accuracy of Implant Surgery with Conventional (Free Hand) Implant Placement vs Computer Fabricated 3D Guide Implant Placement.

Dental implants have been used in a variety of conventional technique-based forms for many years which had its own drawbacks. With the advent of cone beam CT, proper surgical and prosthetic planning is possible now a days. To achieve ideal implant placement, good prosthetic fabrication and overall successful prognosis computer fabricated guide aided surgery have been developed. The aim of this study was to compare and evaluate the accuracy of implant placement in partially edentulous patients with conventional free hand technique and computer fabricated guide of implant placement by comparing pre- and post-CBCT data. The present split mouth study design was conducted with forty sample size on twenty randomly selected patients who were treated with bilateral partially edentulous sites requiring dental implants. Patients were treated with both conventional (free hand) technique and computer fabricated 3D guide aided technique of implant placement. Comparison of accuracy of implant placement was done by comparing the pre- and postoperative CBCT data in terms of mean coronal deviation, mean apical deviation and mean angular deviation. The results showed that there is no statistically significant difference between mean coronal deviation, mean apical deviation and mean angular deviation of planned and placed implants in both conventional technique (free hand technique) and computer fabricated 3D guide aided implant placement technique. Hence, this study concluded that conventional technique of implant placement is equally efficient in comparison with computer fabricated guide aided surgery in terms of accuracy of implant placement.

Comparison of accuracy of hexed and nonhexed pickup impression copings in a multiple variable impression setup for recording multiple straight and angulated implant positions: An in vitro study.

The aim of this study was to evaluate and compare the accuracy of hexed and nonhexed pickup impression copings with and without splinting using polyether (PE) and polyvinyl siloxane (PVS) impression materials in open-tray technique in recording multiple straight and angulated implant positions. An accurate impression results in an accurate definitive cast, thus minimizing the incidence of prosthesis misfit. The critical aspect is to record the three-dimensional location of the implant in bone rather than reproducing fine surface details. Precise fit of a fixed implant-supported prosthesis depends on the accuracy of the implant analog location within the definitive cast. Factors which affect impression accuracy include implant angulation, impression material, impression copings, technique, and splinting. A sample size of 80 study models fabricated from the impression of different groups was included. A reference master model based on All-on-4 implant concept with two parallel (implants 1 and 2) and two angulated (implant 3 at 17° and implant 4 at 30°) was fabricated using implant angulation guide. All impressions were recorded using open-tray impression technique. The groups were divided into two main groups of 40 samples each. Group A used hexed open-tray impression copings and Group B used nonhexed open-tray impression copings. Both the groups involved impression recording using splinted (Subgroup I) and nonsplinted impression copings (Subgroup II). Further, impressions in each subgroup were made using PE (Subsubgroups a) and PVS (Subsubgroup b). A total of eight subsubgroups with ten samples each were included. Impressions were recorded for each group and poured into Type IV die stone for fabrication of study models. After 24 h, the study models and reference master model were fitted with implant abutments for measurement with coordinate measuring machine. The mean differences of the interimplant distance R1 (1-2), R2 (1-3), R3 (2-4), and R4 (3-4) between the reference model and sample models in different subsubgroups were calculated and three-way analysis of variance test was applied with Tukey's post hoc tests. No significant difference was found in mean coronal deviations for distance R1, R2, and R3 (P > 0.05) between different study groups. P = 0.02 for R4 (distance between 17° and 30° implants) between impression materials subsubgroups suggested that significantly less distortion was created in location of highly angulated implants (>30°) using PVS impression material. Splinting and type of coping did not have a significant influence on impression accuracy. Increasing angulation decreased the accuracy. PVS was found equivalent in accuracy to rigid PE for recording parallel or angulated implants. Impressions of implants with higher angulations were recorded more accurately with PVS. The study found no difference in accuracy with or without splinting. Furthermore, nonhexed impression copings facilitate easier and accurate recording of multiple angulated implant location in bone.

