Full-arch Rehabilitation Research Articles

Effects of High Insertion Torques (≥75 Ncm) on Secondary Stability of Implants Placed According to the “All-on-Four Concept”: A 2-Year Clinical Prospective Controlled Case Series Study

Background/Objectives: Primary stability is an important factor for dental implant success, and a high insertion torque (IT) is recommended in cases where an immediate load is required or desired. At the same time, some authors have claimed that it can interfere with bone-to-implant healing. This study aimed to compare the survival rates of implants inserted with different torques in full-arch cases, with or without immediate load, with up to 2-year follow-up. Methods: This study included subjects who required full-arch rehabilitation with implants. All cases were planned for the placement of four implants on each arch and were divided into groups according to the IT and had implant stability quotient (ISQ) measurements taken periodically for up to 2 years. Results: No implant was lost during this period, and no significant differences in peri-implant bone loss were observed. The paired t-test was performed to determine the association between ISQ and IT. Conclusions: The results suggest that initial torques higher than 75 Ncm may not be harmful to the stability of implants placed for full-arch rehabilitation, at least during the study period. Further clinical studies with longer follow-up periods are necessary to confirm these results.

USE OF THE ELECTRICAL DEVICE ON DENTAL IMPLANT’S BACTERIAL BIOFILM: A PRELIMINARY IN VITRO STUDY

Background. Mucositis and peri-implant disease are pathological conditions found following bacterial colonization on the peri-implant soft tissues and on the implant fixture during implant-prosthetic rehabilitation, from single edentulism to full-arch rehabilitation. The therapeutic approaches to the two pathological conditions use surgical and non-surgical therapeutic protocols, with the aim of eliminating the bacterial biofilm from the implant surface, through the use of mechanical, chemical or photodynamic agents. The aim was to evaluate the effect of the electric field generated by the Ximplant machine on the bacterial load and on the biofilm grown on the dental implants. Materials and methods. Twenty-eight dental implants were contaminated with the saliva of a donor, and subsequently fifteen implants were treated with the electric field generating machine while twelve were not treated. The bacterial biofilm was then measured by resazurin assay, both on treated and untreated implants. Results. The results revealed a difference between treated and untreated implants in terms of biofilm activity,as assessed by color change using the resazurin assay. Treated implants (n = 15) showed no color change across all observation time points (2 hours, 1 day, 2 days, 3 days), indicating an absence of bacterial activity or residual biofilm. Conversely, all untreated implants (n = 12) exhibited a consistentcolor change starting at 2 hours, suggesting persistent biofilm activity. A sterile implant used as a negative control (n = 1) showed no color change throughout the experiment, confirming the absenceof contamination. Conclusion.The study showed preliminary success of the electrofield in reducing microbial populations and destroying clinical biofilm, compared to a sterile implant as a control

Integrating Facial Symmetry and Functional Balance in Wax-Up for Optimal Aesthetics

In this case report, the application of complete esthetic and function-centric diagnostic approach employing the wax up approach for anterior and full arch rehabilitation is described. The wax-up served as a crucial diagnostic tool, facilitating fine adjustments and helping to prevent or correct potential clinical issues that could emerge during the restoration process. Thus, when the bipupillary line, the bicommissural line and the facial midline were connected to each other the final restorations both provided esthetic balance and biological compatibility. Lithium disilicate proved to be a durable material and aesthetically pleasing, both of which will enhance the patient’s satisfaction. This case is a good example of the use of wax-up in complex dental rehabilitations and reinforces the understanding as to how effective this technique can be in providing consistency in treatment delivery and the aesthetic outcomes.

Hybrid Full-Arch Rehabilitation Using Conventional And Zygomatic Implants: A Short-Term Retrospective Analysis.

