Effect of surgical guide design and surgeon's experience on 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.

Clinical evaluation of autonomous robotic-assisted full-arch implant surgery: A 1-year prospective clinical study

OBJECTIVES

This prospective clinical study aimed to evaluate the accuracy and 1-year clinical follow-up performance of dental implant placement with an autonomous dental implant robot (ADIR) system in full-arch implant surgery.

MATERIALS AND METHODS

Twelve patients with edentulous arches or final dentition received 102 implants using the ADIR system. Global platform deviation, global apex deviation, and global angular deviation between the planned and actual implants were calculated after surgery. Data were statistically analyzed for factors including jaws, implant positions, patient sequences, implant systems, and implant length. Surgery duration was recorded. Patients were followed for 3 months and 1 year after surgery. Periodontal parameters, buccal bone thickness (BBT), and facial vertical bone wall peak (IP-FC) were recorded.

RESULTS

Among the 102 implants, the mean (SD) global platform deviation, global apex deviation, and global angular deviation were 0.53 (0.19) mm, 0.58 (0.17) mm, and 1.83 (0.82)°, respectively. The deviation differences between the mandible and maxilla did not show statistical significance (p > .05). No statistically significant differences were found for the jaws, implant positions, patient sequences, implant systems, and implant length to the deviations (p > .05). The periodontal parameters, the BBT, and IP-FC remained stable during 1-year follow-up.

CONCLUSION

The ADIR system showed excellent positional accuracy. The 1-year follow-up after full-arch implant surgery indicated that the ADIR system could achieve promising clinical performance. Additional clinical evidence is requisite to furnish guidelines for the implementation of the ADIR system in full-arch implant surgery.

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.

Reliability of a chairside CAD-CAM surgical guide for dental implant surgery on the anterior maxilla: An in vitro study

PURPOSE

This study evaluated the reliability of the chair-side CAD-CAM surgical guide (CSG) in the anterior maxilla by comparing its accuracy with the laboratory 3D-printed surgical guide (3DSG) and manual surgical guide (MSG) concerning different levels of dentists' surgical experience.

MATERIALS AND METHODS

Ten surgical guides of each type (MSG, 3DSG, and CSG) were fabricated on a control study model with missing right and left central incisors. Sixty implants were placed in 30 study models by two dentists (one inexperienced and one experienced) using three different types of surgical guides. Horizontal deviations at shoulder and at apex, vertical, and angular deviations were measured after superimposing the planned and placed implant positions in the software. Kruskal-Wallis and Mann-Whitney U tests were used to compare the accuracy of three types of surgical guides in each dentist group and the accuracy of each surgical guide between two dentists (α = .05).

RESULTS

There were no significant differences in any deviations between CSG and 3DSG, apart from angular deviation, for both dentists' groups. Moreover, both CSG and 3DSG showed no significant differences in accuracy between the two dentists (P > .05). In contrast, MSG demonstrated significant differences from CSG and 3DSG and a significant difference in accuracy between the two dentists (P < .05).

CONCLUSION

CSG provides superior accuracy to MSG in implant placement in the maxillary anterior region and is comparable to 3DSG at different levels of surgical experience, while offering the benefits of shorter manufacturing time and reduced patient visits.

Comparison of accuracy between free-hand and surgical guide implant placement among experienced and non-experienced dental implant practitioners: an in vitro study

PURPOSE

This study investigated the accuracy of free-hand implant surgery performed by an experienced operator compared to static guided implant surgery performed by an inexperienced operator on an anterior maxillary dental model arch.

METHODS

A maxillary dental model with missing teeth (No. 11, 22, and 23) was used for this in vitro study. An intraoral scan was performed on the model, with the resulting digital impression exported as a stereolithography file. Next, a cone-beam computed tomography (CBCT) scan was performed, with the resulting image exported as a Digital Imaging and Communications in Medicine file. Both files were imported into the RealGUIDE 5.0 dental implant planning software. Active Bio implants were selected to place into the model. A single stereolithographic 3-dimensional surgical guide was printed for all cases. Ten clinicians, divided into 2 groups, placed a total of 60 implants in 20 acrylic resin maxillary models. Due to the small sample size, the Mann-Whitney test was used to analyze mean values in the 2 groups. Statistical analyses were performed using SAS version 9.4.

