Design A systematic appraisal and statistical aggregation of primary studies in humans. Data sour... more Design A systematic appraisal and statistical aggregation of primary studies in humans. Data sources The researchers utilized PubMed (Medline) and Scopus databases as the primary data sources for this study. They performed a comprehensive literature search based on free keywords and Medical Subject Heading (MeSH) terms to enhance the search accuracy. The database search was concluded on November 13, 2022. Furthermore, a meticulous examination of the references cited in the selected studies was conducted to identify additional relevant articles that could be incorporated into the analysis. Study selection The systematic review focused on partially or fully edentulous patients receiving dental implants and aimed to determine if the lack of keratinized mucosa at the implant site increased the risk of peri-implantitis compared to patients with adequate keratinized mucosa. Human studies with a minimum of 100 implants, cross-sectional, cohort, or case-control designs, and a follow-up peri...
This study aimed to evaluate the feasibility of a 3-dimensional (3D) planned surgical guide techn... more This study aimed to evaluate the feasibility of a 3-dimensional (3D) planned surgical guide technique designed for impacted supernumerary teeth (STs) extraction using 3D printed simulation models. In total, 17 participants from two university hospitals were recruited. Each participant performed surgery with both the conventional and surgical guide techniques. The following parameters were evaluated: (1) The time required for ST extraction, (2) the area of the window opening, and (3) the volume of the material removed. Time required for ST extraction was 213.65 ± 167.45 sec and 114.76 ± 42.87 sec in the conventional and surgical guide techniques, respectively, with significant differences (p = 0.028). The required area of the window opening was 48.10 ± 9.44 mm2 and 45.90 ± 8.17 mm2, respectively, in the conventional and surgical guide techniques, with no significant differences (p > 0.05). The required volume of the material removed was 121.65 ± 43.69 mm3 and 99.12 ± 17.88 mm3 in ...
Quintessence international (Berlin, Germany : 1985), 2017
Most mesiodens remain impacted and can affect the growth and development of adjacent permanent te... more Most mesiodens remain impacted and can affect the growth and development of adjacent permanent teeth. Impacted mesiodens are usually located in an intraosseous position associated with complicated anatomical structures, necessitating minimally invasive surgical approaches. This article demonstrates a simple customized surgical stent for extraction of impacted mesiodens. Its use and advantages are described.
Aims.To evaluate screw loosening and fracture load and angular deviation of a single implant-supp... more Aims.To evaluate screw loosening and fracture load and angular deviation of a single implant-supported prosthesis under vertical and oblique loading direction and three different loading points at the occlusal surface. Methods. A total of 40 metal crowns were cemented to internal connection implants and were divided as vertical and oblique loading direction. The occlusal surface of the crown was designed with three flat surfaces, contact A, B, and C, representing outer and inner 20-degree inclination for buccal and lingual cusps. The angular deviations of implant crown under static 50N of loading were measured. And screw removal torque was evaluated before and after 52,500 load cycles. Then, fracture load was measured for each specimen. Data analysis was performed using one-way analysis of variance test of significance followed by Tukey honest significant difference (HSD) test(p<0.05). Results. Angular deviation results showed statistical significance between all contact points i...
STATEMENT OF PROBLEM Digital feedback for tooth preparation can provide dental practitioners with... more STATEMENT OF PROBLEM Digital feedback for tooth preparation can provide dental practitioners with more objective and accurate evaluations compared to conventional methods. PURPOSE This study aimed to evaluate the educational effect and satisfaction of digital feedback compared to those of the conventional putty index method for tooth preparation. MATERIAL AND METHODS Forty-eight third-grade dental students were selected. All students performed a full-coverage preparation on a right mandibular first molar resin tooth. They were randomly divided into four groups (n=12)-no guide (control), putty index, digital feedback, and digital and putty index assessment. Three-dimensional analysis was performed using an analysis software (GomInspect 2018, Gom) to evaluate the amount of tooth structure removed. At the end of the practice, the students completed a questionnaire to evaluate the educational satisfaction of the respective methods. RESULTS There was no statistical significance of the amount of preparation among groups in most of the measured areas only except for several specific points. Overall occlusal surface showed 0.99±0.27 mm in the N group (no guide) and 1.15±0.31 mm in the D group (digital feedback) and overall axial surface showed no statistical differences (p>0.05). The groups that used digital assessment showed a high level of satisfaction compared to conventional assessment. CONCLUSIONS It was difficult to confirm that the digital-based feedback promotes accurate tooth preparation compared to conventional feedback within the limitation of this study. However, it improved educational satisfaction and permitted objective evaluation.
