Complete Denture Preclinical Training Program and Digital Tools: A Pilot Study.

PURPOSE: To determine whether digital training improves conceptual skills acquisition for custom tray fabrication and tooth arrangement in the preclinical curriculum for complete denture fabrication. MATERIALS AND METHODS: A crossover design study compared third-year student grades after conventional (manual) and digital training. Half the students were trained with conventional techniques prior to digital, while the other half were trained with digital techniques prior to conventional. The first part of the study (DP1) focused on custom tray fabrication and involved 154 students. The second part (DP2) focused on tooth arrangement with 204 students. The effect of preliminary digital training on conceptual skills was assessed by comparing the results of the students using a Student's t-test. Results were also analyzed by ranking on the students' Perceptual Ability Test (PAT) score. Finally, students' satisfaction with the training was investigated. RESULTS: Students who completed the initial digital session achieved better custom tray fabrication and tooth arrangement in the subsequent manual sessions. For manual laboratory work, the most dexterous students (PAT1 group) demonstrated the best performance. However, PAT2 students had the best performance during the digital sessions during DP1, and PAT1 and PAT2 students had the best performance during the digital sessions during DP2. Additionally, 40% of DP1 and 12% of DP2 students expressed satisfaction with digital sessions. CONCLUSION: With complementary manual and digital teaching, digital tools may be useful for enhanced student learning. Digital training has contributed to improve results in manual sessions but did not affect student satisfaction and remained a limited tool to detect learning difficulties.

Use of digital tools for preclinical training in complete denture: A pilot study.

INTRODUCTION: Advances in CAD-CAM complete dentures open up opportunities in preclinical laboratory education. A cross-over study was conducted to assess the benefit of digital training in custom tray fabrication. Hypotheses were that digital training improved conceptual skill acquisition and that assessment of digital work helps in the discrimination of students' difficulty. MATERIALS AND METHODS: Third-year students were allocated either into group A and took the manual practical classes before the digital ones, or into group B (N = 154). Prior to the sessions, a motor skill test was conducted. The influence on the learning process was evaluated by comparing the groups' results to the manual lab work with a Student's t-test. The effectiveness of the assessment in discriminating manual aptitude and conceptual skill was studied through Spearman's rank coefficient between digital and manual scores in conceptual skill and with a subgroup analysis according to the results of the motor skill test. The level of significance was set up at .05. Students' satisfaction was also assessed with a questionnaire. RESULTS: Students in group B achieved better scores. Spearman's rank coefficient test showed a weak correlation, R = .16. For manual lab work, the most manually skilled students did significantly better. In contrast, for the digital session, the medium manually skilled students did better. More than half of the students (55%) found the manual and digital sessions complementary, without identifying any difference depending on the learning sequence. CONCLUSION: Digital training improved the students' results in the conventional practical exercise. Assessments of the digital and conventional custom trays were complementary in order to distinguish conceptual and motor skills.

Implant Survival Rate in Mandible Reconstructed with Free Fibula Flaps After Oral Tumors: A Systematic Review and Meta-Analysis.

PURPOSE: To assess the implant survival rate in mandibles reconstructed with free fibula flap after oral tumor resection after 1 year of prosthetic loading. A secondary objective was to compare immediate or delayed implant placement protocols in this population. MATERIALS AND METHODS: Electronic and manual searches were performed on different databases for controlled and prospective trials that indicated implant survival rate. This systematic review followed PRISMA guidelines. Risk of bias was evaluated using Cochrane Collaboration tools. Meta-analyses heterogeneity source assessment and GRADE evaluation were performed among studies with identical follow-ups. RESULTS: Among 305 primarily selected articles, 109 were eligible after reading the title and abstract, and 8 were included after full-text reading: 2 randomized controlled trials and 6 prospective studies comprising 140 patients and 507 implants. Meta-analyses estimated an overall survival rate of 97% (95% CI: 94% to 99%) after 1 year of prosthetic loading. The survival rate was 98% (95% CI: 94% to 100%) with immediate implantation and 97% (95% CI: 90% to 99%) with delayed implantation. Only 3 studies reported radiotherapy treatment, with no real impact on implant survival rate. Overall, 69% of tumors were benign. CONCLUSIONS: Implant placement in vascularized fibula flaps in the mandible is recommended for patients undergoing segmental mandibular reconstruction after tumor resection. Within the limitations of this study, no significant difference in survival rates was found between immediate and delayed implant placement.

