Immediate flapless full-arch rehabilitation of edentulous jaws on 4 or 6 implants according to the prosthetic-driven planning and guided implant surgery: A retrospective study on clinical and radiographic outcomes up to 10 years of follow-up

Fixed Full-Arch Maxillary Prostheses Supported by Four Versus Six Implants: 5-Year Results of a Multicenter Randomized Clinical Trial

OBJECTIVES

This 5-year multicenter randomized clinical trial assessed the non-inferiority of maxillary implant-supported fixed complete dentures (FCDs) with four (4-I) compared to six implants (6-I) in terms of radiographic marginal bone level (MBL) changes after 5 years in function.

MATERIALS AND METHODS

Individuals were randomly assigned to the 4-I or 6-I groups. Follow-ups occurred at 1, 3, and 5 years. At each visit, FCDs were unscrewed, clinical parameters (plaque index, bleeding on probing, pocket depth, and keratinized mucosa width) were recorded using a periodontal probe, periapical radiographs were obtained, and maintenance care was performed. MBL changes, incidence of techincal, prosthetic, and biological complications, treatments costs, and satisfaction were evaluated.

RESULTS

Of 47 patients rehabiliated with 233 implants, survival rates were 99.3% for 6-I and 100% for 4-I (one early failure; 6-I group). No significant MBL differences were observed at 5 years between and within the groups. Both groups showed a decrease in keratinized mucosa width and experienced prosthetic and biological complications, but no peri-implantitis. The 4-I exhibited a significantly higher incidence of technical complications (16.6% vs. 0%) Cost analysis favored 4-I for initial and total costs. Clinician and patient satisfaction varied, with 4-I preferred aesthetically and 6-I functionally, particularly in speaking ability at earlier follow-ups.

CONCLUSION

The use of FCDs supported by four implants is non-inferior to six implants in terms of radiographic MBL changes after 5 years in function. Both groups demonstrated comparable survival rates and incidence of biological and prosthetic complications. The 4-I was associated with higher technical complications and reduced overall treatment cost.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02405169.

A retrospective study on patient satisfaction and Oral Health-Related Quality of Life with fixed 4- or 6-implant supported prostheses over 3-7 years

OBJECTIVES

To compare patients' satisfaction and oral health-related quality of life (OHRQoL) in edentulous patients treated by All-on-4 and All-on-6 implant-supported fixed prostheses rehabilitation over 3-7 years.

METHODS

All patients (n = 125) were divided into short-term (3-5 years, n = 71) and long-term (5-7 years, n = 54) follow-up groups. Patients' satisfaction was examined in a cross-sectional survey. OHRQoL and psychological impact were evaluated using the Oral Health Impact Profile (OHIP). Comparison of All-on-4 and All-on-6, including OHIP values, satisfaction scores, treatment duration and complications, were analyzed using the Chi-square test and the Mann-Whitney U test. Potential influence of patient-related factors on patient-reported outcome measures (PROMs) were analyzed via the Mann-Whitney U test, the Kruskal-Wallis test and multiple regression analyses. Power calculation was conducted in R Studio.

RESULTS

Both All-on-4 and All-on-6 follow-up groups showed high scores in total satisfaction and PROMs, including chewing comfort, aesthetics, cleanability, and stability, with no significant difference (p > 0.05). Meanwhile, no significant differences were observed in the OHIP scores between two groups in both follow-up durations (p > 0.05). However, in patients with 3-5 years follow-up, All-on-4 group had significantly lower phonetic satisfaction scores than All-on-6 group (p < 0.05). Additionally, during both follow-up periods, All-on-4 patients exhibited notably superior psychological effect in contrast to All-on-6 patients (p < 0.05).

CONCLUSIONS

Edentulous patients treated by four or six implant-supported fixed prostheses showed same high satisfaction in oral health-related quality of life in both 3-5 years and 5-7 years follow-ups.

Anatomic Variations Important for Dental Implantation in the Mandible-A Systematic Review

