Brian J. Goodacre

Clinical complications and quality assessments with computer-engineered complete dentures: A systematic review

Statement of problem Computer‐engineered complete dentures (CECDs) have significant potential as shown by recent reports of outcomes and specific applications. An understanding of complications and quality assessment factors associated with CECDs from compiled data is lacking in published reports. Purpose The purpose of this systematic review was to determine the clinical complications and quality assessments related to CECDs. Material and methods Electronic searches of publications in English from January 1984 to September 2016 were performed in MEDLINE and Cochrane databases, with the results enriched by manual searches and citation mining to address 2 population intervention comparison outcome (PICO) questions: what are the clinical complications associated with CECDs, and what are the quality assessments with CECDs? Results A review of 5 selected articles (limited data) on CECDs revealed patient dissatisfaction related to overall outcome (25.49%), inadequate retention (20.73%), and esthetic concerns (15.09%) as common complications. Quality assessment factors that were used to report complications were identified. Conclusions Patient dissatisfaction, inadequate retention, and inadequate esthetics were the most common complications with CECDs. The addition of a trial placement option for CECDs could result in a better clinical outcome, reducing the incidence of other complications related to occlusal vertical dimension, centric relationship, tooth arrangement, and esthetics, improving patient satisfaction, and reducing remakes. The difficulty in reading the digital preview for an objective assessment before fabrication is a unique but not a common, complication for CECDs.

Three-dimensional printing in contemporary fixed prosthodontics: A technique article

Digital dentistry has gained in popularity among clinicians and laboratory technicians because of its versatile applications. Three-dimensional (3D) printing has been applied in many areas of dentistry as it offers efficiency, affordability, accessibility, reproducibility, speed, and accuracy. This article describes a technique where 3D printing is used to fabricate a die-trimmed cast and to replicate gingival tissue and implant analogs. The digital workflow that replaces the conventional laboratory procedure is outlined.

A 3D-printed guide for lateral approach sinus grafting: A dental technique

Lateral approach sinus grafting has become a routine and predictable surgical method of augmenting the pneumatized sinus for implant placement. Outlining the lateral window access can be a challenging task for the clinician to envision and execute. Improper extension and access to the maxillary sinus can prevent proper placement of graft materials and lead to complications. The purpose of this report was to demonstrate a technique that will allow the precise planning of the lateral approach using radiographic information and 3-dimensional (3D) software to 3D-print a surgical guide.

A comparison of gingival display with a requested smile, Duchenne smile, grimace of disgust, and funnel-shaped expression.

STATEMENT OF PROBLEM A patients smile may not elicit the maximum amount of maxillary gingiva. PURPOSE The purpose of this study was to measure the amount of gingival display with 4 different facial expressions. MATERIAL AND METHODS Video images of 91 randomly selected adults were evaluated to measure the height of gingival display at the maxillary anterior teeth and first premolars when participants were asked to give their biggest smile (requested smile), make a Duchenne smile, mimic an intense grimace of disgust (grimace), and produce a funnel-shaped expression (funnel). Measurements were compared with the Friedman Test with post hoc comparisons (α=.05 for all tests). RESULTS The intraclass correlation coefficient was (95% CI)=0.913(0.623, 0.984). At the central and lateral incisors, the grimace and funnel expressions produced the greatest amounts of gingival display. At the canines and the first premolars, both smiles (requested and Duchenne) exhibited the largest amount of gingival display of the 4 facial expressions. CONCLUSIONS Neither smile type revealed a significantly greater amount of gingival display above the maxillary central or lateral incisors but the grimace and funnel facial expressions did (P ≤.001). Above the maxillary canines, both smiles displayed a significantly greater amount of gingiva than did the funnel expression (P<.001), but only the Duchenne smile displayed a greater amount than did the grimace expression (P=.05). Superiorly to the maxillary first premolars, both smile types revealed significantly greater amounts of soft tissue when compared with the other 2 facial expressions (P<.001).

