Implant-supported Hybrid Prosthesis Research Articles

A Digital and Conventional Approach to the Rehabilitation of Complete Edentulous with a Toronto Infrastructure-Designed Hybrid Prosthesis: a Case Report

This case describes the prosthetic treatment of a completely edentulous patient treated with the "Toronto Bridge" technique, an implant-supported (all-on-four/all-on-five) hybrid prosthesis.
 A 42-year-old male patient applied to our clinic for aesthetic and functional problems. After clinical and radiographic examination, the all-on-five treatment concept for the edentulous maxilla and an all-on-four treatment concept for the edentulous mandible were planned. In the maxilla, two distal implants were placed at 30-45° angles, and three straight implants were placed in the anterior region. In the mandible, two distal implants were positioned at the anterior to mental foramina at an angle of 30-45°and two straight implants were placed in the anterior region. The digital impressions were taken, and the infrastructures and veneers were designed according to the "Toronto Bridge" protocol. The infrastructures and veneers were fabricated by milling zirconium blocks and cemented. The occlusion was rechecked for any interferences.
 This case report showed successful results for the all-on-four/five treatment concept "Toronto Bridge" prostheses at a six-month follow-up, and no complications were observed. This case report suggests that the implant-supported prosthetic treatment of a completely edentulous patient treated with the "Toronto Bridge" treatment technique provides esthetics, phonetics, oral hygiene, and oral comfort, which may be an alternative to an acrylic resin or porcelain fused metal fixed restorations.

A Comparative Study of the Biological and Prosthetic Complications of CAD/CAM Zirconia and Conventional Cast Implant Supported Hybrid Prostheses

A Comparative Study of the Biological and Prosthetic Complications of CAD/CAM Zirconia and Conventional Cast Implant Supported Hybrid Prostheses

Implant Supported Hybrid Prosthesis in Esthetic Zone: A Case Report

Implant Supported Hybrid Prosthesis in Esthetic Zone: A Case Report

‘Thermo-mechanical behavior of alternative material combinations for full-arch implant-supported hybrid prostheses with short cantilevers’

ObjectivesTo compare the fracture resistance (FR) of three combinations of materials for full-arch maxillary implant-supported hybrid prostheses (HPs) with short cantilevers (≤ 10 mm). MethodsMaxillary HPs were fabricated and classified as follows (n = 5 each): Group-1 (CC-A, control): acrylic-resin-veneered Co-Cr frameworks; Group-2 (CF-A): acrylic-resin-veneered carbon-fiber mesostructures; and Group-3 (CF-R): composite-resin-veneered carbon-fiber frames. Specimens were thermal-cycled (5,000 cycles; 5 °C–55 °C; dwell time: 30 s). Vertical loads were applied until failure, first at the 10-mm-long cantilever (LC), and, afterwards, at the anterior region (AR), using a universal testing machine (crosshead speed: 0.05 mm/s). The fracture pattern was assessed by stereomicroscope and SEM. The one-way ANOVA, the Bonferroni, and the independent samples t tests, were run (α= 0.05). ResultsAt LC, CF-A, and CC-A samples exhibited the highest FR values (p< 0.001), showing no differences to each other. At AR, CC-A specimens recorded the highest FR, followed by CF-A samples (p< 0.001). CF-R HPs displayed the lowest FR at both locations (p< 0.001). The only group with differences between the tested sites was the CC-A, the AR being more resistant (p< 0.001). Most CC-A and CF-A HPs failed cohesively. CF-R prostheses mainly failed adhesively. ConclusionsMaxillary HPs with short cantilevers (≤ 10 mm) made of Co-Cr or carbon-fiber veneered with acrylic resin demonstrated an adequate mechanical resistance (> 900 N). Clinical significanceFor maxillary HPs with cantilevers up to 10 mm, acrylic-veneered carbon- fiber mesostructures may be recommended, whereas coating carbon-fiber frames with composite resin seems not suitable.

