Edentulous Arches Research Articles

Accuracy of different maxillomandibular relationship recording techniques in the edentulous maxillary arch.

This study investigated the effect of three digital bite registration techniques on the accuracy of intraoral scanning in maxillary edentulous and mandibular dentate arches. Maxillary edentulous and mandible fully dentate models were created. Four dental implants were placed in the maxilla, fitted with scan bodies, and reference scans were obtained using a Nikon Altera 10.7.6 scanner. Digital impressions were acquired 10 times for each model using a Trios 4 intraoral scanner. Three different digital bite records were collected for each pair of mandible and maxilla scans. The first one was a bite record without additional material (WSB), the second utilized a silicone index between the models (WSB silicone), and the third followed a pre-preparation scanning protocol (Pre-PREP). The data was exported in standard tessellation language (STL) format, which was assessed for trueness and precision using statistical analysis. According to mean trueness values, WSB exhibited the lowest value, 173 µm, followed by WSB silicone 242 µm and Pre-PREP 620 µm. The differences were significant only when comparing Pre-PREP to WSB and Pre-PREP to WSB silicone (p <0.05). Regarding precision, WSB demonstrated a mean value of 171.5 µm, followed by WSB silicone with 213.8 µm, and Pre-PREP with 222.2 µm with no significant difference between the groups. The presence of interarch bite registration material adversely affected interocclusal record accuracy, while WSB silicone presented a suitable substitute for WSB.

Effect of magnetic resonance imaging protocol on decision-making for positioning of dental implants in edentulous cases.

This study aimed to assess the influence of magnetic resonance imaging (MRI) protocol on the decision-making for the positioning of dental implants in edentulous arches in comparison to planning based on cone beam computed tomography (CBCT). One phantom was scanned with CBCT and two MRI protocols (T1- and T2-weighted). Two calibrated examiners performed digital implant planning (coDiagnostiX, Dental Wings), considering a digital prosthetic planning and alveolar ridge surface scan. Four implants were planned for each patient dataset, and the angular deviation between the long axis of the implants and the prosthetic planning occlusal plane was measured. Each examiner planned 40 implants, 12 implants with CBCT and 28 implants with MRI (16 with T1 and 12 with T2 images). Significant differences in angle deviation were observed between CBCT, T1, and T2 in the anterior region for both examiners (p=0.009 for examiner 1 and p=0.042 for examiner 2). Implants planned with CBCT showed significantly lower angular deviation than those based on the T1 and T2 scans for both examiners (p=0.028 and p=0.046 for examiner 1 and p=0.028 and p=0.027 for examiner 2). No significant difference in angular deviation was found between T1 and T2 for both examiners (examiner 1: p=0.600, examiner 2: p=0.916). Compared to CBCT planning, the MRI protocol influenced decision-making for anterior dental implants, with angular deviations within acceptable clinical thresholds, but further studies are needed to validate these findings.

Effect of prefabricated auxiliary devices in different optical properties and shapes on the accuracy of intraoral scanning of the edentulous arch with multiple implants: An in-vitro study

ObjectivesThis study aimed to evaluate the impact of prefabricated auxiliary devices (PADs) in different optical properties and shapes on the accuracy of digital implant impressions. MethodsAn edentulous maxillary all-on-4 master model was fabricated. PADs were 3D-printed in different resin materials (Grey, Translucent, White, Yellow) and shapes (Cuboid, Cylinder, Sphere) using a 3D printer (AccuFab-C1s, 3DShining, Hangzhou, China). The master model was digitalized using a dental laboratory scanner (D2000, 3Shape, Copenhagen, Denmark) 4 times as the reference models. Test models were obtained without (control group) or with PADs by an intraoral scanner (Aoralscan 3, Shining3D, Hangzhou, China) for ten repetitions of each group using the scanning pattern recommended by the manufacturer. The related files were imported into inspection software to assess Root Mean Square (RMS), linear and angular accuracy. Aligned Ranks Transformation ANOVA, Kruskal-Wallis and Mann-Whitney tests were used to evaluate the differences in these values. The level of significance was set at α=0.05. ResultsPADs in different optical properties and shapes demonstrated accuracy enhancement to different extents depending on their combinations. The PADs in combinations of white-cuboid, grey-sphere and yellow-sphere demonstrated the optimal trueness enhancement. The Aligned Ranks Transformation ANOVA indicated that the optical properties of the PADs significantly influenced the RMS, linear and angular accuracy. The main effect of optical properties indicated that translucent PADs generally generated more deviations than the others. The shapes of the PADs significantly influenced the angular accuracy. The main effect of shapes indicated that cylinder resulted in lower angular trueness on YZ plane than cuboid (p = 0.006) and sphere (p < 0.001). ConclusionThe optical properties and shapes of the PADs significantly influenced the scanning accuracy. Translucent PADs demonstrated more deviations than the others. Lower angular trueness on the YZ plane was seen in cylinder design compared to the others. Clinical significanceThe optical properties and shapes of prefabricated auxiliary devices should be critically considered to optimize the scanning accuracy. Prefabricated auxiliary devices in translucent optical properties and cylinder shape should be avoided.

