3D-printed shell complete dentures as a diagnostic aid for implant planning and fabricating interim restorations for complete arch rehabilitations: A case series.

3D-printed shell complete dentures generated from a scan of the patient's existing prostheses can simplify and expedite the surgical planning and interim restoration design for complete arch rehabilitations. Three patients were rehabilitated with endosteal implants, and interim restorations were generated from the contours of the 3D-printed shell complete dentures used as diagnostic aids. This case series report presents the recommended protocol and its clinical progression, in addition to clinical and radiographic images of the treatment outcomes.

Round and flat zygomatic implants: effectiveness after a 3­year follow­up non­interventional study.

PURPOSE: This non-interventional study investigates variations in the type and frequency of late complications linked to novel zygomatic implant designs, installed adhering to the Zygoma Anatomy-Guided Approach (ZAGA) concept, over an extended follow-up period of at least 3 years. METHODS: Consecutive patients presenting indications for treatment with ZIs were treated according to ZAGA recommendations. Implants were immediately loaded. The ORIS success criteria for prosthetic offset, stability, sinus changes and soft-tissue status were used to evaluate the outcome. RESULTS: Twenty patients were treated. Ten patients received two ZIs and regular implants; one received three ZIs plus regular implants, and nine received four ZIs. Fifty-nine ZIs were placed: thirty-six (61%) Straumann ZAGA-Flat implants and twenty-three (39%) Straumann ZAGA-Round implants. Four patients (20%) presented earlier sinus floor discontinuities. Fifteen patients (75%) had prior sinus opacities. Nineteen patients were followed for between 38 and 53 months (mean 46.5 months). One patient dropped out after 20 months. When comparing pre-surgical CBCT with post-surgical CBCT, 84.7% of the sites presented identical or less sinus opacity; nine locations (15%) showed decreased, and another nine increased (15%) post-surgical sinus opacity. Fifty-three ZIs (89.8%) maintained stable soft tissue. Six ZIs had recessions with no signs of infection. ZIs and prosthesis survival rate was 100%. CONCLUSIONS: The study highlights the effectiveness of ZAGA-based zygomatic implant rehabilitations using Round and Flat designs. Despite patient number constraints, minimal changes in the frequency of late complications from the 1-year follow-up were observed. 100% implant and prosthesis survival rate over a mean follow-up of 46.5 months is reported.

The 3D-printed shell complete denture technique: Simplifying prosthodontic diagnosis prior to implant planning.

Traditionally, artificial teeth arrangements or the definitive complete dentures are used to establish important prosthodontic parameters such as the occlusal plane orientation, vertical dimension, and the incisal edge position. The relationship of these elements with the underlying bony structures is commonly evaluated using advanced planning protocols such as the dual scan technique. This technique article presents an uncomplicated alternative approach to establish these parameters intraorally using a 3D-printed shell complete denture generated from a 3D scan of the patient's existing complete denture.

ITI consensus report on zygomatic implants: indications, evaluation of surgical techniques and long-term treatment outcomes.

OBJECTIVES: The aim of the ITI Consensus Workshop on zygomatic implants was to provide Consensus Statements and Clinical Recommendations for the use of zygomatic implants. MATERIALS AND METHODS: Three systematic reviews and one narrative review were written to address focused questions on (1) the indications for the use of zygomatic implants; (2) the survival rates and complications associated with surgery in zygomatic implant placement; (3) long-term survival rates of zygomatic implants and (4) the biomechanical principles involved when zygoma implants are placed under functional loads. Based on the reviews, three working groups then developed Consensus Statements and Clinical Recommendations. These were discussed in a plenary and finalized in Delphi rounds. RESULTS: A total of 21 Consensus Statements were developed from the systematic reviews. Additionally, the group developed 17 Clinical Recommendations based on the Consensus Statements and the combined expertise of the participants. CONCLUSIONS: Zygomatic implants are mainly indicated in cases with maxillary bone atrophy or deficiency. Long-term mean zygomatic implant survival was 96.2% [95% CI 93.8; 97.7] over a mean follow-up of 75.4 months (6.3 years) with a follow-up range of 36-141.6 months (3-11.8 years). Immediate loading showed a statistically significant increase in survival over delayed loading. Sinusitis presented with a total prevalence of 14.2% [95% CI 8.8; 22.0] over a mean 65.4 months follow-up, representing the most common complication which may lead to zygomatic implant loss. The international experts suggested clinical recommendations regarding planning, surgery, restoration, outcomes, and the patient's perspective.