To report one-year outcomes of prosthetic rehabilitation of the atrophic maxillae, supported by angled abutments on zygomatic implants and conventional implants. In the present retrospective analysis, edentulous maxillary areas treated with fixed-hybrid prostheses supported by angled abutments of 45, 52.5, and 60 degrees screwed to zygomatic implants inserted using an extrasinus surgical approach were included. Prosthesis, implant, and abutment success/survival rates, complications, Mucosal Seal Efficacy Evaluation (MSEE), modified PLaque Index (mPLI), modified Bleeding Index (mBI), and Zygomatic Implants Classification Level (ZICL) were assessed. Ninety-eight straight implants and 81 zygomatic implants (21 abutments of 45 degrees, 23 of 52.5 degrees, and 37 of 60 degrees) were inserted into 35 patients. Biological complications: postoperative sinus opacity was observed in seven patients, two of whom experienced a unilateral perforation of the sinus membrane. ZICL0-1 was recorded in 95% of zygomatic sites; the cumulative success rates were 100% and 94.3% when using the implant and prosthesis as units of analysis, respectively. Survival rate for the implants attested to the highest percentage (100%), whereas survival rate of the prostheses was 94.3%. No differences were registered among the clinical indices related to different inclinations of the abutments.

Anatomically guided full arch implant-prosthetic rehabilitations

Aim: The loss of dental elements causes anatomical, functional, aesthetic, and psychological changes that reduce the patient’s quality of life and comfort. This study aims to show how implant-prosthetic restorations with full-arch immediate loading can be appropriately performed by an anatomically guided method. Materials and methods: Two case reports of two male patients aged 69 and 60 years old who needed an implant-prosthetic full arch rehabilitation were documented to describe the surgical treatment. Discussion: Human anatomy is the basis of any surgical treatment, so in oral surgery, the operator must have a detailed knowledge of the loco-regional anatomy of the head-neck district. For this reason, it is essential to know the topographical limits of the noble structures typically found in daily clinical practice to perform a precise surgical act under safe conditions. The validity of a complete dental arch rehabilitation method is emphasized in literature by inserting two axial implants positioned orthogonally to the occlusal plane in the anterior region and two distal implants inclined with a maximum of 30° distally in the posterior region. The literature reports of inclined implants have been proposed as an alternative to traditional protocols in rehabilitating edentulous jaws. All this can be achieved by carefully studying the clinical case at the beginning of the clinical and radiographic examination. In addition, knowledge of the anatomical reference points must be taken as a reference to obtain a method that is reproducible and adaptable to more clinical cases depending on bone mineralization. Conclusion: Although it may seem excessively invasive, this method allows us to obtain optimal and reproducible results. It allows us to exploit not only the biomechanical advantages obtained by the structure of the prosthetic polygon but above all, those biological ones based on knowledge of the physiology of bone remodeling.

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.

Mandibular full arch rehabilitation of a patient with severely worn dentition after completion of maxillary full arch rehabilitation

Mandibular full arch rehabilitation of a patient with severely worn dentition after completion of maxillary full arch rehabilitation

Comparison of Full-Arch Intraoral Scans Immediately After Implant Insertion Versus Healed Tissue: A Multicentric Clinical Study

Objectives: The purpose of this clinical study is to compare implant full-arch intraoral scans taken immediately after implant placement with those obtained after tissue healing in patients rehabilitated with implant-supported fixed prostheses. Methods: Between September 2023 and March 2024, a total of 19 patients with compromised residual dentition (6 women; 13 men) were rehabilitated using 4-to-6 immediately loaded post-extraction implants. These implants supported fixed full-arch screw-retained prostheses either in the lower jaw (9 patients) or upper jaw (10 patients). Intraoral scans were taken immediately after implant placement (termed “immediate scan”). After a healing period of four months, the provisional prosthesis was removed, and a second intraoral scan was performed using the same scan bodies and scan pattern as the initial scan (termed “delayed scan”). The two scans were overlaid, and the discrepancies between them were measured. Results: The average discrepancy between the immediate and delayed scans was 0.1905 mm. Our statistical analysis revealed larger discrepancies for implants placed in the posterior areas, with the implant in site 1.6 (Implant 1) showing a discrepancy of 0.2326 mm, and the implant in site 2.6 (Implant 4) showing a discrepancy of 0.2124 mm (p = 0.05). No statistically significant difference was observed when comparing patients treated in the upper and lower jaws. Conclusions: Within the limitations of the study and based on this result, clinicians should be aware that an immediate post-surgical intraoral digital scan for implant-supported full-arch rehabilitations may result in a higher risk of imprecision. Furthermore, according to the results of the study, the accuracy of the digital impression on implant full-arch rehabilitations seems to be influenced by the clinician’s skills. Further studies with larger sample sizes are required to confirm our results.