Accuracy of guided dental implant surgery using a fully digital workflow: A case series

Statement of problemComputer-guided implant surgery facilitated by intraoral scanning may enhance the efficiency of the digital workflow. However, it is necessary to assess technique accuracy to evaluate the accuracy of implant placement. PurposeThe purpose of this clinical study was to evaluate the accuracy of a virtual computer-aided design and computer-aided manufacturing (CAD-CAM) static guided surgery technique associated with intraoral scanning in partially edentulous participants by analyzing the overlap among preoperative and postoperative cone beam computed tomography (CBCT) scans, virtual planning, and the guided surgery performed. Material and methodsEleven partially edentulous participants underwent CBCT and intraoral scanning (TRIOS3). Data were integrated into a software program (ImplantViewer 3.5) for the virtual planning of implants and 3-dimensional (3D) printing of the prototype CAD-CAM surgical guide. A total of 18 implants were placed using the CAD-CAM static computer-aided implant surgery technique (Strong SW). After 15 days, postoperative CBCT scans were made and 4 variables (angular, coronal, apical, and vertical deviation) were measured to compare the virtually planned implants and the implants placed by analyzing the overlap between preoperative and postoperative of the virtual planning and guided surgery performed using the ImplantViewer 3.5 and Rhino 6 software programs. ResultsDeviations were found in all parameters analyzed. The mean angular deviation was 2.68 ±1.62 degrees; mean coronal deviation, 0.82 ±0.44 mm; mean apical deviation, 1.14 ±0.44 mm; and mean vertical deviation, 0.62 ±0.44 mm. ConclusionsThe implants placed using the CAD-CAM static guided surgery technique associated with intraoral scanning in partially edentulous participants exhibited angular and linear deviations when compared with virtual planning implants. However, these deviations were not clinically significant.

Accuracy of dental implant placement with 3D-printed surgical templates by using Implant Studio and MGUIDE. An observational study.

The purpose of the present study was to report early surgical template-related and postoperative complications of computer-guided implant placement and to evaluate its accuracy. Data were collected retrospectively from records of patients who had undergone computer-guided implant surgery between 2016 and 2018. Incidence of early surgical template-related and postoperative complications was recorded. Accuracy of implant placement was evaluated by comparing the data from postoperative CBCT records with that from the preoperative virtual implant planning by using appropriate image registration software. Depth, coronal, apical, and angular deviations were measured. A final number of 27 partially edentulous patients who received 52 implants with 31 static surgical templates were included in the study. All implants had been inserted in a fully guided manner using a flapless technique and following a one-stage approach. All implants were reported to have been successfully osseointegrated. Except for one template fracture, no other complication was recorded. The mean depth deviation was 0.57 ± 0.4 mm (95% CI 0.48 to 0.71 mm), the mean coronal deviation was 0.89 ± 0.7 mm (95% CI 0.73 to 1.07 mm), the mean apical deviation was 1.4 ± 1 mm (95% CI 1.16 to 1.71 mm), and the mean angular deviation was 2.74 ± 1.8 degrees (95% CI 2.29 to 3.26 degrees). The use of static surgical templates for fully guided implant placement demonstrated acceptable clinical performance. However, there are some factors affecting accuracy that should be considered during implant planning and surgery for further improvement of the technique. (Int J Comput Dent 2022;25(3):249-256; doi: 10.3290/j.ijcd.b2599735).

Accuracy of Guided Implant Surgery Using an Intraoral Scanner and Desktop 3D-Printed Tooth-Supported Guides.

