Digital Workflow for Fixed Implant Rehabilitation of an Extremely Atrophic Edentulous Mandible in Three Appointments

Outcomes that may affect implant and prosthesis survival and complications in maxillary fixed prosthesis supported by four or six implants: A systematic review and meta-analysis

Objective

To investigate whether the clinical and radiographical outcomes are affected when four or six implants support the maxillary fixed complete denture (FCD).

Materials and methods

This study was registered on PROSPERO (CRD42021226432) and followed the PRISMA guidelines. The focused PICO question was, "For an edentulous maxillary patient rehabilitated with an implant-supported fixed prosthesis, do the clinical and radiographical outcomes differ when four or six implants support the prosthesis ". A thorough search of the relevant studies was designed and performed electronically. The survival rate of implant and prosthesis, marginal bone loss, and complications (mechanical and biological) were the primary outcomes, whereas implant distribution and using the surgical guide, follow-up, and framework material were evaluated as secondary outcomes.

Results

Out of 1099 articles initially retrieved, 53 clearly stated the outcomes of interest and were included in this study. There were no significant differences in implant and prosthesis survival, technical/mechanical complications, and biological complications between the 4-implant group (4-IG) and the 6-implant group (6-IG). However, marginal bone loss (MBL) was significantly higher in the 4-IG (p < 0.01). The surgical guide and follow-up period did not significantly affect implant/prosthesis survival. Additionally, using the CAD/CAM milled framework and anteroposterior implant distribution were associated with significantly higher implant survival in the 6-IG (p < 0.01).

Conclusion

The findings of this study indicated that having a greater number of implants, as seen in the 6-implant group, can lead to a decrease in technical and biological complications and reduce marginal bone loss. It is worth noting that factors such as using CAD/CAM frameworks and the anteroposterior distribution of implants were recognized as important in improving implant survival rates when more implants are present.

Immediate implant placement in the posterior mandibular region was assisted by dynamic real-time navigation: a retrospective study

BACKGROUND

Efficient utilization of residual bone volume and the prevention of inferior alveolar nerve injury are critical considerations in immediate implant placement (IIP) within the posterior mandibular region. Addressing these challenges, this study focuses on the clinical efficacy and implant accuracy of dynamic real-time navigation, an emerging technology designed to enhance precision in implantation procedures.

METHODS

This study included 84 patients with 130 implants undergoing immediate placement in the posterior mandibular region. Stratified into dynamic navigation, static guide plate, and freehand implant groups, clinical indicators, including initial stability, distance to the inferior alveolar nerve canal, depth of implant placement, and various deviations, were systematically recorded. Statistical analysis, employing 1- or 2-way ANOVA and Student's t-test, allowed for a comprehensive evaluation of the efficacy of each technique.

RESULTS

All 130 implants were successfully placed with an average torque of 22.53 ± 5.93 N.cm. In the navigation group, the distance to the inferior alveolar nerve and the depth of implant placement were significantly greater compared to the guide plate and freehand groups (P < 0.05). Implant deviation was significantly smaller in both the navigation and guide plate groups compared to the freehand group(P < 0.05). Additionally, the navigation group exhibited significantly reduced root and angle deviations compared to the guide plate group(P < 0.05), highlighting the superior precision of navigation-assisted immediate implant placement.

CONCLUSIONS

It is more advantageous to use dynamic navigation rather than a static guide plate and free-hand implant insertion for immediate posterior mandibular implant implantation.

Comparative analysis of intaglio surface trueness of cement-retained implant-supported prostheses generated by a cast-free digital workflow and a three-dimensionally printed cast workflow

STATEMENT OF PROBLEM

Comparative analysis of the accuracy of the prostheses produced by a cast-free digital workflow and 3-dimensional (3D) printing cast workflow is lacking.

PURPOSE

The purpose of the present investigation was to compare the intaglio surface trueness of implant-supported prostheses fabricated by using 3 different digital workflows: cast-free computer-aided design (CAD), 3D printed cast CAD (direct insert), and 3D printed cast CAD (indirect insert).