Group 5 ITI Consensus Report: Implant placement and loading protocols.

OBJECTIVES: Working Group 5 was convened to discuss and find consensus on the topics of implant placement and loading protocols associated with single missing teeth in the anterior maxilla (aesthetic zone). Consensus statements, clinical recommendations, patient perspectives and future research suggestions were developed and presented to the plenary for discussion and approval. MATERIALS AND METHODS: Two systematic reviews were developed and submitted prior to the conference. The group considered in detail the systematic reviews and developed statements, clinical recommendations, patient perspectives and future research suggestions based on the findings of the reviews and experience of group members. Definitive versions were developed after presentation to and discussion by the plenary. RESULTS: Five consensus statements were developed and approved from each systematic review. Twelve clinical recommendations were developed by the group based on both reviews and experience. Three patient perspectives were developed, and five suggestions made for future research. CONCLUSIONS: Based on the findings of the systematic reviews and experience of group members, the Type 1A protocol (immediate placement and immediate loading), when utilized in the anterior maxilla under favorable conditions, is considered predictable and is associated with high survival rates. The procedure is considered clinically viable and is associated with aesthetic outcomes, although surgical, technical, and biological complications can occur.

Indications for zygomatic implants: a systematic review.

PURPOSE: The purpose of this systematic review was to assess the evidence regarding the indications for placement of zygomatic implants to rehabilitate edentulous maxillae. MATERIAL AND METHODS: A focused question using the PIO format was developed, questioning "in patients in need of an implant-supported rehabilitation of the edentulous maxillae, what are the indications for the use of zygomatic implants''. The primary information analyzed and collected was a clear description of the indication for the use of zygomatic implants. RESULTS: A total of 1266 records were identified through database searching. The full-text review was conducted for 117 papers, and 10 were selected to be included in this review. Zygomatic implant indications were extreme bone atrophy or deficiency secondary to different factors. The quad zygoma concept (two zygomatic implants bilaterally placed and splinted) was applied to 107 patients, the classic zygoma concept (one zygomatic implant bilaterally placed and splinted to standard anterior implants) was used in 88 patients, and the unilateral concept (one zygomatic implant on one side, splinted with one or more conventional implants) was employed in 14 patients. CONCLUSIONS: The main indication for the use of zygomatic implants was considered extreme maxillary bone atrophy, resulting from many factors. The clear definition of what was considered "extreme bone atrophy" is not uniquely defined in each paper. Further studies are needed to develop clear indications for zygomatic implants.

Bead-anchored surgical templates for static computer-assisted implant surgery: A dental technique.

This technique report describes an alternative method to stabilize surgical templates throughout full-arch static computer-assisted implant surgery (FA s-CAIS). In FA s-CAIS, remaining teeth, mucosa, existing implants, custom occlusal device, bone, or any combination thereof, could be used as an initial positioning mechanism to position surgical templates. Different anchoring mechanisms are then used to stabilize the surgical templates during surgery. In this report, a novel design of surgical templates using remaining dentition and opposing occlusal surfaces as initial positioning mechanism followed by the combination of bone block fixation screw and stainless-steel beads as secondary anchoring mechanisms is described. The advantages, limitations, and comparisons with surgical templates using other anchoring mechanisms are also discussed.

Round and flat zygomatic implants: effectiveness after a 1-year follow-up non-interventional study.

