Clinical problems of computer-guided implant surgery

Mouth opening limitation and influence of age and surgical location for static fully guided dental implant placement: an observational, cross-sectional clinical study

The influence of age and region of the mouth was assessed in regard to mouth opening in fully guided implant placement. Ninety patients were included in this study, 30 in each of three age groups (20-34, 35-55, and >55 years). Maximum passive mouth opening was recorded in three locations: incisal, canine, and molar. The minimum distance required to allow the bone drilling sequence through a static fully guided approach was analysed for four implant systems: Straumann, MIS Dentsply, Astra Tech Dentsply, and Dentium. The mean ± standard deviation maximum mouth opening (all 90 patients) was 46.34 ± 7.70 mm, 36.82 ± 5.92 mm, and 30.99 ± 5.40 mm in the incisal, premolar, and molar region, respectively. No significant difference in mouth opening at any of the three locations was found between the age groups (all P > 0.05). However, a correlation was found between increasing age and decreasing average mouth opening in all three mouth regions; each additional 1 year resulted in a mean reduction of 0.13 mm, 0.09 mm, and 0.08 mm in the incisal, premolar, and molar region, respectively. The minimum required mouth opening was most likely to be met for implant placement in the incisal region (98.9% of all patients) and least likely to be met for placement in the molar region, particularly for older patients (as low as 30% of patients). Mouth opening remains a major limitation in fully guided implant surgery, especially in posterior areas and in older patients. The use of some implant systems in the posterior area may be limited to only one in three patients.

The effect of implant surgery experience on the learning curve of a dynamic navigation system: an in vitro study

BACKGROUND

Dynamic navigation systems have a broad application prospect in digital implanting field. This study aimed to explore and compare the dynamic navigation system learning curve of dentists with different implant surgery experience through dental models.

METHODS

The nine participants from the same hospital were divided equally into three groups. Group 1 (G1) and Group 2 (G2) were dentists who had more than 5 years of implant surgery experience. G1 also had more than 3 years of experience with dynamic navigation, while G2 had no experience with dynamic navigation. Group 3 (G3) consisted of dentists with no implant surgery experience and no experience with dynamic navigation. Each participant sequentially placed two implants (31 and 36) on dental models according to four practice courses (1-3, 4-6, 7-9, 10-12 exercises). Each dentist completed 1-3, 4-6 exercises in one day, and then 7-9 and 10-12 exercises 7 ± 1 days later. The preparation time, surgery time and related implant accuracy were analyzed.

RESULTS

Three groups placed 216 implants in four practice courses. The regressions for preparation time (F = 10.294, R² = 0.284), coronal deviation (F = 4.117, R² = 0.071), apical deviation (F = 13.016, R² = 0.194) and axial deviation (F = 30.736, R² = 0.363) were statistically significant in G2. The regressions for preparation time (F = 9.544, R² = 0.269), surgery time (F = 45.032, R² = 0.455), apical deviation (F = 4.295, R² = 0.074) and axial deviation (F = 21.656, R² = 0.286) were statistically significant in G3. Regarding preparation and surgery time, differences were found between G1 and G3, G2 and G3. Regarding implant accuracy, differences were found in the first two practice courses between G1 and G3.

CONCLUSIONS

The operation process of dynamic navigation system is relatively simple and easy to use. The linear regression analysis showed there is a dynamic navigation learning curve for dentists with or without implant experience and the learning curve of surgery time for dentists with implant experience fluctuates. However, dentists with implant experience learn more efficiently and have a shorter learning curve.

A Novel Approach to Guided Implant Surgery: A Technical Note

Computer-guided software and kits have significantly improved the clinical applications of implant surgery. Nonetheless, some technical problems are still in evidence during clinical procedures because of cumbersome surgical tools that can limit access to implant sites, mainly in posterior areas of the mouth in the presence of bulky anatomical structures and in patients with reduced mouth-opening capacity. The present paper aimed to present a novel approach to guided implant surgery, describing the technical characteristics of an innovative guided surgical kit made up of modified sleeves and modular surgical drills. The proposed guided surgical kit is based on a novel patented system of sleeves and modular burs, with an increased length of the metal sleeves and a reduced height of the drills. The innovative design of the proposed system would allow the clinician to position guided fixtures in all clinical situations; the reduced encumbrance would be particularly helpful to gain access to the posterior areas of both maxilla and mandible, which have limited inter-arch space, with an easy and user-friendly approach. The modular system could overcome anatomical limitations, such as reduced mouth-opening capacity, and permit clinicians to maintain the stability and integrity of the surgical templates, even in cases where there is very limited intermaxillary space.