MATERIAL AND METHODS

The laboratory data of 11 partially edentulous arches for prosthetic implant treatment were obtained. Three different workflows were tested to produce the cement-retained prostheses: cast-free CAD (Group CF), 3D printed cast CAD with direct insert (Group PD), and 3D printed cast CAD with indirect insert (Group PI). The intaglio surfaces of the prosthesis CAD data from Groups CF, PD, and PI were superimposed with 3D printed prosthesis scan data from Group CF to measure 3D surface deviation. Using the prosthesis CAD data from Group CF as a reference, those from Groups PD and PI were compared by superimposition analysis. The root mean square (RMS) estimates, positive average deviations, and negative average deviations were measured. The Kruskal-Wallis test and Dunn test with Bonferroni correction, and the Wilcoxon rank sum test were used for statistical analyses (α=.05).

RESULTS

Significant differences were found among the 3 groups when the 3D printed prosthesis scan data were referenced (P<.05). Group CF showed the lowest RMS, positive average deviation, and negative deviation values, while Group PI showed the highest values. Significant differences in the RMS, positive average deviation, and negative average deviation values were found between Groups PD and PI when the prosthesis CAD data (Group CF) were referenced (P<.05).

CONCLUSIONS

Among the 3 different workflows tested, the prostheses generated from the cast-free CAD flow showed significantly lower intaglio surface deviation than those generated from the 3D printed cast CAD flows, regardless of the insertion method of the implant replicas.

Hybrid Prosthesis versus Overdenture: Effect of BioHPP Prosthetic Design Rehabilitating Edentulous Mandible

Aim

To compare the BioHPP (biocompatible high-performance polymer) as a substructure for the hybrid prosthesis versus the BioHPP bar supporting and retaining implant overdenture by radiographic evaluation to identify bone height alteration around the implants and to evaluate satisfaction based on visual analoge scale questionnaire.

Materials and Methods

Ill-fitting mandibular dentures were chosen for 14 fully edentulous male patients with adequate dental hygiene, enough interarch space, and free of systemic diseases and parafunctional habits. Patients who received new dentures (CDs) were randomly allocated into each group using computer software, and four interforaminal implants were inserted in parallel using a surgical guide. Three months after osseointegration, the patients received either CAD-CAM BioHPP framework hybrid prosthesis (Group I) or BioHPP bar supported and retained overdenture (Group II). Using digital preapical radiography, the bone loss is evaluated 6, 12, and 18 months after insertion. The subjective patient evaluation was done using a questionnaire based on the VAS includes five points for chewing, comfort, esthetics, speech, oral hygiene, and general satisfaction.

Results

The overall marginal bone loss (MBL) revealed that Group I (hybrid prosthesis) was more than Group II (bar overdenture) at all intervals in the anterior and posterior implants' mesial and distal surfaces. The patient satisfaction survey results showed that, after 18 months, the difference was statistically not significant between them all (P > 0.05) except for the comfort (for the overdenture group, 4.43 ± 0.53 while the fixed hybrid was 5.00 ± 0.00).

Conclusion

BioHPP framework material is an alternative material for implant rehabilitation of edentulous mandible with minimal MBL in BioHPP bar overdenture compared to BioHPP hybrid prosthesis.

All-on-Four Case Rehabilitated with Fully Digitally Fabricated Prosthesis Milled from Graphene-Reinforced Poly Methyl Methacrylate Puck Using Indigenously Developed Intraoral and Extraoral Scanning Methods

Digital dentistry is disruptive to conventional methods for performing prosthetic rehabilitation. Fabrication of prosthesis for all-on-four implants involves multiple steps when done conventionally and is prone to error. The use of digital technologies such as intraoral scanners (IOS) and extraoral scanners can marginalize these errors and also reduce the chairside time. This clinical report outlined a method which used a conjunction of extraoral and IOS to collect data for implant position, soft tissue profile, and vertical and centric relations. These data were then combined and used to fabricate a hybrid denture for the patient. The hybrid denture was milled from graphene-reinforced poly methyl methacrylate puck which provided the advantages of monobloc prosthesis and the material advantages of graphene. The entire prosthetic rehabilitation was completed within three appointments.

