Custom-Made Direct Metal Laser Sintering Titanium Subperiosteal Implants in Oral and Maxillofacial Surgery for Severe Bone-Deficient Patients—A Pilot Study

The Evolution of Custom Subperiosteal Implants for Treatment of Partial or Complete Edentulism in Patients with Severe Alveolar Ridge Atrophy

Dental implants have always played an important role in dentistry and have been used to replace missing teeth since around 600 AD. They can be classified into three groups: endosteal, subperiosteal, and transosteal. Over time, different materials have been used to manufacture dental implants and these, in turn, can be divided into three groups: metals, ceramics, and polymers. Today, the most commonly used treatment for edentulism is the use of endosteal implants. However, such an approach cannot be used in patients with severe alveolar ridge atrophy and, in such cases, custom subperiosteal implants are an alternative. This review article focuses on historical developments and improvements that have been made over recent years in treatment options for patients suffering from edentulism and significant resorption of the alveolar ridge. These treatment options involve the utilization of custom subperiosteal implants. This paper looks at the historical evolution of these implants, the significance of diagnostic imaging, and the application of the contemporary methods of production, such as CAD-CAM and additive manufacturing. The research emphasizes the importance of accuracy and personalization provided by these emerging technologies that have rendered subperiosteal implants a more feasible and less intrusive alternative for patients suffering from significant bone loss.

Full-arch rehabilitation of severely atrophic maxilla with additively manufactured custom-made subperiosteal implants: A multicenter retrospective study

The aim of this retrospective study was to analyze a series of patients who underwent full-arch rehabilitation of the atrophic maxilla using additively manufactured subperiosteal implants, between August 2018 and January 2023, at the Universities of Sassari and Poznan. In total, 36 patients and 72 implants were included, with no implants lost during follow-up, and a success rate of 90.3%. Seven (9.7%) of the implants showed class 1 exposure. Bleeding on probing was detected in 10.4% of the abutments at 6 months, 7.9% at 1 year, 10% at 2 years, 7% at 3 years, and 11.4% at 4 years. No significant bone resorption under the abutments was detected during the whole observation period. Based on the findings from this study, additively manufactured subperiosteal implants could represent a safe and reliable technique for full-arch rehabilitation in patients with severe maxillary atrophy.

Evaluation of Clinical Success of the 3D-Printed Custom-Made Subperiosteal Implants

OBJECTIVE

The authors aim to share their experiences in subperiosteal implant applications in atrophic jaws, which have been practiced in their clinic for about 2 years, and evaluate the complications and clinical success of the implants.

MATERIAL AND METHOD

Clinical and radiologic data of 32 patients who underwent subperiosteal implantation for advanced alveolar bone loss were evaluated, but 1 patient was excluded as they smoked. Of the 31 patients included in the study, 27 were operated with the diagnosis of total tooth loss, 3 for maxillectomy and 1 for partial tooth loss. A total of 60 subperiosteal implants were placed in them. The mean follow-up period was 15 months.

RESULTS

During the operation, implant-bone adaptation problems were encountered in 11 patients, implant skeletal fracture in 1 patient, and loss of primary stabilization during mini-screw fixation in 2. Although there were no complications in the early postoperative period, biological and prosthetic complications occurred in the late postoperative period. Soft tissue retraction at various levels in 12 patients (only keratinized tissue retraction in 6 and mucosal retraction exceeding keratinized tissue in 6), soft tissue infection in 5 and oroantral fistula development in 1, mini-screw loosening in 3 were the biological complications that occurred.

CONCLUSIONS

Various complications may occur during or after the application of custom-made subperiosteal implants. However, these are manageable and can be reapplied in case of a possible implant loss, making it an important alternative, especially in atrophic jaws where endosseous dental implants cannot be applied.

Implant-prosthetic rehabilitation of the atrophic posterior mandible with additively manufactured custom-made subperiosteal implants: a cohort study

The aim of this study was to retrospectively analyse a series of patients with posterior mandibular atrophy rehabilitated with custom-made subperiosteal implants. The study included patients with severe posterior mandibular atrophy who had undergone rehabilitation with subperiosteal implants between September 2018 and August 2022 in the Maxillofacial Surgery Operative Unit of the University Hospital of Sassari. Complications and the success rate were reviewed. Data from 30 implants placed in 17 patients were included and analysed. There were no major complications during the surgeries. The main postoperative sequela was oedema, which was reported as moderate by most patients and had completely regressed within 10 days of surgery. No partial or complete exposures, infections, or loss of the implants were detected during follow-up (average follow-up 22.5 months). Control computed tomography scans, performed at 6 months and then annually in all cases, did not show significant bone loss below the abutments, displacement of the implants, or loss or loosening of the osteosynthesis screws. Subperiosteal implants may represent a safe and reliable technique for the rehabilitation of severe atrophy of the posterior mandible. Prospective studies with a long follow-up will be needed to establish the long-term results of this type of implant-prosthetic rehabilitation.