Microbial adhesion and viability on novel CAD/CAM framework materials for implant-supported hybrid prostheses.

The aim of the study was to investigate the adhesion and viability of Streptococcus oralis and Candida albicans under in vitro conditions on CAD/CAM framework materials for implant-supported hybrid prostheses. Twenty-nine specimens were prepared from each of three different materials: ZR (zirconia), PEEK (polyether ether ketone) and CoCr4 (CoCr4 alloy). The experimental part included surface roughness (SR) and contact angle of water (CAW) measurements, followed by colony forming unit (CFU), cell viability assay and scanning electron microscopy (SEM) analyses of Strep. oralis and C. albicans biofilms on the materials' surfaces. Kruskal-Wallis and one-way analysis of variance (ANOVA) tests were used for differences between materials, and the correlation between measurements was estimated using Spearman's correlation coefficient. PEEK specimens revealed higher SR, CAW and CFU mean values, than ZR and CoCr4 specimens. Strong positive correlation was found between SR and CFU and between CAW and CFU for both microbial species. Cell viability assay revealed similar values for both species across materials. Higher numbers of Strep. oralis and C. albicans on PEEK specimens confirm the impact of the higher surface roughness and contact angle values on the microbial adhesion and describes PEEK as less desirable than ZR and CoCr4 from microbiological aspect.

Editorial: Prosthetically Driven or Periodontally Maintainable? We Need Both.

Emil Capetta, DMD/Howard Drew, DMD/Joel Pascuzzi, DMD/Andrew Sullivan, DDS: We were educated in the age of periodontal prostheses, when periodontics and prosthetics were integrated and dependent upon each other. The authors of this editorial would often travel to hear the masters, including Abrams, Amsterdam, Cohen, Kramer, Nevins, Skurow, Weisgold, and others. We were taught restorations had to be hygienic. Rules about contour, emergence profile, embrasures, attached gingiva, tooth positioning, adequate support, and balanced occlusion, to name a few, were emphasized and mandated. In the era of periodontal prostheses, we were nervous about long teeth, small gingival overhangs on restorations, and inadequate embrasures. In the 1980s, we embraced implants, but Brånemark again emphasized “high water” cases that allowed access for oral hygiene, debridement, and maintenance. Years later, as a reaction to the concept of placing implants “where the bone is,” we embraced the concept of prosthetically driven implant placement. Adopting this concept has not solved all of our problems, and improvements in guided bone regeneration (GBR) and prosthetic abutments are not always the complete solution. Presently, many treatment plans are based on the prosthesis that is currently preferred or can be marketed profitably. It is not uncommon to see periodontally maintainable teeth extracted, or 5 to 8 mm of vertical bone removed, to make room for prosthetic materials. That removed bone could prove to be critical if, in time, peri-implantitis strikes the patient. We often see prostheses inserted with inadequate access for patients or clinicians to debride the area, or hybrid prostheses with significant buccal/facial cantilevers that are not maintainable. Due to patient esthetic demands, we often place a fixed appliance when it should be removeable. Staging cases with natural teeth and/or transitional implants may add additional time and cost to the case, but there are benefits: Very often, bone can be preserved, hygiene assessed, GBR sites kept from loading forces, soft tissue managed, vertical dimension maintained or adjusted, and better implant positioning achieved. Years ago, when an implant-supported hybrid prosthesis was placed, it was common to remove it during maintenance visits to access the implants for debridement, and we often saw significant amounts of plaque and calculus on the intaglio surfaces. The implants were debrided, the prosthesis was cleaned, and many times the screws were removed and changed. Why have peri-implantitis rates skyrocketed? The literature lists multiple possible explanations, including plaque-retentive surfaces, active periodontal disease on remaining teeth, occlusion, inadequate zones of attached keratinized gingiva, and poorly positioned implants, among others. At what point do we embrace restorations, which are both prosthetically driven and periodontally maintainable? Restorations should be esthetic but must be cleansable by both the patient and the clinician. We need to remember the masters, and an appliance placed in a sound periodontal environment needs to be our primary goal. Why have peri-implantitis rates skyrocketed? The literature lists multiple possible explanations, including plaque-retentive surfaces, active periodontal disease on remaining teeth, occlusion, inadequate zones of attached keratinized gingiva, and poorly positioned implants, among others. At what point do we embrace restorations, which are both prosthetically driven and periodontally maintainable? Restorations should be esthetic but must be cleansable by both the patient and the clinician. We need to remember the masters, and an appliance placed in a sound periodontal environment needs to be our primary goal. Emil Capetta, DMD Howard Drew, DMD Joel Pascuzzi, DMD Andrew Sullivan, DDS Newark, New Jersey, USA