INTRODUCTION: There are few zygomatic implants (ZI) designs available. The objective of this non-interventional study was to report the effectiveness of two new site-specific ZI, selected and placed following the zygoma anatomy-guided approach (ZAGA). MATERIALS AND METHODS: Consecutive patients presenting indications for rehabilitation using ZI were treated according to ZAGA Concept recommendations. Implants were immediately loaded following the manufacturer's instructions. Success criteria regarding prosthetic offset, rhino-sinus status, soft tissue condition, and implant stability were additionally used as outcome parameters. RESULTS: Twenty patients were followed for a period of 12 to 28 months (average 18.8 months). Ten received 2 ZI plus regular anterior implants; One received 3 ZI plus regular implants and nine received 4 ZI. In total, 59 ZI were placed, 34 (58%) Straumann ZAGA-Flat design, and 25 (42%) ZAGA-Round. Forty-nine percent of the sites were classified as ZAGA-4 type and 27% as ZAGA-2. Four patients (20%) presented discontinuities of the sinus-nose floor before surgery and 15 patients (75%) presented previous sinus opacities. All implants bar one reached more than 45 N.cm of insertion torque. No surgical complications were observed. After 1 year, the modified Lund-Mackay score was negative in 17 patients. Seventeen sites in 11 patients exhibited decreased opacity when pre-surgical imaging was compared to 1-year post-surgical CBCT. All implants and prostheses remained stable and in function. CONCLUSIONS: The study concluded 100% implant/prosthesis survival rates and low complication levels. Within the limitations of the sample and observation period, results suggest that even in cases of extremely resorbed maxillae (as per cases in this study), ZAGA-Flat and ZAGA-Round ZI are viable treatment options when restoring atrophic maxillae following the ZAGA protocol.

Use of a CAD-CAM Surgical Template to Improve Accuracy for Simultaneous Implant Removal, New Implant Placement, and Bone Graft.

A fractured implant is considered a catastrophic failure that leads to the loss of the implant and the prosthesis. Available methods of implant removal include the reverse screw technique, use of trephines, or osteotomies around the implant. In case of a fractured implant, the access hole for the reverse screw technique is impossible, leading to the need for an osteotomy. When the apical part of the fractured implant is embedded in bone, finding the piece may lead to a more ample osteotomy and significant bone loss, complicating future implant placement. This technique presented utilized a CAD-CAM surgical template that was designed with the purpose of improving accuracy in finding the fractured part with minimal osteotomy, allowing for simultaneous placement of a new implant in the same site, with additional bone graft, utilizing the same template.

Immediate Loading of Straumann® TLX Implant in Grafted Maxillary First Molar Site.

The patient treatment described in this case report demonstrates management of a failing maxillary first molar utilizing an immediate loading approach. Following extraction, the site was successfully managed with socket grafting (ridge preservation) and allowed to heal prior to implant placement. A Straumann® TLX implant was placed using a guided approach and restored using CAD/CAM.

Identification of the Pathway and Appropriate Use of Four Zygomatic Implants in the Atrophic Maxilla: A Cross-Sectional Study.

PURPOSE: This cross-sectional study aimed to identify and characterize the pathway for appropriate placement of four zygomatic implants in the severely atrophic maxilla and to group the anatomical variations of the osteotomy trajectory for anterior zygomatic implants. MATERIALS AND METHODS: CBCT images of patients presenting indications for the use of four zygomatic implants to withstand a maxillary rehabilitation were reviewed. Cross-sectional planes corresponding to the implant trajectories, designed according to a zygoma anatomy-guided approach for implants placed in the anterior and posterior maxilla, were assessed separately. The relationship of the implant osteotomy trajectory with the correlated residual alveolar bone, nasal and sinus cavities, maxillary wall, and zygomatic bone anatomies was established. RESULTS: The study population included 122 globally recruited patients, with 488 zygomatic implants, 244 of which had their starting point on the anterior incisor-canine area and 244 on the posterior premolar-molar area. The anatomy of the osteotomy path designed for the anterior implants ("A") was named and grouped into five assemblies from zygomatic anatomy-guided ZAGA A-0 to A-4, representing 2.9%, 4.5%, 19.7%, 55.7%, and 17.2% of the studied sites. Percentages for posterior implant ("P") trajectories of the osteotomy were grouped and named as ZAGA P-0 to P-4, representing 5.7%, 10.2%, 8.2%, 18.4%, and 57.4% of the sites, respectively. Approximately 70% of the population presented anatomical intra-individual differences. CONCLUSION: The trajectory of the zygomatic implant followed different anatomical pathways depending on its coronal point being anteriorly or posteriorly located, which justifies a new zygoma anatomy-guided approach classification for anteriorly placed zygomatic implants. Topographic characteristics of the anatomical structures that are cut by an anterior oblique plane joining the lateral incisor-canine area to the zygomatic bone, representing the planned anterior osteotomy path in a quadruple-zygoma indication, have not been previously reported. Adaptation of surgical procedures and implant sections/designs to individual patients' anatomical characteristics is essential to reduce early and long-term complications.