Replacement of missing lateral incisors for patients with cleft lip and palate: A decision-making tree based on a systematic review of the literature.

STATEMENT OF PROBLEM: Cleft lip and palate are the most frequent congenital anomalies of the face and are often linked with lateral incisor agenesis. The therapeutic decision on whether and how to replace the lateral incisors is not straightforward, and a decision-making tree is needed. PURPOSE: The purpose of this systematic review was to evaluate the available literature reporting on treatments for the replacement of missing lateral incisors in cleft areas. By analyzing the success and survival rates of these treatments, a decision-making tree was developed. MATERIAL AND METHODS: The literature search was performed on the PubMed (MEDLINE), Web of Science, Cochrane, EMBASE, Dentistry of Oral and Science Source, and Google Scholar databases and was based on the question: Which treatment for patients with lateral incisor agenesis and cleft lip and palate has a good success rate? RESULTS: Twenty-six articles were included in this systematic review. A meta-analysis was performed on 14 articles (20 case series, 6 case controls). The estimated overall 5-year survival rates were 96.4% for implant-supported prostheses. CONCLUSIONS: Different treatment options are available, depending on the clinical situation. If the patient meets the conditions for implant placement, this treatment remains a preferred solution. If the prosthetic space is reduced, orthodontic space closure and composite resin restorations are possible. When these options are not possible, a resin-bonded fixed partial denture is the preferred option. If the teeth adjacent to the edentulous area require extensive restorations, a fixed partial denture may be a suitable alternative.

Accuracy of Complete-Arch Implant Digital Scans: Effect of Scanning Protocol, Number of Implants, and Scan Body Splinting.

PURPOSE: To determine the effect of scanning protocol, number of implants, and implant splinting on the accuracy of digital scanning in the edentulous arch. MATERIALS AND METHODS: A resin-based model of an edentulous mandible with six implants was scanned with a coordinate measurement machine as a reference and then with two intraoral scanner (IOS) systems (Trios 3 and Primescan). Ten scans were taken per IOS for three experiments, and each scan was compared to the reference data to evaluate trueness and precision. Analysis involved measurement of linear and angular discrepanices using engineering software. In experiment 1, three scanning protocols were compared (curvilinear, zigzag, and half-arch). In experiment 2, three clinical situations were simulated (6 implants, 4 implants-short arch, and 4 implants-long arch). In experiment 3, the effect of implant splinting with a suture thread was measured. Normal distribution of data was examined with Shapiro-Wilk test. Levene test was used for equality of variance (α = .05). Statistical differences in distance and angular deviations were analyzed using Student t test or ANOVA with post hoc Tukey test (α = .05). RESULTS: The best results in terms of trueness and precision were obtained with a linear scanning protocol and six implants. The results were as follows: Trios 3: trueness = 52 µm/0.42 degrees, precision = 40 µm/0.26 degrees; Primescan: trueness = 24 µm/0.28 degrees, precision = 18 µm/0.27 degrees. The scanning protocol did not significantly affect distance or angular deviation accuracy. Trueness and precision significantly decreased with four implants using Primescan and TRIOS 3. Splinting implants negatively affected accuracy with both IOS devices. CONCLUSION: Both IOS devices achieved clinically satisfying accuracy for distance (< 100 µm) and angular (< 0.5 degrees) deviations with six implants and a linear scanning protocol. With four implants, angular deviations sometimes differed between implants within the same group depending on the IOS and the clinical situation. Int J Prosthodont 2023;36:219-227. doi: 10.11607/ijp.7332.

Radiographic evaluation of a bone substitute material in alveolar ridge preservation for maxillary removable immediate dentures: A randomized controlled trial.