Impact of scanning strategies on the accuracy of virtual interocclusal records in partially edentulous arch using intraoral scanner: an in vitro study

PurposeTo evaluate the scanning strategies affecting the accuracy of virtual interocclusal records (VIR) in partially edentulous arches using an intraoral scanner in vitro.MethodsA reference model of a partially edentulous arch with implant analogs in positions 45,46 and 47 was constructed. Six pairs of 1-mm diameter metal beads were placed on the gingival tissue as markers for measurement. Four scanning strategies were tested: Quadrant-arch Scan (group 1), Quadrant-arch Scan with Auxiliary occlusal devices (AOD) (group 2), Full-arch Scan (group 3), Full-arch Scan with AOD (group 4). The model was digitalized with a lab scanner as a reference and 15 scans were obtained for each group. The accuracy of VIR was assessed by comparing the experiment data to the reference digital model.ResultsThe mean surface deviations of VIR for Groups 1–4 were 89.4 ± 105.2 μm,95.6 ± 132.8 μm,152.3 ± 159.7 μm and 107.6 ± 138.2 μm respectively. Quadrant-arch scans resulted in lower errors of VIR than full-arch scan (P < 0.001). There was a significant interaction between the AOD and scanning span (P = 0.017). The Quadrant-arch scan with AOD (group 2) produced the least error in the distally extended edentulous area.ConclusionsQuadrant-arch scans showed better accuracy of VIR than full-arch scans across all tooth positions. The combination of AOD and quadrant-arch scan further enhances VIR accuracy in distally extended edentulous areas.

Evaluation of effect of low-level laser therapy on alleviation of pain in patients with implant-supported mandibular overdenture: A pilot study

Aim: Rehabilitation of edentulous jaws with implant-supported overdenture has achieved a comprehensive acclamation across the globe due to compromised retention and stability in conventional complete dentures. In dentistry, low-level laser therapy (LLLT) has become a viable treatment option for lowering inflammation, easing pain, and speeding up wound healing. This study aimed to evaluate the effect of LLLT on alleviation of pain in patients with two implant-supported mandibular overdentures. Study Setting and Design: This study was carried out in the Department of Prosthodontics at Index Institute of Dental Sciences, Indore, Madhya Pradesh. Completely edentulous patients willing for implant-supported mandibular overdenture and who gave consent, were enrolled. Materials and Methods: A total of ten implants were placed in five patients with completely edentulous mandibular arch willing for implant-supported mandibular overdenture. Individuals from the outpatient division of Department of Prosthodontics, Crown &amp; Bridge, Index Institute of Dental Sciences, Indore were chosen as patients. Bilateral implants were inserted into the mandible at locations B and D. On the experimental side, low-level laser therapy (wavelength 810 nm) was administered immediately following implant insertion and on the third day. Over the course of 72 hours, pain after surgery was assessed using visual analogue scale (VAS) values, beginning at baseline. Statistical Analysis Used: The Mann-Whitney U test was used for statistical analysis of the intergroup pain alleviation scores. Results: The results showed that on intergroup comparison, the experimental side exhibited significantly reduced VAS pain scores relative to the control side (P&lt;0.05). Conclusion: LLLT can be used as a promising adjuvant therapy to lower the degree and duration of pain after undergoing dental implant surgery.