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.

to retrospectively evaluate clinical and radiographic outcomes of immediate, flapless full-arch prostheses, supported by 4/6 implants according to prosthetic-driven planning and guided surgery. The study involved 28 edentulous patients (20 female/8 males; average age 67.75 ± 8.627 years), 32 prostheses (17 all-on-4/15 all-on-6) and 164 implants. The Implants survival, prostheses success/survival, peri-implant marginal bone loss, incidence of biological and prosthetic complications were evaluated. Multiple linear regression analysis was performed to analyze the influence of implant and patient characteristics on marginal bone loss. Cumulative implant survival rate was 89.7% for all-on-four (seven failures) and 99.0% for all-on-six (one failure) after a mean follow-up of 6.46 ± 2.236 years (range 1-10 years). Cumulative prosthesis success rate was 51.5% (58.8% for all-on-four/ 43.8% for all-on-six). Prosthesis survival rate was 88.2% for all-on-four. No failure was registered in all-on-six. Mean value of marginal bone loss was 1.38 ± 0.1.28 mm at 5-year and 2.09 ± 0.56 mm at 10-year follow-up. No difference was found in the mean value of marginal bone resorption between all-on-four (1.56 ± 1.61 mm) and all-on-six (1.20 ± 0.85 mm) (p= 0.104) and between tilted (1.22 ± 1.29 mm) and axial implants (1.44 ± 1.27 mm) (p= 0.385) after 5-year follow-up. The incidence of biological complications was 1.0% in all-on-six (one mucositis) and 10.3% in all-on-four (two peri-implantitis). Prosthetic complications affected teeth of final rehabilitations with 3 detachments, 10 chippings or fractures, and 3 severe occlusal wears. Based on the results and within the limitations of the present study, the implant-supported hybrid prosthesis according to prosthetic-driven planning and guided surgery showed to be an efficient, safe, and effective approach to rehabilitate edentulous jaws.

Polyetheretherketone computer-aided design and computer-aided manufacturing framework for All-on-Four mandibular full-arch prosthesis: 3 Years' retrospective study of peri-implant soft tissue changes and ridge base relationship.

This study was conducted to evaluate the clinical peri-implant soft tissue changes during the first year after occlusal loading and the ridge base relation after 3 years for mandibular computer-aided design and computer-aided manufacturing (CAD-CAM) screw-retained implant-supported hybrid prosthesis of polyetheretherketone (PEEK) framework utilized with All-on-Four treatment concept. Sixteen completely edentulous patients were rehabilitated by four implants following the All-on-Four protocol. After 3 months, the definitive prosthesis was constructed to be a screw-retained CAD-CAM milled framework from the modified PEEK (BioHPP), bonded to polymethylmethacrylate teeth and a pink shaded indirect light-polymerized nanofilled composite resin imitating the soft tissues. Peri-implant soft tissue changes regarding plaque, bleeding, gingival scores, and probing depth were evaluated at prosthesis insertion (T0), 6 months (T1), and 12 months (T2) after insertion. Also, monitoring of the ridge base relation was performed using cone beam computed tomography at time of insertion (T0), and 1 year (T1), 2 years (T2), and 3 years (T3) after mandibular fixed detachable All-on-Four framework insertion. Using Shapiro-Wilk tests using SPSS® software version 22 (SPSS Inc., Chicago, IL), all clinical data were nonparametric, while the ridge base relation data were parametric. There were statistically significant differences regarding a plaque, gingival, and bleeding scores for all implants with the advancement of time. However, there was a statistically insignificant difference regarding probing depth in the posterior implants (p = 0.581). Regarding ridge base relation, there was a significant difference between observation times only in the anterior ridge area in between the two anterior implants (p = 0.011). Within the limitations of the study, the full-arch PEEK framework of fixed-detachable, hybrid prosthesis used with the All-on-Four concept for rehabilitation of mandibular edentulous arches is an acceptable treatment approach. Based on the stable ridge base relation posteriorly found in this study, less stress is distributed to the underlining bone due to the shock-absorbing ability of PEEK. Special considerations for frequent soft tissue follow-up and regular maintenance of oral hygiene measures are recommended.

