Stereolithographic Surgical Guides Research Articles

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.

Clinical Accuracy of Flapless Computer-Guided Surgery for Implant Placement in Edentulous Arches

Although flapless computer-guided implant placement provides important benefits, deviations from the planned implant placement in the edentulous arch may pose significant risks. This study evaluated the reliability and accuracy of a flapless computer-guided surgical approach. Computer-generated preoperative implant planning was compared to actual placement by cone-beam computerized tomography (CBCT) scanning of patients before and after surgery. A well-fitting complete denture or optimized prosthetic tooth arrangement was used and converted to a radiographic template. Prior to scanning, esthetics and functional aspects were checked clinically. The implant positions were virtually determined by the implant planning software relative to the bone structure and prospective tooth position. After implant placement, new CBCT scans were obtained for each subject. Software was used to fuse the images of the planned and placed implants, and the locations and axes were compared. The normality of the data distribution was evaluated by the Kolmogorov-Smirnov test. Mean values were compared between groups based on the upper or lower jaws with the t test for independent samples. The level of significance was fixed at 5%. Sixty-two implants were placed in edentulous arches with stereolithographic surgical guides in 14 patients. Damage due to implant placement was not observed in any critical anatomical structure. Compared to the planned implants, placed implants showed mean and standard deviation linear measurements at the cervical, middle, and apical implant portions of 2.17 (± 0.87), 2.32 (± 1.52), and 2.86 (± 2.17) mm, for the maxilla, and 1.42 (± 0.76), 1.42 (± 0.76), and 1.42 (± 0.76) mm, for the mandible, respectively. The angular deviations were 1.93 (± 0.17) and 1.85 (± 0.75) degrees for the maxilla and mandible, respectively. The linear deviation differed significantlybetween the upper and lower jaws, but the angular deviation did not. Flapless computer-guided surgery may be a viable treatment option for rehabilitating the edentulous arch.

Implant Positioning Errors in Freehand and Computer-Aided Placement Methods: A Single-Blind Clinical Comparative Study

Simultaneous insertion of multiple implants may exhibit suboptimal positions, especially in edentulous jaws considered for a fixed restoration. The aim of this study was to compare the incidence of and confounding factors in implant positioning errors related to the use of freehand and computer-aided treatment methods. A total of 353 implants were placed in 54 patients with at least one edentulous jaw using freehand and computer-aided methods involving 16 mucosa- and 12 bone-supported single- and multiple-type stereolithographic surgical guides. At the stage of prosthesis delivery, a blinded examiner evaluated seven positioning error criteria. Results were analyzed by chi-square test and logistic regression. Interproximal emergence (OR = 2.82, P < .0001), insufficient interimplant distance (OR = 1.42, P < .0001), and improper parallelism (OR = 1.24, P = .001) errors were significantly higher in implants placed by the freehand method. The highest probability of positioning error (88%) was associated with the use of the freehand method, whereas the lowest (6%) was associated with single-type, mucosa-supported guides with other significant confounding factors. Utilizing computer-aided methods may alleviate the occurrence of implant positioning errors that are frequently associated with the freehand method. The use of software planning with enhanced viewing capabilities and single-type, mucosa-supported stereolithographic surgical guides in suitable patients minimizes errors.

Accuracy of three different types of stereolithographic surgical guide in implant placement: An in vitro study

Precise treatment planning before implant surgery is necessary to identify vital structures and to ensure a predictable restorative outcome. The purpose of this study was to compare the accuracy of implant placement by using 3 different types of surgical guide: bone-supported, tooth-supported, and mucosa-supported. Thirty acrylic resin mandibles were fabricated with stereolithography (SLA) based on data from the cone beam computerized tomography (CBCT) scan of an edentulous patient. Ten of the mandibles were modified digitally before fabrication with the addition of 4 teeth, and 10 of the mandibles were modified after fabrication with soft acrylic resin to simulate mucosa. Each acrylic resin mandible had 5 implants virtually planned in a 3-D software program. A total of 150 implants were planned and placed by using SLA guides. Presurgical and postsurgical CBCT scans were superimposed to compare the virtual implant placement with the actual implant placement. For statistical analyses, a linear mixed models approach and t-test with the 2-sided alpha level set at .016 were used. All reported P values were adjusted by the Dunn-Sidak method to control the Type I error rate across multiple pairwise comparisons. The mean angular deviation of the long axis between the planned and placed implants was 2.2 ±1.2 degrees; the mean deviations in linear distance between the planned and placed implants were 1.18 ±0.42 mm at the implant neck and 1.44 ±0.67 mm at the implant apex for all 150 implants. After the superimposition procedure, the angular deviation of the placed implants was 2.26 ±1.30 degrees with the tooth-supported, 2.17 ±1.02 degrees with the bone-supported, and 2.29 ±1.28 degrees with the mucosa-supported SLA guide. The mean deviations in linear distance between the planned and placed implants at the neck and apex were 1.00 ±0.33 mm and 1.15 ±0.42 mm for the tooth-supported guides; 1.08 ±0.33 mm and 1.53 ±0.90 mm for the bone-supported guides; and 1.47 ±0.43 mm and 1.65 ±0.48 mm for the mucosa-supported SLA surgical guides. The results of this study show that stereolithographic surgical guides may be reliable in implant placement and that: 1) there was no statistically significant difference among the 3 types of guide when comparing angular deviation and 2) mucosa-supported guides were less accurate than both tooth-supported and bone-supported guides for linear deviation at the implant neck and apex.

