Accuracy of computer-guided surgery for dental implant placement in fully edentulous patients: A systematic review

Accuracy of implant placement using a mixed reality-based dynamic navigation system versus static computer-assisted and freehand surgery: An in Vitro study

PURPOSE

This in vitro study aimed to compare the accuracy of dental implant placement in partially edentulous maxillary models using a mixed reality-based dynamic navigation (MR-DN) system to conventional static computer-assisted implant surgery (s-CAIS) and a freehand (FH) method.

METHODS

Forty-five partially edentulous models (with teeth missing in positions #15, #16 and #25) were assigned to three groups (15 per group). The same experienced operator performed the model surgeries using an MR-DN system (group 1), s-CAIS (group 2) and FH (group 3). In total, 135 dental implants were placed (45 per group). The primary outcomes were the linear coronal deviation (entry error; En), apical deviation (apex error; Ap), XY and Z deviations, and angular deviation (An) between the planned and actual (post-surgery) position of the implants in the models. These deviations were computed as the distances between the stereolithographic (STL) files for the planned implants and placed implants captured with an intraoral scanner.

RESULTS

Across the three implant sites, the MR-DN system was significantly more accurate than the FH method (in XY, Z, En, Ap and An) and s-CAIS (in Z, Ap and An), respectively. However, S-CAIS was more accurate than MR-DN in XY, and no difference was found between MR-DN and s-CAIS in En.

CONCLUSIONS

Within the limits of this study (in vitro design, only partially edentulous models), implant placement accuracy with MR-DN was superior to that of FH and similar to that of s-CAIS.

STATEMENT OF CLINICAL RELEVANCE

In vitro, MR-DN showed greater accuracy in implant positioning than FH, and similar accuracy to s-CAIS: it could, therefore, represent a new option for the surgeon. However, clinical studies are needed to determine the feasibility of MR-DN.

In vitro and in vivo accuracy of autonomous robotic vs. fully guided static computer-assisted implant surgery

OBJECTIVES

To assess the accuracy of autonomous robotic and fully guided static computer-assisted implant surgery (sCAIS) performed on models and patients.

MATERIALS AND METHODS

This study was divided into in vitro and in vivo sections. In vitro, 80 operators were assigned to two groups randomly. Forty operators performed forty autonomous robotic implant (ARI group) surgeries and the remaining forty operators carried out forty fully guided sCAIS (FGI group) surgeries on maxillary models, respectively. Each operator placed an implant in one maxillary model. In vivo, 60 patients with 113 implants from 2019 to 2023 (ARI group: 32 patients, 58 implants; FGI group: 28 patients, 55 implants) receiving implant surgeries were incorporated in this retrospective research. The preoperative and postoperative cone beam computer tomographs (CBCTs) were utilized to estimate the linear deviations and angular deviations in two-dimensional (2D) and three-dimensional (3D) space. The Pearson's chi-square test, Shapiro-Wilk test, Student's t test, Mann-Whitney U test and mixed models were applied, and p <0.05 was considered statistically significant.

RESULTS

In vitro, a total of 80 implants were enrolled and significant differences were found between the two groups (p < 0.001): The 3D deviation at the platform of ARI and FGI group was 0.58 ± 0.60 mm and 1.50 ± 1.46 mm, respectively, at the apex was 0.58 ± 0.60 mm and 1.78 ± 1.35 mm, respectively, and angle was 1.01 ± 0.87° and 2.93 ± 1.59°, respectively. Also, except for mesiodistal deviation at the implant platform, the rest linear and angular deviations in the ARI group were significantly lower than those in the FGI group in 2D space (p < 0.001). In vivo, a significantly lower mean of angular deviation (0.95 ± 0.50°, p < 0.001) and the linear deviation at both platform (0.45 ± 0.28 mm, p < 0.001) and apex (0.47 ± 0.28 mm, p < 0.001) were observed in ARI group when compared to the FGI group (4.31 ± 2.60°; 1.45 ± 1.27 mm; 1.77 ± 1.14 mm).

CONCLUSIONS

The use of autonomous robotic technology showed significantly higher accuracy than the fully guided sCAIS.

Impact of 3D imaging techniques and virtual patients on the accuracy of planning and surgical placement of dental implants: A systematic review

Aim

The integration of advanced technologies, including three-dimensional (3D) imaging modalities and virtual simulations, has significantly influenced contemporary approaches to preoperative planning in implant dentistry. Through a meticulous analysis of relevant studies, this review synthesizes findings related to accuracy outcomes in implant placement facilitated by 3D imaging in virtual patients.

Methods

A comprehensive literature search was conducted across relevant databases to identify relevant studies published to date. The inclusion criteria were studies utilizing 3D imaging techniques, virtual patients, and those focusing on the accuracy of dental implant planning and surgical placement. The selected studies were critically appraised for their methodological quality.

Results

After a rigorous analysis, 21 relevant articles were included out of 3021 articles. This study demonstrates the versatility and applicability of these technologies in both in vitro and in vivo settings. Integrating Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), cone bean computed tomography (CBCT), and advanced 3D reconstruction methodologies showcases a trend toward enhanced precision in implant planning and placement. Notably, the evaluation parameters varied, encompassing distances, discrepancies, and deviations in the implant placement. The ongoing integration of systems such as dynamic navigation systems, augmented reality, and sophisticated software platforms shows a promising trajectory for the continued refinement of virtual reality applications in dental implantology, providing valuable insights for future research and clinical implementation. Moreover, using stereolithographic surgical guides, virtual planning with CBCT data, and 3D-printed templates consistently demonstrates enhanced precision in dental implant placement compared to traditional methods.

Conclusion

The synthesis of the available evidence underscores the substantial positive impact of 3D imaging techniques and virtual patients on dental implant planning and surgical placement accuracy. Utilizing these technologies contributes to a more personalized and precise approach that enhances overall treatment outcomes. Future research directions and potential refinements to the application of these technologies in clinical practice should be discussed.

Clinical accuracy of partially guided implant placement in edentulous patients: A computed tomography-based retrospective study

OBJECTIVES

This retrospective study was intended to evaluate the clinical accuracy of partially guided template in guiding implant placement in edentulous patients.

METHODS

A total of 120 implants were placed in 24 patients with at least one completely edentulous arch with a partially guided system. Based on CBCT data, a repeatable method was used to measure linear and angular deviations of implants at 3D level in Mimics medical software. The influence of supporting tissue and implant region on the accuracy was assessed, followed by the evaluation of direction of linear deviations in biologically vital areas.