A simple method to identify implant sites in totally edentulous arches: a pilot study with thermo-printed templates used with cone beam computed tomography.

All dental implants must be placed following radiological, clinical and aesthetic indications in compliance with prosthetic principles avoiding iatrogenic damage to patients. In implantology, among the key choices, to obtain predictable results, it is essential to establish (by cone beam computed tomography [CBCT]) the sites where to insert the implants; these sites must be identified, during the surgical phase, in the oral cavity. Surgical guides represent a valid aid especially in complex cases that require multiple implants. For some clinical conditions, expert operators choose the free hand technique during which identifying the chosen implant sites on CBCT in the oral cavity is more difficult. This experimental study is based on the use of thermo-molded mask as an alternative to surgical guides when the freehand technique is adopted in totally edentulous patients. These innovative masks, containing radiopaque references, are initially worn by patients during the execution of the CBCT, and later during surgery to identify the implant sites in the oral cavity. The procedure described proved to be very useful and able to increase the precision of the freehand technique even if it does not provide information on the inclination of the implants. The metal references help clinical identification of the implant site. Our thermo-molded masks, in particular clinical conditions, could represent a valid and economical alternative to the classic surgical guide. The described procedure does not increase costs for the patient and significantly increases the precision in inserting the implants during free-hand techniques.

Automated Classification of Partially Edentulous Arches Using Artificial Intelligence

Automated Classification of Partially Edentulous Arches Using Artificial Intelligence

Scalp-Split Technique: A Concept of Bone Splitting and Expansion for Thin Alveolar Ridges to Place Dental Implants.

Bone expansion is when the existing bone at the implant site is split and separated to create a gap to widen it. This article introduces a novel concept of bone expansion for the ultrathin alveolar ridges to place dental implants with zero wastage of existing natural bone in long-term edentulous arches. Instead of using twist drills and piezo surgery kits, the bone is split with a surgical scalpel blade to prevent natural bone wastage. The split helps to expand the bone horizontally by using expanders to accommodate the smaller diameter implants. This technique was applied to 12 individuals to rehabilitate their atrophic edentulous mandibles to facilitate the implant-supported overdentures, and it revealed that all the cases achieved successful osseointegration after placing implants following this method. The scalp-spilt technique is promising for providing implant-retained or implant-supported prostheses over ultrathin edentulous alveolar ridges.

Digital Analysis of the Denture Foundation Surface Area ratio of Maxillary and Mandibular Edentulous Arches: A Cross-sectional Study

Digital Analysis of the Denture Foundation Surface Area ratio of Maxillary and Mandibular Edentulous Arches: A Cross-sectional Study

Precision Test of a Multifunctional Scan Body for the Scan and Cross-Mount of an Edentulous Arch: A Pilot Case-Control Study.

The primary goal of this pilot study was to evaluate, via 3D analysis, the scan body precision of an intraoral digital scan utilizing a custom multifunctional scan body compared to that of digitized stone models fabricated from a conventional open tray impression in the fully edentulous maxilla and mandible. The secondary goal of this study was to showcase a method for utilizing the scan body library to generate a fixed fiducial marker for the cross-mount of an edentulous arch. Comparative analysis was performed as a case-control study. A custom scan body was utilized to generate the positions of the titanium bases from the intraoral models and digitized stone models of three maxillary arches (All-On-6, All-On-5, and All-On-4) and two mandibular arches (both All-On-4). The titanium base positions were compared using advanced 3D inspection software. The mean ± SD deviation was 30.38 ± 17.78 μm (95% CI: [14.8 to 45.97 μm]), with mean deviations of 38.73 ± 19.24 μm (95% CI: 16.96 to 60.5 μm) in the maxilla and 17.85 ± 0.92 μm (95% CI: 16.58 to 19.12 μm) in the mandible. The present results were promising, showing that deviations between the intraoral impressions and the digitized stone models fell within established tolerance ranges. Initial studies showed promising results that the digital workflow could be implemented with success similar to the conventional approach. Using the scan body library to generate a fiducial marker successfully demonstrated an efficient method for cross-mounting the edentulous arch.