Comparison of denture tooth movement between CAD-CAM and conventional fabrication techniques

Statement of problem. Data comparing the denture tooth movement of computer‐aided design and computer‐aided manufacturing (CAD‐CAM) and conventional denture processing techniques are lacking. Purpose. The purpose of this in vitro study was to compare the denture tooth movement of pack‐and‐press, fluid resin, injection, CAD‐CAM‐bonded, and CAD‐CAM monolithic techniques for fabricating dentures to determine which process produces the most accurate and reproducible prosthesis. Material and methods. A total of 50 dentures were evaluated, 10 for each of the 5 groups. A master denture was fabricated and milled from prepolymerized poly(methyl methacrylate). For the conventional processing techniques (pack‐and‐press, fluid resin, and injection) a polyvinyl siloxane putty mold of the master denture was made in which denture teeth were placed and molten wax injected. The cameo surface of each wax‐festooned denture was laser scanned, resulting in a standard tessellation language (STL) format file. The CAD‐CAM dentures included 2 subgroups: CAD‐CAM‐bonded teeth in which the denture teeth were bonded into the milled denture base and CAD‐CAM monolithic teeth in which the denture teeth were milled as part of the denture base. After all specimens had been fabricated, they were hydrated for 24 hours, and the cameo surface laser scanned. The preprocessing and postprocessing scan files of each denture were superimposed using surface‐matching software. Measurements were made at 64 locations, allowing evaluation of denture tooth movement in a buccal, lingual, mesial‐distal, and occlusal direction. The use of median and interquartile range values was used to assess accuracy and reproducibility. Levene and Kruskal‐Wallis analyses of variance were used to evaluate differences between processing techniques (&agr;=.05). Results. The CAD‐CAM monolithic technique was the most accurate, followed by fluid resin, CAD‐CAM‐bonded, pack‐and‐press, and injection. CAD‐CAM monolithic technique was the most reproducible, followed by pack‐and‐press, CAD‐CAM‐bonded, injection, and fluid resin. Techniques involving compression during processing showed increased positive occlusal tooth movement compared with techniques not involving compression. Conclusions. CAD‐CAM monolithic dentures produced the best combination of accuracy and reproducibility of the tested techniques. The results from this study demonstrate that varying amounts of tooth movement can be expected depending on the processing technique. However, the clinical significance of these differences is unknown.

Using Virtual Ridge Augmentation and 3-Dimensional Printing to Fabricate a Titanium Mesh Positioning Device: A Novel Technique Letter

This technique describes a novel approach for planning and augmenting a large bony defect using a titanium mesh (TiMe). A 3-dimensional (3D) surgical model was virtually created from a cone beam computed tomography (CBCT) and wax-pattern of the final prosthetic outcome. The required bone volume (horizontally and vertically) was digitally augmented and then 3D printed to create a bone model. The 3D model was then used to contour the TiMe in accordance with the digital augmentation. With the contoured / preformed TiMe on the 3D printed model a positioning jig was made to aid the placement of the TiMe as planned during surgery. Although this technique does not impact the final outcome of the augmentation procedure, it allows the clinician to virtually design the augmentation, preform and contour the TiMe, and create a positioning jig reducing surgical time and error.

Using Intraoral Scanning to Fabricate Complete Dentures: First Experiences

The newest impression techniques use intraoral scanners to capture both the hard and soft tissues. However, with edentulous patients, the accuracy of an intraoral scanner to capture an acceptable impression for the fabrication of a complete denture needs to be evaluated. Therefore, the purpose of this report of two patient treatments is to describe a technique that used intraoral scanning to record mucosal morphology and fabricate computer-aided design/computer-assisted manufacture (CAD/CAM) complete dentures.

Using Intraoral Scanning to Capture Complete Denture Impressions, Tooth Positions, and Centric Relation Records.

Intraoral scanning was used to capture the soft tissue surfaces of both maxillary and mandibular edentulous ridges and the denture borders. Additionally, an intraoral scanner was used to digitize existing dentures with their tooth positions and base forms and a centric relation record obtained with a Gothic arch-tracing device. These scans provided all the required records for fabrication of computer-aided design/computer-assisted manufacturing of complete dentures.