Accuracy and Complications Using Computer‐Designed Stereolithographic Surgical Guides for Oral Rehabilitation by Means of Dental Implants: A Review of the Literature

In the last decade several stereolithographic guided surgery systems were introduced to the market. In this context, scientific information regarding accuracy of implant placement and surgical and prosthodontical complications is highly relevant as it provides evidence to implement this surgical technique in a clinical setting. To review data on accuracy and surgical and prosthodontical complications using stereolithographical surgical guides for implant rehabilitation. PubMed database was searched using the following keywords: "three dimensional imaging,""image based surgery,""flapless guided surgery,""customized drill guides,""computer assisted surgery,""surgical template," and "stereolithography." Only papers in English were selected. Additional references found through reading of selected papers completed the list. In total 31 papers were selected. Ten reported deviations between the preoperative implant planning and the postoperative implant locations. One in vitro study reported a mean apical deviation of 1.0 mm, three ex vivo studies a mean apical deviation ranging between 0.6 and 1.2 mm. In six in vivo studies an apical deviation between 0.95 and 4.5 mm was found. Six papers reported on complications mounting to 42% of the cases when stereolithographic guided surgery was combined with immediate loading. Substantial deviations in three-dimensional directions are found between virtual planning and actually obtained implant position. This finding and additionally reported postsurgical complications leads to the conclusion that care should be taken whenever applying this technique on a routine basis.

A Prospective Study on the Accuracy of Mucosally Supported Stereolithographic Surgical Guides in Fully Edentulous Maxillae

Flapless implant placement using guided surgery is widespread, although clinical publications on the precision are lacking. The purpose of this study was to evaluate the accuracy of mucosal-supported stereolithographic guides in the edentulous maxillae. Seventy-eight OsseoSpeed™ implants (Astra Tech AB, Mölndal, Sweden) of 3.5 to 5 mm width and 8 to 15 mm length were installed consecutively in 13 patients. Implants were functionally loaded on the day of surgery, and implant location was assessed with a computed tomography scan. Mimics 9.0 software (Materialise N.V., Leuven, Belgium) was used to fuse the images of the virtually planned and actually placed implants, and the locations, axes, and interimplant distances were compared. One implant was lost shortly after insertion because of abscess formation caused by remnants of impression material. Seventy-seven implant locations were analyzed. The deviation at the entrance point ranged between 0.29 mm and 2.45 mm (SD: 0.44 mm), with a mean of 0.91 mm. Average angle deviation was 2.60° (range 0.16-8.86°; SD: 1.61°). At the apical point, the deviation ranged between 0.32 mm and 3.01 mm, with a mean of 1.13 mm (SD: 0.52 mm). The mean deviation of the coronal and apical interimplant distance was respectively 0.18 mm (range 0.07-0.32 mm; SD: 0.15) and 0.33 mm (range 0.12-0.69 mm; SD: 0.28). These deviations are lower than the global coronal and apical deviations. The present study is the first to investigate the accuracy of stereolithographic, full, mucosally supported surgical guides in the treatment of fully edentulous maxillae. Clinicians should be warned that angular and linear deviations are to be expected. Short implants show significantly lower apical deviations compared with longer ones. Reasons for implant deviations are multifactorial; however, it is unlikely that the production process of the guide has a major impact on the total accuracy of a mucosal-supported stereolithographic guide.