RESULTS

The accuracy of implant placement using a surgical guide was significantly higher than that of free-hand implantation. The mean difference between the planned and actual implant positions at the apex was 0.68 mm for the experienced group using the free-hand technique and 0.14 mm for the non-experienced group using the surgical guide technique (P=0.019). At the top of the implant, the mean difference was 1.04 mm for the experienced group using the free-hand technique and 0.52 mm for the non-experienced group using the surgical guide technique (P=0.044).

CONCLUSIONS

The data from this study will provide valuable insights for future studies, since in vitro studies should be conducted extensively in advance of retrospective or prospective studies to avoid burdening patients unnecessarily.

Evaluating augmented reality e-typodont to improve a patient's dental implant health literacy

STATEMENT OF PROBLEM

Information regarding dental implants can be difficult to understand for participants. Improving patients' dental implant health literacy remains a challenging process.

PURPOSE

The purpose of this clinical study was to develop and evaluate patients' understanding of the implant treatment procedure, components, and sequences using traditional typodont and augmented reality (AR) applications (e-typodont), with the goal of improving their oral health literacy.

MATERIAL AND METHODS

Participants who had sought dental implant treatment at the group practice and implant clinic at the University of Illinois Chicago (UIC) College of Dentistry were invited to enroll in this study. Participants were asked to fill out the first questionnaire (Q1) assessing their understanding of implant treatment procedures, components, and sequences. The participants were randomly exposed to 1 of the 2 modes of delivering education, typodont or AR e-typodont. The participants were asked to complete the additional 2 questionnaires (Q2 and Q3), and the posttest questionnaire (Q1) to re-evaluate their understanding of the implant treatment procedure, components, and sequences. All data were entered and coded into a spreadsheet. Descriptive (mean) and statistical (Wilcoxon Signed Ranks and Mann-Whitney U test) analyses were used (α=.05).

RESULTS

Both interventions significantly increased participants' understanding of implant treatments (typodont: P=.004; e-typodont: P<.001), implant components (typodont: P=.003; e-typodont: P<.001), and implant treatment sequences (typodont: P=.001; e-typodont: P<.001). The e-typodont group significantly improved participants' understanding of implant treatments (P=.006), implant components (P=.023), and implant treatment sequences (P=.008) compared with the typodont group. Participants perceived the e-typodont mode of delivery to be significantly more interesting (P=.002), interactive (P=.008), educational (P=.002), user-friendly (P=.016), and "Wow" (P=.002) compared with the traditional typodont mode of delivery.

CONCLUSIONS

Both interventions improved participants' understanding of implant treatment procedures, components, and sequences. The e-typodont showed better improvement in participants' understanding of dental implants compared with the traditional typodont.

An In Vitro Study of the Reproducibility of the Drilling Access of Digitalized Surgical Guides Generated via Three Different Implant Planning Software Programs

Several implant planning software programs are widely use in implant treatments, but there has been no evidence of how different software programs affect the accuracy of static surgical guides used for implant placement. Thus, in this in vitro study, we aimed to compare the accuracy of static surgical guides that were prefabricated from three different software programs, including Implant Studio (Program A) (3Shape®, Copenhagen, Denmark), coDiagnostiX® (Program B) (Straumann®, Basal, Switzerland), and Blue Sky Plan (Program C) (Blue Sky Bio®, LLC, Libertyville, IL, USA). A total of 90 drillable polyurethane models were used as samples in this in vitro study; 30 study models were used to plan the same implant positions and design the surgical guides by each software program (n = 30) and then 90 implants were placed in the models using the surgical guides. The outcomes of the surgical guide accuracy were autonomically measured by the evaluation tool in the coDiagnostiX® (Straumann®, Basal, Switzerland) software program. The deviations between the planned and placed implants were automatically evaluated as three-dimensional and angular deviations. The mean three-dimensional implant position deviations from the implant platform of Program A, Program B, and Program C were 0.55 ± 0.25 mm, 0.52 ± 0.31 mm, and 0.56 ± 0.22 mm, respectively. The mean three-dimensional implant position deviations from the implant apex of Program A, Program B, and Program C were 0.72 ± 0.37 mm, 0.73 ± 0.4 mm, and 0.9 ± 0.46 mm, respectively. The mean depth deviations of Program A, Program B, and Program C were 0.19 ± 0.13 mm, 0.31 ± 0.32 mm, and 0.31 ± 0.22 mm, respectively. The mean angulation deviations of Program A, Program B, and Program C were 1.72 ± 0.88 degrees, 2.05 ± 1.24 degrees, and 2.74 ± 1.81 degrees, respectively. The results indicated that there were no significant differences among the three-dimensional positions at the implant platform, the three-dimensional positions at the implant apex, and the depth deviations between all three groups. However, it was found that there was a significant difference in the angular deviation of the implant position between the three groups (p = 0.02). The mean angular deviation of Program C was significantly greater than the Program A group (p = 0.001). In terms of the deviation directions of the implant platform and implant apex for the three groups, most of the deviations of a larger magnitude were toward the mesio-buccal direction. No matter which program was used to plan the implant position, deviations between the placed implant position and the planned position still occurred. Therefore, when planning implant positions with any implant planning software program, one must take into account an implant position deviation.