Background: This is a systematic review on the subject of anatomic landmarks and variations in the mandible that influence implantation placement. With this systematic review, we would like to summarize the results from different studies that are relevant to this subject and that are up to date, presenting their main findings, the measurements of mentioned landmarks, and giving clinical implications that will be helpful to practitioners in their better understanding of this topic. Methods: This study followed all of the elements of PRISMA. The criteria for inclusion and exclusion are described in detail. The following bibliographic databases were searched: PubMed (MEDLINE), The Cochrane Library, Wiley Online Library, EMBASE, and, additionally, Google Scholar. The search of articles was carried out using a combination of different keywords with a Boolean operator for each keyword. A total of 30 studies were included in this review and the risk of bias for each study was assessed. This review was registered with the PROSPERO ID number CRD42024609308. Results: The structure "SPIDER" was used to present the findings in the summation table, followed by a detailed description of the quantitative findings and overall mean values of the most commonly used measured points. The morphometric measurements of anatomic details and variations in the mandible, such as the mandibular canal, mental foramen, lingual foramina, lingual canal, incisive canal, and mandibular concavity, are of high significance for clinicians dealing with implantation where gender, ethnicity, age groups, the side of the mandible, or remaining teeth can influence implantation planning. Conclusions: The distances of the named anatomic landmarks to the surrounding bone structures that are used as a guide during planning are of huge importance, so proper and detailed measurements must be executed by experienced professionals using CBCT. Knowledge of the position and variation in these landmarks may be used for any bone-guided augmentation, surgical transpositions of anatomic landmarks, and surgery intervention planning. The results of this study can aid in choosing appropriate measurement points and give the gross picture, for clinicians, in therapy planning, considering all the landmarks of significance in the mandible.

Retrospective clinical follow-up of implants placed in edentulous jaws after computer-guided surgery and immediate loading, in geriatric patients

BACKGROUND

Although there are many works analyzing the clinical behavior of immediate loading of implants inserted by guided surgery, the literature referring specifically to elderly patients is scarce. The aim of this investigation is to present the clinical outcomes of immediate loading of implants inserted by guided surgery in geriatric patients with edentulous maxilla.

MATERIAL AND METHODS

The clinical data of 20 elderly patients with edentulous jaws are analyzed retrospectively. All were diagnosed with cone beam computed tomography, oral examination, and articulator-mounted models to analyze the intermaxillary relationship. They were treated with 4 to 10 implants by flapless guided surgery with immediate loading. After surgery, the implants were loaded with a temporary acrylic prosthesis and six months later, a definitive full-arch ceramic prosthesis was placed.

RESULTS

Twenty patients with an average age of 68.8 years (11 males and 9 females) underwent treatment with a total of 139 implants. Among them, 15 patients (75%) had a history of periodontitis. Ten patients (50%) smoked. Thirteen patients (65%) report a history oof systemic disease. The mean follow-up was 53.1 ± 21.4 months. The clinical outcomes indicated a 100% success rate for the implants. Twenty full-arch fixed maxillary rehabilitations were performed, with an average marginal bone loss of 1.37 mm (S.D. 0.53 mm.) Marginal bone loss was significantly greater for patients with a longer period of clinical follow-up. Peri-implantitis is reported in 17 implants (12.2%) in 8 patients (40%). Four patients (20%) showed some kind of mechanical prosthodontic complications.

CONCLUSIONS

The present work indicates that treatment with implant-supported fixed full-arch prostheses, in geriatric patients with edentulous jaws and through guided surgery and immediate loading, this implant protocol seems to be a successful.

Immediate full-arch rehabilitation of edentulous jaws on 4 or 6 implants using a photogrammetry system: A retrospective study up to 2 years of follow-up

Accurately recording the deficiency of the three-dimensional position of dental implants and the predetermined occlusal relationship of edentulous jaws presents a significant challenge. This study aimed to achieve a truly digital workflow of immediate full-arch implant restoration by combinedcone-beam computed tomography (CBCT), photogrammetry (PG) devices, and intraoral scanners (IOS). This approach significantly reduces patient tooth loss time, minimizes the overall "chair time", and provides precise, comfortable, and efficient implant restoration treatment. A total of 11 edentulous patients (mean age 64.72 ± 9.83 years) were treated, and outcomes such as implant survival, prosthesis survival rates, marginal bone resorption, and incidences of complications were evaluated. The results demonstrated that immediate full-arch rehabilitation of edentulous jaws on 4 or 6 implants using a PG system is an effective, safe, and efficient approach to rehabilitation.

Four locator attachments of mandibular implant-retained overdentures with two different distributions: A 10-year retrospective preliminary study of residual alveolar ridge changes

OBJECTIVES

There is little information on the long-term function of the four Locator attachment of the mandibular implant retained overdenture (OD), particularly with different distributions.

PURPOSE

To compare the effect of different four inter-foraminal implant distributions retaining a mandibular OD after 10 years of function on posterior mandibular ridge resorption (PMandRR), anterior maxillary ridge resorption (AMaxRR), and the amount of marginal bone loss (MBL) around all four implants.