Multiple pterygoid approach: A novel technique with single-piece implants

The intended target site to engage a fixture distal into the tuberosity is the pterygoid apophysis that comprises the maxillary tuberosity, pyramidal process of the palatine bone, and the pterygoid process of the sphenoid bone. Pterygoid implants are incorrectly labeled in literature owing to the fact that they are actually root form conventional implants and should hence be termed as 'tubero-pterygoid implant'. An implant engaging the pterygoid apophysis/pillar taking distal maxillary support and avoiding successfully the cantilever situation is called a pterygoid implant. It essentially does not acquire primary with support of distal maxilla initially from the tuberosity. Instead, it makes its way into the apophysis and sometimes via a transsinus approach. A tubero-pterygoid implant, because of the root form screw shape fixture that is wide at the crestal aspect and converging toward the apex, takes the primary support from the tuberosity and engages the pterygoid pillar apically, thus allowing more bone to implant contact but has its limitation in deficient/atrophied tuberosity.

Zygomatic approach with single-piece implants: A technical note

Single piece zygomatic implant, or a remote anchorage implant, is an effective tool for the rehabilitation of the atrophic/resected jaws with least postoperative complications such as screw loosening, screw fractures, bone loss, mucositis, and peri implantitis. The aim of this paper was to summarize a technique for the use of a zygomatic approach for single piece implants. We used the key-words 'single piece implants” and the search revealed 700 papers in the PubMed database. After screening through the abstracts, we selected 50 articles that we finally reviewed. Zygomatic fixtures avoid the grafting procedures and cantilever situation, restoration of atrophic or postablative jaws are completed with immediate loading. It is advisable placement of zygomatic implant flapless with surgical guide, but the author believes more on the tactile perception and when the splint is at mucosal or bone level, a small change in orientation will lead the dramatic error in desired angulation leading to unwanted complication.

Influence of bone condition on implant placement accuracy with computer-guided surgery

BACKGROUND

The impact of the jaw bone condition, such as bone quantity and quality in the implant placement site, affecting the accuracy of implant placement with computer-guided surgery (CGS) remains unclear. Therefore, this study aimed to evaluate the influence of bone condition, i.e., bone density, bone width, and cortical bone thickness at the crestal bone on the accuracy of implant placement with CGS.

METHODS

A total of 47 tissue-level implants from 25 patients placed in the posterior mandibular area were studied. Implant placement position was planned on the simulation software, Simplant® Pro 16, by superimposing preoperative computed tomography images with stereolithography data of diagnostic wax-up on the dental cast. Implant placement surgery was performed using the surgical guide plate to reflect the planned implant position. The post-surgical dental cast was scanned to determine the position of the placed implant. Linear and vertical deviations between planned and placed implants were calculated. Deviations at both platform and apical of the implant were measured in the bucco-lingual and mesio-distal directions. Intra- and inter-observer variabilities were calculated to ensure measurement reliability. Multiple linear regression analysis was employed to investigate the effect of the bone condition, such as density, width, and cortical bone thickness at the implant site area, on the accuracy of implant placement (α = 0.05).

RESULT

Intra- and inter-observer variabilities of these measurements showed excellent agreement (intra class correlation coefficient ± 0.90). Bone condition significantly influenced the accuracy of implant placement using CGS (p < 0.05). Both bone density and width were found to be significant predictors.

CONCLUSIONS

Low bone density and/or narrow bucco-lingual width near the alveolar bone crest in the implant placement site might be a risk factor influencing the accuracy of implant placement with CGS.

The Role of Digital Devices in Dentistry: Clinical Trends and Scientific Evidences

In recent years, digital technologies have significantlychanged the clinical approach to medicine and dentistry. Innovative operative techniques and restorative materials have paved the way to a significant active boost towards full digital workflows. Particularly, novel dental materials offer undeniable advantages such as optimal mechanical resistance, excellent esthetic and optical properties, and reliable accuracy and precision, widening the clinical scenario and allowing for innovative and less invasive restorative solutions.

[Comparative study of 3D printing implant guide in different implant surgeries in anterior tooth defect area]

OBJECTIVE

To study the accuracy of 3D printing implant-guided anterior tooth implantation under flap or flapless surgery.

METHODS

Twenty-one cases (32 teeth) with missing teeth were divided into two groups: tooth implantation on the maxillary models under flap surgery (FP group) and tooth implantation on the maxillary models under flapless surgery (FPS group). A dental implant guide was designed and used in the two groups. The actual position of the dental implants in the two groups was compared with the preplanned deviation values of implant top, bottom, vertical distance, and angle deviation. SPSS 19.0 software was used for statistical analysis.

RESULTS

The deviation values of implant top, bottom, vertical distance, and angle were significantly lower in the FP group than in the FPS group (P<0.05).

CONCLUSIONS

High accuracy of tooth implantation can be realized by using the 3D printing implant guide. The different surgical methods influence the precision of tooth implantation. Clinicians can choose the surgery reasonably depending on the actual situation.