RESULTS

Linear deviations of all implants were 1.91 ± 0.68 mm, 1.47 ± 0.68 mm, and 1.02 ± 0.69 mm at apical, apical lateral, and apical vertical levels. When at the cervical, cervical lateral, and cervical vertical levels, the linear deviations were 1.53 ± 0.65 mm, 0.98 ± 0.53 mm, and 1.01 ± 0.69 mm, respectively. Angular deviation of all implants was 7.14 ± 3.41°. Implants guided by mucosa + tooth-supported templates showed higher linear deviations at apical vertical level (1.21 ± 0.72 mm vs. 0.86 ± 0.63 mm, p < .05) and cervical vertical level (1.18 ± 0.72 mm vs. 0.87 ± 0.63 mm, p < .05) than mucosa-supported templates, and implants in maxilla were found higher angular deviation than mandible (7.89 ± 3.61° vs. 6.29 ± 2.97°, p < .05).

CONCLUSIONS

The partially guided template served as clinically viable surgical assistance in implant placement in edentulous patients. When using mucosa + tooth-supported template or placing implants in maxilla, more caution was required, especially in biologically vital areas.

Accuracy in static guided implant surgery: Results from a multicenter retrospective clinical study on 21 patients treated in three private practices

PURPOSE

To evaluate the accuracy of a static computer-assisted implant surgery (s-CAIS) system across different private practices.

METHODS

This retrospective clinical study was based on data retrieved from 21 patients who received 61 implants between 2018 and 2020 in 3 private practices run by surgeons with extensive experience with s-CAIS. All patients were treated using the same s-CAIS system, planning software, template manufacturing process, and surgical guides. The standard tessellation language (STL) file of the intraoral scan of the fixture taken immediately after implant placement was matched with that of the preoperative plan for comparisons of preoperative and planned implant positions with postoperative and actual implant positions. The study outcomes were linear and angular deviations between the planned and actual implant positions.

RESULTS

No surgical or postsurgical complications occurred. The overlap of the two STL files resulted in a mean angular deviation of 2.94° The mean linear deviation at the implant shoulder was 0.73 mm, and that at the apex was 1.06 mm. The mean vertical deviations at the implant shoulder and the apex were 0.29 mm and 0.01 mm, respectively.

CONCLUSION

All cases showed satisfactory accuracy within the limits of this study (small number of patients and retrospective design). These results might be related to the use of a standardized digital workflow by experienced operators.

STATEMENT OF CLINICAL RELEVANCE

The study shows that careful control of each step, from data acquisition to final execution, is key for the accuracy of stent-guided systems.

Accuracy of autonomous robotic surgery for dental implant placement in fully edentulous patients: A retrospective case series study

OBJECTIVES

This study evaluated the accuracy of dental implant placement using the robotic computer-assisted implant surgery (r-CAIS) technology in fully edentulous patients.

MATERIALS AND METHODS

Fully edentulous and terminal dentition patients were enrolled for r-CAIS technology. Based on the cone-beam computed tomography (CBCT) examination, a customized positioning marker and a preoperative surgical plan were created before surgery. During the implant surgery, the implant osteotomy and placement were automatically performed using an autonomous robotic surgery system under the surgeon's supervision. A postoperative CBCT scan was used to determine the discrepancies between the planned and placed implants.

RESULTS

Ten patients with 59 implants underwent autonomous robotic surgery. No adverse surgical events occurred. The deviations of global coronal, global apical, and angular were 0.67 ± 0.37 mm (95% CI: 0.58-0.77 mm), 0.69 ± 0.37 mm (95% CI: 0.59-0.78 mm), and 1.27° ± 0.59° (95% CI: 1.42°-1.11°), respectively.

CONCLUSIONS

The autonomous r-CAIS technology proved an accurate surgical approach for implant placement in fully edentulous patients due to the control of the angular deviation. Autonomous robotic surgery seems promising as an accurate technology for treating fully edentulous patients. However, further trials are required to provide more hard clinical evidence.

Advancing accuracy in guided implant placement: A comprehensive meta-analysis: Meta-Analysis evaluation of the accuracy of available implant placement Methods

OBJECTIVES

This meta-analysis aimed to determine the accuracy of currently available computer-assisted implant surgery (CAIS) modalities under in vitro conditions and investigate whether these novel techniques can achieve clinically acceptable accuracy.

DATA

In vitro studies comparing the postoperative implant position with the preoperative plan were included. Risk of bias was assessed using the Quality Assessment Tool For In Vitro Studies (QUIN Tool) and a sensitivity analysis was conducted using funnel plots.

SOURCES

A systematic search was performed on April 18, 2023, using the following three databases: MEDLINE (via PubMed), EMBASE, and Cochrane Central Register of Controlled Trials. No filters or restrictions were applied during the search.

RESULTS

A total of 5,894 studies were included following study selection. Robotic- and static CAIS (sCAIS) had the most accurate and clinically acceptable outcomes. sCAIS was further divided according to the guidance level. Among the sCAIS groups, fully guided implant placement had the greatest accuracy. Augmented reality-based CAIS (AR-based CAIS) had clinically acceptable results for all the outcomes except for apical global deviation. Dynamic CAIS (dCAIS) demonstrated clinically safe results, except for horizontal apical deviation. Freehand implant placement was associated with the greatest number of errors.

CONCLUSIONS

Fully guided sCAIS demonstrated the most predictable outcomes, whereas freehand sCAIS demonstrated the lowest accuracy. AR-based and robotic CAIS may be promising alternatives.

CLINICAL SIGNIFICANCE

To our knowledge, this is the first meta-analysis to evaluate the accuracy of robotic CAIS and investigate the accuracy of various CAIS modalities.

An additively manufactured, magnetically retained, and stackable implant surgical guide: A dental technique

The digital workflow for designing and fabricating a magnetically retained and stackable additively manufactured implant surgical guide is described. The technique should improve the stability of the stackable surgical guide and the accuracy of implant placement.

The accuracy of implant placement using a combination of static and dynamic computer-assisted implant surgery in fully edentulous arches: A prospective controlled clinical study

OBJECTIVE

To compare the accuracy of implant position, using a combination of static and dynamic computer-assisted implant surgery (CAIS), with either static, dynamic, or freehand implant placement, in fully edentulous arches.

MATERIALS AND METHODS

Twenty-one patients with a total of 88 fixtures were included. Implants were divided equally into four groups: a combination of static and dynamic CAIS (SD group), static CAIS (S group), dynamic CAIS (D group), and freehand placement (FH group). Angular deviation, as well as the 3D platform and apex deviations, were measured for all groups. Furthermore, the direction of implant deviation was recorded and compared.