The reliability of cone‐beam computed tomography to assess bone density at dental implant recipient sites: a histomorphometric analysis by micro‐CT

The aim of this study was to objectively assess the reliability of the cone-beam computed tomography (CBCT) as a tool to pre-operatively determine radiographic bone density (RBD) by the density values provided by the system, analyzing its relationship with histomorphometric bone density expressed as bone volumetric fraction (BV/TV) assessed by micro-CT of bone biopsies at the site of insertion of dental implants in the maxillary bones. Thirty-nine bone biopsies of the maxillary bones at the sites of 39 dental implants from 31 edentulous healthy patients were analyzed. The NobelGuide™ software was used for implant planning, which also allowed fabrication of individual stereolithographic surgical guides. The analysis of CBCT images allowed pre-operative determination of mean density values of implant recipient sites along the major axis of the planned implants (axial RBD). Stereolithographic surgical guides were used to guide implant insertion and also to extract cylindrical bone biopsies from the core of the exact implant site. Further analysis of several osseous micro-structural variables including BV/TV was performed by micro-CT of the extracted bone biopsies. Mean axial RBD was 478±212 (range: 144-953). A statistically significant difference (P=0.02) was observed among density values of the cortical bone of the upper maxilla and mandible. A high positive Pearson's correlation coefficient (r=0.858, P<0.001) was observed between RBD and BV/TV, with the regression equations: (1) Axial RBD=-19.974+10.238·BV/TV; (2) BV/TV=14.258+0.72·Axial RBD. RBD was also positively correlated with the trabecular thickness (Tb.Th) and trabecular number (Tb.N), but negatively correlated with trabecular separation (Tb.Sp), structural model index, and inverse connectivity (Tb.Pf). Density values upper than 450 were associated with BV/TV upper than 50%, mean Tb.Th upper than 0.2mm, mean Tb.Sp lower than 0.3mm, and mean Tb.N upper than 2. RBD assessed by CBCT has a strong positive correlation with BV/TV assessed by micro-CT at the site of dental implants in the maxillary bones. Pre-operative estimation of density values by CBCT is a reliable tool to objectively determine bone density.

Conventional Multi‐Slice Computed Tomography (CT) and Cone‐Beam CT (CBCT) for Computer‐Assisted Implant Placement. Part I: Relationship of Radiographic Gray Density and Implant Stability

The relationship of conventional multi-slice computed tomography (CT)- and cone beam CT (CBCT)-based gray density values and the primary stability parameters of implants that were placed by stereolithographic surgical guides were analyzed in this study. Eighteen edentulous jaws were randomly scanned by a CT (CT group) or a CBCT scanner (CBCT group) and radiographic gray density was measured from the planned implants. A total of 108 implants were placed, and primary stability parameters were measured by insertion torque value (ITV) and resonance frequency analysis (RFA). Radiographic and subjective bone quality classification (BQC) was also classified. Results were analyzed by correlation tests and multiple regressions (p < .05). CBCT-based gray density values (765 ± 97.32 voxel value) outside the implants were significantly higher than those of CT-based values (668.4 ± 110 Hounsfield unit, p < .001). Significant relations were found among the gray density values outside the implants, ITV (adjusted r(2) = 0.6142, p = .001 and adjusted r(2) = 0.5166, p = .0021), and RFA (adjusted r(2) = 0.5642, p = .0017 and adjusted r(2) = 0.5423, p = .0031 for CT and CBCT groups, respectively). Data from radiographic and subjective BQC were also in agreement. Similar to the gray density values of CT, that of CBCT could also be predictive for the subjective BQC and primary implant stability. Results should be confirmed on different CBCT scanners.

Conventional Multi‐Slice Computed Tomography (CT) and Cone‐Beam CT (CBCT) for Computer‐Aided Implant Placement. Part II: Reliability of Mucosa‐Supported Stereolithographic Guides

Deviations of implants that were placed by conventional computed tomography (CT)- or cone beam CT (CBCT)-derived mucosa-supported stereolithographic (SLA) surgical guides were analyzed in this study. Eleven patients were randomly scanned by a multi-slice CT (CT group) or a CBCT scanner (CBCT group). A total of 108 implants were planned on the software and placed using SLA guides. A new CT or CBCT scan was obtained and merged with the planning data to identify the deviations between the planned and placed implants. Results were analyzed by Mann-Whitney U test and multiple regressions (p < .05). Mean angular and linear deviations in the CT group were 3.30° (SD 0.36), and 0.75 (SD 0.32) and 0.80 mm (SD 0.35) at the implant shoulder and tip, respectively. In the CBCT group, mean angular and linear deviations were 3.47° (SD 0.37), and 0.81 (SD 0.32) and 0.87 mm (SD 0.32) at the implant shoulder and tip, respectively. No statistically significant differences were detected between the CT and CBCT groups (p = .169 and p = .551, p = .113 for angular and linear deviations, respectively). Implant placement via CT- or CBCT-derived mucosa-supported SLA guides yielded similar deviation values. Results should be confirmed on alternative CBCT scanners.