Influence of implant number on the retention and support of mandibular overdentures

Background: There are two distinct categories of attachments—magnetic attachments and positioner attachments—currently in use for dental implants. Many implants required for implant-retained overdentures need support from implant-retained overdentures. Purpose: The aim of this study is to evaluate the effect of different implant numbers and attachment types on the retention and support of implant-retained overdentures. Methods: This experimental work involved the utilization of a model that replicated a mandibular edentulous arch, a total of five models. Within this model, seven dental implant analogues were implanted to mimic the tooth positioning observed in the natural dentition. Thirty-five titanium dental implant analogues (Dentium, South Korea) were employed in this study. A total of ten overdenture housings were fabricated using 3D printer acrylic resin, with each housing including a specific type of attachment (magnetic and positioner attachment). These attachments were equipped with three loops that were affixed to the occlusal surface of the housing. Subsequently, three chains were connected between the loops and a force gauge testing equipment. Results: The positioner was found to be more retentive and supportive than the magnetic one in the three directions of the dislodgement test as well as under unilateral and bilateral load, according to an independent t-test comparing magnetic and positioner attachment (p&lt;0.05). Conclusion: Depending on the method of attachment that is used, variations in implant number have varying effects on the retention and support of an implant-held overdenture.

Effects of wax rim in image registration of intraoral and face scan in edentulous arch condition

Effects of wax rim in image registration of intraoral and face scan in edentulous arch condition

Effect of Scanbody Material and Mucosa Modification Technique on The Accuracy of Digital Impressions of Edentulous Arches with Multiple Implants

Effect of Scanbody Material and Mucosa Modification Technique on The Accuracy of Digital Impressions of Edentulous Arches with Multiple Implants

Replacing Missing Teeth with Screw-Cement Retained Implant Supported Fixed Partial Denture: A Case Report

An accurate impression with proper interocclusal relationship are the two essential criteria used for the best fit and functionality of the final prosthesis when replacing a partly edentulous arch with an implant-supported fixed partial denture. A detailed process about the open tray impression technique and registering the interocclusal relationship for implant- supported partial denture has been described in this case report.

Implant Mechanics, Biological Milieu, and Peri-Implantitis: A Narrative Review.

Dental implants constitute an important treatment modality for rehabilitating edentulous and partially edentulous arches. With more implant systems in the market, understanding the mechanical aspects of implants is crucial in understanding this indispensable therapy. However, microflora-related factors i.e. biological factorsare also crucial. Despite the tremendous success rate of dental implants, it is not averse to failure. Both mechanical and microbial aspects in seclusion or together predispose to implant failure. Newer technological advances have paved the way for advanced techniques to identify the not-so-common flora causing implant failure. This review focuses on detailed mechanical and biological aspects and the sealing agent used to seal the implant-abutment interface. It also focuses on advanced molecular techniques like metagenomics and transcriptomics. A thorough literature search was performedwith selected articles from electronic databases. A combination of in-vivo and in-vitro studies were considered to provide comprehensive information on the subject. Both the biomechanical aspects like micro gap, and microleakage,as well as microbial movements play confluent roles in implant failure. The focus should be on the different aspects through which microflora can penetrate the inner parts of the implant. Also, newer culture-independent techniques of detecting previously undetected oral flora should be included in future studies.

Seating accuracy of removable partial denture frameworks fabricated by different digital workflows in comparison to conventional workflow.

To evaluate the seating accuracy of removable partial denture (RPD) frameworks fabricated by two digital workflows involving selective laser melting (SLM) in comparison to the conventional workflow. A Kennedy class III modification 1 partially edentulous mandibular arch was used as a master model. Three RPD framework groups were included: (1) a conventional workflow group with conventional impression and casting (CC), (2) a partial digital workflow group with conventional impression and digital fabrication (CD), and (3) a complete digital workflow group with digital impression and digital fabrication (DD). A total of 10 frameworks were produced for each group. The marginal gaps at the occlusal rests, retention arms, and reciprocating arms were measured by a traveling microscope. The data were analyzed with the one-way analysis of variance test. At the framework level, the most superior fit was observed for the CD group (79.5µm) followed by DD (85.3µm) and CC (114.2µm) groups. The CD and DD groups were significantly superior to CC (p<0.001). This fit pattern was consistent for the retention and reciprocating arms, while the occlusal rest fit was similar among all the groups. The SLM frameworks had a promising seating accuracy in comparison to conventional frameworks. The type of impression, conventional or digital, did not affect the accuracy of SLM frameworks. The differences observed in the present study are likely to be of minimal clinical significance.