Journal of Computational Design and Engineering, 2020
Few studies have examined the biomechanical effects of dental implant placement in the implant-su... more Few studies have examined the biomechanical effects of dental implant placement in the implant-supported mandibular advancement device (MAD) for the treatment of obstructive sleep apnea in completely edentulous patients. This biomechanical study aimed to evaluate the stability of the implant-supported MAD for different numbers and positions of dental implants. A 3D edentulous maxillofacial model with the one-piece MAD was considered for various numbers and positions of implants. On each mandible and maxilla, one, two, four, or six implants were placed symmetrically in various positions. Total 42 implant placements were considered. A static finite element analysis was performed under the mandibular posterior restorative force for 40% protrusion. The maximum and minimum principal stresses on the cortical and cancellous bones and the von Mises stresses on the implant were measured. When four implants were placed on each maxilla and mandible, the maximum average stress on the cancellous...
The design of the attachment must provide an optimum stress distribution around the implant. In t... more The design of the attachment must provide an optimum stress distribution around the implant. In this study, for implant overdentures with a bar/clip attachment or a locator attachment, the stress transmitted to the implant in accordance with the change in the denture base length and the vertical pressure was measured and analyzed. Test model was created with epoxy resin. The strain gauges made a tight contact with implant surfaces. A universal testing machine was used to exert a vertical pressure on the mandibular implant overdenture and the strain rate of the implants was measured. Means and standard deviations of the maximum micro-deformation rates were determined. 1) Locator attachment: The implants on the working side generally showed higher strain than those on the non-working side. Tensile force was observed on the mesial surface of the implant on the working side, and the compressive force was applied to the buccal surface and on the surfaces of the implant on the non-working...
Evaluating the cement space of various dental prostheses is important because it is related to th... more Evaluating the cement space of various dental prostheses is important because it is related to the stability and retention of the prosthesis. However, a method for evaluating an overall cement space is complex. The purpose of this technique was to simplify the evaluation of prosthesis cement space by using a digital scanner. The form and thickness of the cement space could be simply recognized in any section the clinician or dental researcher wishes. Moreover, the cement space of several dental prostheses for the same abutment could also be precisely evaluated by superimposition. The method can be applied to various prosthodontic treatments.
PURPOSE To evaluate the accuracy of superimposition of customized abutment library data onto scan... more PURPOSE To evaluate the accuracy of superimposition of customized abutment library data onto scanned abutment data according to the extent of the scanning area. MATERIALS AND METHODS A patient model was fabricated by a 3D printer (Probo, DIO Implant), and a customized abutment was fabricated using a four-axis milling machine (ARUM 4X-100, Doowon). The customized abutment library data were generated using a laboratory scanner (E3, 3Shape) for superimposition after intraoral scanning. A cone-shaped structure was embedded into the library data at the center of the connection part. The customized abutment was placed on the model, and the model was scanned using a laboratory scanner to produce reference data. Three different test group datasets were generated using intraoral scanner and computer-aided design software: (1) fully scanned customized abutment; (2) insufficiently scanned proximal surface; and (3) insufficiently scanned margin, assuming challenging intraoral conditions. The li...
PURPOSE This study examined a new 3D volumetric analysis method for the assessment of baseline-to... more PURPOSE This study examined a new 3D volumetric analysis method for the assessment of baseline-to-12-month changes of the soft tissue volume at early and immediately placed tapered implants after loading with ceramic single crowns. MATERIALS AND METHODS Eligible patients with one incisor, canine, or premolar to be extracted were included. The patients were divided randomly into early-placement or immediate-placement groups. Tapered implants (BLT, Institut Straumann) were placed after the extractions. In the early-placement group, the implants were placed 8 weeks after extraction. In the immediate-placement group, the implants were placed immediately after the extraction. All implants healed transmucosally, and the final crowns were inserted after healing (baseline). Impressions were made at screening, baseline, and 12 months after crown insertion (Permadyne, 3M). The casts were scanned (Imetric 4D) and aligned, and a superimposed area of interest (AOI) (labial/buccal aspects) was de...