STATEMENT OF PROBLEM: Maxillary bone resorption after multiple extractions can jeopardize the success of an immediate denture, but whether bone volume preservation techniques are effective is unclear. PURPOSE: The purpose of this randomized controlled trial was to evaluate the efficacy of socket grafting with a xenogenic bone substitute in participants receiving maxillary immediate removable complete dentures in terms of bone volume preservation (height and width of the bone ridge). MATERIAL AND METHODS: The study was a single-blinded, randomized controlled clinical trial with 2 balanced parallel arms. Thirty-six participants who had Kennedy Class I edentulous posterior areas bilaterally for at least 3 months and required maxillary immediate removable complete dentures were enrolled. Duplicates of the removable complete denture were made and converted into radiographic and surgical guides. Participants allocated to the test group received deproteinized bovine bone mineral blended with 10% porcine collagen (DBBM-C) in the extraction sockets, and participants in the control group received no grafting material. With a radiographic guide in place, cone beam computed tomography scans were made 10 days after tooth extraction, when the immediate removable complete denture was delivered (D10, baseline), after 3 months (D90), and after 1 year (D365). The scans were superimposed, and measurements were made on the cross-sectional plane of each extraction site. The influence of various prognosis factors associated with bone volume preservation, including the location of tooth extraction, smoking habits, periodontal disease, and operator team, were analyzed. RESULTS: Of 36 participants, 3 were lost to follow-up. The mean ±standard deviation loss of height of the buccal crest was 1.2 ±1.8 mm in the control group and 0.3 ±1.2 mm in the test group after 3 months of healing (P<.001) and 2.1 ±2.0 mm in the control group and 0.7 ±1.4 mm in the test group after 1 year of follow-up (P<.001). Mean ±standard deviation horizontal ridge width change was 1.3 ±1.4 mm in the control group and 0.5 ±0.8 mm in the test group after 3 months (P<.001) and 2.2 ±1.4 mm in the control group and 0.9 ±1.1 mm in the test group after 1 year of follow-up (P<.001). None of the other prognostic factors had a significant effect at either time period. CONCLUSIONS: Grafting DBBM-C into the extraction socket after removing anterior teeth for immediate removable denture therapy resulted in significantly less vertical buccal crest and horizontal ridge resorption as compared with spontaneous socket healing after 1 year of follow-up. This procedure may be useful for preserving bone, especially when a fixed implant-supported prosthesis is planned.

Digital scanning for complete-arch implant-supported restorations: A systematic review.

STATEMENT OF PROBLEM: Scanning of completely edentulous arches remains a challenge because of the large surface to scan and the lack of anatomic indexes. Whether the presence of impression transfer copings with digital scanning provides enough markers for acceptable precision and clinical use has not been determined. PURPOSE: The purpose of this systematic review was to assess the accuracy of digital scanning for complete-arch implant-supported restorations. MATERIAL AND METHODS: A systematic review of peer-reviewed literature was conducted to analyze articles published between 2008 and 2019. Among the 208 retrieved articles, 20 were selected for review. RESULTS: Five articles reported the use of digital scanning in clinical situations and satisfying short-term results. Fifteen in vitro studies were also included for complementary information, including measurement accuracy. Most of the intraoral scanners used in vitro provided acceptable accuracy below a threshold of 150 µm. When directly compared, the digital technique was at least equivalent to conventional impression techniques. CONCLUSIONS: In vitro, intraoral scanners have shown acceptable accuracy. The main parameters identified for their influence on precision were interimplant distance, body scan design, scanning pattern, and operator experience. Clinical evidence is limited by the lack of a definitive method of assessing the fit of the framework.

Immediate Loading of Two Unsplinted Implants in Edentulous Patients with Mandibular Overdentures: A 10-year Retrospective Review of Patients from a Previously Conducted 1-year Cohort Study

PURPOSE: This 10-year retrospective study aimed to report implant bone changes in completely edentulous patients after a mandibular immediate loading protocol using two ball attachments. MATERIALS AND METHODS: This study was initially designed as a prospective 1-year cohort study, then extended with a 10-year retrospective evaluation of implant bone change. In the first part of the study, 43 edentulous patients wearing satisfactory maxillary and mandibular dentures for at least 3 months were included. Two interforaminal implants (Brånemark system, Nobel Biocare) were placed symmetrically in the anterior mandible using a surgical template and a torque greater than 40 Ncm. Immediately following surgery, 2.25-mm-diameter ball abutments were screwed to the implants, and their matrices (Dalbo Plus, Cendres et Métaux) were incorporated in the denture base. In an initial 1-year study, clinical recalls were scheduled 3, 6, and 12 months after implant placement with a team of two investigators. The follow-up consisted of a clinical examination and a standardized radiographic assessment of the vertical bone change. Implant stability was then monitored. The patient satisfaction was evaluated with a questionnaire before and 3 months after loading. The second part of the study occurred 10 years after the inclusion, as patients were recalled for an implant bone change monitoring. RESULTS: The included patients were 28 to 80 years of age (mean: 61 ± 11.4 years). Three out of 86 implants failed during the healing phase (survival rate of 96.5% [90.1%, 99.2%]). Implant stability was maintained all along the 1-year follow-up (Δ = 73.33, 95% CI [72.39 to 74.26], P = .032). The mean radiographic bone loss was 0.27 ± 0.35 mm at 3 months after surgery, 0.47 ± 0.42 mm after 1 year, and 0.95 ± 0.98 mm after 10 years. General visual analog scale satisfaction was increased by 25 units with the treatment. No patients were lost to follow-up at 1 year, but five were lost at 10 years. CONCLUSION: This protocol of immediate loading of two unsplinted mandibular implants in overdenture patients using ball attachments is a clinically viable treatment with a high implant success rate and improved satisfaction.