Analysis of Linear and Angular Deviations of Implants Installed With a Tomographic-Guided Surgery Technique: A Prospective Cohort Study

The aim of this study was to evaluate the linear and angular deviations of the implants installed by the computerized tomography (CT)-guided surgery technique. Eighteen patients who underwent implant insertion by means of CT-guided surgery participated in this study. Ten of these patients had a fully edentulous maxilla, and 8 had a fully edentulous mandible. The patients received a total of 115 implants, of which 81 implants were installed in the maxilla and 34 installed in the mandible. Tomographic guides were made for tomographic examination in both the upper and lower jaws. After the image acquisition, the virtual planning of the positioning of the implants was performed in relation to the previously made prosthesis. The measurement of the linear and angular deviations between the virtual planning and the final position of the implants was performed with the overlap of the planning and postoperative tomography. There were no differences in the linear and angular deviations of the implants installed in the maxilla and mandible. Compared with the coronal region, there was a trend of greater linear deviations in the apical regions of the implants and a greater tendency toward deviations in the posterior regions than in the anterior regions of both arches. The CT-guided surgery promoted the installation of implants with high accuracy and allowed the installation of straight pillars in all cases evaluated. The linear deviations were not different in the different regions of the mouth or in the different portions of the implants.

A Flapless Surgical Placement of Implants in Mandibular Arch Using Computer-Guided Surgical Stent

The loss of teeth is always challenging for the patients. It is not only a functional loss but also a psychological and social loss. But with the advent of dental implants, this clinical situation can be dealt with tactfully. In an edentulous arch, prosthetic rehabilitation by all on 6 implants require accurate placement of implants for a successful result. A computer-guided surgical stent can be advantageous over arbitrary placement of implants and can overcome the difficulties associated with arbitrary placement. Using the cone beam computed tomography of the patient, virtual planning of implant is done. The exact implant angulations can be visualized to achieve the best possible esthetics and occlusion. This information is then converted to fabricate a stent using three-dimensional printing. Using this stent, a flapless surgical implant placement can be done which will reduce the post-operative trauma. This case report describes a case of a patient having an edentulous mandibular arch. The prosthetic rehabilitation of the mandibular arch was done by flapless surgical placement of six implants using a computer-guided surgical stent.

Double Guided Surgery in All-on-4® Concept: When Ostectomy Is Needed

Background

The rehabilitation of edentulous jaws with guided and flapless surgery applied to the All-on-4 concepts is a predictable treatment with a high implant and prosthetic survival rates, but there are several contraindications for this technique like when bone reduction is needed due to a high smile line in the maxilla or when there is an irregular or thin bone crest.

Purpose

To report a technique with double guided surgery for bone reduction and implant placement with the All-on-4 concept.

Materials and Methods

7 patients were included in the study. Guided implant planning was performed using CBCT, and the virtual templates were created with three dedicated software. Custom surgical templates were made for the ostectomy and for implants positioning.

Results

28 implants were placed using a double bone-supported surgical guide. The mean angular errors between the preoperative-planned implant and the postoperative-placed implant were 2.155° ± 2.03°; the mean distance errors between the planned and the placed implants were 0.763 mm ± 0.55 mm on the shoulder implant and 0.570 mm ± 0.40 mm on the apex implant.

Conclusions

The results of our study indicate that this treatment is predictable with an excellent survival rate allowing excellent results even when bone reduction is mandatory.

Recent advances in dental implants

Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

3D printing guide implant placement: A case report

Background: Cone Beam Computer Tomography (CBCT) is representing a new concept of radiological diagnostics and its application occupies a special place in implantology. Today, preoperative planning, and quantitative and qualitative jaw bone analysis cannot be done without the use of these techniques. The latest in a series of achievements in this field is a method of making a guide for implant using a 3D printing technique. This way pre implantology planning reduces the chance of surgical complications to a minimum and allows installation of dental implants in the most optimal position for future prosthetic work. Aim: To show benefits of guide implantation in clinical practice. Case report: The patient M.D. 36 years old. After making CBCT there was a qualitative and quantitative analysis of bone tissue, after which we decided to install five implants in positions #36, #37, #45, #46 and #47. The software appliance made virtually implants in the most optimal positions; treatment plan was forwarded by the internet connection into the DICOM format to Simplant Company, along with a folder of scanned plaster models in order to develop a guide. A few days later, after approval sent, we received the guide. Preparation by the pilot bur we did through transmucosal plum of the guide, and then we continued the classic flap surgery technique. Control footage shows the optimal position of the implant from both surgical and prosthetic aspects. Conclusion: Application guide implantology represents a safe and modern method that provides ability of implant placement in optimal positions in terms of future prosthetic rehabilitation.