The increasing popularity of desktop 3D printers makes guided surgery more accessible. The aim of this in vitro study was to evaluate the accuracy of single-tooth guided implant surgery by means of a 3D-printed tooth-supported guide. Fifteen implants were virtually planned to replace a missing first mandibular molar, using planning software for guided implant surgery (Exoplan, Exocad). A tooth-supported guide was designed and manufactured using a desktop 3D printer (Asiga MAX UV). The implants were placed fully guided in resin casts, and a digital impression was taken to register their position. This scan was compared with the virtual implant position in the planning software, and the internal fit of the guides was evaluated using metrology software. One planning was executed six times for measuring precision. For trueness, the mean angular deviation was 2.63 degrees (SD: 1.69 degrees; range: 0.38 to 5.99 degrees), the mean coronal deviation was 0.52 mm (SD: 0.25; range: 0.09 mm to 1.07 mm), and the mean apical deviation was 0.90 mm (SD: 0.47; range: 0.14 to 1.74 mm). The absolute apical mean deviation in the buccolingual direction (x-axis) was 0.70 mm (SD: 0.42, 0.12 to 1.65 mm; P < .001); in the mesiodistal direction (y-axis), it was 0.34 mm (SD: 0.26; range: 0.01 to 0.80 mm; P = .650); and in the vertical direction (z-axis), it was 0.32 mm (SD: 0.27; range: 0.02 to 1.00 mm; P = .010). The mean internal fit of the guides was 79.5 μm (SD: 19.6 μm; range: 51 to 118 μm). Desktop 3D-printed tooth-supported guides demonstrate an acceptable fit and acceptable level of accuracy for single implant placement.

Accuracy of Sterile and Non-Sterile CAD/CAM Insertion Guides for Orthodontic Mini-Implants

AimThe aim of this study was to measure the transfer accuracy of computer-aided design/computer-aided manufacturing (CAD/CAM) insertion guides using mini-implants. The target value is the virtual planned position (100%). It is also clinically mandatory to use sterilised surgical guides (autoclaved at 137°C). The results obtained using sterilised and non-sterilised insertion guides were compared. In addition, the actual position of the mini-implants, as implemented, was compared with the digitally planned positions.Materials and MethodsFollowing CAD/CAM planning and production of 60 insertion guides made from synthetic resins that had been previously tested for suitability, 120 mini-implants were inserted in pairs and in blocks of the bone of the substitute material. Half of the insertion guides were sterilised, while the other half were non-sterilised. Compared with the position of the mini-implants in the digital plans, deviations in the apical and coronal distances between the mini-implants and insertion depth, as well as the included angle of the mini-implants to one another and to the surface of the bone substitute material, were determined.ResultsIn post-sterilisation, the dimensional and material changes were observed. When compared, the deviations to the virtual planned position were achieved when the performed insertion using sterilised insertion guides were lower than those achieved when using non-sterilised insertion guides. The heat treatment during the sterilisation process improved the accuracy of the insertion guides. When comparing sterile insertion guides to the digital planned position (100%), the mean coronal deviation was 0.057 mm (0.81%), the apical deviation was 0.428 mm (6.11%), and insertion depth mean deviation at the right side was 0.15 mm (2.15%), while that on the left was 0.073 mm (1.04%).ConclusionThe CAD/CAM TAD insertion guide could not achieve 100% accuracy in translating the digitally planned position into the real anatomic location. Deviations to the ideal position between 0.81 and 6.11% were observed. Clinically, for appliances that fit post-mini-implant insertion, the coronal distance of the mid-mini-implant head is the most important. At this point, the mean deviation to the planned positions is 0.81%, which is clinically acceptable and most likely reproducible by using CAD/CAM insertion guides.

Determining accuracy of sleeveless tooth-supported surgical guide for guided implant surgery: A retrospective observational study

Aim: The advances in CAD/CAM technique have enabled digital data from the virtual setting to be transferred to the real clinical output using surgical guides. Evidence for the accuracy of surgical guides with metal sleeves has been documented. However, the sleeveless surgical guide has not yet been analyzed for its accuracy in clinical situations. The purpose of the study is to determine the accuracy of the sleeveless tooth-supported surgical guide for guided implant surgery. Materials and Methods: This retrospective observational study evaluates data of 25 patients selected randomly with single implants placed using the sleeveless surgical guide, which was collected from a single center at Thane. Cone-beam computed tomography of the treatment planning and the post-implant placement data were superimposed on each other and analyzed using Evalunav (3.0 version, Claronav, Toronto, Canada) software. Descriptive analysis was done. Coronal, apical, and angular deviations were calculated and assessed using a one-sample t-test. Results: It was found that the mean coronal deviation between the planned and placed implants was 0.73± 0.4 mm (0.12–1.81 mm), the mean apical deviation was 0.81± 0.43 mm (0.12–1.66 mm), and the angular deviation was 2.32° ± 0.98° (0°–4.78°). There was a statistically highly significant difference between the achieved and accepted values (P < 0.01) with a lower deviation achieved when compared with the acceptable values. Conclusion: It was concluded that the 3d printed tooth-supported surgical guide with no metal sleeves has acceptable accuracy for placing dental implants using the guided technology.