Design A systematic appraisal and statistical aggregation of primary studies in humans. Data sour... more Design A systematic appraisal and statistical aggregation of primary studies in humans. Data sources The researchers utilized PubMed (Medline) and Scopus databases as the primary data sources for this study. They performed a comprehensive literature search based on free keywords and Medical Subject Heading (MeSH) terms to enhance the search accuracy. The database search was concluded on November 13, 2022. Furthermore, a meticulous examination of the references cited in the selected studies was conducted to identify additional relevant articles that could be incorporated into the analysis. Study selection The systematic review focused on partially or fully edentulous patients receiving dental implants and aimed to determine if the lack of keratinized mucosa at the implant site increased the risk of peri-implantitis compared to patients with adequate keratinized mucosa. Human studies with a minimum of 100 implants, cross-sectional, cohort, or case-control designs, and a follow-up peri...
This study aimed to evaluate the feasibility of a 3-dimensional (3D) planned surgical guide techn... more This study aimed to evaluate the feasibility of a 3-dimensional (3D) planned surgical guide technique designed for impacted supernumerary teeth (STs) extraction using 3D printed simulation models. In total, 17 participants from two university hospitals were recruited. Each participant performed surgery with both the conventional and surgical guide techniques. The following parameters were evaluated: (1) The time required for ST extraction, (2) the area of the window opening, and (3) the volume of the material removed. Time required for ST extraction was 213.65 ± 167.45 sec and 114.76 ± 42.87 sec in the conventional and surgical guide techniques, respectively, with significant differences (p = 0.028). The required area of the window opening was 48.10 ± 9.44 mm2 and 45.90 ± 8.17 mm2, respectively, in the conventional and surgical guide techniques, with no significant differences (p > 0.05). The required volume of the material removed was 121.65 ± 43.69 mm3 and 99.12 ± 17.88 mm3 in ...
Quintessence international (Berlin, Germany : 1985), 2017
Most mesiodens remain impacted and can affect the growth and development of adjacent permanent te... more Most mesiodens remain impacted and can affect the growth and development of adjacent permanent teeth. Impacted mesiodens are usually located in an intraosseous position associated with complicated anatomical structures, necessitating minimally invasive surgical approaches. This article demonstrates a simple customized surgical stent for extraction of impacted mesiodens. Its use and advantages are described.
Aims.To evaluate screw loosening and fracture load and angular deviation of a single implant-supp... more Aims.To evaluate screw loosening and fracture load and angular deviation of a single implant-supported prosthesis under vertical and oblique loading direction and three different loading points at the occlusal surface. Methods. A total of 40 metal crowns were cemented to internal connection implants and were divided as vertical and oblique loading direction. The occlusal surface of the crown was designed with three flat surfaces, contact A, B, and C, representing outer and inner 20-degree inclination for buccal and lingual cusps. The angular deviations of implant crown under static 50N of loading were measured. And screw removal torque was evaluated before and after 52,500 load cycles. Then, fracture load was measured for each specimen. Data analysis was performed using one-way analysis of variance test of significance followed by Tukey honest significant difference (HSD) test(p<0.05). Results. Angular deviation results showed statistical significance between all contact points i...
STATEMENT OF PROBLEM Digital feedback for tooth preparation can provide dental practitioners with... more STATEMENT OF PROBLEM Digital feedback for tooth preparation can provide dental practitioners with more objective and accurate evaluations compared to conventional methods. PURPOSE This study aimed to evaluate the educational effect and satisfaction of digital feedback compared to those of the conventional putty index method for tooth preparation. MATERIAL AND METHODS Forty-eight third-grade dental students were selected. All students performed a full-coverage preparation on a right mandibular first molar resin tooth. They were randomly divided into four groups (n=12)-no guide (control), putty index, digital feedback, and digital and putty index assessment. Three-dimensional analysis was performed using an analysis software (GomInspect 2018, Gom) to evaluate the amount of tooth structure removed. At the end of the practice, the students completed a questionnaire to evaluate the educational satisfaction of the respective methods. RESULTS There was no statistical significance of the amount of preparation among groups in most of the measured areas only except for several specific points. Overall occlusal surface showed 0.99±0.27 mm in the N group (no guide) and 1.15±0.31 mm in the D group (digital feedback) and overall axial surface showed no statistical differences (p>0.05). The groups that used digital assessment showed a high level of satisfaction compared to conventional assessment. CONCLUSIONS It was difficult to confirm that the digital-based feedback promotes accurate tooth preparation compared to conventional feedback within the limitation of this study. However, it improved educational satisfaction and permitted objective evaluation.