Significance of cone beam computed tomography based implant treatment planning and fabrication of stereolithographic surgical guides for implant therapy in the nasopalatine canal region

Implants are being used in practice today with ever increasing types of implants and simple procedures through which dentists can place them. However, the chance for a complication to occur while placing implants has been largely under-estimated. This is primarily because emphasis is not placed in avoiding important neurovascular structures such as the nasopalatine canal during implant surgery. Cone beam computed tomography (CBCT) is being widely utilized in implant treatment planning. Third-party software is applied to CBCT data to enable treatment planning. Several of these treatment plans are used to fabricate stereo lithographic guides which will help with placement of the implant at the planned site with total precision. This case-review explains how CBCT can help in placing implants with the help of a surgical guide in anatomically challenged areas such as the nasopalatine canal.

Stereoscopic Technique for Conversion of Radiographic Guide into Implant Surgical Guide

The aim of this study was to develop and evaluate a new stereoscopic technique for conversion of radiographic guide into surgical guide for dental implant placement. Ten partially dentate patients requiring 18 implants for tooth replacement were recruited. Radiographic guides were modified with the addition of index rods for double computed tomography scanning. Implant positions were planned with implant planning software, and the stereoscopic angulations were measured. The radiographic guides were converted into surgical guides using either a generic bench drill (Group A, n = 9) or a milling machine (Group B, n = 9). Stereolithographic surgical guides were also made for three patients (Group S, n = 5). Differences between the planned and actual angulations were tested by pair-sample t-test. Difference of mean angle deviation among groups was tested by Brown-Forsythe test. Differences were considered significant if p < .05. Eighteen implant sites were successfully treated with the converted surgical guides. The mean angle deviation of Group A (1.3 ± 0.6°) was significantly greater than Group S (0.4 ± 0.6°), while no differences were found between Group B (0.9 ± 0.3°) and Group S. The linear error was greatest in Group A with 1.5 mm at the head and 1.8 mm at the apex of the implant. The use of this new stereoscopic technique appears to be an acceptable alternative method for converting radiographic guide into surgical guide.

Correlation Between Bone Density and Angular Deviation of Implants Placed Using CT-Generated Surgical Guides

The aim of this study was to evaluate the correlation between the density of bone where implants were placed and the angular deviations that occurred between the virtually planned and actually placed implants using 2 different stereolithographic surgical guides. The study population consisted of 54 patients who received 216 implants. Computed tomography machine was used for preoperative evaluation of the jawbone for implant therapy as well as determination of the bone density values (Hounsfield units [HU]) of the implantation site. All implant sockets were prepared using 2 different types of stereolithographic surgical guide. Ninety-four implants were installed using the surgical guides (Stentcad Beyond, Ay-Design; Kos-gep, ODTU, Ankara, Turkey) in the mouth, whereas 122 implants were placed after the surgical guides (Stentcad Classic; Kos-gep, ODTU) were removed. The mean bone densities of maxilla and mandible were 561.36 (SD, 229.46) HU and 890.63 (SD, 361.85) HU, respectively. The mean angular deviations between planned and placed implants using Stentcad Classic and Stentcad Beyond surgical guides were 5.32 (SD, 1.96) degrees and 3.73 (SD, 1.14) degrees, respectively. Highly negative correlation was found between the bone density of the placed implant sites and angular deviations in the group in whom implants were installed with freehand. The lower bone density values have resulted in the greater angular deviations in the group, in whom the implants were placed after the surgical guides were removed. This deviation might have been derived from the freehand placement of the implants and the poor quality of the bone.