Comparison of the Accuracy of Implant Position Using Surgical Guides Fabricated by Additive and Subtractive Techniques.

To evaluate the accuracy of implant position using surgical guides fabricated by additive and subtractive techniques. A partially edentulous standardized mandibular implant model with different bone densities and soft tissue was duplicated and a diagnostic wax-up was performed for the #30 area. A reference radiographic guide was fabricated and cone beam computed tomography (CBCT) was made with the reference radiographic guide in place. A surgical guide was designed using BlueSky Plan 4 software and a reference implant was placed in the #30 region. The STL file of the surgical guide was exported and specimens (n = 15) were fabricated by two different techniques: additive (3D printing) and subtractive (milling). The standardized mandibular model was surface-scanned and duplicated with printed dental model resin (n = 30). Each surgical guide was used to place an implant in thirty duplicate printed models. Differences in implant position as compared to the reference were measured from digital scans with scan bodies in place. The angular deviations, differences in depth, coronal and apical deviations were measured using GeoMagic Control X software. Results were analyzed by Wilcoxon-Mann-Whitney test and PERMANOVA (Permutational Multivariate Analysis of Variance). Intraclass correlation was used to assess measurement reproducibility with Bonferroni adjustment for multiple testing as needed (α = 0.05). There were no significant differences in accuracy of implant placement using guides fabricated using additive vs subtractive techniques. The mean angular deviations between the reference and actual position of implant in mesio-distal cross-section were 0.780 ± 0.80° for printed group and 0.77 ± 0.72° for the milled group. The differences in bucco-lingual cross-section were 1.60 ± 1.22° in in printed group and 1.77 ± 0.76° in the milled group. The differences in depth (mm) were measured at the top of the scan body at four locations: mesial, distal, buccal and lingual. The mean differences in depth for the group that used printed surgical guides were (mesial) 0.37 ± 0.29 mm, (distal) 0.32 ± 0.23 mm, (buccal) 0.24 ± 0.23 mm, and (lingual) 0.25 ± 0.17 mm. The mean differences in depth for the group that used milled surgical guides were (mesial) 0.51 ± 0.33 mm, (distal) 0.40 ± 0.32 mm, (buccal) 0.22 ± 0.23 mm, and (lingual) 0.23 ± 0.12 mm in those four aspects, respectively. The mean coronal deviation showed 0.32 mm in the printed group and 0.27 mm in the milled group. For the apical deviation, the results of this study showed mean apical deviation 0.84 mm in the printed group and 0.80 mm in the milled group. Results indicate that 3D-printed surgical guides are statistically as accurate as milled guides for guided-implant surgery with the benefits of high accuracy, ease of fabrication, less waste compared to subtractive techniques, and reduction of laboratory time thereby increasing cost-effectiveness.

The Accuracy of Computer-Assisted Implant Surgery Performed Using Fully Guided Templates versus Pilot-Drill Guided Templates

