IU Indianapolis ScholarWorks :: Browsing by Author "Lin, Wei-Shao"

Browsing by Author "Lin, Wei-Shao"

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3D‐printed shell complete dentures as a diagnostic aid for implant planning and fabricating interim restorations for complete arch rehabilitations: A case series
(Wiley, 2025) Azpiazu-Flores, Francisco X.; Yang, Chao-Chieh; Lin, Wei-Shao; Polido, Waldemar D.; Morton, Dean; Prosthodontics, School of Dentistry
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.
Accelerated denture base festooning using a free 3D modeling computer program: A dental technique
(Elsevier, 2024-05) Azpiazu-Flores, Francisco X.; Morton, Dean; Lin, Wei-Shao; Prosthodontics, School of Dentistry
Denture bases should be contoured to recreate the natural contours of the tissues being replaced to ensure optimum phonetics, esthetics, and function.1 Several suggestions have been made regarding the desired shape and contours of the artificial root eminences, denture base extension contours, and surface characterization of the denture base.2–4 Traditionally, achieving these contours has been a time-consuming process done manually during the waxing stage of denture fabrication and requiring significant skill and artistry.2
Accuracy of digital duplication scanning methods for complete dentures
(Wiley, 2023) Alehaideb, Abdullah; Lin, Wei-Shao; Levon, John A.; Chu, Tien-Min G.; Yang, Chao-Chieh; Prosthodontics, School of Dentistry
Purpose To compare the accuracy of four digital scanning methods in duplicating a complete denture. Material and Methods Four scanning methods were used: cone beam computed tomography (CBCT), Straumann desktop scanner (DS), Trios intraoral scanner (TIO), and Virtuo Vivo intraoral scanner (VVIO). Each method was used to duplicate all the surfaces of a printed complete denture. The denture was scanned 10 times in each group. The trueness (in root mean square, RMS) and precision (in standard deviation, SD) were calculated by comparing the combined dentition, denture extension, and intaglio surfaces with the reference file. One-way analysis of variance and F-tests were used to test statistical differences (α = 0.05). Results For the scanning accuracy of the whole denture, CBCT showed the highest RMS (0.249 ± 0.020 mm) and lowest trueness than DS (0.124 ± 0.014 mm p < 0.001), TIO (0.131 ± 0.006 mm p < 0.001), and VVIO (0.227 ± 0.020 mm p = 0.017), while DS and TIO showed smaller RMS than VVIO (p < 0.001). For the trueness of dentition, denture extension, and intaglio surfaces, CBCT also showed the highest mean RMS and lowest trueness among all groups (p < 0.001). DS and TIO had smaller mean RMS and higher trueness among all groups in all surfaces (p < 0.001, except VVIO in intaglio surface, p > 0.05). TIO had significantly lower within-group variability of RMS and highest precision compared to DS (p = 0.013), CBCT (p = 0.001), and VVIO (p < 0.001) in the combined surface. For dentition and denture extension surfaces, TIO showed similar within-group variability of RMS with the DS group (p > 0.05) and lower than CBCT and VVIO (p < 0.001). Conclusion The 7 Series desktop scanner and Trios 4 intraoral scanner can duplicate dentures in higher trueness than CBCT and the Virtuo Vivo intraoral scanner. The Trios 4 intraoral scanner was more precise in the combined surfaces than other scanning methods, while the 7 Series desktop scanner and Trios 4 intraoral scanner were more precise in the denture extension surface.
Bead-anchored surgical templates for static computer-assisted implant surgery: A dental technique
(Wiley, 2022-10) Orgev, Ahmet; Pellerito, John; Polido, Waldemar; Morton, Dean; Lin, Wei-Shao; Prosthodontics, School of Dentistry
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.
CAD-CAM Hollow Obturator Prosthesis: A Technical Report
(Wiley, 2022) Alfaraj, Amal; Su, Fang-Yu; Lin, Wei-Shao; Prosthodontics, School of Dentistry
An obturator with a hollow bulb can decrease the overall weight of the prosthesis, stress on the underlying tissues, and patient discomfort. Although many techniques and materials have been proposed in the literature for hollowing the obturator prosthesis, they are often time-consuming and technique sensitive. This proposed technique used an open-source software program to hollow digital design of solid obturator base from a commercially available software in one single convenient step. The hollowing process allowed precise control of prosthesis thickness at the hollow space area for desirable hermetic seal and prosthesis strength.