Clinical Application of Stereolithographic Surgical Guide With a Handpiece Guidance Apparatus: A Case Report

The success of implant-supported restorations depends on the treatment planning and the transfer of planning through the surgical field. Recently, new computer-aided design and manufacturing (CAD/CAM) techniques, such as stereolithographic (SLA) rapid prototyping, have been developed to fabricate surgical guides to improve the precision of implant placement. The objective of the present case is to introduce a recently developed SLA surgical guide system into the rehabilitation of a 62-year-old male patient with mandibular edentulism. After obtaining a cone-beam computerized tomography (CBCT) scan of the mandible with a radiographic template, the images were transferred into a 3-dimensional (3D) image-based software for implant planning. The StentCad Beyond SLA surgical guide system, which is a combination of a currently used surgical template with pilot hollows and a surgical handpiece guidance apparatus, was designed to transfer a preoperatively defined implant position onto the surgical site without any drill-surgical guide contact. For the fabrication of this system, a surgical handpiece was scanned by a laser optical scanner and a mucosa-supported surgical guide was designed according to the patient's 3D model, which was attained from the CBCT images. Four dental implants were inserted through the SLA surgical guide system by a torque-controlled surgical handpiece to the interforaminal region via a flapless surgical procedure. Implants were assessed 3 months after surgery, and an implant-retained mandibular overdenture was fabricated. The present case emphasizes that CAD/CAM SLA surgical guides, along with CBCT images and scanning data, may help clinicians plan and place dental implants.

Accuracy of Two Stereolithographic Surgical Templates: A Retrospective Study

The use of computer software and stereolithography for dental implant therapy has significantly increased during the last few years. The aim of this study was to evaluate and compare the mean accuracy and maximum deviations values of dental implant placement using two stereolithographic (SLA) guide systems. Twenty patients were selected and 227 implants were inserted using bone-, tooth- and mucosa-supported SLA surgical guides. Thirty-one guides, both single- and multiple-type, were used. Some of the single-type surgical guides were fixed with osteosynthesis screws. A postoperative computer tomography (CT) was performed and an iterative closest point algorithm was used to match the jaw of the CT preoperative with the jaw of the postoperative CT. Quantitative data of each group were described. The t-test was used to determine the influence of the utilization of the different types of SLA on accuracy values. t-Test demonstrated a better accuracy of the multiple-type guides in almost all deviation values when the mucosa-supported guides were considered. Regarding the bone-supported template, the single-type fixed group showed a better accuracy while the highest values of deviation were registered by the multiple-type guides. The single-type group showed a better accuracy when the tooth support was considered. The results of the present study indicated best accuracy of the single-type guide using a bone or tooth support. The multiple-type guide recorded the best accuracy data when the mucosa support was considered comparing either a fixed and a not-fixed single-type guide.

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.

Accuracy Evaluation of Computed Tomography–Derived Stereolithographic Surgical Guides in Zygomatic Implant Placement in Human Cadavers

Presurgical planning is essential to achieve esthetic and functional implants. For implant planning and placement, the association of computer-aided design (CAD) and computer-aided manufacturing (CAM) techniques furnishes some advantages regarding tridimensional determination of the patient's anatomy and fabrication of both anatomic models and surgical guides. The goal of this clinical study was to determine the angular deviations between planned and placed zygomatic implants using stereolithographic surgical guides in human cadavers. A total of 16 zygomatic implants were placed, 4 in each cadaver, with the use of stereolithographic (SLA) surgical guides generated by computed tomography (CT). A new CT scan was made after implant insertion. The angle between the long axis of the planned and actual implants was calculated. The mean angular deviation of the long axis between the planned and placed implants was 8.06 ± 6.40 (mean ± SD) for the anterior-posterior view, and 11.20 ± 9.75 (mean ± SD) for the caudal-cranial view. Use of the zygomatic implant, in the context of this protocol, should probably be reevaluated because some large deviations were noted. An implant insertion guiding system is needed because this last step is carried out manually. It is recommended that the sinus slot technique should be used together with the CT-based drilling guide to enhance final results. Further research to enhance the precision of zygomatic implant placement should be undertaken.

Accuracy of Two Stereolithographic Guide Systems for Computer‐Aided Implant Placement: A Computed Tomography‐Based Clinical Comparative Study

Stereolithographic surgical guides provide significant benefits during the simultaneous placement of multiple implants with regard to the final prosthetic plan. However, deviation from the planning poses a significant risk. Deviations of implants that were placed by bone-, tooth-, and mucosa-supported stereolithographic surgical guides were examined in this study. After enrolling 54 eligible patients, 294 implants were planned on cone-beam computerized tomography CB(CT)-derived images. Sixty guides, both single- and multiple-type, were produced using two commercial systems. Mucosa-supported guides were fixed with osteosynthesis screws. Implants were inserted, and at the end of osseointegration period, a new CB(CT) scan was performed. Preoperative planning was merged with the new CB(CT) data to identify the deviations between the planned and placed implants for each support type and manufacturer. The Kruskal-Wallis and Mann-Whitney U tests were used for comparison (P <0.05). There were no damage-related complications in any critical anatomy. Implants that were placed by bone-supported guides had the highest mean deviations (5.0 degrees +/- 1.66 degrees angular, and 1.70 +/- 0.52 mm and 1.99 +/- 0.64 mm for implant shoulder and tip, respectively), whereas the lowest deviations were measured in implants that were placed by mucosa-supported guides (2.9 degrees +/- 0.39 degrees angular, and 0.7 +/- 0.13 mm and 0.76 +/- 0.15 mm for implant shoulder and tip, respectively). Computer-aided planning and manufacturing surgical guides in accordance with CB(CT) images may help clinicians place implants. Rigid screw fixation of a single guide incorporating metal sleeves and a special drill kit further minimizes deviations.