Purpose. Computer-assisted stereolithographically guided surgery allows an ideal implant placement for prosthetic restoration. Two types of stereolithographic templates are currently available: a fully guided template and a pilot-drill guided template. The purpose of this study was (i) to evaluate the accuracy of implant insertion using these types of surgical templates and (ii) to define parameters influencing accuracy. Materials and Methods. 20 patients were enrolled and divided into 2 study groups: in group A, implants were placed using CAD-CAM templates with fully guided sleeves; in group B, implants were placed with a template with only pilot-drill guided sleeves. Pre- and postoperative computed tomographies were used to measure differences between final positions of implants and virtually planned positions. Three linear discrepancies (coronal, apical, and depth) and two angular ones (buccolingual and mesiodistal) were measured. Correlations between accuracy and jaws of interest, implant length and diameters, and type of edentulism were also analysed. Results. A total of 50 implants were inserted in 15 patients using CAD-CAM templates: 23 implants in group A and 27 in group B. The mean coronal deviations were 1.16 and 1.11 mm (P = 0.35), respectively; the mean apical deviations were 1.65 and 1.71 mm (P = 0.22); the mean depth deviations were 0.95 and −0.68 mm (P = 0.032); the mean buccolingual angular deviations were 4.16° and 6.72° (P = 0.042); and the mean mesiodistal ones were 2.81° and 5.61° (P = 0.029). In addition, the accuracy was statistically influenced only by implant diameter for coronal discrepancy (P = 0.035) and by jaw of interest for mesiodistal angulation (P = 0.045). Conclusion. Fully guided implant surgery was more accurate than pilot-drill guided surgery for different parameters. For both types of surgery, a safety margin of at least 2mm should be preserved during implant planning to prevent damage to nearby anatomical structures.

Accuracy of Three-Dimensional Printed Templates for Guided Implant Placement Based on Matching a Surface Scan with CBCT.

Reference elements are necessary to transfer a virtual planning into reality for guided implant placement. New systems allow matching optical scans with three-dimensional radiographic images. To test whether digitally designed three-dimensional printed templates (D-temp) fabricated by matching surface scans and cone beam computed tomography (CBCT) images differ from the templates fabricated in-lab (L-temp) by using a physical transfer device for the positioning of the guiding sleeves. L-temp were fabricated for eight human lower cadaver-jaws applying a digital planning software program (smop, Swissmeda AG, Zürich, Switzerland) using a Lego® (Lego Group, KIRKBI A/S, Billund, Denmark) brick as reference element and the respective transfer device (X1-table). Additionally, digital templates (D-temp) using the identical planning data sets and software were virtually designed and three-dimensional printed, after matching a surface scan with CBCT data. The accuracy of both templates for each planning was evaluated determining the estimated coronal, apical, and angular deviation if templates were used for implant placement. Mean coronal deviations for L-temp were 0.31 mm (mesial/distal), 0.32 mm (lingual/buccal), and 0.16 mm and 0.23 mm for D-temp, respectively. The mean apical deviations for L-temp were 0.50 mm (mesial/distal), 0.50 mm (lingual/buccal). and 0.25 mm and 0.34 mm for the D-temp, respectively. Differences between both devices were statistically significant (p < .05). A higher accuracy of implant placement can be achieved by using three-dimensional printed templates produced by matching a surface scan and CBCT as compared with templates which use physical elements transferring the virtual planning into reality.

Implant Bed Preparation with an Erbium, Chromium Doped Yttrium Scandium Gallium Garnet (Er,Cr: YSGG) Laser Using Stereolithographic Surgical Guide.

Implant bed preparation with laser is taken into consideration owing to the increased interest in use of lasers in hard tissue surgery. The purpose of this study is to determine the deviations in the position and inclination between the planned and prepared implant beds with Erbium, Chromium doped Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser using stereolithographic (SLA) surgical guides. After 3-dimensional (3D) imaging of six sheep lower jaws, computed tomography (CT) images were transformed into 3D models. Locations of implant beds were determined on these models. Two implant beds in each half jaw were prepared with an Er,Cr:YSGG laser system and a conventional drilling method using a total of 12 SLA surgical guides. A new CT was taken to analyze the deviation values between planned and prepared implant beds. Finally, a software program was used to superimpose the images on 3D models, then the laser and conventional drilling groups were compared. Differences of mean angular deviations between the planned and prepared implant beds were 5.17±4.91° in the laser group and 2.02±1.94° in the conventional drilling group.The mean coronal deviation values were found to be 0.48±0.25 mm and 0.23±0.14 mm in the laser group and conventional drilling group, respectively. While the mean deviation at the apex between the planned and prepared implant beds were 0.70±0.26 mm and 0.26±0.08 ,the mean vertical deviations were 0.06±0.15 mm and 0.02±0.05 mm for the laser group and the conventional drilling group, respectively. It is possible to prepare an implant bed properly with the aid of Er,Cr:YSGGlaser by using SLA surgical guide.