Long-Term Clinical Outcomes of 3D-Printed Subperiosteal Titanium Implants: A 6-Year Follow-Up

As an alternative to regenerative therapies, numerous authors have recently proposed bringing back subperiosteal implants. The aim of the study was to present our clinical experience with a subperiosteal jaw implant that needs minimal bone preparation and enables the rapid implantation of prosthetic teeth in edentulous, atrophic alveolar bone. The research included 36 complete or partial edentulous patients (61 subperiostal implants) over a period of 6 years. To create the patient-specific subperiostal implants design, DentalCAD 3.0 Galway software (exocad GmbH, Darmstadt, Germany) was used and fabricated with a Mysint 100 (Sisma S.p.A., Piovene Rocchette, Italy) by titanium alloy powder. The results showed that only 9 of the 36 cases were successful at 6-year follow-up, while 27 cases had complications, including exposure of the metal frame (early or delayed), mobility of the device prior to the first 4-6 months, and late mobility due to recurrent infections and progressive structure exposure; 1 case failed for reasons unrelated to the device. This study indicated that the prudent application of fully customized subperiosteal jaw implants is a dependable alternative for the dental rehabilitation of atrophic edentulous cases that necessitate bone grafts for traditional fixed dental implant solutions.

Subperiosteal implants constructed with digital technology: A systematic review

STATEMENT OF PROBLEM

Atrophied jaw is a condition where there is insufficient bone quantity and quality. Several treatment plans are available for treating atrophied jaws, including subperiosteal implants.

PURPOSE

To evaluate the spectrum of subperiosteal implants for severely atrophied jaws using digital technology.

MATERIALS AND METHODS

An electronic and manual search was conducted in the PubMed, Scopus, and Google Scholar databases. Publications of cohort studies, case series, and case reports written in English without data restrictions that reported on subperiosteal implant management of patients with severely atrophied jaws in a completely and partially edentulous population.

RESULTS

A total of 26 articles, comprising 302 cases, were analyzed. In patients with severely atrophied jaws. The success rate was 87.7%, the surviving rate was 95.3%. The most common complications were biological, such as dehiscence and framework exposure. The rates of biologic complications were 11.5%, and the rates of prosthetic problems were 5.9%.

CONCLUSIONS

Subperiosteal implants designed and constructed using digital technology are a promising treatment in the short term. Attention should be directed to decrease the biological complication. Correct designing, implanting, fixing, and patient selection and maintenance are critical for the success of the treatment. Longer prospective studies with larger population are needed to view the effect on hard and soft tissue.

Clinical performance of additively manufactured subperiosteal implants: a systematic review

PURPOSE

The aim of this study was to assess implant survival and complications rate of modern subperiosteal implants (CAD designed and additively manufactured).

METHODS

A systematic review was conducted using three electronic databases; Medline (Pubmed), Cochrane library, and SCOPUS, following the PRISMA statement recommendations to answer the PICO question: "In patients with bone atrophy (P), do additively manufactured subperiosteal implants (I), compared to subperiosteal implants manufactured following traditional approaches (c), present satisfactory implant survival and complication rates (O)? The study was pre-registered in PROSPERO (CRD42023424211). Included articles quality was assessed using the "NIH quality assessment tools".

RESULTS

Thirteen articles were finally selected (5 cohort studies and 8 case series), including 227 patients (121 female / 106 male; weighted mean age 62.4 years) and 227 implants. After a weighted mean follow-up time of 21.4 months, 97.8% of implants were in function (5 failures reported), 58 implants (25.6%) presented partial exposure, 12 patients (5.3%) suffered soft tissue or persistent infection. Fracture of the interim prosthesis was reported in 8 of the155 patients (5.2%) in which the use of a provisional prosthesis was reported. A great heterogeneity was found in terms of study design and methodological aspects. For this reason, a quantitative analysis followed by meta-analysis was not possible.

CONCLUSIONS

Within the limitations of this study, modern additively manufactured subperiosteal implants presented a good survival in the short-time, but a noticeable number of soft-tissue related complications were reported. Further studies are needed to assess the clinical behavior in the medium- and long-term.

Customized Subperiosteal Implants for the Rehabilitation of Atrophic Jaws: A Consensus Report and Literature Review

(1) Background: The aim was to perform a literature review on customized subperiosteal implants (CSIs) and provide clinical guidelines based on the results of an expert consensus meeting held in 2023. (2) Methods: A literature search was performed in Pubmed (MEDLINE) in July 2023, including case series and cohort studies with a minimum follow-up of 6 months that analyzed totally or partially edentulous patients treated with CSIs. Previously, an expert consensus meeting had been held in May 2023 to establish the most relevant clinical guidelines. (3) Results: Six papers (four case series and two retrospective cohort studies) were finally included in the review. Biological and mechanical complication rates ranged from 5.7% to 43.8% and from 6.3% to 20%, respectively. Thorough digital planning to ensure the passive fit of the CSI is mandatory to avoid implant failure. (4) Conclusions: CSIs are a promising treatment option for rehabilitating edentulous patients with atrophic jaws; they seem to have an excellent short-term survival rate, a low incidence of major complications, and less morbidity in comparison with complex bone grafting procedures. As the available data on the use of CSIs are very scarce, it is not possible to establish clinical recommendations based on scientific evidence.