Guided Insertion of Temporary Anchorage Device in Form of Orthodontic Titanium Miniscrews with Customized 3D Templates—A Systematic Review with Meta-Analysis of Clinical Studies

(1) Background: Miniscrew insertion, using a surgical guide, aims to avoid possible adverse effects or complications. With the higher availability of both 3D imaging and printing, 3D surgical guides have been used more frequently in orthodontics. The aim of the present systematic review was to find scientific clinical evidence concerning the precision of the 3D guided insertion of miniscrews for temporary orthodontic anchorage. (2) Methods: Literature searches were performed in the following five search engines: Pubmed (Medline), Pubmed Central, Scopus, Web of Science and Embase on 10 September 2021 (articles from 1950 to 10 September 2021). A meta-analysis was performed using the random-effect model, with Standardized Mean Differences (SMD) and 95% confidence intervals (95% CI) calculated as effect estimates. The heterogeneity was assessed quantitatively. (3) Results: The search strategy identified 671 potential articles. After the removal of duplicates, 530 articles were analyzed. Subsequently, 487 papers were excluded, because they were not associated with the subject of the study. Of the remaining 43 papers, 34 were excluded because they did not meet the methodological criteria. Finally, only nine papers were subjected to a qualitative analysis. (4) Conclusions: The current literature concerning guided miniscrew insertion reveals, for the most part, a low methodological level. High-quality clinical trials are in the minority. The use of surgical guides increases insertion accuracy, stability and reduces the failure rate of orthodontic miniscrews. Tooth-borne insertion guides supported on the edges of the teeth ensure a higher insertion precision compared to mucosa-borne ones. The study protocol was registered in PROSPERO under the number CRD42021267248.

Accuracy of commercial 3D printers for the fabrication of surgical guides in dental implantology

OBJECTIVES

To evaluate the accuracy of two different surgical guides (small extent = single implant and large extent = full arch) fabricated by five additive manufacturing technologies (SLA=Stereolithography, DLP= Digital Light Processing, FDM=Fused Deposition Modeling, SLS=Selective Laser Sintering, Inkjet).

METHODS

Overall, 72 guides (6 per type) were obtained with the different machines (SLA=Form2; DLP=Rapid Shape D40 and Cara Print 4.0; FDM=Raise 3D Pro2; SLS=Prodways P1000; Polyjet®=Stratasys J750). The guides were surface-scanned with an optical dental scanner, and the resulting files were compared with the initial design files using a surface matching software. Root Mean Square (RMS) and standard deviation were calculated, representing respectively trueness and precision. Kruskall-Wallis non-parametric test was used to compare trueness and precision between small-extent and large-extent guides and 3D printer by pairs. The threshold for significance was α=0.05, except for the comparison of printers by pairs where a Bonferroni-corrected level of 0.0033 was used.

RESULTS

Significant differences were observed for trueness and precision between small-extent and large-extent guides, regardless the printer except for DLP (trueness and precision) and SLS (precision). SLA, DLP and Polyjet® technologies showed similar results in terms of trueness and precision for both small-extend and large-extend guides (P>0.05).