Survival rates, patient satisfaction, and prosthetic complications of implant fixed complete dental prostheses: a 12-month prospective study

PURPOSE

To determine the survival rate, incidence of prosthetic complications, and patient satisfaction of implant fixed complete dental prostheses (IFCDPs) after a mean observation period of 1.4 years.

MATERIALS AND METHODS

Twenty-eight (28) eligible participants were recruited according to specific inclusion and exclusion criteria. The definitive metal-acrylic resin IFCDPs consisted of titanium bars veneered with acrylic resin and acrylic denture teeth. Prosthodontic complications, divided into major and minor, were monitored. Parameters such as gender, jaw location, bruxism, and occlusal scheme were evaluated. Moreover, a questionnaire was administered throughout the study to assess patient satisfaction. Poisson regression as well as repeated measures ANOVA were used for statistical analysis.

RESULTS

Fourteen (14) males and 14 females were enrolled and followed-up at 3, 6, and 12 months. All IFCDPs survived (100% survival rate). The most frequent minor complication was the loss of material used to close the screw access hole (20% out of total complications). The most frequent major complication was chipping of the acrylic denture teeth (77.14% out of total complications). Gender (p = 0.008) and bruxism (p = 0.030) were significant predictors for the total major complications (major wear and major chipping) while occlusal scheme was a significant predictor for major chipping events (p = 0.030).

CONCLUSIONS

While IFCDPs demonstrated high prosthetic survival rates, they also exhibited a high number of chipping events of the acrylic veneering material, especially in males, bruxers, and individuals with canine guidance occlusion. However, the occurrence of these prosthetic complications did not negatively affect patient satisfaction.

Assessing the Effect of Interimplant Distance and Angle on Different Impression Techniques

We aimed to evaluate the trueness of digital and conventional impression techniques based on different angles and distances between implants and the deviation caused by the angle and distance parameters varying between implants. Eight implants were placed in a polyurethane edentulous mandibular model at different angles and distances. After obtaining a 3-dimensional (3D) reference model by using an optical scanner, the model was scanned with three intraoral scanners: Cerec Omnicam (DO), Trios 3 (DT), and Carestream 3500 (DC). Then, the master casts obtained from the conventional impressions (C) were also digitized, and all impression data were imported into reverse engineering software to be compared with the 3D reference model. Distance and angle measurements between adjacent implants were performed, and the data were analyzed with ANOVA–Tukey and Kruskal Wallis tests. The significance level was accepted as p < 0.05. While DT and C groups gave the best results for high interimplant distances, the trueness of intraoral scanners was found to be superior to the conventional method between closer implants. At higher angulations, the angular trueness of C group was found to be significantly lower. At short distances, digital groups showed superiority, and the trueness of conventional impression decreased with higher angulations.

Digital Workflow for Full-Arch Immediate Implant Placement Using a Stackable Surgical Guide Fabricated Using SLM Technology

The failing dentition of partially edentulous individuals may be used as an initial reference for stackable restrictive surgical guides during full-arch immediate implant placement. The stackable guide option derived from a digital workflow increases the predictability of the performance of bone reduction, immediate implant placement, and immediate loading of provisional implant-supported fixed dental prostheses. The present paper aims to report a practical approach to design and produce a metal framework with occlusal rests to facilitate the use of a tooth-supported surgical guide when full-arch immediate implant placement is indicated in patients with failing dentition.

Accuracy of 3-dimensional printing of dental casts: A proposal for quality standardization

STATEMENT OF PROBLEM

A digital workflow in fixed prosthodontics may use a 3D printer to obtain a cast for porcelain application. Standards exist that define the accuracy of traditional casts, but the accuracy requirements of 3D-printed casts have not been defined.

PURPOSE

The purpose of this retrospective study was to investigate how the accuracy of 3D-printed casts affected prosthesis fit and whether they correctly reproduced interproximal contacts.