RESULTS

The FH group showed significantly more deviation compared to all groups, considering all the aspects, and at both the implant platform and apex. A significant difference in angular deviation between the SD and S groups (p < .001), and between the SD and D groups (p < .001) was noted, favoring the SD group. When evaluating implant distribution, the FH group showed a tendency towards the buccal, apical, and distal directions at platform and apex, while in the D group, implants shifted more to the buccal. In contrast, the SD group did not show a trend toward any specific direction. The S and SD groups did not show a statistical significance considering any direction.

CONCLUSIONS

The combination of static and dynamic CAIS increases the accuracy of implant placement in fully edentulous arches when compared with either static or dynamic CAIS alone, as well as freehand placement.

Accuracy and patient-centered results of static and dynamic computer-assisted implant surgery in edentulous jaws: a retrospective cohort study

OBJECTIVES

This study aimed to compare implant positioning accuracy and patient-centered results between static and dynamic computer-assisted implant surgery (s-CAIS and d-CAIS) in edentulous jaws.

MATERIAL AND METHODS

The current study retrospectively evaluated a total of 110 implants placed in 22 fully edentulous patients via s-CAIS or d-CAIS (n = 11). The accuracy of implant positioning was assessed by measuring the implant's angular deviation and deviation at the platform and apex from the preoperative design postoperatively. Patient-centered results, including preoperative and intraoperative patient-reported experiences and postoperative patient-reported outcomes, were extracted from the medical records. The nested t test and chi-square test were used to compare accuracy and patient-centered results between s-CAIS and d-CAIS postoperatively.

RESULTS

The implants in the s-CAIS group showed significantly smaller angular deviation (2.32 ± 1.23°) than those in the d-CAIS group (3.87 ± 2.75°). In contrast, the platform and apical deviation were significantly larger in s-CAIS (1.56 ± 1.19 mm and 1.70 ± 1.09 mm, respectively) than d-CAIS (1.02 ± 0.45 mm and 1.00 ± 0.51 mm, respectively). Furthermore, the implants in the s-CAIS group deviated significantly (p < 0.001) more toward the coronal direction than those in the d-CAIS group. Notably, all patients in the s-CAIS group reported an obvious foreign body sensation during surgery, representing a significant difference from the d-CAIS group.

CONCLUSIONS

Compared to s-CAIS, d-CAIS is a reliable technique for the placement of multiple implants in fully edentulous patients with less linear deviation and less foreign body sensation.

TRIAL REGISTRATION

The retrospective study was registered on the Chinese Clinical Trial Registry on August 8th, 2022, with registration number No. ChiCTR2200062484.

CLINICAL RELEVANCE

Despite the increasing use of computer- assisted implant surgery in fully edentulous patients, clinical evidence comparing implant positioning accuracy and patient-centered results between static and dynamic CAIS systems is scarce. Our study demonstrated that compared to s-CAIS, d-CAIS is a reliable technique for the placement of multiple implants in fully edentulous patients with less linear deviation.

Correlation between Accuracy in Computer-Guided Implantology and Peri-Implant Tissue Stability: A Prospective Clinical and Radiological Pilot Study

The present pilot study was designed by hypothesizing a possible correlation between lack of accuracy in implant placement and peri-implant hard and soft tissue health. A total of five patients underwent computer-guided implant surgery and full-arch immediate loading between 2013 and 2014. They subsequently underwent postoperative cone-beam computed tomography (CBCT). After a follow-up of 5 years, all patients were recalled for a clinical-radiographic evaluation of peri-implant health status. The mean linear deviation was 0.5 ± 0.2 mm at the implant's head and 0.6 ± 0.2 mm at the implant's apex, while the mean angular deviation of the long axis was 2.8° ± 1.2°. A mean marginal bone loss (MBL) of 1.16 ± 0.94 mm and 2.01 ± 1.76 mm was observed after 1 and 5 years of follow-up, respectively. At 5 years, the mean peri-implant probing depth (PPD) was 4.09 ± 1.44 mm, 66.6% of the evaluated implants showed peri-implant bleeding on probing (BOP), keratinized mucosa (KM) was <2 mm in 48.4% of cases, and mucosal recession (REC) ≥ 1 mm was assessed in 45.4% of the included implants. A negative correlation was observed between bucco-palatal/lingual linear inaccuracy and MBL, PPD, BOP, and KM.

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.

Clinical Outcome of Immediate Loading UV-Photofunctionalized Implants in Patients with Completely Edentulous Mandible, Placed with Guided Surgery

Objectives

The purpose of this study was to evaluate clinical results of immediate loading UV-photofunctionalized dental implants placed using guided surgery in patients with completely edentulous mandible.

Material and Methods

In this study, 58 fully edentulous patients were treated with immediate loading implant-supported mandibular prostheses. All patients underwent a thorough clinical examination according to the generally accepted scheme; qualitative and quantitative parameters of the jaw bones patients were diagnosed with cone beam computerized tomography (CBCT). Surgical templates modeled in the 3 Shape software were made from biocompatible polymeric materials and provided with depth-calibrated drill sleeves for preparing osteotomies using a 3D printer (Stratasys). Before short implant placement, ultraviolet functionalization of implant surfaces was performed by UV Activator YWJ-QSY001 (Foshan, Wenjian Medikal Enstriman) in the device for 20 s. After flapless surgery, implant sockets were prepared with guided surgery and implants were placed through the sleeves of the surgical template tightening torque of 35-45 Ncm. An implant-supported temporary prosthesis made of acrylic resin was installed 6 h after implantation. Final dental prosthetics was performed 2 months after implant placement.The patients had 128 short (length 5-6 mm, diameters 4,5-5 mm) and 256 implants with length greater than 10 mm in bone segments with sufficient bone parameters. The following parameters were assessed: implant success, prosthetics survival and changes in peri-implant marginal bone loss (MBL).

Results

During a clinical examination, no serious biological or prosthetic complications have been reported. The esthetic result evaluated from patients was excellent. The mean ISQ of short implants was 69.2 ± 8 for primary stability at implant placement and 73.6 ± 4 ISQ after 3 months. The mean of implants with length greater than 10 mm was 71,2ISQ at implant placement, respectively, and 75,6 ISQ after 3 months. After 3 months of prosthetic loading for short implants marginal bone loss (MBL) 0.74 mm, after 1 year of MBL 11.21 mm, after 5 years of MBL 1,37 mm, for implants with length greater than 10 mm after 3 months of MBL 0.72 mm, after 1 year of MBL 1.19 mm and after 5 years of MBL 1.35. There was no statistically significant difference in clinical indices between short and standard implants. After 5 years of follow-up, stable levels of bone tissue around the implants and healthy tissues around the implants were recorded, and postoperative occlusal function was favorable. The success rates of the short implants in maxilla were 95.5%, and the success rates of the short implants in mandible were 98.7%. The success rates of the implants with length greater than 10 mm in maxilla were 97.8%, and the success rates of the implants with length greater than 10 mm in mandible were 98.8%.