Zirconia abutments in the anterior region: A systematic review of mechanical and esthetic outcomes.

STATEMENT OF PROBLEM: The success of single, anterior, implant-supported restorations relies on mechanical and esthetic outcomes. Titanium has been the most commonly used material for abutments, but zirconia is increasingly chosen for its appearance despite its unclear mechanical performance. Today, manufacturers market prefabricated, computer-aided design and computer-aided manufacturing (CAD-CAM) custom and zirconia abutments with titanium connections. PURPOSE: The purpose of this study was to systematically review the mechanical and esthetic outcomes of implant zirconia abutments used in the anterior region, considering the design changes of the past 5 years. MATERIAL AND METHODS: An electronic search was conducted in Medline (PubMed) for studies on zirconia abutments. All clinical studies with at least a 1-year follow-up and case series (>5 abutments) published after 2013 were included. Mechanical and esthetic outcomes were collected. RESULTS: Of the 231 retrieved studies, 20 remained for quantitative analysis. Twelve described mechanical outcomes, and 15 focused on esthetics, using mainly the pink esthetic score. Five articles reported abutment fractures and no chipping. No difference was found between prefabricated and custom abutments or internal and external implant connections regarding fractures or screw loosening. All authors reported "good to excellent" esthetic integration in terms of restorations and soft-tissue color and the presence and height of papillae. The most difficult esthetic parameters to achieve were root convexity, soft-tissue color, and texture and level of mucosa. CONCLUSIONS: Esthetics remain the major advantage of zirconia abutment when compared with titanium, despite reservations concerning the risk of mechanical complications. Data are lacking for zirconia abutments with titanium inserts, although the prospects for this design are promising.

Efficacy of bone substitute material in preserving volume when placing a maxillary immediate complete denture: study protocol for the PANORAMIX randomized controlled trial.

BACKGROUND: Bone preservation is an essential issue in the context of last teeth extraction and complete edentulism. The intended treatment, whether a complete denture or an implant placement, is facilitated with a voluminous residual ridge. Bone resorption after multiple extractions has not been as well studied as the bone resorption that occurs after the extraction of a single tooth. Recent advances in bone substitute materials have revived this issue. The purpose of this study is to evaluate the interest in using bone substitute material to fill the socket after last teeth extraction in a maxillary immediate complete denture procedure compared with the conventional protocol without socket filling. METHODS/DESIGN: A randomized, controlled, clinical trial was designed. The 34 participants eligible for maxillary immediate complete denture were divided into two groups. Complete dentures were prepared despite persistence of the last anterior teeth. The control group received a conventional treatment including denture placement immediately after extractions. In the experimental group, in addition to the immediate denture placement, a xenograft bone-substitute material (Bio-Oss Collagen®) was placed in the fresh sockets. The primary outcome of the study is to compare mean bone ridge height loss 1 year after maxillary immediate complete denture placement, with or without bone-substitute material, in incisor and canine sockets. The secondary outcomes are to compare the average bone ridge height and width loss for each extraction site. An original quantitative evaluation method using cone beam computed tomography was designed for reproducible measurements, with a radio-opaque denture duplicate. Two independent operators perform the radiologic measurements. DISCUSSION: The immediate complete denture technique limits bone resorption in multiple extraction situations and thus allows better denture retention and better options for implant placement. To compare the benefit of using any bone socket-filling material, we proposed a quantitative evaluation protocol of resorption in the specific case of the last anterior maxillary teeth extraction with immediate denture placement. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02120053 . Registered on 18 April 2014.

On Comparing Two Different Tray-Holding Techniques for Edentulous Maxillary Impressions.

PURPOSE: This study compared tissue three-dimensional (3D) displacements during the material setting phase of two maxillary impression tray-holding techniques: clinician manual pressure and patient occlusal pressure. MATERIALS AND METHODS: The resultant two maxillary casts for each of 10 edentulous patients were compared using an optical 3D measurement system. RESULTS: The junction between the hard and soft palates acted like a rotation center during impression making. The vertical displacements were significantly lower and posteriorly set when the impression was taken with the patient's occlusion, in contrast to being located at the anterior two-thirds during the manual impression technique. CONCLUSION: Use of patient's occlusion as a tray-holding technique may be preferred during the material setting phase of maxillary impressions.