MATERIAL AND METHODS

Copings with different die spacings were used to test different 3D-printed casts of the same dental arch. The accuracy of the 3D casts was assessed by imaging and comparing the resulting standard tessellation language (STL) files with the original through a matching software program. Accuracy scores were then correlated with a score measuring how well the copings fit the casts. The first data set was obtained from a patient receiving restoration of the 4 maxillary incisors. The teeth were prepared, the dental arch was imaged intraorally, and 10 resin casts were printed with four 3D printers. Two sets of 4 zirconia test copings were prepared, and 3 clinicians assessed their fit on each cast. A further set of casts was created from a second patient requiring prosthetic restoration for 5 adjacent teeth to assess whether undersizing affected the best fit of the copings on their dies.

RESULTS

The clinical scores and accuracy scores did not correlate. The results suggested that printed dies showing a certain degree of undersizing might provide a better fit than those showing better correspondence to the actual anatomic structure. The oversized dies were the worst. Only 7 of 17 casts being assessed were deemed suitable for veneering of the copings. The undersized casts tested clinically better than casts printed by using the same printer under standard settings.

CONCLUSIONS

This retrospective study indicated that 3D-printed casts that do not allow copings to fit appropriately usually show mean excess oversizing. Axially undersizing the printed dies on casts might allow a better fit of copings to be veneered.

Digital workflow: In vitro accuracy of 3D printed casts generated from complete-arch digital implant scans

STATEMENT OF PROBLEM

Data on the accuracy of printed casts from complete-arch digital implant scans are lacking.

PURPOSE

The purpose of this in vitro study was to compare the 3D accuracy of printed casts from a complete-arch digital implant intraoral scan with stone casts from conventional impressions.

MATERIAL AND METHODS

An edentulous mandibular cast with 4 multiunit abutments with adequate anteroposterior spread was used as the master cast. Digital scans (n=25) were made by using a white light intraoral scanner (IOS). The generated standard tessellation language (STL) data sets were imported into a computer-assisted design (CAD) software program to generate complete-arch implant casts through 3D printing technology. The 25 printed casts and the mandibular master cast were further digitized by using a laboratory reference scanner (Activity 880; Smart Optics). These STL data sets were superimposed on the digitized master cast in a metrology software program (Geomagic Control X) for virtual analysis. The root mean square (RMS) error and the average offset were measured.

RESULTS

When compared with the master cast, the printed casts had a mean ±standard deviation RMS error of 59 ±16 μm (95% CI: 53, 66). The maximum RMS error reached 98 μm. The average offsets were all negative, with a significant difference compared with zero (P<.001).

CONCLUSIONS

The implant 3D deviations of the printed casts from complete-arch digital scans had statistically significant differences compared with those of the master cast but may still be within the acceptable range for clinical application.

Immediately loaded interim complete-arch implant-supported fixed dental prostheses fabricated with a completely digital workflow: A clinical technique

A digital method for delivering an immediately loaded interim complete-arch implant-supported prosthesis is described. Reference pins were used to accurately superimpose a postoperative scan with the scan bodies in place on a preoperative scan with the framework design, including the interocclusal relationship and the occlusal scheme. A prefabricated auxiliary device was used after surgery to record the position of the implants and after scanning to obtain an accurate transfer of the implant positions by means of a free software program, allowing an excellent fit of the fabricated prosthesis. This technique can help in the fabrication of an interim prosthesis with better fit and comfort and reduced chair time than conventional techniques.

Complications and survival rates of 55 metal-ceramic implant-supported fixed complete-arch prostheses: A cohort study with mean 5-year follow-up

STATEMENT OF PROBLEM

Long-term outcomes with metal-ceramic (MC) implant-supported fixed complete dental prostheses (IFCDPs) are scarce.

PURPOSE

The purpose of this retrospective study was to assess the rate of biologic and technical complications in a cohort of edentulous patients treated with MC IFCDPs by residents after a mean clinical follow-up of 5 years (range: 1 to 12 years).

MATERIAL AND METHODS

Forty-one participants with 55 MC IFCDPs underwent a single-visit comprehensive examination that included a medical and dental history review and clinical and radiographic examinations. All supporting implants and prostheses were examined for biologic and technical complications. Life table analysis and Kaplan-Meier survival curves were calculated.