Conclusion

Computer-guided implant surgery and immediate loading of UV-photofunctionalized implants in patients with completely edentulous mandible are a predictable and effective method with a minimum rehabilitation period.

Comparison of the accuracy of implant position among freehand implant placement, static and dynamic computer-assisted implant surgery in fully edentulous patients: a non-randomized prospective study

The optimal implant position is a critical factor for long-term success in fully edentulous patients. Implants can be placed through conventional freehand, static computer-assisted implant surgery (CAIS), or dynamic CAIS protocols, but at present there is very limited clinical evidence on their accuracy in fully edentulous patients. This study was performed to evaluate the accuracy of implant placement using three protocols in fully edentulous patients. Thirteen patients received 60 implants with the freehand (n = 20), static CAIS (n = 20), or dynamic CAIS (n = 20) protocol. Postoperative cone beam computed tomography was utilized to evaluate the accuracy of implant placement in relation to the planned optimal position. The data were analysed by ANCOVA followed by Bonferroni analysis. The mean angular deviation (standard deviation) in the freehand, static CAIS, and dynamic CAIS groups was 10.09° (4.64°), 4.98° (2.16°), and 5.75° (2.09°), respectively. The mean three-dimensional deviation (standard deviation) at the implant platform in the freehand, static CAIS, and dynamic CAIS groups was 3.48 (2.00) mm, 1.40 (0.72) mm, and 1.73 (0.43) mm, while at the implant apex it was 3.60 (2.11) mm, 1.66 (0.61) mm, and 1.86 (0.82) mm, respectively. No difference in terms of accuracy was found between static and dynamic CAIS; both demonstrated significantly higher accuracy when compared to the freehand protocol in fully edentulous patients.

Accuracy and Technical Predictability of Computer Guided Bone Harvesting from the Mandible: A Cone-Beam CT Analysis in 22 Consecutive Patients

This study assesses the accuracy and technical predictability of a computer-guided procedure for harvesting bone from the external oblique ridge using a patient-specific cutting guide. Twenty-two patients needing bone augmentation for implant placement were subjected to mandibular osteotomy employing a case-specific stereolithographic surgical guide generated through computer aided design. Differences between planned and real cut planes were measured comparing pre- and post-operative Cone Beam Computed Tomography images of the donor site according to six validated angular and displacement indexes. Accuracy and technical predictability were assessed for 119 osteotomy planes over the study population. Three different guide fitting approaches were compared. An average root-mean-square discrepancy of 0.52 (0.30-0.97) mm was detected. The accuracy of apical and medial planes was higher than the mesial and distal planes due to occasional antero-posterior guide shift. Fitting the guide with an extra reference point on the closest tooth performed better than using only the bone surface, with two indexes significantly lower and less disperse. The study showed that the surgical plan was actualized with a 1 mm safety margin, allowing effective nerve preservation and reducing technical variability. When possible, surgical guide design should allow fitting on the closest tooth based on both radiological and/or intra-oral scan data.

Assessment of Deviations of Implants Installed with Prototyped Surgical Guide and Conventional Guide: In Vitro Study

OBJECTIVE

 The study aimed to assess the angular and linear deviations of implants installed in mannequins aided by surgical guides produced with the techniques of dual tomography (DT), model-based tomography (MT), and nonprototyped guide.

MATERIALS AND METHODS

 Implants were installed in mannequins of a partially edentulous maxilla and divided into three groups: Group C (n = 20), implants installed using the conventional technique with flap opening and conventional guide; Group DT (n = 20), implants installed using guided surgery with the dual tomography technique; and Group MT (n = 20), implants installed using the model-based tomography technique. After implant installation, the mannequin was subjected to a computed tomography (CT) to measure the linear and angular deviations of implant positioning relative to the initial planning on both sides.

RESULTS

 There was a higher mean angular deviation in group C (4.61 ± 1.21, p ≤ 0.001) than in groups DT (2.13 ± 0.62) and MT (1.87 ± 0.94), which were statistically similar between each other. Similarly, the linear deviations showed group C with the greatest discrepancy in relation to the other groups in the crown (2.17 ± 0.82, p = 0.007), central (2.2 ± 0.77, p = 0.004), and apical (2.34 ± 0.8, p = 0.001) regions.

CONCLUSION

 The techniques of DT and MT presented smaller angular and linear deviations than the conventional technique with the nonprototyped guide. There was no difference between the two-guided surgery techniques.

Digitally designed guided implant surgery in deficient maxillary ridges: Case reports

Periodontitis can lead to the loss of hard and soft tissues of the oral cavity. Dental implants have become a reliable treatment modality in recent times, especially with the evolution of digital technology such as CBCT, implant planning software, computer-assisted manufacturing, and guided implant surgery. Documentation of such advancements and their clinical implications would add to the existing knowledge on implant dentistry, encouraging dentists to approach complex implant surgeries confidently. This paper discusses the rehabilitation of missing teeth by applying computer-assisted guided implant placement in two cases with deficient bone volume anteriorly and posteriorly in the maxilla, respectively. Digital planning and careful execution have resulted in precise implant placement and complete osseointegration. In these cases, we could devise treatment plans with both anatomical and prosthetic considerations while being minimally invasive and more predictable, with shorter treatment time and greater patient comfort.

Prosthetic Surgical Templates and Dental Implant Site Time Preparation: An In Vitro Study

Numerous types of prosthodontics surgical guides, with and without metallic sleeves, have been found to be useful in clinical studies. The aim of this in vitro research was to compare the time required to complete the surgical procedure with two differently designed surgical prosthetic templates. Ten identical prototype models of mandible based on a CBCT and optical scan of a partially edentulous patient with missing teeth numbers 37, 46, and 47 were prepared and then printed. Five of these models were used for implant site preparation with a surgical guide without metal sleeves and dedicated surgical kit, and the other five models were used for the same procedure performed with a surgical guide with metal sleeves and a dedicated surgical kit. The time of implant site preparation was measured and recorded. Statistical analysis was performed using Student’s t-test for independent samples. Differences between groups were found to be statistically significant (t = −9.94; df = 28; p = 0.0000) with a lower value in favor of the surgical templates without metallic sleeves. Different types of prosthodontics surgical guides, with or without metallic sleeves, seemed to be an important factor which can significantly impact the time of implant site preparation and, therefore, the overall surgical procedure.

Implant survival after graftless sinus floor augmentation in highly atrophic maxillae: a randomized controlled trial in a split mouth study

PURPOSE

The success rate of dental implants after graftless sinus augmentation versus conventional sinus augmentation surgery in atrophic maxillae in edentulous patients was investigated.