Restoration of Hybrid Prosthesis for Misplaced Implants – A Case Report

An implant-supported hybrid prosthesis is an acrylic resin complete fixed dental prosthesis and supported by implants might be a solution in extreme cases that the need of the restoration for esthetics, function, lip support, and speech. This clinical report aims to present the esthetic and functional prosthetic rehabilitation of a borderline case with implant-supported hybrid prostheses. A 31yrs old female patient was referred to the department of prosthodontics for rehabilitation of angulated implants. The intra-arch dimension of the patient was excessive and an insufficient peri-oral soft tissue support was observed. The clinical and radiologic examinations showed satisfactory implant health. After 3 years of follow-up, no functional, phonetic, or esthetic problems with the restorations were noted. This case reports suggest that implant-supported hybrid prostheses can be a reliable alternative treatment procedure when a porcelain-fused metal fixed restoration does not satisfy a patient's requirements for esthetics, phonetics, oral hygiene, and oral comfort.

Implant-Supported Hybrid Prosthesis using All on Six Concept for Atrophic Ridges with Severe Gag Reflex: A Case Report

Aims: Edentulism is correlated to poor self-esteem and depression in both young and old individuals due to social rejection. For edentulous patients who are not interested in removable prosthesis, implant-supported fixed prosthesis might be an appropriate treatment modality. The aim of this case report is to rehabilitate the completely edentulous patient with severe gag reflex by maxillary implant supported hybrid prosthesis and mandibular conventional complete denture.&#x0D; Presentation of case: A 58 years old female patient had reported to the outpatient wing of department of prosthodontics with chief complaint of missing teeth in maxillary and mandibular arches. Patient had a history of severe gagging and discomfort with old denture. The treatment progresses as six implant placed and hybrid prosthesis was fabricated in maxillary arch and conventional complete denture was fabricated in mandibular arch and delivered to the patient.&#x0D; Discussion: Implant-supported complete arch rehabilitation can be accomplished with either a fixed or removable prosthesis. For a satisfactory outcome, proper patient selection, accurate surgical procedure, and meticulous prosthetic planning are required. Cement-retained implant restorations are becoming more popular because they are simple, aesthetic, and cost-effective. However, such restorations are hard to retrieve, and any residual cement in the soft tissue around the implant might cause peri-implant illness.&#x0D; Conclusion: A screw retained fixed prosthesis was planned for this patient in maxillary arch and conventional complete denture in mandibular arch which gave a successful outcome and avoid gag reflex.