Decision making for residual palatoalveolar cleft defects: a new classification.

Oral rehabilitation of adult patients with cleft lip and palate is related to the severity of the anatomical and functional alterations that hamper the proper closure of the nasopharynx. The ideal treatment is closure by bone graft and orthodontics. However, when surgery is not possible or when the patient does not wish to undergo surgery, a palatal prosthesis may offer the best solution in most clinical situations. The authors of this article propose a new classification to help the practitioner with decision making and prosthetic treatment planning for residual palatoalveolar cleft defects.

Radiographic and surgical guide fabrication for implant-retained mandibular overdenture.

A simple technique is presented to make a multipurpose duplicate of the patient's complete denture to plan and fabricate a mandibular implant-retained overdenture. This duplicate serves 3 different functions. It can be used as a radiographic guide, surgical template, and custom tray adapted to the patient's occlusion. Advantages of the technique described are twofold: it is cost effective and makes use of equipment and materials commonly found in dental practices. The use of a single guide allows the clinician to refer to the recorded prosthetic data at each step of implant treatment.

Aesthetic demand of French seniors: a large-scale study.

OBJECTIVES: The needs of seniors for oral health and aesthetics are growing, as are their demands for aesthetics. This large-scale study aims to identify the demand for aesthetics for a population aged over 55, and the influence of age and gender. METHODS: A 15-item questionnaire was placed on the web in partnership with a major magazine dedicated to seniors. It reflected practitioners' questions with regard to senior patient expectations: aesthetic demand assessment, most commonly expressed complaints, the importance given to tooth colour, knowledge of available therapeutic treatments and motivation levels for treatment. RESULTS: The survey generated 3868 responses, 61% from women; 77% of respondents declared being satisfied to very satisfied with their smile. Their highest priority to improve their smile was tooth alignment, followed by their shape, length and shade. Although 60% of respondents were satisfied with their current shading, 53% would prefer to have them whitened. Aesthetic treatments were well-known to seniors. Over four-fifths of them had heard of dental implants and ceramic crowns. Two-thirds of those who wished to improve their smile were considering dental treatment. CONCLUSION: The high number of collected questionnaires confirms the strong interest shown by seniors for dental aesthetics, particularly from women. Baby-boomers seem more attentive to the appearance of their smile than their elders. However, the importance of appearance decreases with age, as it becomes less of a priority, with attention more focused on general health.

Application of a 3-dimensional measurement system to complete denture impressions.

STATEMENT OF PROBLEM: Little is known about tissue displacement at the tissue/denture base interface during impression making. PURPOSE: This study used a new 3-dimensional measurement system to analyze and compare 2 complete denture reline impression techniques (1 occluding and 1 digital) to determine which resulted in less displacement of the tissue/denture base interface during impression making. MATERIAL AND METHODS: The experiment included 10 completely edentulous subjects. For each subject, 3 mandibular casts were obtained: (1) a reference cast of the existing denture base, (2) a cast made with an occluding reline impression technique, and (3) a cast made with a digital reline impression technique. With the use of an optical 3-dimensional measurement system, the corresponding casts in a common coordinate system were analyzed geometrically. For each cast, the coordinates of the barycentric point and the high point were determined. For the same subject, the differences between the coordinates of the barycentric points of the 3 casts were calculated 2-by-2. The same calculation was performed for the high points. To determine whether these differences, which represent the displacements of the barycentric points and the high points, were statistically significant, the Wilcoxon signed-rank test for paired group comparisons was applied (P<.05). Cartographic differences among the casts from the same subject also were compared. RESULTS: The uncertainty of measurement for the location of the barycentric and highest point was +/-57 microm. The uncertainty in the differences among the cartographic displays was +/-0.1 mm. Vertically, the mean distance that separated the barycentric points obtained with the 2 impression methods was 0.04 mm. Cartography data showed that the greatest dimensional differences between the 2 impression techniques (minimum 0.25 mm; maximum 1.5 mm) were located near the retromolar pad and along the lingual flange. CONCLUSION: Within the limitations of this 3-dimensional in vivo study, displacement of the tissue/denture base interface was essentially equivalent with the use of an occluding and a digital mandibular impression technique.