RESULTS

Of 359 moderately rough surface dental implants, 2 had failed in 1 patient after 11 years of functional loading, yielding a cumulative implant survival rate of 99.4%. Owing to the implant failure, 1 of 55 edentulous arches restored with IFCDPs failed, yielding a cumulative prosthesis survival rate of 98.2% after mean observation period of 5.0 years. Soft tissue recession was the most frequent minor biologic complication (annual rate 7.8% at the prosthesis level) for both cement and screw-retained IFCDPs (group C and S), and peri-implantitis (annual rate 1.6% at the implant level) the most frequent major biologic complication. Wear of porcelain (annual rate 8.0% at the prosthesis level) was the most frequent minor technical complication for both groups, and fracture of porcelain (annual rate 0.8% at the dental-unit level) was the most frequent major technical complication. Minor complications were the most frequent in both the groups (cement and screw retained).

CONCLUSIONS

High implant and prosthesis survival rates (above 98%) were achieved, yet substantial complication rates were encountered. The most frequent major biologic complication was peri-implantitis, with a 5-year implant-based rate of 8% (95% confidence interval [CI]: 5.8-11.1), whereas the most frequent major complication was fracture of porcelain with a 5-year dental unit-based rate of 4%. The estimated cumulative rates for "prosthesis free of biologic complications" were 50.4% (95% CI: 36.4% to 63.0%) at 5 years and 10.1% (95% CI: 3.5% to 20.8%) at 10 years, whereas for "prosthesis free of technical complications," they were 56.4% (95% CI: 41.7% to 68.8%) at 5 years and 9.8% (95% CI: 3.2% to 21.0%) at 10 years.

Conventional versus Digital Impressions for Full Arch Screw-Retained Maxillary Rehabilitations: A Randomized Clinical Trial

Background: The objective of this study was to compare conventional versus digital impressions for Full-Arch maxillary rehabilitations. Methods: Patients selected for this study were treated with full-arch screw-retained rehabilitations supported by six immediately loaded dental implants. Patients have been scheduled randomly into control (conventional impression group, CIG) and test (digital impression group, DIG) groups respectively for a fully conventional workflow and a fully digital workflow. In both groups, within 24 h, temporary prostheses were delivered. Four months after the implant positioning, the two groups dealt with the fabrication of definitive restorations: conventional pick-up was performed in the control group, and definitive digital impressions were carried out in the test group. The time involved following these two procedures was recorded. Patients underwent intraoral digital radiographs to evaluate the accuracy of the framework-implant connection, check for the presence of voids at the bar-implant connection and measure bone level. Criteria used to assess success at the prosthetic level were the occurrence of prosthetic maintenance, the absence of fractures of the acrylic resin superstructure and voids. Results: A total of 50 patients received immediately loaded prostheses supported by six implants (total 300 implants). A fixture and prosthetic survival rate of 100% was observed. All digital X-ray examinations revealed a bar-implant connection accuracy and no voids. Differences that were not statistically significant (p > 0.05) in marginal bone loss were found between control and test groups. Significantly less time was spent to perform digital impression procedure (p < 0.05). Conclusions: Clinical and radiological results of the test group advocate a satisfactory accuracy and predictability of the intraoral scanner (IOS) to be a reliable alternative in clinical practice for implant full-arch rehabilitations and suggest fabrication of definitive restorations with a successful marginal fit precision.

Model-less digital workflow for the replication of an existing complete fixed implant-supported prosthesis using an intraoral scanner

The use of an intraoral scanner was efficient to produce a full-contour zirconia CAFIP, with improved esthetics when compared to the original prosthesis.

Double Full-Arch Fixed Implant-Supported Prostheses: Outcomes and Complications after a Mean Follow-Up of 5 Years

PURPOSE

To retrospectively assess complications and clinical and radiographic outcomes of edentulous patients treated with double full-arch implant-supported fixed complete dental prostheses (IFCDPs) after a mean observation period of 5.1 years.