CONCLUSIONS

The size affected the accuracy of CAD-CAM surgical guides. The different additive manufacturing technologies had a limited impact on the accuracy.

CLINICAL SIGNIFICANCE

This study is of clinical interest as it shows that the 3D printing technology (SLA/DLP) has a limited impact on 3D printed surgical guides accuracy. However, the size of the guide can have a significant impact, as small-extent guides were more accurate than large-extent guides.

The Influence of Surgical Experience and Bone Density on the Accuracy of Static Computer-Assisted Implant Surgery in Edentulous Jaws Using a Mucosa-Supported Surgical Template with a Half-Guided Implant Placement Protocol-A Randomized Clinical Study

The aim of our randomized clinical study was to analyze the influence of surgical experience and bone density on the accuracy of static computer-assisted implant surgery (CAIS) in edentulous jaws using a mucosa-supported surgical template with a half-guided implant placement protocol. Altogether, 40 dental implants were placed in the edentulous jaws of 13 patients (novice surgeons: 18 implants, 6 patients (4 male), age 71 ± 10.1 years; experienced surgeons: 22 implants, 7 patients (4 male), age 69.2 ± 4.55 years). Angular deviation, coronal and apical global deviation and grey level measurements were calculated for all implants by a blinded investigator using coDiagnostiX software. 3DSlicer software was applied to calculate the bone volume fraction (BV/TV) for each site of implant placement. There were no statistically significant differences between the two study groups in either of the primary outcome variables. There was a statistically significant negative correlation between angular deviation and both grey level measurements (R-value: −0.331, p < 0.05) and BV/TV (R-value: −0.377, p < 0.05). The results of the study suggest that surgical experience did not influence the accuracy of implant placement. The higher the bone density at the sites of implant placement, the higher the accuracy of static CAIS.

Accuracy of static computer-assisted implant placement in anterior and posterior sites by clinicians new to implant dentistry: in vitro comparison of fully guided, pilot-guided, and freehand protocols

Background

One of the challenges encountered by clinicians new to implant dentistry is the determination and controlling of implant location. This study compared the accuracy of fully guided (FG) and pilot-guided (PG) static computer-assisted implant placement (sCAIP) protocols against the conventional freehand (FH) protocol for placing single anterior and posterior implants by recently introduced clinicians to implant dentistry.

Material and methods

Ten clinicians new to implant dentistry inserted one anterior (central incisor) and one posterior (first molar) implants per protocol in training maxillary models. The FG protocol involved drilling and implant placement through the guide, while the PG protocol controlled the pilot drilling only. The FH implant placement was completed without the aid of any guide. A total of 30 models were used, and 60 implants were inserted. The implant vertical, horizontal neck, horizontal apex, and angle deviations from planned positions were calculated.

Results

The FG protocol provided the most accurate implant placement in relation to horizontal neck (0.47 mm–0.52 mm), horizontal apex (0.71 mm–0.74 mm), and angle deviations (2.42^o–2.61^o). The vertical deviation was not significantly different among the different protocols. The PG protocol was generally similar to the FH protocol with a horizontal neck deviation of 1.01 mm–1.14 mm, horizontal apex deviation of 1.02 mm–1.35 mm, and angle deviation of 4.65^o–7.79^o. The FG protocol showed similarity in the accuracy of the anterior and posterior implants. There was a tendency for inferior accuracy for posterior implants compared with anterior implants for the PG and FH protocols.

Conclusions

In the hands of recently introduced clinicians to implant dentistry, it appears that the accuracy of the FG protocol was superior to the other protocols and was not influenced by the position of the implants. The PG and FH protocols showed inferior accuracy for posterior implants compared with anterior implants.

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.

Clinical benefits and effectiveness of static computer-aided implant surgery compared with conventional freehand method for single-tooth implant placement

PURPOSE

To evaluate the effectiveness of static computer-aided surgery technique with the conventional freehand method to assess the role of the surgical template in terms of duration of operation and postoperative pain levels.