Clinical performance of intentionally tilted implants versus axially positioned implants: A systematic review
(Wiley, 2018-10) Lin, Wei-Shao; Eckert, Steven E.; Prosthodontics, School of Dentistry
Objectives The aim of this review was to determine the clinical performance of dental implants that are intentionally tilted when compared with implants that are placed following the long axis of the residual alveolar ridge. Materials and methods A systematic review of the scientific literature using a predefined research question (PICO) and search strategy was undertaken. This search included five electronic databases. Two independent reviewers examined electronic databases and performed a manual review following search strategy to accomplish the item generation and reduction. Included articles were evaluated to determine the level of evidence. Data were extracted only from level I and level II studies, based on the Oxford Centre for Evidence‐based Medicine—Levels of Evidence (March 2009). If included studies were homogeneous in nature, data were to be accumulated. However, if included studies were heterogeneous in nature, only descriptive data would be reviewed and analyzed. Results A total of 811 articles were identified through the PICO question and search strategy. Detailed review of the abstracts and articles resulted in further item reduction, and 46 articles were included for full‐text review. A total of 42 articles were then selected for inclusion in the systematic review. The identified articles included two level I and 20 level II studies. In addition, 15 level IV, one gray literature, and four previous systematic reviews with meta‐analyses were also used in the study. The extracted data from the included studies demonstrated heterogeneity that prevented quantitative assessment, and only one level II study directly compared tilted and axially placed implants. Assessment of the descriptive data demonstrated no differences in implant survival, marginal bone loss, prosthesis survival, or patient‐reported outcome measures (PROMs) whether implants are placed axially or with intentional inclination of the coronal aspect of the implant toward the distal aspect of edentulous jaws. Conclusions Based upon the systematic review of the literature, an analysis of the descriptive data suggested no differences in clinical performance between implants that are placed in an axial position relative to the residual alveolar ridge when compared with implants that are intentionally tilted toward the distal aspect of edentulous jaws.
Color reproduction trueness of 3D-printed full-color dental casts with scans derived from an intraoral scanner
(Wiley, 2023) Alfaraj, Amal; Lin, Wei-Shao; Prosthodontics, School of Dentistry
Purpose To investigate the effects of shade tab color variations (tooth-colored vs. gingiva-colored) and surface treatment (application of mineral oil) on the trueness of color reproduction from dental shade tabs to 3D-printed full-color dental casts, using digital scans obtained from an intraoral scanner. Materials and Methods Pristine tooth-colored (with 16 shade tabs) and gingiva-colored (with five shade tabs) shade guides were digitally scanned using an intraoral scanner, and subsequently, 3D-printed replicas were created using a full-color material jetting 3D printer. Three color measurements using a contact type digital spectrophotometer were recorded, including actual shade tabs (R0), dried 3D-printed study samples (RP1), and study samples with mineral oil application (RP2), in this study to calculate color differences between the actual shade tabs and 3D-printed ones. The CIEDE2000 formula was used to calculate the color differences (color reproduction trueness) between reference shade tabs and 3D-printed full-color study samples—without and with mineral oil, ∆E00(RP1), and ∆E00(RP2). ∆E00(RP1) and ∆E00(RP2) were compared with a 50:50% accessibility threshold (AT) and a 50:50% perceptibility threshold (PT). A grading system, based on the relative ranges of AT and PT, was employed. The percentage of samples falling into each color-matching category was then recorded. The data collected were subjected to statistical analysis, utilizing a mixed model ANOVA to evaluate the effects of shade tab color and mineral oil application on color differences, α = 0.05. Results The application of mineral oil significantly affected the ∆E00 [F(1, 378) = 19.1, p = < 0.0001]. However, this effect was only significant for the gingiva-colored study samples; the mineral oil application significantly decreased color difference, showing ∆E00(RP1) of 8.71 ± 3.78 and ∆E00(RP2) of 6.55 ± 2.14 (p < 0.0001). For the tooth-colored groups, the mineral oil application did not yield any color difference, showing ∆E00(RP1) of 7.05 ± 2.35 and ∆E00(RP2) of 6.94 ± 2.35 (p = 0.497). In the absence of mineral oil, gingiva-colored samples revealed a significantly larger ∆E00(RP1) of 8.71 ± 3.78 compared to tooth-colored samples at 7.05 ± 2.35 (p = 0.017). Conversely, mineral oil application rendered comparable ∆E00(RP2) values between gingiva-colored (6.55 ± 2.14) and tooth-colored (6.94 ± 2.35) samples (p = 0.558). All 3D-printed full-color samples showed Grade 1 (extremely unacceptable mismatch) and Grade 2 (clearly unacceptable mismatch), regardless of the shades or the presence of mineral oil. Conclusions Utilizing an intraoral scanner to gather digital color data, along with an MJ 3D printer, offers the potential for producing 3D-printed full-color dental casts for prosthesis characterization in the dental laboratory. While mineral oil improves the color reproduction trueness of gingiva-colored objects, all 3D-printed full-color samples exhibited unacceptable mismatches when compared to their target objects. This underscores the need for future improvement in the digital color data acquisition process and color optimization protocols in 3D printing processes.