An interdisciplinary approach for the management and rehabilitation of a fibro-osseous neoplasm using platelet-rich gel and an implant-supported hybrid prosthesis

Fibro-osseous neoplasms such as central ossifying fibroma (COF) can lead to destructive expansile lesions involving the maxilla or the mandible. Management of such lesions usually involves surgical intervention in the form of enucleation or resection. Platelet-rich gel (PRG) has been known to expedite bone regeneration due to its osteoconductive property. PRG initiates a greater and faster initial cellular response in comparison to platelet-rich plasma and has better handling characteristics. The challenge in rehabilitation often occurs due to the size of the osseous defects postsurgery. Fixed prosthodontic rehabilitation with endosteal implants is a viable treatment approach in such cases, improving the oral health quality of life and masticatory efficiency, when compared to a removable partial denture. This case report describes the management of an extensive lesion of COF using PRG and rehabilitation with a screw-retained, implant-supported hybrid prosthesis.

Fracture resistance of cantilevered full-arch implant-supported hybrid prostheses with carbon fiber frameworks after thermal cycling

ObjectivesThis in vitro study aimed to find the best combination of mesostructure and veneering materials for full-arch implant-supported hybrid prostheses (HPs) in terms of the fracture resistance (FR) of their cantilevers. MethodsThree groups (n = 5 each) of maxillary HPs were fabricated: Group-1 (CC-A, control): Co-Cr frameworks coated with acrylic resin; Group-2 (CF-A): carbon fiber veneered with acrylic resin; and Group-3 (CF-R): carbon fiber coated with composite resin. All specimens were submitted to 5,000 thermal cycles (5 °C – 55 °C, dwell time: 30 s), and subjected to a single cantilever bending test in a universal testing machine (crosshead speed: 0.5 mm/min) until failure. The fracture pattern was assessed using stereo microscope and SEM. The one-way ANOVA and Bonferroni tests were run (α= 0.05). ResultsThe FR yielded significant differences among the three groups (p< 0.001). CC-A samples reached the highest FR values (p ≤ 0.001), whereas both CF-A and CF-R HPs exhibited the comparably (p = 0.107) lowest FR. CC-A specimens failed cohesively (100%): mostly without chipping (80%). CF-A mesostructures were always broken at the connections of the distal implants. CF-R prostheses often failed adhesively (80%). ConclusionsThe HPs made of Co-Cr veneered with acrylic demonstrated the best mechanical behavior, being the only group whose 13-mm long cantilevers exceeded the clinically acceptable FR of 900 N. The HPs constructed with carbon fiber frameworks showed, additionally, more unfavorable fracture patterns. Clinical significanceFor HPs with cantilevers up to 13 mm, Co-Cr mesostructures coated with acrylic may represent the optimum combination of materials.

A multicentric study to evaluate the treatment outcome and complications after oral rehabilitation with implant-supported hybrid prostheses

BackgroundAs a newer modality of rehabilitation of completely edentulous patients, there is no conclusive evidence on which of the variants of hybrid prosthesis, namely acrylic teeth on a metal substructure or porcelain fused to metal teeth over on a metal substructure, is better in terms of treatment outcome, reduced mechanical complications, and better patient compliance. MethodsSixteen completely edentulous patients, both male and female, were selected from the OPD of the study centers during the study period. Group A: Eight patients rehabilitated by maxillary and mandibular hybrid prosthesis using a substructure of metal covered by acrylic teeth, which was screwed on the implants. Group B: Eight patients rehabilitated by maxillary and mandibular hybrid prosthesis using a substructure of metal covered by porcelain fused to metal teeth, which was screwed on implants. The patients were recalled at 3 months, 6 months, and 1 year following rehabilitation, and necessary clinical and radiological observations were made to evaluate the overall health and complications. Oral health–related quality of life was measured using the Oral Health Impact Profile (OHIP)-EDENT questionnaire before treatment and after rehabilitation. The same methodology, clinical procedures, and evaluation criteria were followed in all the study centers. The data obtained were then compiled and analyzed. ResultsNone of the patients in group A or B showed any signs of need to remake. There was no statistically significant difference in proportions of cases showing signs of loosening of components, soft tissue overgrowth, breakage of acrylic, chipping of porcelain, and wear of teeth in both the groups. The amount of screw loosening, wear of prosthetic superstructure, and bone loss around implants were less (even though not statistically significant) in group A. Both the groups showed satisfactory esthetics. OHIP- EDENT evaluation gave completely satisfactory report after rehabilitation in both groups. ConclusionBoth the types of complete rehabilitation, hybrid prosthesis of acrylic teeth on a metal substructure and hybrid prosthesis of porcelain fused to metal teeth on a metal substructure were successful and comparably reliable.