Evaluation of Internal and External Hexagon Connections in Immediately Loaded Full-Arch Rehabilitations: A Multicenter Randomized Split-Mouth Controlled Trial With a 6-Year Follow-Up.

Full-arch immediate loading rehabilitations are now a widely used rehabilitation method that guarantees predictable medium- and long-term results. Numerous factors can influence its success and stability in the medium and long term. Among these the implant-abutment connection seems to play an important role, however there is still little information on which is the most suitable in this type of treatment. The aim of the present multicenter split-mouth controlled trial is to evaluate whether external hexagonal connections (EHC) and internal hexagonal connections (IHC) can influence success, bone resorption and peri-implant parameters in immediate-load full-arch rehabilitations. Twenty patients were rehabilitated with immediately loaded fixed full-arch rehabilitations. All the implants presented the same macro- and micro-topography but different implant-abutment connection. IHC were used in one randomly selected side of the jaw and EHC was used in the other side. Outcome measures were implant survival rate, peri-implant marginal bone loss (MBL), plaque index (PI), probing depth (PD), and bleeding on probing (BoP) evaluated at 3, 6, 12, 36, and 72-month post-loading. Technical and biological complications were recorded. In 20 patients, 43 EHC and 40 IHC implants were placed. Between 32 and 72 months of follow-up two patients withdrew (died) and no implants were lost. The cumulative survival rate (CSR) was 97.44% for EHC implants and 97.22% for IHC implants. The MBL presented a resorption of 2 mm in the EHC group and 1.9 mm in the IHC group. No statistically significant differences were found between the two groups for any of the parameters at any time. No biological or technical complications were detected between the 36th and 72nd month of follow-up. After 72 months in function, both internal and external hexagon connections provided good clinical outcomes and were not associated with any significant difference in the clinical outcomes.

Digital Approach Provides Predictability in Increasing the VDO in Erosive Wear: Clinical Technique and 9-Year Follow-Up.

This clinical case describes a digital workflow using face scans and CAD/CAM technology for a full-mouth rehabilitation with increased vertical dimension of occlusion (VDO) with adhesive lithium disilicate restorations after 9 years. A healthy, 46-year-old man displaying severe tooth wear, underwent an extensive full-mouth rehabilitation involving an increase of the VDO through laminate veneers and adhesive partial coverage lithium disilicate restorations. Anatomical landmarks of the face and reference planes were captured using a digital face scanning system. The anatomical position of the maxilla was registered with a transfer device. Digital data sets of the intraoral situation combined with a facial scan enabled precise virtual planning, guiding minimally invasive preparations. Long-term provisional restorations, milled from high-performance polycarbonate, were used to test the novel VDO before the final lithium disilicate restorations were fabricated. This approach provided a time- and cost-efficient treatment solution. No failures were observed at the 9-year follow-up. Utilizing face scans and design software enable a virtual visualization and comprehensive quality control for patients with dental wear, resulting in significant time savings and increased predictability for the dental technician, dentist and patient. The described digital workflow optimizes the planning and implementation of a comprehensive adhesive full-arch rehabilitation with an increase of the VDO. The clinical long-term follow up result of CAD/CAM assisted minimally invasive lithium disilicate restorations after 9 years demonstrates to clinicians a reliable treatment concept for patients with dental wear.