SAC Assessment Tool in Implant Dentistry: Evaluation of the Agreement Level Between Users.

PURPOSE: The SAC Assessment Tool is a clinical decision support system based on the foundations of the SAC Classification System in Implant Dentistry developed by the International Team for Implantology in 2009. It objectively classifies a patient's rehabilitation with dental implants as straightforward, advanced, or complex, from both a surgical and restorative perspective. The aim of this research was to test the agreement between observers with different qualification levels and clinical experience when using this clinical decision support system as a method that mitigates risk. MATERIALS AND METHODS: A total of 30 patients were randomly selected from clinical records, and diagnostic casts, intraoral and extraoral images, and panoramic radiographs were obtained. All data were analyzed with and without the SAC Assessment Tool by a dentist with advanced training and clinical experience in implant dentistry (control dentist) and compared with three colleagues (dentists 1, 2, and 3) with fewer qualifications and less clinical experience. All data were analyzed using statistical agreement tests (Fless kappa), interclass correlation, and agreement rate. The level of significance (α) was set at .05. RESULTS: All patients included in this research presented 104 edentulous areas, which were subjected to surgical evaluation for possible placement of dental implants. Concerning the degree of risk evaluation for dental implant treatment, the results of this study found that the agreement rate of the control dentist without SAC and control dentist with SAC was excellent (81.7%); the agreement rate of the control dentist and dentists 1, 2, and 3 with the use of SAC was satisfactory (67.3% to 76.0%); the variable that presented a lower agreement rate (34.6%) was the comparison between dentists 1, 2, and 3 without use of the SAC Assessment Tool. CONCLUSION: The SAC classification seems to be a useful tool to assist dentists with less experience in implant dentistry with defining the complexity of the treatment and hence with patient selection. It helps in the collection and homogenization of important clinical data to assess the risk of implant-based rehabilitations, thus contributing to an increase in the agreement rate.

Is There a Correlation Between Airway Volume and Maximum Constriction Area Location in Different Dentofacial Deformities?

PURPOSE: The purpose of the present study was to correlate the airway volume and maximum constriction area (MCA) with the type of dentofacial deformity in patients who required orthognathic surgery. MATERIALS AND METHODS: The present retrospective cohort study included orthognathic surgery patients selected from the private practice of one of us. The selected cases were stratified into 5 different groups according to the clinical and cephalometric diagnosis of their dentofacial deformity. The preoperative airway volume and anatomic location of the MCA were calculated using the airway tool of the Dolphin Imaging software module (Dolphin Imaging and Management Solutions, Chatsworth, CA) and correlated with the diagnosed dentofacial deformity. Differences in the pretreatment airway volumes and MCA location were compared among the deformities. RESULTS: The MCA location was more often the nasopharynx for maxillary deficiency and the oropharynx for mandibular deficiency deformities. The nasopharynx volume was significantly smaller statistically (P < .005) for maxillary deficiency plus mandibular excess compared with mandibular deficiency. The hypopharynx volume was significantly smaller statistically (P < .005) for vertical maxillary excess plus mandibular deficiency than for both maxillary deficiency and maxillary deficiency plus mandibular excess. No statistically significant difference was found among the different deformity groups in relation to the mean airway volume (P > .005). CONCLUSIONS: The location of the airway MCA seems to have a strong correlation with the horizontal position of the maxilla and mandible. The MCA in maxillary deficiencies (isolated or combined) was in the nasopharynx, and the MCA in mandibular deficiencies (isolated or combined) was in the oropharynx. Clinicians should consider these anatomic findings when planning the location and magnitude of orthognathic surgery movements to optimize the outcomes.