METHODS

Total of 26 implants were placed: 13 using tooth-supported surgical templates; and 13 using the conventional freehand method. Duration of the surgery was recorded for all operation sites. After implant insertion, all patients were asked to evaluate two separate visual analog scales (VAS) at regular intervals for 1 week. All patients underwent cone beam computed tomography (CBCT) evaluation to assess the depth of deviation of the planned and placed implants.

RESULTS

The deviation of implants inserted using the computer-aided surgical technique and conventional freehand technique demonstrated no significant differences (P<0.05). However, the computer-aided surgery technique significantly decreased the duration of the surgery and post-op pain levels.

CONCLUSION

Tooth supported surgical templates had no particular effect on the accuracy of single implant placement. Nevertheless, this procedure allows flappless surgery with minimal invasive approach, reduce operation time and post-op pain levels. If further studies with larger study samples confirm the abovementioned results, surgical templates may be recommeded even in patients with single tooth loss.

[Criterion assessment system of the actual level of expertise of dental professionals practicing implant dentistry]

The aim of the study was to develop criterion assessment system of the actual level of expertise of dental professionals practicing Implant dentistry. The study comprised fifteen dental experts aged from 35 to 47 years with the average 15 years clinical experience. For evaluation of the clinical portfolio of the dentists we developed 10 reference points and to ensure unification of the assessment approach we organised consensus methodical conference for our expert group. Scores were applied by parity of reasoning with point-rating system applied in continuing education programs of Medical University. Assessment of 43 clinical portfolios with short term and long term results of implant supported restorations was performed. Treatment was provided with the use of Nobel Biocare implants and prosthodontic rehabilitation was achieved with the use of CAD/CAM 'Procera' technology. The study showed that dentists who practice implant dentistry from 1 to 7 years have good manual skills and clinical expertise sufficient for achieving positive treatment outcome. At the same time in general their actual diagnostic skills are not sufficient, they misapply additional diagnostic methods, do not perform risk analysis of potential clinical complications that leads to shifting responsibilities on the patients in case of complications emergence. Methods of Computer Assisted Design are widely popular during all stages of rehabilitation (diagnostic, surgical stent, final prosthesis framework). Actual level of expertise of dental professionals doesn't depend on sex distribution. Males and females who practice implant dentistry have similar levels of clinical expertise.

Risks of angled implant placement on posterior mandible buccal/lingual plated perforation: A virtual immediate implant placement study using CBCT

Background/purpose

Immediate implant placement has been considered to be a successful treatment procedure. The bone plate perforation (BPP) may be one of severe complication and potentially life-threatening situation. The aim of this virtual study is to evaluate the influences of angled implant insertion on BPP during immediate implant installation in the posterior mandible.

Materials and methods

Cone beam computed tomography images of 488 posterior teeth from 61 patients were selected. Virtual immediate implant placement (VIIP) was performed at each posterior tooth following the appropriate axis with the prosthetic-driven planning and different deviation angles of 3-, 6-, or 9-degree. BPP was then examined from cross-sectional images obtained. Furthermore, the relation of lingual bony morphology and BPP were also determined.

Results

The incidence of buccal and lingual BPP increased as the deviation angle increased in posterior mandible area. Incidence of lingual BPP was significantly influenced by angular deviation and type of lingual bony morphology after adjusting for age, gender, tooth type, and right/left side. An increase in incidence odds of over 6-fold (OR = 6.583) was noted for placements angled by 9° compared with placements made without angulation, and an increase in incidence odds of over 3-fold (OR = 3.622) was noted for teeth with the undercut-type lingual morphology compared with the other types.

Conclusion

The present Results indicate that accurate selection of the implant insertion angle and full awareness of the bony anatomy at the implant recipient site are essential to prevent BPP in the posterior mandible.

Development of a dental handpiece angle correction device

Background

Preparation of a uniform angle of walls is essential for making an ideal convergence angle in fixed prosthodontics. We developed a de novo detachable angle-correction apparatus for dental handpiece drills that could help the ideal tooth preparation.