Hybrid Polyetheretherketone (PEEK)-Acrylic Resin Prostheses and the All-on-4 Concept: A Full-Arch Implant-Supported Fixed Solution with 3 Years of Follow-Up.

Background: The aim of this three-year prospective study was to examine the outcome of a solution for full-arch rehabilitation through a fixed implant-supported hybrid prosthesis (polyetheretherketone (PEEK)-acrylic resin) used in conjunction with the All-on-4 concept. Methods: Thirty-seven patients (29 females, 8 males), with an age range of 38 to 78 years (average: 59.8 years) were rehabilitated with 49 full-arch implant-supported prostheses (12 maxillary rehabilitations, 13 mandibular rehabilitations and 12 bimaxillary rehabilitations). The primary outcome measure was prosthetic survival. Secondary outcome measures were marginal bone loss, plaque and bleeding scores, veneer adhesion issues, biological complications, mechanical complications, and the patients’ subjective evaluation. Results: There were two patients (maxillary rehabilitations) lost to follow-up, while one patient withdrew (maxillary rehabilitation). One patient with bimaxillary rehabilitation fractured the mandibular PEEK framework, rendering a 98% prosthetic survival rate. Implant survival was 100%. Average (standard deviation) marginal bone loss at 3-years was 0.40 mm (0.73 mm). Veneer adhesion was the only technical complication (n = 8 patients), resolved for all patients. Nine patients (n = 11 prostheses) experienced mechanical complications (all resolved): fracture of acrylic resin crowns (n = 3 patients), prosthetic and abutment screw loosening (n = 4 patients and 3 patients, respectively), abutment wearing (n = 1 patient). One patient experienced a biological complication (peri-implant pathology), resolved through non-surgical therapy. A 90% satisfaction rate was registered for the patients’ subjective evaluation. Conclusions: Based on the results, the three-year outcome suggests the proposed rehabilitation solution as a legitimate treatment option, providing a potential shock-absorbing alternative that could benefit the implant biological outcome.

A Customized Impression Technique for Highly Placed Mal-Aligned Implant for a Hybrid Over Denture Patient: A Case Report

A hybrid implant denture is a fixed prosthesis over a metal framework and engaged by screws into the implant abutments. The anterior and posterior part of a mandibular hybrid denture is rigid on implants. Implant supported hybrid prosthesis provide satisfactory results on the mastication, esthetics and phonetics. This article describes a customized impression technique for highly mal aligned placed implants for hybrid implant denture. The total of five implants was present in the mandibular arch. Author advocates surveying of mal aligned implant analogue cast. The current technique depicts a customized resin impression tray with open border at two sites that concomitant at highly mal aligned implant position (canine region). Technique also uses the hard elastic chain for splinting of impression analogue. Final impression is recorded with single putty wash technique with polyvinyl siloxane elastomeric material. Although, technique is quite clinical sensitive. Asserting over this technique, it eliminates the use of transmucosal or multi unit abutments. This advocated technique is also economical for both clinician and patient. Impression was quite satisfactory.

Maxillary Implant-supported Hybrid Prosthesis Fabricated using a Polyetherketoneketone Framework: A Case Report

This clinical report describes a case involving a 74-year-old woman with maxillary edentulism who was successf ully treated using an implant-supported hybrid prosthesis. The f ramework of the prosthesis was fabricated using polyetherketoneketone (PEKK), which is a high-performance polymer, and individual lithium disilicate ceramic crowns were cemented for optimal esthetics. No mechanical or biological complications were observed during a 3-year follow-up period. Further clinical studies and long-term clinical data regarding the usef ulness of PEKK as a f ramework material for dental prostheses are necessary.