CAD-CAM cobalt-chromium surgical template for static computer-aided implant surgery: A dental technique.

A digital process for designing and manufacturing a cobalt-chromium (Co-Cr) surgical template for static computer-aided implant surgery (s-CAIS) is described. The use of Co-Cr provides the advantage of a material with improved mechanical properties to reduce the possibility of surgical template fracture during s-CAIS. The stronger material also allows for a thinner surgical template, which in turn allows better access when the interarch operative space is limited or a longer implant is inserted. Limitations of the technique include the need for computer-aided manufacturing technology and, with the use of Co-Cr, a higher overall cost.

A "Graft Less" Approach for Dental Implant Placement in Posterior Edentulous Sites.

Vertical bone augmentation techniques are more invasive than other procedures, and success rates often vary according to the surgical expertise of the clinician. As a result, there has been a trend over time towards minimally invasive treatment options in implant dentistry. This article discusses a "graft less" treatment philosophy that emphasizes the use of less-demanding augmentation techniques for the purpose of placing shorter implants in atrophic posterior sites, avoiding more complicated procedures for implant placement. In the posterior maxilla and mandible, the use of short implants (< 8.0 mm) can reduce the need for vertical bone grafting. Patients often prefer this strategy over more complex procedures that can cause complications, increase morbidity, and require longer treatment times with higher costs. When inadequate available bone is present for implant placement, planned bone augmentation procedures may be performed for the purpose of placing shorter implants; these procedures are less demanding, less invasive, and more predictable, allowing long-term outcomes for the implant-supported restoration.

Accuracy, reproducibility, and dimensional stability of additively manufactured surgical templates.

STATEMENT OF PROBLEM: Additively manufactured surgical templates are commonly used for computer-guided implant placement. However, their accuracy, reproducibility, and dimensional stability have not been thoroughly investigated with the different 3D printers and materials used for their fabrication. PURPOSE: The purpose of this in vitro study was to evaluate the accuracy, reproducibility, and dimensional stability of additively manufactured surgical templates fabricated by using different 3D printers. MATERIAL AND METHODS: Thirty surgical templates were designed and additively manufactured from 3 different 3D printers as follows: group SLA (n=10) was fabricated by using a desktop stereolithography (SLA) 3D printer and photopolymerizing resin; group PolyJet (n=10) was fabricated by using a PolyJet 3D printer and photopolymerizing resins; and group DMP (n=10) was fabricated by using a direct metal printing (DMP) system and Co-Cr metal alloy. All surgical templates were scanned by using a laser scanner within 36 hours of production and digitalized again 1 month later. All scanned files were compared with the corresponding designed files in a surface matching software program. The mean deviation root mean square (RMS, measured in mm, representing accuracy), percentage of measurement data points within 1 standard deviation of mean RMS (in %, representing reproducibility), and dimensional changes were determined and compared. RESULTS: At the postproduction stage, group PolyJet was most accurate with the lowest RMS value of 0.10 ±0.02 mm and highest reproducibility with 93.07 ±1.54% of measurement data points within 1 standard deviation of mean RMS. After 1-month storage, group PolyJet(1month) remained the most accurate with the lowest RMS value of 0.14 ±0.03 mm and the highest reproducibility value of 92.46 ±1.50%. For dimensional stability, group SLA versus group SLA(1month) comparison showed a significant decrease in accuracy (RMS values of 0.20 ±0.08 mm versus 0.25 ±0.08 mm, P<.001) and reproducibility (88.16 ±3.66% versus 86.10 ±4.16%, P=.012). Group PolyJet versus group PolyJet(1month) comparison only showed significant changes in accuracy (RMS values of 0.10 ±0.02 mm versus 0.14 ±0.03 mm, P=.011). Group DMP versus group DMP(1month) comparison showed no significant changes in accuracy (RMS values of 0.19 ±0.03 mm versus 0.20 ±0.04 mm, P=.981) or reproducibility (89.77 ±1.61% versus 89.74 ±2.24%, P=1.000). CONCLUSIONS: Printed resin surgical templates produced by using the PolyJet 3D printer showed higher accuracy and reproducibility than those produced by using the desktop SLA 3D printer and printed Co-Cr surgical templates at both the postproduction stage and after 1-month storage. The level of accuracy and reproducibility in printed Co-Cr surgical templates was not affected by 1-month storage.