In-Vitro Accuracy of Digital Versus Conventional Workflows for Complete Arch Implant Supported Frameworks - A Scoping Review.

Purpose: To investigate the available evidence on the accuracy of conventional and digital workflows for complete arch implant supported frameworks. Materials and methods: This scoping review was conducted according to the 5-stage framework of Arksey and O'Malley. A systematic literature search was performed adhering to the PRISMA guidelines to identify studies with a direct comparison of conventional and digital methods for the fabrication of complete arch implant supported frameworks. 58 in-vitro studies with the focus on edentulous arches with at least four implants published between 2000 and 2024 were included. The reported outcomes were examined to determine the value of a statistical analysis for adding up the individual errors to a cumulative error of the workflow. Results: Evidence on the accuracy assessment of digital and conventional workflows for complete arch implant supported frameworks is available. However, also studies with the same assessment methods and outcome units appear to be too heterogeneous to perform a statistical analysis of error accumulation. While there is no consensus in the impression and cast fabrication stage, digital techniques show a superior accuracy for the fabrication of complete arch implant supported frameworks compared to conventional casting. Conclusion: In-vitro studies assessing the accuracy of entire workflows and classifying their outcomes regarding the clinical relevance are lacking.

Depth distortion and angular deviation of a fully guided tooth-supported static surgical guide in a partially edentulous patient: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to evaluate the depth distortion and angular deviation of fully-guided tooth-supported static surgical guides (FTSG) in partially edentulous arches compared to partially guided surgical guides or freehand. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the Open Science Framework (OSF). The formulated population, intervention, comparison, and outcome (PICO) question was: "In partially edentulous arches, what are the depth distortion and angular deviation of FTSG compared to partially guided surgical guides or freehand?" The search strategy involved four main electronic databases, and an additional manual search was completed in November 2023 by following an established search strategy. Initial inclusion was based on titles and abstracts, followed by a detailed review of selected studies, and clinical studies that evaluated the angular deviations or depth distortion in FTSG in partial arches, compared to partially guided surgical guides or freehand, were included. In FTSG, two surgical approaches were compared: open flap and flapless techniques, and two digital methods were assessed for surgical guide design with fiducial markers or dental surfaces. A qualitative analysis for clinical studies was used to assess the risk of bias. The certainty of the evidence was assessed according to the grading of recommendations, assessment, development, and evaluations (GRADE) system. In addition, a single-arm meta-analysis of proportion was performed to evaluate the angular deviation of freehand and FTSG. Ten studies, published between 2018 and 2023, met the eligibility criteria. Among them, 10 studies reported angular deviations ranging from -0.32° to 4.96° for FTSG. Regarding FTSG surgical approaches, seven studies examined the open flap technique for FTSG, reporting mean angular deviations ranging from 2.03° to 4.23°, and four studies evaluated flapless FTSG, reporting angular deviations ranging from -0.32° to 3.38°. Six studies assessed the freehand surgical approach, reporting angular deviations ranging from 1.40° to 7.36°. The mean depth distortion ranged between 0.19mm to 2.05mm for open flap FTSG, and between 0.15mm to 0.45mm for flapless FTSG. For partially guided surgical guides, two studies reported angular deviations ranging from 0.59° to 3.44°. Seven studies were eligible for meta-analysis, focusing on the FTSG in open flap technique, with high heterogeneity (I2 (95%CI) = 92.3% (88.7%-96.4%)). In contrast, heterogeneity was low in studies comparing freehand versus FTSG in open flap techniques (I2 (95%CI) = 21.3% (0.0%-67.8%)), favoring the FTSG surgical approach. In partially edentulous arches, FTSG systems exhibited less angular deviation than freehand and partially guided surgical guides. Flapless surgical approaches were associated with reduced angular deviation and depth distortion, suggesting a potential preference for the FTSG method in these procedures.