METHODS

This randomized study was performed in ten edentulous patients with marked maxillary atrophy. On the graftless side, the sinus membrane was lifted by a resorbable membrane. The control side was augmented with a mixture of autografts and xenografts. Implant placement followed 6 months postoperatively. Outcomes were implant survival, success of prosthetic rehabilitation and stability of vertical bone gain.

RESULTS

Ten patients were included. Postoperative radiology showed sufficient bone gain on both maxillary sides. Follow-up varied from 57 to 88 months. The conventional side showed significant (p = 0.041) more bone gain than the experimental side (respectively, 9.69 mm and 6.20 mm). A total of 59 implants were placed: 30 after conventional, 29 after graftless augmentation. One implant was lost on the conventional side and four on the experimental side. The implant survival was significantly higher on the conventional side (96.7% vs. 86.2%, p < 0.001, RR = 4.14). Prosthetic restoration was functionally successful in all cases.

CONCLUSION

Bone gain and implant survival were significantly lower in the non-grafted side versus the grafted side. Prosthetic rehabilitation was possible in all ten patients. The non-grafted technique may have some potential for clinical use, although it showed poorer results. Trial registration The Netherlands Trialregister. NTR NL3541 (NTR3696). Registered 20 January 2013, https://www.trialregister.nl/trial/3541 .

Failure rates associated with guided versus non-guided dental implant placement: a systematic review and meta-analysis

Objective

The purpose of the systematic review and meta-analysis was to evaluate implant failure rates and their association with guided and free-hand implant placement techniques.

Materials and methods

A literature search was conducted across PubMed, Medline via Ovid, Cochrane database, and Google Scholar. The search was completed in September 2020. Series of meta-analyses were conducted to compare implant failure rates with guided and free-hand techniques.

Results

A total of 3387 articles were identified from the electronic search. After applying the inclusion criteria, eight articles were selected for qualitative assessment and four for quantitative synthesis (meta-analysis). The included studies had a risk ratio of 0.29 (95% CI: 0.15, 0.58), P < 0.001 for the use of guided implant placement. Implant failure rates were affected by the different placement techniques indicated by the test for overall effect (Z = 3.53, P = 0.0004). The incidence of implant failure in guided surgery versus free-hand surgery was found to be 2.25% and 6.42%, respectively.

Conclusion

Both guided and free-hand implant placement techniques resulted in a high implant survival rate. However, implant failure rates were almost three times higher in the free-hand implant placement category. A guided implant placement approach is recommended for a successful outcome.

A cast-free approach to fabricating an implant-supported interim restoration: A dental technique

A cast-free approach is described to fabricate an implant-supported interim restoration by using the postoperative cone beam computed tomography (CBCT) scan to locate the placed implant. A postoperative intraoral scan was aligned to the postoperative CBCT scan through a dental implant planning software program. An attached interim abutment and implant analog complex was then scanned and superimposed on the placed implant in the postoperative CBCT scan. Once the best alignment was achieved, a virtual cast was generated, and an interim restoration with bilateral positioning wings was fabricated on the interim abutment and inserted during the second-stage surgery. This technique offers a cast-free approach to inserting an implant-supported interim restoration immediately after the second-stage surgery to guide the healing of the soft tissue that can minimize chairside time and optimize the clinical workflow.

Prosthetically-Driven Full-Mouth Implant-Supported Prostheses Using Guided Surgical Implant Planning with Composite Resin Markers: A Case Report

This report describes a prosthetically-driven implant planning method, guided by the alignment procedures between the cone beam computed tomography, intraoral digital scans, and digitized maxillary and mandibular interim complete dentures using intraoral composite resin markers as a common reference. The markers were attached to the keratinized oral mucosa of the edentulous ridges using cyanoacrylate and kept in place during the digitizing procedures. The technique provides a simpler and more economical alternative to conventional prosthetically-driven static implant planning methods.

The accuracy of implant placement with computer-guided surgery in partially edentulous patients and possible influencing factors: A systematic review and meta-analysis

PURPOSE

To review the current clinical studies regarding the accuracy of implant computer-guided surgery in partially edentulous patients and investigate potential influencing factors.

STUDY SELECTION

Electronic searches on the PubMed and Cochrane Central Register of Controlled Trials databases, and subsequent manual searches were performed. Two reviewers selected the studies following our inclusion and exclusion criteria. Qualitative review and meta-analysis of the implant placement accuracy were performed to analyze potential influencing factors. Angular deviation, coronal deviation, apical deviation, and depth deviation were evaluated as the accuracy outcomes.

RESULTS

Eighteen studies were included in this systematic review, including six randomized controlled trials, nine prospective studies, and three retrospective clinical studies. A total of 1317 implants placed in 642 partially edentulous patients were reviewed. Eight studies were evaluated using meta-analysis. Fully guided surgery showed statistically higher accuracy in angular (P <0.001), coronal (P <0.001), and apical deviation (P <0.05) compared with pilot-drill guided surgery. A statistically significant difference (P <0.001) was also observed in coronal deviation between the bounded edentulous (BES) and distal extension spaces (DES). A significantly lower angular deviation (P <0.001) was found in implants placed using computer-aided design/computer-aided manufacturing (CAD/CAM) compared to the conventional surgical guides.

CONCLUSIONS

The edentulous space type, surgical guide manufacturing procedure, and guided surgery protocol can influence the accuracy of computer-guided surgery in partially edentulous patients. Higher accuracy was found when the implants were placed in BES, with CAD/CAM manufactured surgical guides, using a fully guided surgery protocol.

Accuracy of Guided Implant Surgery in the Edentulous Jaw Using Desktop 3D-Printed Mucosal Supported Guides

Purpose: The aim of this in vitro study is to evaluate the accuracy of implant position using mucosal supported surgical guides, produced by a desktop 3D printer. Methods: Ninety implants (Bone Level Roxolid, 4.1 mm × 10 mm, Straumann, Villerat, Switzerland) were placed in fifteen mandibular casts (Bonemodels, Castellón de la Plana, Spain). A mucosa-supported guide was designed and printed for each of the fifteen casts. After placement of the implants, the location was assessed by scanning the cast and scan bodies with an intra-oral scanner (Primescan^®, Dentsply Sirona, York, PA, USA). Two comparisons were performed: one with the mucosa as a reference, and one where only the implants were aligned. Angular, coronal and apical deviations were measured. Results: The mean implant angular deviation for tissue and implant alignment were 3.25° (SD 1.69°) and 2.39° (SD 1.42°) respectively, the coronal deviation 0.82 mm (SD 0.43 mm) and 0.45 mm (SD 0.31 mm) and the apical deviation 0.99 mm (SD 0.45 mm) and 0.71 mm (SD 0.43 mm). All three variables were significantly different between the tissue and implant alignment (p < 0.001). Conclusion: Based on the results of this study, we conclude that guided implant surgery using desktop 3D printed mucosa-supported guides has a clinically acceptable level of accuracy. The resilience of the mucosa has a negative effect on the guide stability and increases the deviation in implant position.