Methods

We utilized a gyro sensor to measure the angular velocities to calculate the slope of an object by integrating the values, acceleration sensor to calculate the slope of an object by measuring the acceleration relative to gravity, and Kalman filter algorithm. Converting the angulation of the handpiece body to its drill part could be performed by a specific matrix formulation set on two reference points (2° and 6°). A flexible printed circuit board was used to minimize the size of the device. For convergence angle investigation, 16 volunteers were divided randomly into two groups for performing tooth preparation on a mandibular first molar resin tooth. All abutments were scanned by a 3D scanner (D700^®, 3Shape Co., Japan), the convergence angle and tooth axis deviation were analyzed by a CAD program (SolidWorks 2013^®, Dassault Systems Co., USA) with statistical analysis by Wilcoxon signed-rank test (α = 0.05) using SPSS statistical software (Version 16.0, SPSS Inc.).

Results

This device successfully maintained the stable zero point (less than 1° deviation) at different angles (0°, 30°, 60°, 80°) for the first 30 min. In single tooth preparation, without this apparatus, the average bucco-lingual convergence angle was 20.26° (SD 7.85), and the average mesio–distal (MD) convergence angle was 17.88° (SD 7.64). However, the use of this apparatus improved the average BL convergence angle to 13.21° (SD 4.77) and the average MD convergence angle to 10.79° (SD 4.48). The angle correction device showed a statistically significant effect on reducing the convergence angle of both directions regardless of the order of the directions.

Conclusions

The angle correction device developed in this study is capable of guiding practitioners with high accuracy comparable to that of commercial navigation surgery. The volume of the angle correction device is much smaller than that of any other commercial navigation surgery system. This device is expected to be widely utilized in various fields of orofacial surgery.

The Use of Orientation Templates and Free-Hand Implant Insertion in Artificial Mandibles-An Experimental Laboratory Examination in Fifth-Year Dental Students

Implant dentistry is a growing field in the education of undergraduate dental students. The present laboratory study evaluates factors which may potentially influence the accuracy of free-hand implant insertion and the use of an orientation template. After three-dimensional planning using coDiagnostiX^TM, orientation templates, including sleeves for the pilot-drill in regions 41 and 45, were manufactured by thermoforming. Sixty-one fifth year dental students inserted one implant using the orientation template and another implant free-hand in an artificial mandible. Information regarding age, sex, handedness, education, and the time required for implant insertion were recorded. Subsequently, the mandibles were scanned using cone-beam-computed tomography and the accuracy of the implant position was assessed, while statistical analysis followed. The free-hand implant insertion resulted in a distal deviation of −1.34 ± 5.15° and a mesial mismatch of 0.06 ± 0.79 mm at the artificial bone level compared to the sleeves. When using the orientation templates, the deviation decreased to −0.67 ± 3.48° and a distal mismatch of −0.22 ± 0.62 mm was achieved. The difference was statistically significant for the mismatch (p < 0.049). Regarding the limitations of our study, it could be said that the accuracy level achieved by dental undergraduates using implant placement with orientation templates is comparable to that in other studies.

Bimaxillary simultaneous immediate loading of full-arch restorations: A case series

Aim

To describe a bimaxillary simultaneous immediate loading protocol with full-arch implant-supported fixed prostheses.

Material and Methods

A prospective case series of 8 patients who required full-arch rehabilitation was conducted. The main inclusion criteria were patients with teeth that required extraction. At least 1 molar per arch was temporarily employed to stabilize the surgical template and the provisional prosthesis during intraoral relining.

Results

Two upper implants failed in 1 patient. Structural fracture was registered in 3 patients, around 3 months after loading. All of them had bruxism. Three esthetic complications were registered: midline deviation, canting of the oclusal plane and color mismatch.

Conclusions

Although this protocol achieves optimal results, some mechanical complications were encountered. The fracture of the provisional prosthesis is a relatively common mechanical complication but does not seem to jeopardize the final treatment result.

Key words:Implant-supported full-arch, provisional prosthesis fracture, bimaxillary simultaneous rehabilitation, conical abutments.

Learning Curve of a Minimally Invasive Technique for Transcrestal Sinus Floor Elevation: A Split-Group Analysis in a Prospective Case Series With Multiple Clinicians

AIMS

To assess the learning curve of a minimally invasive procedure for maxillary sinus floor elevation with a transcrestal approach (tSFE) and evaluate the influence of clinician's experience in implant surgery on its outcomes.