Comparison of surface characteristics of denture base resin materials with two surface treatment protocols and simulated brushing
(Wiley, 2023) Alouthah, Hesham; Lippert, Frank; Yang, Chao-Chieh; Levon, John A.; Lin, Wei-Shao; Prosthodontics, School of Dentistry
Purpose To investigate the effects of 4 denture base materials, 2 surface treatment protocols, and simulated brushing (SB) on the surface hardness, surface roughness, surface gloss, and the surface loss of denture base materials. Materials and Methods Four denture base resin material groups (compression-molded, injection-molded, 3D-printed, and milled) with two different surface treatment protocols (polished and glazed) were utilized in this study. A total of 80 samples (n = 10) were evaluated for surface hardness (Vickers) before SB. SB was performed for each sample (custom-built V8 cross brushing machine, 50,000 reciprocal strokes). Surface roughness (Ra) was measured before and after SB with a non-contact optical profilometer. Surface gloss was performed using a glossmeter to determine changes in surface reflectivity of the specimens before and after SB. Surface loss (wear resistance) was measured after SB using optical profilometry. The effects of material, surface treatment, and SB on all surface characteristics were examined with two-way and three-way analysis of variance models (ANOVA) (α = 0.05). Results The polished compression-molded group had significantly higher surface hardness than all other groups. The protective glaze coating significantly increased the surface hardness for all groups (P < 0.001). SB increased the surface roughness of all groups regardless of surface treatments (P < 0.001). The increase in surface roughness after SB was significantly higher with polished surface treatment than with a glazed surface treatment in all groups (P < 0.001). Surface gloss was significantly higher with the glazed surface treatment than with the polished surface treatment for all denture base materials (P < 0.001). After SB, milled denture base material showed the highest, and 3D-printed material showed the second highest surface gloss compared to the other groups (P < 0.001), regardless of surface treatment. In all materials tested, surface glaze significantly decreased surface loss (P < 0.001). With the glaze surface treatment, compression-molded denture base material had significantly less surface loss (more surface gain) than other materials, while with the polished surface treatment, 3D-printed denture base material had the least surface loss when compared with other groups. Conclusions A single layer of nano-filled, light-polymerizing protective glaze coating has displayed potential for enhancing the longevity of denture base materials, as evidenced by increased hardness and wear resistance. Following simulated brushing, the milled denture material exhibited the highest surface gloss and lowest surface roughness among all groups, regardless of the surface treatment protocol. This indicates that milled denture base material possesses favorable surface properties and may serve as a viable alternative to traditional denture base materials.
Coronavirus disease 2019 (COVID-19): Experiences and protocols from the Department of Prosthodontics at the Wuhan University
(Elsevier, 2020-07-10) Sa, Yue; Lin, Wei-Shao; Morton, Dean; Huang, Cui; Prosthodontics, School of Dentistry
Statement of problem: The novel Coronavirus Disease 2019 (COVID-19) is a global pandemic, and many countries and regions are still currently in the midst of the outbreak. This pandemic has caused prosthodontics units to suspend their clinical and educational operations in academia. Purpose: The purpose of this article was to review the experiences from the Department of Prosthodontics, Wuhan University School and Hospital of Stomatology (DP-WHUSHS) during the COVID-19 outbreak and the protocols DP-WHUSHS utilized to resume clinical activities after the outbreak. Material and methods: The descriptive approach was used in this article to provide a chronological narrative of the experiences and protocols from the DP-WHUSHS during the COVID-19 outbreak and after the outbreak. Results: During the COVID-19 outbreak period, clinical care was provided for patients with dental emergencies using enhanced Grade 2 or Garde 3 personal protective equipment (PPE). Teledentistry was used to provide care for patients with non-emergency needs. Online webinars and lectures were provided for the predoctoral students, residents, and dentists to minimize the interruption in their education and engage the dental community amid the pandemic. Various factors were considered before clinical activities resumed after the outbreak subsided. Additional resources were allocated for facility preparation and management and employee training. New infection control and clinical operation protocols were developed to minimize the healthcare-associated infection of airborne transmission diseases. The psychological health and mental wellness of the employees were emphasized. Distance or online education is still under rapid development to provide students and dentists opportunities to advance their knowledge amid the pandemic. Conclusions: Within the limitation of this descriptive review, the following conclusions were drawn. Patient welfare and emergency needs should be considered amid the pandemic. Enhanced Grade 2 or Grade 3 PPE should be used during the outbreak. Multifactorial considerations for work resumption after the outbreak included facility preparation and management, training for employees, and clinical operation management. In-person psychological consultation and online mental wellness programs were available to employees to improve their mental wellness. Distance or online education was under rapid development to minimize the interruption in education for the students and to engage the dental community amid a pandemic.
Digital Gothic Arch Tracing Device with Open-Source Software for CAD/CAM Denture Fabrication
(Quintessence Publishing, 2022) Orgev, Ahmet; Lin, Wei-Shao; Morton, Dean; Prosthodontics, School of Dentistry
Digital or CAD/CAM workflows and protocols are being increasingly utilized because of their improved efficiency and reproducibility. For the fabrication of complete dentures, digital workflows can reduce treatment time and clinical visits while enhancing the reliability and reproducibility of the laboratory phase and materials. However, establishing centric relation (CR) and vertical dimension of occlusion (VDO) in a reproducible way is still a challenging step for complete denture fabrication in both analog and digital workflows. This clinical report describes a digital workflow utilizing an individualized gothic arch tracing device (GATD) using open-source software for the fabrication of complete dentures. With this workflow, clinicians can offer customized solutions according to patient rehabilitation, with good reproducibility using gothic arch tracing to be implemented in the digital workflow.

Browsing by Author "Lin, Wei-Shao"

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