Clinical Accuracy of 3 Different Types of Computed Tomography-Derived Stereolithographic Surgical Guides in Implant Placement

Presurgical planning is essential to achieve esthetic and functional implants. The goal of this clinical study was to determine the angular and linear deviations at the implant neck and apex between planned and placed implants using stereolithographic (SLA) surgical guides. A total of 110 implants were placed using SLA surgical guides generated from computed tomography (CT). All patients used the radiographic templates during CT scanning. After obtaining 3-dimensional CT scans, each implant insertion was simulated on the CT images. SLA surgical guides using a rapid prototyping method including a laser beam were used during implant insertion. A new CT scan was made for each patient after implant insertion. Special software was used to match images of the planned and placed implants, and their positions and axes were compared. The mean angular deviation of all placed implants was 4.1 degrees+/-2.3 degrees, whereas mean linear deviation was 1.11+/-0.7 mm at the implant neck and 1.41+/-0.9 mm at the implant apex compared with the planned implants. The angular deviations of the placed implants compared with the planned implants were 2.91 degrees+/-1.3 degrees, 4.63 degrees+/-2.6 degrees, and 4.51 degrees+/-2.1 degrees for the tooth-supported, bone-supported, and mucosa-supported SLA surgical guides, respectively. The results of this study suggested that stereolithographic surgical guides using CT data may be reliable in implant placement, and tooth-supported SLA surgical guides were more accurate than bone- or mucosa-supported SLA surgical guides.

Complete arch implant rehabilitation using subtractive rapid prototyping and porcelain fused to zirconia prosthesis: A clinical report

The applications of various technological advances in implant dentistry and in all aspects of the diagnostic, treatment planning, surgical, and restorative phases are gaining popularity. Additive rapid prototyping and computer-aided design/computer-aided manufacturing (CAD/CAM) technology are used to generate stereolithographic surgical guides and prefabricated interim prostheses to facilitate implant surgery and immediate loading, respectively. Subtractive rapid prototyping is used for fabrication of zirconia frameworks for definitive implant prostheses. This clinical report describes the comprehensive application of these technological advances in implant rehabilitation to optimize surgical and prosthodontic outcomes as well as patient comfort.

Reliability of Implant Placement With Stereolithographic Surgical Guides Generated From Computed Tomography: Clinical Data From 94 Implants

Dental implant placement requires precise planning with regard to anatomic limitations and restorative goals. The aim of this study was to evaluate the match between the positions and axes of the planned and placed implants using stereolithographic (SLA) surgical guides. Ninety-four implants were placed using SLA surgical guides generated from computed tomography (CT) between 2005 and 2006. Radiographic templates were used for all subjects during CT imaging. After obtaining three-dimensional CT images, each implant was virtually placed on the CT images. SLA surgical guides, fabricated using an SLA machine with a laser beam to polymerize the liquid photo-polymerized resin, were used during implant placement. A new CT scan was taken for each subject following implant placement. Special software was used to fuse the images of the planned and placed implants, and the locations and axes were compared. Compared to the planned implants, the placed implants showed angular deviation of 4.9 degrees+/-2.36 degrees, whereas the mean linear deviation was 1.22+/-0.85 mm at the implant neck and 1.51+/-1 mm at the implant apex. Compared to the implant planning, the angular deviation and linear deviation at the neck and apex of the placed maxillary implants were 5.31 degrees+/-0.36 degrees, 1.04+/-0.56 mm, and 1.57+/-0.97 mm, respectively, whereas corresponding figures for placed mandibular implants were 4.44 degrees+/-0.31 degrees, 1.42+/-1.05 mm, and 1.44+/-1.03 mm, respectively. SLA surgical guides using CT data may be reliable in implant placement and make flapless implant placement possible.