MATERIALS AND METHODS

Twenty-two participants with total edentulism who had worn mandibular OVDs retained by four inter-foraminal implants for 10 years of functional life were selected for this study. They were divided into two groups based on implant distribution: Group I with a quadrilateral distribution (QD) of implants and Group II with a linear distribution (LD) of implants. PMandRR, AMaxRR, and MBL around implants were measured.

RESULTS

After 10 years of function, PMandRR was significantly higher in the LD group than in the QD group (p < 0.001*). There was no significant difference in AMaxRR between the QD and LD groups (p = 0.431). The QD group showed a significantly greater amount of MBL around dental implants when compared with the LD group (p = 0.002*).

CONCLUSIONS

The LD of implants demonstrates more PMandRR compared with the QD. The QD of implants demonstrates a greater amount of MBL around dental implants compared with the LD. Both implant distributions demonstrate the same effect on the AMaxRR. MBL around implants remained within normal accepted values after 10 years of function.

Immediate Loading Full-Arch 3D-Printed Implant-Supported Fixed Rehabilitation: A Case Report with 24-Month Follow-Up

Implant-supported immediate loading full-arch rehabilitation has been documented in the literature. More recently, computed surgical guides have frequently been used since they facilitate planning and performing surgical treatment without the need to raise a flap, thus reducing trauma and morbidity. This case report describes an immediate full-arch, fixed rehabilitation with full loading placed on four commercially available 3D-printed implants, with a 24-month follow-up. The implants were placed with the help of a digitally planned 3D-printed surgical guide. The provisional fixed prosthesis installed immediately was replaced after 3 months. At the time, the soft and hard tissue around the implants appeared stable, without signs of inflammation. The same situation was observed at the 24-month follow-up. Three-dimensional-printed implants seem to be a promising choice in this case. However, further clinical studies with longer follow-up periods are necessary to confirm their efficacy.

Artificial intelligence and mixed reality for dental implant planning: A technical note

AIM

The aim of this work is to present a new protocol for implant surgical planning which involves the combined use of artificial intelligence (AI) and mixed reality (MR).

METHODS

This protocol involves the acquisition of three-dimensional (3D) patient data through intraoral scanning (IOS) and cone beam computed tomography (CBCT). These data are loaded into AI software which automatically segments and aligns the patient's 3D models. These 3D models are loaded into MR software and used for planning implant surgery through holography. The files are then exported and used to design surgical guides via open-source software, which are 3D printed and used to prepare the implant sites through static computer-assisted implant surgery (s-CAIS). The case is finalized prosthetically through a fully digital protocol. The accuracy of implant positioning is verified by comparing the planned position with the actual position of the implants after surgery.

RESULTS

As a proof of principle, the present protocol seems to be to be reliable and efficient when used for planning simple cases of s-CAIS in partially edentulous patients. The clinician can plan the implants in an authentic 3D environment without using any radiology-guided surgery software. The precision of implant placement seems clinically acceptable, with minor deviations.

CONCLUSIONS

The present study suggests that AI and MR technologies can be successfully used in s-CAIS for an authentic 3D planning. Further clinical studies are needed to validate this protocol.

Prosthodontic criteria for maxillary immediate occlusal loading, surgical classifications of atrophic maxillae, and presentation of a new implant/anatomic classification system for immediate maxillary rehabilitation

PURPOSE

Immediate full-arch occlusal loading for patients with atrophic edentulous maxillae satisfies critical needs for this specific type of edentulous patient after placement of implants with high levels of primary implant stability. The needs include improved aesthetics, limited immediate improved function, and elimination of removable prostheses. Classification systems exist for edentulous maxillae but they do not include specifics regarding posterior implant placement. In conjunction with anterior implants, posterior implants improve Anterior/Posterior (A/P) spreads, decrease cantilevered segments (CLs), and likely will improve implant and prosthetic success rates. The purposes of this article include presenting a new classification system that outlines the different types of implants now available which will likely achieve the requisite primary stability for immediate fixed rehabilitation. This proposed classification system identifies a relationship between different implant options currently available and the remaining quantity of bone in the first and second maxillary molar zones.

MATERIALS AND METHODS

The available literature regarding current classification systems was reviewed. The benefits and limitations of each system were described. The parameters associated with Immediate Occlusal Loading (IOL) for full arch maxillary prostheses include: posterior cantilever lengths of full arch fixed prostheses; existing A/P spread considerations for full arch prostheses; and introduction of a new classification system for atrophic posterior maxillary edentulous ridges were identified.