Consideration for Contemporary Implant Surgery.

The advancement of technology often provides clinicians and patients better clinical alternatives to achieve optimal treatment outcomes. Computer-guided options allow clinicians to realize the virtual prosthodontically driven surgical plan, facilitating more predictable implant placement. Although the use of technology does not mean the clinicians can forgo the fundamental treatment principles when treating a patient, proper assessment and diagnostic approach from prosthodontic, surgical, and radiographic perspectives are still essential for a successful clinical outcome. The purpose of this article is to review the fundamental concepts for the use of computer-guided surgery to facilitate prosthodontic treatment.

Computer-guided implant surgery and full-arch immediate loading with prefabricated-metal framework-provisional prosthesis created from a 3D printed model.

OBJECTIVE: In this article, we describe the planning phase and clinical procedure where a CAD CAM 3D printed master model was utilized to create a prefabricated-titanium reinforced-fixed provisional prosthesis for a full-arch immediate loading after computer-guided implant placement. CLINICAL CONSIDERATIONS: The clinical procedure should be performed based on digital planning through an advanced surgical planning software and following the guidelines of full-arch immediate loading protocol. The fact that the master model is fabricated under a computer-assisted design and computer-assisted manufacturing approach before implant placement makes the whole process considerably easier, faster, more precise and cheaper. CONCLUSIONS: The use of a prefabricated-metal framework-provisional prosthesis for full-arch immediate loading created from a 3D printed master model seems to be a predictable treatment option when computer-guided implant surgery is performed. CLINICAL SIGNIFICANCE: The presented article described an interesting and innovative technique to optimize implant treatment based on digital technologies and 3D printing. The presented technique will help to diminish treatment costs and times especially for immediate loading procedures in fully edentulous patients because it allows to fabricate a prosthetic structure prior implant placement based on a 3D printing process.

Group 2 ITI Consensus Report: Prosthodontics and implant dentistry.

OBJECTIVES: Working Group 2 was convened to address topics relevant to prosthodontics and dental implants. Systematic reviews were developed according to focused questions addressing (a) the number of implants required to support fixed full-arch restorations, (b) the influence of intentionally tilted implants compared to axial positioned implants when supporting fixed dental prostheses (FDPs), (c) implant placement and loading protocols, (d) zirconia dental implants, (e) zirconia and metal ceramic implant supported single crowns and (f) zirconia and metal ceramic implant supported FDPs. MATERIALS AND METHODS: Group 2 considered and discussed information gathered in six systematic reviews. Group participants discussed statements developed by the authors and developed consensus. The group developed and found consensus for clinical recommendations based on both the statements and the experience of the group. The consensus statements and clinical recommendations were presented to the plenary (gathering of all conference attendees) and discussed. Final versions were developed after consensus was reached. RESULTS: A total of 27 consensus statements were developed from the systematic reviews. Additionally, the group developed 24 clinical recommendations based on the combined expertise of the participants and the developed consensus statements. CONCLUSIONS: The literature supports the use of various implant numbers to support full-arch fixed prostheses. The use of intentionally tilted dental implants is indicated when appropriate conditions exist. Implant placement and loading protocols should be considered together when planning and treating patients. One-piece zirconia dental implants can be recommended when appropriate clinical conditions exist although two-piece zirconia implants should be used with caution as a result of insufficient data. Clinical performance of zirconia and metal ceramic single implant supported crowns is similar and each demonstrates significant, though different, complications. Zirconia ceramic FDPs are less reliable than metal ceramic. Implant supported monolithic zirconia prostheses may be a future option with more supporting evidence.