Journal of Computational Design and Engineering, 2020
Few studies have examined the biomechanical effects of dental implant placement in the implant-su... more Few studies have examined the biomechanical effects of dental implant placement in the implant-supported mandibular advancement device (MAD) for the treatment of obstructive sleep apnea in completely edentulous patients. This biomechanical study aimed to evaluate the stability of the implant-supported MAD for different numbers and positions of dental implants. A 3D edentulous maxillofacial model with the one-piece MAD was considered for various numbers and positions of implants. On each mandible and maxilla, one, two, four, or six implants were placed symmetrically in various positions. Total 42 implant placements were considered. A static finite element analysis was performed under the mandibular posterior restorative force for 40% protrusion. The maximum and minimum principal stresses on the cortical and cancellous bones and the von Mises stresses on the implant were measured. When four implants were placed on each maxilla and mandible, the maximum average stress on the cancellous...
The design of the attachment must provide an optimum stress distribution around the implant. In t... more The design of the attachment must provide an optimum stress distribution around the implant. In this study, for implant overdentures with a bar/clip attachment or a locator attachment, the stress transmitted to the implant in accordance with the change in the denture base length and the vertical pressure was measured and analyzed. Test model was created with epoxy resin. The strain gauges made a tight contact with implant surfaces. A universal testing machine was used to exert a vertical pressure on the mandibular implant overdenture and the strain rate of the implants was measured. Means and standard deviations of the maximum micro-deformation rates were determined. 1) Locator attachment: The implants on the working side generally showed higher strain than those on the non-working side. Tensile force was observed on the mesial surface of the implant on the working side, and the compressive force was applied to the buccal surface and on the surfaces of the implant on the non-working...
Evaluating the cement space of various dental prostheses is important because it is related to th... more Evaluating the cement space of various dental prostheses is important because it is related to the stability and retention of the prosthesis. However, a method for evaluating an overall cement space is complex. The purpose of this technique was to simplify the evaluation of prosthesis cement space by using a digital scanner. The form and thickness of the cement space could be simply recognized in any section the clinician or dental researcher wishes. Moreover, the cement space of several dental prostheses for the same abutment could also be precisely evaluated by superimposition. The method can be applied to various prosthodontic treatments.
PURPOSE To evaluate the accuracy of superimposition of customized abutment library data onto scan... more PURPOSE To evaluate the accuracy of superimposition of customized abutment library data onto scanned abutment data according to the extent of the scanning area. MATERIALS AND METHODS A patient model was fabricated by a 3D printer (Probo, DIO Implant), and a customized abutment was fabricated using a four-axis milling machine (ARUM 4X-100, Doowon). The customized abutment library data were generated using a laboratory scanner (E3, 3Shape) for superimposition after intraoral scanning. A cone-shaped structure was embedded into the library data at the center of the connection part. The customized abutment was placed on the model, and the model was scanned using a laboratory scanner to produce reference data. Three different test group datasets were generated using intraoral scanner and computer-aided design software: (1) fully scanned customized abutment; (2) insufficiently scanned proximal surface; and (3) insufficiently scanned margin, assuming challenging intraoral conditions. The li...
PURPOSE This study examined a new 3D volumetric analysis method for the assessment of baseline-to... more PURPOSE This study examined a new 3D volumetric analysis method for the assessment of baseline-to-12-month changes of the soft tissue volume at early and immediately placed tapered implants after loading with ceramic single crowns. MATERIALS AND METHODS Eligible patients with one incisor, canine, or premolar to be extracted were included. The patients were divided randomly into early-placement or immediate-placement groups. Tapered implants (BLT, Institut Straumann) were placed after the extractions. In the early-placement group, the implants were placed 8 weeks after extraction. In the immediate-placement group, the implants were placed immediately after the extraction. All implants healed transmucosally, and the final crowns were inserted after healing (baseline). Impressions were made at screening, baseline, and 12 months after crown insertion (Permadyne, 3M). The casts were scanned (Imetric 4D) and aligned, and a superimposed area of interest (AOI) (labial/buccal aspects) was de...
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