Assessment of the reproducibility and precision of milling and 3D printing surgical guides

BACKGROUND

Technology advancement has rising in the past decade and brought several innovations and improvements. In dentistry, this advances provided more comfortable and quick procedures to both the patient and the dental surgeon, generating less predictability in the final result. Several techniques has been developed for the preparation of surgical guides aiming at the optimization of surgical procedures. The present study aimed to evaluate the reproducibility and precision of two types of surgical guides obtained using 3D printing and milling methods.

METHODS

A virtual model was developed that allowed the virtual design of milled (n = 10) or 3D printed (n = 10) surgical guides. The surgical guides were digitally oriented and overlapped on the virtual model. For the milling guides, the Sirona Dentsply system was used, while the 3D printing guides were produced using EnvisionTEC's Perfactory P4K Life Series 3D printer and E-Guide Tint, a biocompatible Class I certified material. The precision and trueness of each group during overlap were assessed. The data were analyzed with GraphPad software using the Kolmogorov-Smirnov test for normality and Student's t test for the variables.

RESULTS

The Kolmogorov-Smirnov test showed a normal distribution of the data. Comparisons between groups showed no statistically significant differences for trueness (p = 0.529) or precision (p = 0.3021). However, a significant difference was observed in the standard deviation of mismatches regarding accuracy from the master model (p < 0.0001).

CONCLUSIONS

Within the limits of this study, surgical guides fabricated by milling or prototyped processes achieved similar results.

Atrophic Maxilla Rehabilitation Through Dental Implants Using the V-4 Strategy Associated With Guided Surgery: A Case Report and Technique Description

Atrophic maxilla rehabilitation through dental implants is always a challenging procedure. However, alternative approaches such as guided surgery and the installation of short implants are progressively supplanting more invasive bone regeneration procedures. A V-4 technique described in 2016 facilitates the installation of dental implants in patients with atrophic maxilla; however, its authors recommend incision, flap opening, and elevation of the anterior area of the maxillary sinuses. This case report describes a less invasive proposal for modifying the technique through the association of guided surgery, which improves implant placement accuracy, shortens surgical time, and reduces morbidity.

Anticytokine Activity Enhances Osteogenesis of Bioactive Implants

In dental clinical practice, systemic steroids are often applied at the end of implant surgeries to reduce postsurgical inflammation (tissue swelling, etc.) and to reduce patient discomfort. However, the use of systemic steroids is associated with generalized catabolic effects and with a temporarily reduced immunological competence. We hypothesize that by applying locally anticytokine antibodies (antitumor necrosis factor alpha and anti-interleukin-1 beta) together with a bioactive osteogenic implant at the time of the surgical intervention for the placement of a construct, we will be able to achieve the same beneficial effects as those using systemic steroids but are able to avoid the generalized antianabolic effects and the reduced immunocompetence effects, associated with the systemic use of steroids. In an adult rat model, a collagen sponge, soaked with the osteogenic agent bone morphogenetic protein-2, was used as an example for a bioactive implant material and was surgically placed subcutaneously. In the acute inflammatory phase after implantation (2 days after surgery) we investigated the local inflammatory tissue response, and 18 days postsurgically the efficiency of local osteogenesis (to assess possible antianabolic effects). We found that the negative control groups, treated postsurgically with systemic steroids, showed a significant suppression of both the inflammatory response and the osteogenetic activity, that is, they were associated with significant general antianabolic effects, even when steroids were used only at a low dose level. The local anticytokine treatment, however, was able to significantly enhance new bone formation activity, that is, the anabolic activity, over positive control values with BMP-2 only. However, the anticytokine treatment was unable to reduce the local inflammatory and swelling responses.

Effects of supporting conditions and anchor microscrew on the stabilization of the implant guide template during the drilling process: An in vitro study

STATEMENT OF PROBLEM

Implant placement errors have been reported in guided surgeries because of movement of the guide template during implant placement. With a completely limiting guide design with high restrictions, guide template stabilization is essential to minimize mobility during the drilling process.

PURPOSE

The purpose of this in vitro study was to evaluate the effects of supporting conditions and the use of an anchor microscrew on the seating and functional stabilization of a computer-aided design and computer-aided manufacturing (CAD-CAM) implant surgical guide with a completely limiting design.

MATERIAL AND METHODS

Twelve implant surgical guide templates were fabricated under different supporting conditions: tooth-mucosa, tooth-tooth, tooth-screw, and screw-screw (n=3 per group). In the tooth-screw and screw-screw groups, anchor microscrews and anchor caps were used to fix the guide templates. The seating stability of the templates was evaluated by using a micromovement assessment. The functional stability of the templates was analyzed during the drilling process by using a motion tracking method. One-way analysis of variance and the Tukey HSD post hoc test were conducted to compare the differences among the groups (α=.05).

RESULTS

The tooth-tooth, tooth-screw, and screw-screw groups exhibited similar seating stability, which was significantly more stable than that of the tooth-mucosa group (P<.001). In terms of functional stability, the tooth-mucosa group reported the highest positional deviation and motion magnitude, whereas low values were found in the tooth-screw and screw-screw groups (P<.001).

CONCLUSIONS

The use of anchor microscrews can increase the seating and functional stability of CAD-CAM guide templates during the drilling process for implant placement.

Pediatric Stainless-Steel Crown Cementation Finite Element Study

Objective  To study the effect of using different cement types under pediatric stainless-steel crown (SSC) around mandibular second primary molar using three-dimensional (3D) finite element analysis.

Materials and Methods  A 3D finite element model was built for pediatric mandibular molar by laser scanning of natural extracted tooth. Four types of cement (zinc phosphate, glass ionomer, resin-modified glass ionomer, and resin) of 200 μm layers thickness were tested under a stainless-steel crown of 130-μm thickness. Twelve case studies were reported within this research, as the applied load of 330 N was tested with three angulations: vertical, oblique at 45°, and laterally.

Results  Linear static stress analysis was performed. The resultant stresses and deformations' distribution patterns did not change with cement type, while the values were altered. All deformations and stresses were found within the normal range.

Conclusions  Analysis results indicated that using stiffer cement material increases tooth structure stresses and reduces crown body stresses and deformations, while bone was nearly insensitive to cement type.