Clinical Outcomes of Full Arch Immediate Fixed Prostheses Supported By a Novel Implant System with Low Speed Site Preparation A 5 Years Retrospective Case Series

Background: The aim of this case series was to evaluate the 5-years clinical and radiographic outcomes of immediate full-arch fixed prosthesis supported by a novel implant system characterized by a low-speed site preparation protocol. Methods: Six medically compromised patients (3 females and 3 males) were consecutively enrolled and treated. Each patient received a fixed full-arch rehabilitations supported by two axial and two tilted implants. A total of 24 implants (N1 System, Nobel Biocare AB, Göteborg, Sweden) were placed in three mandibles and three maxillae using a low-speed drilling protocol with no irrigation. Prosthetic loading was applied within 2 hours of surgery, while then definitive restorations were placed 4 months later. Patients were scheduled for follow-up every 6 months up to 2 years and then annually. Radiographic evaluation of marginal bone level change was performed on regular intervals. Results: Between February 2019 and July 2019, six patients received a full-arch fixed prosthesis on four implants. All implants reached a minimum insertion torque of 30 Newton for immediate loading. After 5 years of observation (range 62-67 months), no implants failed and all definitive prostheses were stable and functional, resulting in a cumulative survival rate of 100%. After 5 years, the marginal bone loss was 1.46 ± 0.16 mm for the mandible and 1.85 ± 0.18 mm for the maxilla. Two implants (one axial and 1 tilted) in 1 patient treated in the maxillary arch reported more then 2 mm of marginal bone loss after 5 years. Conclusions: Within the limitations of this study, the successful medium-term results seem to confirm that immediate fixed full-arch rehabilitation, supported by two anterior axial and two posterior tilted implants, could be an effective and biologically beneficial treatment for complete arch edentulism. The reduced bone remodeling evidenced after 5 years of function confirm the biologically friendly concept behind this novel implant system.

Immediate Loading Implant-Supported Fixed Full-Arch Rehabilitation Using a New Clinical Decision-Support System: A Case Series.

Background Implant-supported full-arch rehabilitation is an effective treatment for edentulous patients. It restores mastication, facial aesthetics, and psychological well-being. Patient-related outcome measures support the validity of this approach, emphasizing the importance of effective prosthodontic interventions for this patient population. This study aims to present a case series for fixed implant-supported full-arch rehabilitation using the new Carames classification (CC). Methods A total of seven patients with generalized periodontitis or non-restorable multiple teeth were indicated for extraction and replacement with a fixed full-arch implant-supported prosthesis. According to the Carames classification, most cases were categorized as CCI or CCII classes for both the upper and lower jaws. Before the surgery, screw-retained provisional complete dentures were constructed and adjusted for the vertical occlusal dimension and smile lines. After the extractions, 70 implants were immediately placed in one or both arches for the seven patients, followed by bone grafts with the dual-zone grafting technique. Multi-unit abutments were then placed and welded to a metal bar for stable fixation. The provisional denture was fitted snugly over the metal bar for immediate functional loading. After three months of healing, it was used as a biocopy to fabricate the final prosthesis. The implant loss and the peri-implant marginal tissue health status were assessed annually for three years. Statistical analysis compared the marginal bone loss as a change from the baseline over the year. Results No implant or prosthesis loss was reported over the three years. Peri-implant marginal tissue health showed promising results without bleeding and suppuration on probing and probing depths between 3 and 3.5 millimeters. Marginal bone loss was minimal over the three years, with some cases showing bone gain. Conclusion Using the Carames classification as a clinical decision support system in implant-supported full-arch rehabilitation showed promising results in peri-implant tissue health and no implant loss during three years of follow-up. The implant placement and prosthesis fabrication protocol in this study could be valuable for further research.

Five- and 18-Year Outcome of Two Cases with Full-Arch Rehabilitations Ad modum All-on-4 in the Presence of Challenging Conditions.

Placing implants in fresh postextraction sites is a borderline rehabilitation procedure. The purpose of this report is to describe the pre-, per-, and postoperative procedures for maintaining long-term stability of two full-arch rehabilitations through the All-on-4 protocol, performed in the presence of challenging conditions. Two patients were referred for full-arch rehabilitation with immediate function, with both patients presenting infection in the jaws: patient 1 with an implant (position #45) inserted in a cystic cavity; patient 2 with one implant (position #24) inserted transsinus after the removal of a cyst on the base of the maxillary sinus and another implant (position #15) inserted with a dehiscence. Both patients received a preoperative dental hygiene appointment, a regenerative surgical protocol, and were enrolled in a postoperative maintenance protocol. After surgery a provisional prosthesis was provided ensuring immediate function, and 6 months after surgery, the final prosthesis was delivered. During the follow-up appointments (final follow-up at 5 and 18 years), the implants were stable, and no infection was observed for both patients. The present case report describes two full-arch rehabilitations in immediate function, supported by dental implants inserted in the presence of challenging conditions that do not represent the norm, rather are highly demanding for the clinical team, warranting caution in the interpretation of the results.