3D Printing Applications for Craniomaxillofacial Reconstruction: A Sweeping Review

The field of craniomaxillofacial (CMF) surgery is rich in pathological diversity and broad in the ages that it treats. Moreover, the CMF skeleton is a complex confluence of sensory organs and hard and soft tissue with load-bearing demands that can change within millimeters. Computer-aided design (CAD) and additive manufacturing (AM) create extraordinary opportunities to repair the infinite array of craniomaxillofacial defects that exist because of the aforementioned circumstances. 3D printed scaffolds have the potential to serve as a comparable if not superior alternative to the "gold standard" autologous graft. In vitro and in vivo studies continue to investigate the optimal 3D printed scaffold design and composition to foster bone regeneration that is suited to the unique biological and mechanical environment of each CMF defect. Furthermore, 3D printed fixation devices serve as a patient-specific alternative to those that are available off-the-shelf with an opportunity to reduce operative time and optimize fit. Similar benefits have been found to apply to 3D printed anatomical models and surgical guides for preoperative or intraoperative use. Creation and implementation of these devices requires extensive preclinical and clinical research, novel manufacturing capabilities, and strict regulatory oversight. Researchers, manufacturers, CMF surgeons, and the United States Food and Drug Administration (FDA) are working in tandem to further the development of such technology within their respective domains, all with a mutual goal to deliver safe, effective, cost-efficient, and patient-specific CMF care. This manuscript reviews FDA regulatory status, 3D printing techniques, biomaterials, and sterilization procedures suitable for 3D printed devices of the craniomaxillofacial skeleton. It also seeks to discuss recent clinical applications, economic feasibility, and future directions of this novel technology. By reviewing the current state of 3D printing in CMF surgery, we hope to gain a better understanding of its impact and in turn identify opportunities to further the development of patient-specific surgical care.

Finite Element Analysis (FEA) of a Premaxillary Device: A New Type of Subperiosteal Implant to Treat Severe Atrophy of the Maxilla

Extreme atrophy of the maxilla still poses challenges for clinicians. Some of the techniques used to address this issue can be complex, risky, expensive, and time consuming, often requiring skilled surgeons. While many commonly used techniques have achieved very high success rates, complications may arise in certain cases. In this context, the premaxillary device (PD) technique offers a simpler approach to reconstruct severely atrophic maxillae, aiming to avoid more complicated and risky surgical procedures. Finite element analysis (FEA) enables the evaluation of different aspects of dental implant biomechanics. Our results demonstrated that using a PD allows for an optimal distribution of stresses on the basal bone, avoiding tension peaks that can lead to bone resorption or implant failure. ANSYS® was used to perform localized finite element analysis (FEA), enabling a more precise examination of the peri-crestal area and the PD through an accurate mesh element reconstruction, which facilitated the mathematical solution of FEA. The most favorable biomechanical behavior was observed for materials such as titanium alloys, which helped to reduce stress levels on bone, implants, screws, and abutments. Additionally, stress values remained within the limits of basal bone and titanium alloy strengths. In conclusion, from a biomechanical point of view, PDs appear to be viable alternatives for rehabilitating severe atrophic maxillae.

Biomechanical evaluation of custom-made short implants with wing retention applied in severe atrophic maxillary posterior region restoration: A three-dimensional finite element analysis

Severe bone atrophy in the maxillary posterior region poses a big challenge to implant restoration. Digitally designed and customized short implants with wing retention provide a safer and minimally invasive implant restoration scheme in such circumstances. Small titanium wings are integrated with the short implant supporting the prosthesis. Using digital designing and processing technology, the wings fixed by titanium screws can be flexibly designed, providing the main fixation. The design of the wings will influence the stress distribution and implant stability. This study analyzes the position, structure, and spread area of the wings fixture scientifically by means of three-dimensional finite element analysis. The design of the wings is set to linear, triangular, and planar styles. Under the simulated vertical and oblique occlusal forces, the implant displacement and stress between the implant and the bone surface are analyzed at different bone heights of 1 mm, 2 mm, and 3 mm. The finite element results show that the planar form can better disperse the stress. By adjusting the cusp slope to reduce the influence of lateral force, short implants with planar wing fixtures can be used safely even if the residual bone height is only 1 mm. The results of the study provide a scientific basis for the clinical application of this new customized implant.