MATERIALS AND METHODS

Patients were treated by clinicians with different levels of experience in implant surgery and inexperienced with respect to the investigated tSFE technique. The initial (n = 13) and final (n = 13) groups treated by the expert clinician were compared for tSFE outcomes. Additionally, the high, moderate, and low groups (n = 20 each) treated by the expert, moderately experienced, and low experienced clinician, respectively, were compared.

RESULTS

(1) No significant differences in clinical and radiographic outcomes were observed between initial and final groups; (2) high, moderate, and low groups showed substantial vertical augmentation in limited operation time with treatment outcomes being influenced by the level of experience in implant surgery.

CONCLUSIONS

The investigated technique allows for a substantial vertical augmentation at limited operation times when used by different clinicians. The extent of sinus lift (as radiographically assessed) seems to be influenced by the clinician's level of experience in implant dentistry.

Effect of Bisphosphonate and Age on Implant Failure as Determined by Patient-Reported Outcomes

The aim of the current study was to elucidate whether there is an association between selected risk factors and implant failure, as determined by patient-reported outcomes. A trained clinician administered a formal survey questionnaire to 415 patients who had received a total of 963 implants through the University of Kentucky College of Dentistry's implant training program. The questionnaire was designed to obtain information about potential risk factors that may affect implant failure. Patients were also asked to rate their satisfaction with the appearance and function of the implant, their surgical experience, and the levels of pain and mobility associated with the implant(s). Both patient-level and implant-level data were analyzed in this study. Multiple logistic regression analysis at the patient level indicated that the following variables did not contribute to the success or failure of the implants: sex, smoking status, diabetes, osteoporosis, and use of bisphosphonates. When the statistical analyses controlled for these variables, the odds of patient-reported implant failure increased with the patient's age (by 15% every 5 years). The results of implant-level analyses adjusted for smoking status, diabetes, and osteoporosis showed that the patient's age (odds of failure increased by 12% every 5 years) and no use of bisphosphonates (odds ratio, 9.22; 95% confidence interval, 1.849, 45.975) were significantly associated with poor implant outcome. Our findings suggest a possible association between implant failure and the patient's age and use of bisphosphonates.

Axial relationship between dental implants and teeth/implants: a radiographic study

The relationship of dental implants with neighboring teeth will affect both occlusal relationship and distribution of forces; thus, the purpose of this study was to examine implants' axial relationship with adjacent and opposing teeth/implants. Data of dental implants patients was retrieved. Panoramic X rays were digitized. Computer-based software was used to measure the angular relationship between the implants and adjacent/opposing teeth and implants. Data was further sorted by the mode of placement and implants position. 50 patients (219 implants) were included. Mean angle to adjacent tooth/implant was 178.71° ± 9.18° (range 129.7°-206°). Implants were more parallel to adjacent teeth (180.99° ± 1.06°) than to adjacent implants (176.32° ± 0.54°; P = .0001). Mean angular relationship to opposite tooth was 167.88° ± 8.92° (range 137.7°-179.8°). Implants that were placed freehand or with positional guide had similar intra-arch relationship (178.22° and 178.81°, respectively) and similar inter-arch angulations (164.46° and 167.74°). Molars had greater deviation of the angular relationship (175.54°) compared to premolars (181.62°) and incisors (180.55°, P = .0001). Implants placed in the maxilla had smaller axial deviation compared to implants in the mandible (180.41° ± 0.64 vs 177.14° ± 1.02; P = .0081). Good axial relationship may be obtained in most implants placed by an experienced clinician, even when placed freehand. The mandibular posterior region is more prone to axial deviation and as such requires special attention.

Software tools and surgical guides in dental-implant-guided surgery

Cone beam computed tomography has become an essential tool in the diagnosis and planning for implant dentistry. New hardware and software developments have emerged to help implant surgeons to successfully adopt and use different systems in patients requiring prosthetically driven implant dentistry. However, there is the need to develop an adequate planning protocol that includes appropriate acquisition/data manipulation, appropriate use of software tools for interpretation, and appropriate application of such systems during implant surgery. This article examines essential characteristics of the entire implant-guided surgery planning process and points out potential sources of error that could affect clinical accuracy outcomes.