Immediate implant-supported full-arch hybrid prosthesis on an edentulous patient using a bar-retained overdenture in the mandible: Case Report.

The hybrid prosthesis is a very predictable treatment option that allows patients to recover their oral functionality. It is a good alternative to conventional treatments and overdentures. The present report describes controlled an 80 year old female patient with controlled hypertension, who came for consultation with a bar overdenture with attachment holders on two external hexagonal dental implants; an immediate loading hybrid prosthesis was installed over four mandibular dental implants.

Prosthodontic Rehabilitation of Edentulous Patient with Implant Supported Hybrid Prosthesis: A Case Report

AbstractA hybrid denture is fabricated over a metal framework that is retained by screws into the implants. The anterior part of a hybrid denture is fixed on implants and the posterior part of the denture is cantilevered. This case report presents the fabrication of a maxillary implant retained hybrid prosthesis. Four implants were placed in the maxillary arch. Framework was waxed, castable abutments were used, after-casting denture teeth were waxed to the hybrid framework, and a final try-in was done to verify and correct maxillomandibular relations before processing. The prosthesis was inserted after verifying fit of the framework.

Clinical outcomes and cost effectiveness of computer-guided versus conventional implant-retained hybrid prostheses: A long-term retrospective analysis of treatment protocols.

Computer-guided systems were developed to facilitate implant placement at optimal positions in relation to the future prosthesis. However, the time, cost and, technique sensitivity involved with computer-guided surgery impedes its routine practice. The aim of this study is to evaluate survival rates and complications associated with computer-guided versus conventional implant placement in implant-retained hybrid prostheses. Furthermore, long-term economic efficiency of this approach was assessed. Patients were stratified according to implant placement protocol into a test group, using computer-guided placement, and a control group, using traditional placement. Calibrated radiographs were used to measure bone loss around implants. Furthermore, the costs of the initial treatment and prosthetic complications, if any, were standardized and analyzed. Forty-five patients (149 implants in the test group and 111 implants in the control group) with a minimum follow-up of 5 years, and a mean follow-up of 9.6 years, were included in the study. While no significant difference was found between both groups in terms of biologic and technical complications, lower incidence of implant loss was observed in the test group (P<0.001). A statistically significant difference in favor of the non-guided implant placement group was found for the initial cost (P<0.05) but not for the prosthetic complications and total cost (P>0.05). Computer-guided implant placement for an implant-supported hybrid prosthesis is a valid, reliable alternative to the traditional approach for implant placement and immediate loading. Computer-guided implant placement showed higher implant survival rates and comparable long-term cost to non-guided implant placement.

The modified lip-tooth-ridge classification: a guide for edentulous maxillary arches

According to the width and height of the maxillary alveolar ridge, the maxillary edentulous jaws can be divided into three categories by using modified lip-tooth-ridge (MLTR) classification. Class Ⅰ is characterized by sufficient bone available for implants in the vertical and horizontal aspects and is suitable for fixed implant-supported prostheses. Class Ⅱ is characterized by sufficient bone amount available for implants in a horizontal aspect but insufficient for lip support and is suitable for a fixed detachable implant-supported prosthesis. Class Ⅲ is characterized by inadequate amount of bone for implants (with vertical or horizontal components) and is suitable for the use of zygomatic implants or traditional complete denture. Patients belonging to Class Ⅰ can be further classified into two sub-categories according to the height of the alveolar ridge. The first subclass is characterized by minimal bone deficiency and is suitable for a conventional implant-supported "crown and bridge" prosthesis. The second subclass is characterized by a larger vertical deficiency than that of the first subclass and is suitable for implant-supported hybrid prosthesis. The MLTR classification system can help the dentist to determine whether the patient is suitable for implanting dentures and whether fixed denture or removable denture is appropriate for the patient, select indications, reduce complications, and achieve long-term results.