Digitally planned root end surgery with static guide and custom trephine burs: A case report

INTRODUCTION

Apicoectomy is an endodontic surgical intervention that requires high precision. The computer-assisted static guided approach has proven to increase the precision of dental implantation in a significant manner. The authors sought to transfer this precision to root-end resection with the use of custom designed trephine burs manufactured specifically for use in targeted endodontic microsurgery.

METHODS

A set of custom bone trephines were designed and manufactured, then their digital models were integrated into an already existing implant surgical planning software, in cooperation with the software developer. Apicoectomy was performed in an actual case with the help of the new system.

RESULTS

It has become possible to plan root end removal in the virtual space and to manufacture 3D printed static surgical guides to help the execution of the surgery. A patient with persistent periapical lesion was successfully treated without complication. The 6-month follow-up found uneventful healing.

CONCLUSION

The presented system is a step toward a standardized digital system and workflow dedicated to guided endodontic surgery.

The Effects of Distribution of Image Matched Fiducial Markers on Accuracy of Computer-Guided Implant Surgery

PURPOSE

Image registration of the optical intraoral scan to computed tomography image is essential for computer-guided implant surgery. The remaining teeth, which are considered to be congruent structures observed in the scan and radiographic images, are used to perform the image registration. The purpose of this study was to evaluate the effects of the distribution of matching fiducial points on the accuracy of the image registration.

MATERIALS AND METHODS

A partially edentulous model with three anterior remaining teeth was prepared. Two mini dental implants were inserted in the posterior edentulous areas on both sides, and computed tomography and surface scan data were obtained. Three groups were set according to the distribution of the image matching points used: localized distribution, unilateral distribution, and bilateral distribution. Fifteen graduate students performed the registration process in each group using the same image matching method. The accuracy of image registration was evaluated by measuring the geometric discrepancies between the radiographic and registered scan images in the anterior, middle, and posterior regions. One-way and two-way analysis of variance with the Tukey HSD post hoc test were used for statistical analysis (α = 0.05) RESULTS: In general, the registration discrepancy was lowest in the bilateral distribution group, followed by the unilateral distribution and localized distribution groups (p< 0.001). In the regional analysis, the registration error tended to increase as the measurement region moved farther from the matching points. The distribution of the matching points and measurement regions had a statistical interaction in the accuracy of image registration.

CONCLUSION

The accuracy of image registration of the surface scan to the computed tomography is affected by the matching point distribution that can be improved by placing artificial markers in the edentulous areas.

Fully Digital Workflow for Planning Static Guided Implant Surgery: A Prospective Accuracy Study

The accuracy of static guided implant surgery (sGIS) using conventional planning workflow has been extensively examined; however, more information is required to justify the application of fully digital planning protocol. The purpose of this study was to investigate the clinical accuracy of sGIS with a fully digital planning workflow. Twenty-one partially edentulous patients were enrolled in this prospective study. Cone-beam computed tomography (CBCT) and intraoral scans were taken and superimposed by matching the dental surface images directly (surface registration protocol) or by matching fiducial markers on a stereolithographic (SLA) radiographic template fabricated from the digital data of the intraoral scan (fiducial marker registration protocol). Virtual implant treatment plans were then determined, and tooth-supported SLA surgical guides were fabricated according to the plans. Twenty-six implant surgeries were performed via the surgical guide by one surgeon. Pre- and post-operative CBCT images were superimposed, and the positional and angular deviations between placed and planned implants were measured with metrology software. A total of 43 fully guided implants were placed, in which 25 implants were planned with the surface registration protocol. Implants planned based on the surface registration protocol had a larger mean angular deviation than the fiducial marker registration protocol. No significant differences were found for any deviations of the examined variables. Within the limits of this study, we concluded that the clinical accuracy of the sGIS planned with a fully digital workflow was consistent with the conventional workflow for partially edentulous patients.

Auxiliary Reflectance Sensor for Guided Surgery with Dental Implants: In Vitro Study

Objectives  The aim of this research was to develop a sensor of approximation by reflectance for guided surgery with dental implants without flap detachment, and verify the effectiveness of this system.

Materials and Methods  Ten models of total edentulous arches were divided into two groups. Two implants of 3.5 × 11.5 mm (NeoDent) were inserted in each model; in Group 1 (G1), a stereolithographic guide NeoGuide system was used. In Group 2 (G2), the experimental approximation sensor was used for the insertion of the implants. The evaluation of the results was performed by overlapping the virtual planning images with the tomographies of the models of the implants inserted.

Results  There were no statistically significant differences between the guide and the sensor groups. The averages and standard deviations observed at the angulation of the guide was 4.15 (2.65 degrees) and 5.48 (2.85 degrees) at the sensor. The linear deviations at the cervical level were 0.002 (1.37) and 0.11 (1.47) mm and at the apical level 0.19 (1.28) and 0.21 (1.42) mm, respectively.

Conclusions  The use of a guide is important for the stabilization of the drills; the greatest challenge is to control the apical position of the implants, especially in highly reabsorbed edges. The experimental sensor can become an auxiliary tool to the stereolithographic guides; however, several difficulties must still be overcome to recommend the use of a sensor.

Influence of the Digital Mock-Up and Experience on the Ability to Determine the Prosthetically Correct Dental Implant Position during Digital Planning: An In Vitro Study

The purpose of this study was to analyze the influence of the digital mock-up and operator experience on the dental implant planning position. A total of 200 dental implants were planned, which were distributed into two study groups: A. dental implant planning by dental surgeons with 5–10 years of experience (n = 80); and B. dental implant planning by dental surgery students without experience (n = 120). Operators were required to plan eight dental implants in the same maxillary edentulous case uploaded in 3D implant-planning software, before and after using the digital mock-up. Deviations between the dental implant planning positions before and after using the digital mock-up were analyzed at platform, apical and angular levels, and were analyzed using a 3D implant-planning software using Student’s t test. The paired t-test revealed statistically significant differences between the deviation levels of participants with 5–10 years’ experience and no experience at the platform, apical and angular levels. Digital mock-ups allow for more accurate dental implant planning regardless of the experience of the operator. Nevertheless, they are more useful for operators without dental surgery experience.

Accuracy of guided implant surgery: an experimental set-up

BACKGROUND

The aim of the study was to evaluate the opportunities of guided implant surgery compared to conventional implant surgery.

METHODS

For this purpose 7 mandibles were prepared, which were sectioned in order to have an edentulous area. Seven half-mandibles were assigned to guided implant surgery group (test) and an equal number to conventional surgery group (control).