STL & DICOM complementarity for fully guided full arch rehabilitation

STL & DICOM complementarity for fully guided full arch rehabilitation

Full arch rehabilitation of patients with severe atrophy of the upper jaw using the transnasal technique of implants placement

Full arch rehabilitation of patients with severe atrophy of the upper jaw using the transnasal technique of implants placement

Three-Year Outcome of Full-Arch Fixed Prosthetic Rehabilitation through the All-on-4® Concept Using Dynamic 3D Navigated Surgery (X-Guided™): A Retrospective Study.

Background/Objectives: The insertion of dental implants using dynamic 3D navigated surgery while applying immediate function protocols for full-arch rehabilitations warrants further research. This study aimed to evaluate the outcomes of All-on-4® rehabilitations using 3D Dynamic navigated surgery (X-Guide™). Methods: This study included 10 patients (women: 7; men: 3; average age: 59.9 years) rehabilitated with full-arch prostheses through the All-on-4® concept, with 48 dental implants inserted using navigated surgery. The primary outcome evaluation was prosthetic/implant cumulative survival (CS), estimated using life tables. Secondary outcome evaluations were marginal bone resorption (MBR), biological complications, and mechanical complications. The evaluation parameters were measured between 1 and 3 years. Results: No patients were lost to follow-up. Two implants (4.2%) were lost in one patient (10%) with smoking habits, resulting in an implant CS rate of 95.8%. The average MBR was 0.51 mm ± 0.62 mm at the 1-year follow-up. The incidence rate of mechanical complications was 40% (n = 4 patients), all occurring in provisional prosthesis. No biological complications were registered. The patients maintained their prostheses in function throughout the follow-up of the study. Conclusions: Within the limitations of this study and based on the results, it can be concluded that the insertion of dental implants assisted by dynamic navigation for full-arch rehabilitation through the All-on-4® concept may be a valid treatment alternative in the short-term follow-up. However, more studies are necessary to validate this treatment modality.

A Retrospective Multicentric Study of 52 Nasal and Trans-nasal Implants in 31 Severe Atrophic Patients to Reduce Anterior Cantilever Bending in Full Arch Implant-supported Fixed Rehabilitation.

Severe anterior maxillary atrophy offers few implant-supported rehabilitation solutions to Quad Zygoma characterized by a wide anterior cantilever. One of the possible alternatives to consider before the quad zygoma is the extra-long nasal/trans-nasal implant placement. This retrospective multicentric study shows the predictability of nasal/transnasal implant placement in patients affected by severe anterior maxilla atrophy, with residual anatomical features that indicate this surgery. This specific remote anchorage can often be safely involved in immediate loading with other remote anchorages, such as zygoma and pterygoid implants. In this rehabilitation, it's mandatory to reduce the instability of the frameworks and mechanical stress that could unfavorably affect the implant's prognosis due to the overloading derived from anterior bending. In this retrospective multicentric study, 52 nasal or trans-nasal implants were inserted in 31 atrophic anterior maxillas (Cawood and Howell's class V-VI). All implants were successful after the healing period; even if 27 nasal implants reached an insertional torque equal to or greater than 50 n/cm2, the threshold value estimated to be able to support an immediate load. All 52 implants were successful, so the proportion of success was 100%, with a 97.5% one-sided confidence interval of 88.8-100%. The success rate is achieved only if at least two of the following criteria are met: 1) a greater torque than 50 Ncm as a minimum sufficient condition to plan immediate loading; 2) after a healing period of 16 weeks, the secondary stability is clinically and radiographically evaluated to exclude possible coronal bone resorption: this condition allows the successive prosthetic finalization; 3) the possibility of carrying out a full arch rehabilitation with minimal anterior spread. Insertion torque was <50 Newton centimeters (Ncm) in 14 patients (45%) and 50 Ncm in 17 (55%). Mechanical load was delayed in the former and immediate in the latter. The proportion of torque <50 Ncm was higher in men than in women (69% versus 28%, p=0.033). Immediate torque was not significantly affected by age. Although the sample is not extremely numerically significant, it conveys a clear and significant clinical, surgical indication as never before in the literature; we can state that nasal/trans nasal implants have been very useful in reducing the anterior cantilever and overcoming the anatomical limitations affecting conventional Quad Zygoma.