Accuracy of a Newly Developed Cone-Beam Computerized Tomography-Aided Surgical Guidance System for Dental Implant Placement: An Ex Vivo Study

The aim of the present study was to measure the accuracy of the cone-beam computerized tomography (CBCT)- aided StentCad Beyond surgical guidance system and to compare bone-supported and tooth/bone-supported guidance by using this system in dental implant placement ex vivo. Five cadaver mandibles were scanned using an Iluma CBCT scanner. After scanning, DICOM slices were transferred to the StentCad Beyond implant simulation software, which was used for preoperative implant planning. Using the StentCad Beyond guidance system, 9 implant drills were inserted using a bone-supported guidance system and 11 using a tooth/bone-supported guidance system. Mandibles were scanned again and these data were transferred to the StentCad Beyond software. Pre- and postoperative information was superimposed using the Rhinoceros version 4 software program, and deviations between planned and actual drill positions were calculated for each implant. In addition, differences between bone-supported and tooth/bone-supported guidance systems were analyzed by t-test, with a significance level of P < .05. Data analysis found a mean coronal deviation of 1.2 ± 0.3 mm and 0.6 ± 0.6 mm, mean apical deviation of 1.3 ± 0.6 mm and 0.7 ± 0.6 mm, mean apical and coronal depth deviation of 1.4 ± 0.3 mm and 1.3 ± 0.3 mm, and mean angular deviation of 4.2° ± 2.0° and 3.0° ± 1.5° for tooth/bone supported and bone-supported guides, respectively. No statistical differences were found in depth or angular deviations between groups (P > .05); however, statistically significant differences between groups were found in mean horizontal coronal deviation (P = .016) and mean horizontal apical deviation (P = .047). The StentCad Beyond system was found to be a reliable guide for placing implants ex vivo.

Effect of Smoking Habits on Accuracy of Implant Placement Using Mucosally Supported Stereolithographic Surgical Guides

Smoking is considered as a factor for implant survival and peri-implant bone loss of dental implants. Several studies revealed the negative effect of smoking on osseointegration and its dose-related effect. To evaluate the effect of smoking habits on accuracy of implant placement using mucosally supported stereolithographic surgical guides. Six OsseoSpeed™ implants (Astra Tech AB, Mölndal, Sweden) were inserted into the maxilla in 13 patients. Patients were excluded if they suffered from any systemic disease or if they were actually taking any kind of medication. Software (Mimics® 9.0) was used to fuse images of the virtually planned and actually placed implants, and locations and axes were compared between the nonsmoking and smoking subgroups. As the mucosal biotype could probably influence accuracy data, 12 reference points were defined within each patient to define a mean mucosal thickness value. In the smoking subgroup, 36 implants were placed compared with 42 in the nonsmoking subgroup. Mean coronal deviation was 1.04mm (range: 0.29-2.45mm) among the smokers compared with 0.80mm among the nonsmokers (range: 0.29-1.67mm). At apical point, mean deviation was 1.26mm (range: 0.39-3.01mm) among the smokers compared with 1.02mm among the nonsmokers (range: 0.32-2.59mm). Mean angular deviation was 2.64° (range: 0.41-6.81°) among the smokers compared with 2.57° among the nonsmokers (range: 0.16°-8.86°). Significant differences were found when comparing global coronal and apical deviation between the smokers and the nonsmokers (p<.05). Evaluating mucosal thickness, mean value was 3.19mm (range: 2.39-4.01mm) among the smokers compared with 2.43mm among the nonsmokers (range: 1.44-3.03mm). Statistically significant differences were found when comparing the accuracy of dental implant placement of the smokers with the nonsmokers. Smokers have significant thicker supporting mucosal tissues compared with nonsmokers, which may explain inaccuracy due to less stability of the surgical guide or the scanning prosthesis.