RESULTS

The results of the test group were as follows: mean vertical implant level discrepancy 0.44±0.29 mm, buccolingual implant position discrepancy 1.31±0.65 mm, mesio-distal implant position discrepancy 0.68±0.42 mm, implant apex discrepancy 1.92±0.92 mm, mean distance between the two fixtures 0.26±0.19 mm. The results of the control group are as follows: mean vertical implant level discrepancy 1.1±0.4 mm, mean bucco-lingual implant position discrepancy 2.14±0.89 mm, mean mesio-distal implant position discrepancy 1.7±0.79 mm, mean implant apex discrepancy 2.91±0.50 mm, mean distance between the two fixtures 0.78±0.63 mm.

CONCLUSIONS

Within the limitations of an experimental set up, the results may demonstrate how the use of guided implant surgery may be a valid help for the clinician for a more accurate and safe implant placement.

A novel guided surgery system with a sleeveless open frame structure: a retrospective clinical study on 38 partially edentulous patients with 1 year of follow-up

Background

This retrospective clinical study aims to present results of experience with a novel guided surgery system with a sleeveless, open-frame structure, in which the surgical handpiece (not the drills used for preparation) is guided.

Methods

This study was based on an evaluation of the records of partially edentulous patients who had been treated with a sleeveless open-frame guided surgery system (TWIN-Guide®, 2Ingis, Brussels, Belgium), between January 2015 and December 2017. Inclusion criteria were patients with good systemic/oral health and a minimum follow-up of 1 year. Exclusion criteria were patients who had been treated without a guide, or with a guide with sleeves, patients with systemic/oral diseases and who did not have a follow-up of 1 year. The main outcomes were surgical (fit and stability of the surgical guide, duration of the intervention, implant stability, and any intra-operative or immediate post-operative complication), biologic, and prosthetic.

Results

Thirty-eight patients (24 males, 14 females; mean age 56.5 ± 14.0 years) were included in the study. These patients had been treated with 110 implants inserted by means of 40 sleeveless, open-frame guides. With regard to fit and stability, 34 guides were excellent, 4 acceptable, and 2 inadequate for use. The mean duration of the intervention was 23.7 (± 6.7) minutes. Immediately after placement, 2 fixtures were not stable and had to be removed. Two patients experienced pain/swelling after surgery. The 108 surviving implants were restored with 36 single crowns and 32 fixed partial prostheses (24 two-unit and 8 three-unit bridges); these restorations survived until the 1-year follow-up, with a low incidence of biologic and prosthetic complications.

Conclusions

Within the limits of this study, this novel guided surgery system with sleeveless, open frame–structure guides seems to be clinically reliable; further studies on a larger sample of patients are needed to confirm these outcomes.

Guided Nitinol-Retained (Smileloc) Single-Tooth Dental Restorations

Nitinol metal alloy that changes shape according to temperature has been in clinical use at select clinics worldwide for the past 2 years and is now released for general use. The Smileloc Abutment and nitinol sleeve enable "cementless," "screwless," crown fastening that saves time and cost with the prospect of replacement of much of the present, sometimes troublesome, anthropic, soon to be anachronistic, technology.

Computer-assisted, template-guided immediate implant placement and loading in the mandible: a case report

BACKGROUND

Computer-assisted implant planning has become an important diagnostic and therapeutic tool in modern dentistry. This case report emphasizes the possibilities in modern implantology combining virtual implant planning, guided surgery with tooth and implant supported templates, immediate implant placement and loading.

CASE PRESENTATION

A straight forward approach was followed for the mandible presenting with hopeless lower incisors. Diagnosis, decision making and treatment approach were based on clinical findings and detailed virtual three-dimensional implant planning. Extractions of the hopeless mandibular incisors, immediate and guided implant placement of six standard implants, and immediate loading with a provisional fixed dental prosthesis (FDP) were performed fulfilling patient's functional and esthetic demands. The final computer assisted design / computer assisted manufacturing (CAD/CAM) FDP with a titanium framework and composite veneering was delivered after 6 months. At the 1-year recall the FDP was free of technical complications. Stable bony conditions and a healthy peri-implant mucosa could be observed.

CONCLUSIONS

Computer assisted implantology including three-dimensional virtual implant planning, guided surgery, and CAD/CAM fabrication of provisional and final reconstructions allowed for a concise treatment workflow with predictable esthetic and functional outcomes in this mandibular full-arch case. The combination of immediate implant placement and immediate loading was considerably more complex and required a high level of organization between implantologist, technician and patient. After the usage of a first tooth-supported surgical template with subsequent extraction of the supporting teeth, a second surgical template stabilized on the previously inserted implants helped to transfer the planned implant position in the extraction sites with a guided approach.

Full in-Office Guided Surgery with Open Selective Tooth-Supported Templates: A Prospective Clinical Study on 20 Patients

Background: Guided implant surgery appears to have several benefits, such as the possibility of inserting flapless implants in a prosthetically driven manner, avoiding dangerous anatomical structures. However, to date, only a few surgeons routinely use guided surgery in partially edentulous patients. Aim: To present the results obtained with tooth-supported surgical templates characterized by an innovative open design with selective support, and manufactured via a full in-office procedure with a low-cost desktop 3D printer. Methods: Over a two-year period (2016–2018), all partially edentulous patients with one to three missing teeth (in maxilla and/or mandible), referred to a private dental practice for restoration with dental implants, were considered for inclusion in this prospective clinical study. An intraoral scanner (CS 3600^®, Carestream Dental) and cone beam computed tomography (CS 9300^®, Carestream Dental) were used to acquire the 3D information on the patients. Guided surgery software (SMOP^®, Swissmeda) was used to plan the surgeries and to design open, selective, tooth-supported templates that were fabricated with a stereolithographic (SLA) desktop 3D printer (XFAB2000^®, DWS). Guided implant surgeries were performed and patients were followed for a period of one year. The study outcomes were fit and stability of surgical templates, duration (time) of surgery, intra and post-operative complications, and implant stability and survival. Results: Twenty (20) partially edentulous patients (9 males, 11 females; mean age 54.4 ± 9.4 years) were included in the study; 28 open, selective, tooth-supported templates were designed with the aim of inserting 38 implants. Among the surgical templates, 24 had optimal fit and stability, three had optimal fit and sufficient stability, and only one had inadequate fit and unsatisfactory stability and was therefore not suitable for clinical use. The average time of the intervention was 15.7 ± 5.2 min per template. No intra-operative complications were reported, but one implant was not stable at placement and had to be removed. In total, 36 implants were restored with 10 two-unit fixed partial prostheses and 16 single crowns. All implants were successfully functioning at one year, even if, in two single crowns, minor prosthetic complications (abutment screw loosening) occurred. Conclusions: Full in-office guided surgery with open, selective, tooth-supported templates seem to represent a clinically predictable surgical procedure to restore partially edentulous patients. Further studies are needed to confirm these positive outcomes.