MATERIALS AND METHODS

The single-visit clinical and radiographic examination included medical and dental history review and clinical assessment of biologic and technical complications encountered with all implants and IFCDPs. Life table analysis and Kaplan-Meier survival curves were calculated. Analysis was conducted to evaluate the association between prosthesis survival and several risk factors such as type of opposing occlusion, nightguard use, and presence of bruxism.

RESULTS

Nineteen edentulous patients restored with 38 IFCDPs were included. A total of 249 implants were placed and 2 implants failed after a mean observation period of 5.1 years (range: 1-12 years), yielding an overall implant survival rate of 99.2% and prosthesis survival rate of 92.1%. Three out of 38 IFCDPs were lost, 1 after implant losses and 2 due to technical complications. The most frequent minor biologic complication was soft tissue recession with an estimated 5-year rate of 45.5% (95% CI: 39.4-57.5), while the most frequent major complication was peri-implantitis with an estimated 5-year implant-based rate of 9.5% (95% CI: 6.7-11.3). The most frequent minor technical complication was wear of the prosthetic material with an estimated 5-year rate of 49.0% (95% CI: 37.4-76.4), while the most frequent major technical complication was fracture of the prosthetic material with an estimated 5-year dental unit-based rate of 8.0% (95% CI: 6.6-10.1).

CONCLUSIONS

After a mean use time of 5.1 years, high implant and prosthesis survival rates were observed. The most frequent major biologic complication was peri-implantitis, and the most frequent major technical complication was fracture of the prosthetic material. The 5-year estimated cumulative rates for "prosthesis free of biologic complications" was 50.7% (95% CI: 33.7-65.4) and for "prosthesis free of technical complications" was 57.1% (95% CI: 39.3-71.5).

Implant survival rates and biologic complications with implant-supported fixed complete dental prostheses: A retrospective study with up to 12-year follow-up

OBJECTIVES

To assess the rate of biologic complications and implant survival in edentulous patients treated with implant-supported fixed complete dental prostheses (IFCDPs) after a mean observation period of 5.2 years (range: 1-12 years).

MATERIALS AND METHODS

A single-visit clinical and radiographic examination was performed to assess types and rates of biologic complications with ceramic IFCDPs (Group 1) and metal-resin IFCDPs (Group 2).

RESULTS

Of 457 rough surface dental implants supporting 71 IFCDPs (52 patients), six had failed, yielding an implant survival rate of 98.7% after a mean observation period of 5.2 years after definitive prosthesis insertion. The most frequent minor biologic complication was soft tissue recession (7.7% annual rate), inflammation under the IFCDP (7.4% annual rate), and peri-implant mucositis (6.3% annual rate). The most frequent major biologic complication was peri-implantitis (2.0% annual rate), in 46/457 implants (10.1%) supporting 19 IFCDPs and late implant failure (0.3% annual rate). The frequency of biologic complications was not statistically different between Group 1 and Group 2. The presence of high plaque index had significant effect on bone loss.

CONCLUSIONS

After a mean exposure time of 5.2 years postdefinitive prosthesis insertion (range: 1-12 years), implant survival rate of 98.7% was achieved. The six implant failures in three patients occurred after 5 years and affected the prosthesis survival. Soft tissue recession was the most frequent minor biologic complication, whereas peri-implantitis was the most frequent major biologic complication. A 10-year implant-based mucosal recession rate of 77% (95% CI: 68.2-87.9) and a 10-year implant-based peri-implantitis rate of 20% (95% CI: 16.9-24.9) were found.

Implant-Supported PMMA Monolithic Full-Arch Rehabilitation with Surgical Computer-Planned Guide and Immediate Provisional: A Case Report with One Year Follow-Up

The aim of this case report is to describe the surgical and prosthetic procedures to achieve maxillary and mandibular implant-supported PMMA monolithic full-arch rehabilitation (PMFR) with surgical computer-planned guide and immediate provisional. In such cases, the correct planning of dental implants' position, length, and diameter and the prosthetic phases via computer-aided design are very important to achieve good aesthetic and functional long-lasting results.