Impact of vertical alveoloplasty on changes in keratinized mucosa width following full-arch immediate implant placement and rehabilitations: A prospective case series.

This prospective case series aimed to investigate the effect of vertical alveoloplasty on the changes in keratinized mucosa width (KMW) following full-arch immediate implant placement and rehabilitation. A total of 17 potential edentulous patients were enrolled and received implant placement and full-arch implant-supported immediate rehabilitations. The main outcome was to analyze the effect of vertical alveoloplasty on the changes in KMW. The amount of vertical alveoloplasty during implant surgery as well as the changes in KMW at buccal aspects from the day of surgery to 6 months post-surgery were recorded on the implant-level using a periodontal probe. The secondary outcome was to analyze the other possible factors that affected the changes in KMW. The included factors were the initial KMW, the distribution of implants in the maxilla and mandible, the distribution of implants in the anterior and posterior regions, the distribution of implants in extraction sockets and healed ridges, and gender. Mann-Whitney non-parametric tests and multiple linear regression adjusted by generalized estimating equations (GEE) were used to statistically analyze the data. A total of 121 implant positions were analyzed. The KMW was 4.1± 2.0mm on the day of the surgery and 4.1± 1.7mm 6 months post-surgery. The mean changes in KMW following 6 months were -0.1± 1.6mm (p = 0.824). From the results of GEE, the vertical amount of alveoloplasty had no significant effect on changes in KMW. Both initial KMW and the distribution of implants in the anterior and posterior regions had significant impacts on the changes in KMW (p<0.0001). The amount of vertical alveoloplasty during implant surgery has no significant impact on the KMW. The KMW remained stable from baseline to 6 months after alveoloplasty, implant placement, and immediate rehabilitations in potential edentulous arches. The initial KMW and the distribution of implants in the anterior and posterior regions were the possible factors affecting changes in KMW.

In vitro evaluation of the impact of intraoral scanner, scanning aids, and the scanned arch on the scan accuracy of edentulous arches.

To assess the accuracy of complete maxillary and mandibular edentulous arch scans obtained using two different intraoral scanners (IOSs), with and without scanning aids, and to compare these results to those obtained using conventional impression methods. Two IOSs were used (TRIOS 4 [TRI] and Emerald S [EMR]) to scan maxillary and mandibular typodonts. The typodonts were scanned without scanning aids [TRI_WSA and EMR_WSA groups] (n = 10). The typodonts were then scanned under four scanning aid conditions (n = 10): composite markers [TRI_MRK and EMR_MRK groups], scanning spray [TRI_SPR and EMR_SPR groups], pressure indicating paste [TRI_PIP and EMR_PIP groups], and liquid-type scanning aid [TRI_LQD and EMR_LQD groups]. Conventional impressions of both arches were also made using irreversible hydrocolloids in stock trays [IHC] and using polyvinyl siloxane (PVS) impression material in custom trays (n = 10) which were digitized using a laboratory scanner. Using a metrology software program, all scans were compared to a reference scan in order to assess trueness and to each other to assess precision. Trueness and precision were expressed as the root mean square (RMS) of the absolute deviation values and the statistical analysis was modeled on a logarithmic scale using fixed-effects models to meet model assumptions (α = 0.05). The main effect of arch (p = 0.004), scanner (p < 0.001), scanning aid (p = 0.041), and the interaction between scanner and scanning aid (p = 0.027) had a significant effect on mean RMS values of trueness. The arch (p = 0.015) and scanner (p < 0.001) had a significant effect on the mean RMS values of precision. The maxillary arch had better accuracy compared to the mandible. The TRIOS 4 scanner had better accuracy than both the Emerald S scanner and conventional impressions. The Emerald S had better precision than conventional impressions. The scanning spray and liquid-type scanning aids produced the best trueness with the TRIOS 4 scanner, while the liquid-type scanning aid and composite markers produced the best trueness for the Emerald S scanner. The scanned arch and the type of scanner had a significant effect on the accuracy of digital scans of completely edentulous arches. The scanning aid had a significant effect on the trueness of digital scans of completely edentulous arches which varied depending on the scanner used.