Additively manufactured custom-made subperiosteal implant rehabilitation for severely atrophic maxillary molar area: A technical note

Implant-prosthetic rehabilitations of severely atrophic posterior maxillary sectors currently is challenging, often requiring multiple surgeries and long rehabilitation times. Recently, graftless techniques (e.g. zygomatic, pterygoid and nasal implants) have gained popularity as they offer a reduction in rehabilitation time, aligning more closely with patient preferences but may not be feasible for sectorial rehabilitations. Subperiosteal implants, suggested for full-arch rehabilitations of atrophic maxilla, haven't been explored for sectorial rehabilitations. In this report we present the case of a patient with maxillary molar edentulism, rehabilitated with a subperiosteal implant.

All-on-4 Hybrid with Extra-Long Transnasal Implants: Descriptions of the Technique and Short-Term Outcomes in Three Cases.

Background/Objectives: There is a need for alternative approaches to full-arch rehabilitation of atrophic maxillae. The aim of this short case series was to describe the technique and assess the short term-outcomes of atrophic maxillae rehabilitation using transnasal implants in conjunction with zygomatic implants. Methods: Three female patients (average age: 62 years) presenting comorbidities and atrophic maxillae preventing the insertion of standard maxillary anchored implants received a full-arch fixed prosthesis supported by transnasal implants together with zygomatic implants, using the ad modum all-on-4 concept. Patients were followed during the functional osseointegration period. Primary outcome measures were prosthetic and implant survival based on function. Secondary outcome measures were complication parameters (biological and mechanical), plaque and bleeding levels, and probing pocket depths > 4 mm. Results: No implant failures were registered, and all prostheses remained in function. The only complication was a fracture of a provisional crown that was resolved. Plaque and bleeding scores were mild during the follow-up period. Conclusions: The present manuscript describes the use of extra-long transnasal implants in combination with zygomatic implants in immediate function for full-arch fixed prosthetic rehabilitation of atrophic maxillae, with the objective of promoting more research into this relatively recent technique. More studies are needed to validate the technique.

Short (≤6 mm) compared with ≥10-mm dental implants in different clinical scenarios: A systematic review of randomized clinical trials with meta-analysis, trial sequential analysis and quality of evidence grading.

To systematically identify, synthesize and critically summarize the available scientific evidence from randomized controlled trials (RCTs) regarding whether short (≤6 mm) perform as well as long (≥10 mm) implants regarding implant survival, marginal bone loss, and biologic and prosthetic complications in different clinical scenarios. Cochrane Collaboration's risk of bias tool and the GRADE approach were applied. Results were synthesized using random-effects meta-analyses assessed by trial sequential analyses. Forty reports on 19 RCTs comprising 2214 (1097 short; 1117 long) implants were included. Moderate/high certainty/quality evidence demonstrated similar 5-year survival rates for ≤6-mm and ≥10-mm implants in non-augmented bone and full-mouth rehabilitation in either jaw, and for 6-mm implants in the maxilla instead of sinus lift. Nevertheless, the evidence for 5-year survival rates remains inconclusive or insufficient for the remaining combinations of implant lengths and clinical scenarios. They include 4-mm and 5-mm implants as alternatives to sinus lift as well as placing all implant lengths ≤6 mm instead of vertical ridge augmentation with long implants. Marginal bone level and short- and long-term biologic or prosthetic complications were similar. Based on moderate/high certainty/quality evidence from 5-year RCTs, implants ≤6 mm may be viable alternatives to ≥10-mm implants in either jaw in native bone and full-arch rehabilitation, and 6-mm implants may be used as an alternative to sinus lift. PROSPERO ID: CRD42021254365.