RESULTS

Currently, there are no available classification systems that outline specific implant options for posterior maxillae which will likely achieve the minimum primary stability needed for immediate rehabilitation. A new classification system was proposed where the rationale was to show clinicians that when a certain amount of bone remains in the posterior maxilla, there are specific implants designed to maximize primary stability. High implant primary stability is required for rehabilitation with immediate fixed implant-supported provisional prostheses. The proposed classification system assists clinicians in understanding what implant geometry is available and can be expected to achieve the requisite primary stability for immediate occlusal loading based on the available bone in the posterior maxillary molar zone.

CONCLUSIONS

This article reviewed current classification systems for edentulous maxillary patients, as well as clinical parameters required for full arch, immediate occlusal loading.  It also presented a new classification system to assist clinicians in selecting appropriate implants and surgical techniques for immediate fixed rehabilitation of patients with atrophic maxillae.

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.

A Technical Note on a Modified Subcrestal Buccal Flap Approach to All-on-Four: A Case Report

This case report describes a dual full-arch rehabilitation focusing on a modified buccal incision for installation of four implants for full-arch rehabilitation of an edentulous maxilla. A modified buccal incision was performed in the subcrestal buccal region to promote direct access to the periosteum without incising the muscles in the region. For the installation of anterior implants, an 8.5 mm implant was locked in the cortical bone of the alveolar ridge and in the cortical bone of the floor of the pyriform cavity. The drilling point of the posterior implants was defined using the anterior implants as a visual reference, and the entry point could be visually estimated from the topography of the palatal surface of the maxilla. After bone leveling, the drilling enlargement sequence was carried out using drills that allowed the installation of long implants (18 mm). Straight mini-abutments were installed in the anterior implants and angled at 30º in the posterior implants. The flap was then perforated in the exact region where the mini-abutments were located. The buccal incision line was sutured with continuous 5-0 nylon suture. On the following day, aesthetic tests were carried out with teeth mounting. The patient presented minimal edema, and the lip motricity and smile width were completely preserved. The prosthesis was delivered five days after surgery. The suture was removed, and the prosthesis was installed while maintaining compression on the gingival tissue. The patient reported no pain during the prosthesis installation. The modified buccal flap enables implant placement for full-arch rehabilitation of an edentulous maxilla.

Lower Jaw Full-Arch Restoration: A Completely Digital Approach to Immediate Load

The digital transformation has revolutionized various sectors, including dentistry. Dentistry has emerged as a pioneer in embracing digital technologies, leading to advancements in surgical and prosthetic oral healthcare. Immediate loading for full-arch edentulous dental implants, once debated, is now widely accepted. This case report describes a 74-year-old patient with dental mobility and significant bone loss who was rehabilitated using a Toronto Bridge protocol on four dental implants with immediate loading. Digital planning, surgical guides, 3D printing, and precision techniques were employed. The surgery involved implant placement and prosthetic procedures. The patient reported minimal post-operative discomfort, and after four months, the definitive prosthesis was successfully placed. This case demonstrates the efficacy of immediate loading in complex dental scenarios with digital innovation, resulting in improved patient outcomes. The full digital workflow, including 3D printing and the use of modern materials, enhances the efficiency and predictability of oral rehabilitation, marking a transformative era in dental care. The integration of digital technology in all phases of treatment, from diagnosis to finalization, makes this approach safer, reliable, and efficient, thereby benefiting both patients and clinicians.

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.

Immediate Loading of Fixed Prostheses in Fully Edentulous Jaws: A 7-Year Follow-Up from a Single-Cohort Retrospective Study

The aim of this retrospective single-cohort study was to evaluate the clinical outcome of four-to-five implants immediately restored with metal-resin screw-retained cross-arch fixed prostheses in edentulous jaws 10 years after loading. One-hundred-and-four consecutive patients received four to five implants placed with a torque superior 35 Ncm. One-hundred-and-twenty-seven metal-resin screw-retained fixed prostheses (59 mandibular and 68 maxillary) were to be delivered within 3 days. Outcome measures, evaluated by the treating clinician, were: prosthesis and implant failures, prosthetic modifications, peri-implant mucositis, and biological and prosthetic complications. A total of 549 implants were placed. Twenty-one implants failed in 14 patients and 102 prostheses were remade, at least once, in 81 patients: 2 due to implant failures and 33 because of fractures of the prostheses. In particular, 25 original metal-resin prostheses had to be remade because of fractures versus only eight of the replacement monolithic metal-resin prostheses. All patients were wearing fixed prostheses at the end of the follow-up. Thirty-six biological complications occurred in 22 patients. Eighty-six prosthetic complications occurred in 42 patients. In conclusion, immediately loaded cross-arch prostheses supported by four-to-five immediately placed implants are a viable therapeutic option if robust prostheses are made.