Role of Computer Technology in Changing Smile

In the ever changing complex society, where success has become a mantra for both young and old, facial appearance that includes smile, plays a pivotal role. Among many attractive components in a person’s face, smile reflects the persona of an individual. In the present day next gen age, science in unison with technology and techniques which are rapidly getting ingrained into day to day dental practice, has changed the perception of healthy smile by more effective and less invasive approach. In this scenario, the onus lies on the dentist to give that perfectionist touch to a customised smile using computer aided software and hardware apparatus, and to avail the best state of the art material, equipment and techniques. Hence, it is imperative for us to understand and inculcate the role of modern cutting edge computer-aided technologies used in designing and changing the smile of an individual

Optical Coherence Tomography – Variations on a Theme

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Optical Coherence Tomography (OCT) has developed extensively over the last 23 years. This paper reviews some of the imaging techniques based on OCT with particular reference to the trade-offs between lateral and axial resolution, working distance, imaging depth, acquisition speed (enabling real time observation and 3D imaging), imaged area/volume, contrast enhancement – including velocity measurement, and system complexity – including detectors, light sources and the optical path. The majority of applications of OCT are biomedical, especially ophthalmology, endoscopy and intravascular imaging. However, some industrial applications are emerging particularly for non-destructive testing and quality control, such as in the production of MEMS devices, or the non-destructive detection of sub-surface strain fields in injected moulded polymer parts

Three Dimensional Printing: Modern Medical Applications

3-D printing is an additive printing process based on inkjet printing principles. Using this technology, a variety of materials can be used to create a three-dimensional product. Currently this technology is expensive, however it is slowly becoming more affordable. 3-D printing has the potential to change the future of medical model production and prototyping, due to the beneficial products it can produce. The objective of this research study is to discover the technological advancements in 3-D printing that could greatly affect several aspects of the medical industry. The areas discussed include high-risk surgery, dentistry, and prosthetics. After conducting six interviews with medical professionals, it was discovered that 3-D printing is a viable technological source that all professionals are eager to use and implement into their medical line of work. 3-D printing is a revolutionary technology that has the possibility to positively affect the work of medical professionals, while enhancing the lives of others

Comparison of digital scanning and polyvinyl siloxane impression techniques by DMD students : instructional efficiency and attitudes toward technology.

The aim of this research was compare the ability of dental students to learn an digital scanner (3M LAVA) and material-based (PVS) impression techniques and to determine attitudes and preferences towards each. D2 dental students (n=25) were recruited and instructed on the use of 3M LAVA and PVS techniques using three pedagogic methods: 1) video lecture (P1), 2) investigator-led demonstration (P2), and 3) independent clinical exercise (P3). The amount of time for each pedagogic method was measured, averaged (± s.d.) and compared using Wilcoxon Signed-Ranks tests. A pre- and post-test was administered assessing their attitudes towards both techniques using a Likert scale and compared using dependent t-tests. Instructional time for 3M LAVA was higher for each pedagogic method (P1; 15.95 vs.10.07 min, p=0.0000: P2; 8.68 vs. 4.51 min, p=0.000: P3; 20.37 vs.14.17, p=0.000). Prior to instruction, students were more familiar with the PVS techniques (3.96 vs. 1.95, p=.0000) and expected both to be similar in difficulty (3.52 and 3.84, p=.106). After instruction, PVS techniques were considered easier to perform than expected (4.08, p=.002) with no change in perceived difficulty for 3M LAVA (3.56, p=.106). 96% of participants expected 3M LAVA to become their primary impression technique in their career

Principles of the magnetic resonance imaging movie method for articulatory movement : a review

Magnetic resonance imaging (MRI) has become a critical tool for dental examination. MRI has many advantages over radiographic examination methods, including the lack of a requirement for patient exposure and the ability to capture high-contrast images of various tissue and organ types. However, MRI also has several limitations, including long examination times and the existence of metallic or motion artifacts. A cardiac imaging method using cine sequences was developed in the 1990s. This technique allows for analysis of heart movement and functional blood flow. Moreover, this method has been applied in dentistry. Recent research involving 3T MRI has led to the achievement of a temporal resolution of <10 ms, surpassing the frame rate of typical video recording. The current review introduces the history and principles of the cine sequence method and its application to the oral and maxillofacial regions

3종 구강스캐너의 정확도 비교 평가를 위한 비임상 연구

학위논문(석사) -- 서울대학교대학원 : 치과대학 치의과학과, 2023. 2. 임범순.As a result of the technological advances, digitalization is being applied in various areas of dentistry. As intraoral scanners are widely used for digital impression with the advantage of being easy to use and comfortable for patients, many studies are being conducted. However, new intraoral scanners with various mechanisms and characteristics are constantly pouring out, and comparative evaluation for clinical application is continuously needed. The purpose of this study is to evaluate and verify the performance of the intraoral scanner through trueness and precision comparison. In this study, trueness and precision are evaluated for the accuracy comparison of intraoral scanners (ISO 5725). The object was designed with the CAD software (SolidworksTM 2016, 3D Systems SolidWorks Corp., Waltham, MA, USA) and the model was fabricated from the NextDent C&B MFH (3D Systems, Rockhill, USA) using the 3D printer (NextDent 5100, 3D Systems, Rockhill, SC, USA). Inlay, Onlay and three-unit Bridge were produced by representing deep and narrow forms frequently used in clinical practice, and the same resin model was used in all experimental groups. Three types of intraoral scanners were evaluated: TRIOS 4® (3 Shape, Copenhagen, Denmark), I500 (Medit Co, Seoul, South Korea), COMFORT+ (DDS, Seoul, South Korea), and five scan data were obtained by the same trained researcher for consistency. The acquired data was superimposed with the reference data by the 'best-fit alignment' of the Geomagic Control XTM (3D Systems, Rock Hill, SC, USA) software, and the tolerance range was set to ±30μm for 3D comparison to calculate RMS (Root Mean Square). For comparison, the one-way ANOVA and Bonferroni t-test were performed with a significance level of 0.05. For trueness, the RMS values in the Inlay (36.32μm~37.22μm) model increased in the order of TRIOS4, COMFORT+, and I500, but the trueness tended to decrease. In Onlay (35.98μm~37.22μm) and three-unit Bridge (52.24μm~ 56.64μm) models, RMS values increased in order of I500, TRIOS4, and COMFORT+, but the trueness tended to decrease. But no significance was found between each scanner group on the All pairwise multi-analysis Bonferroni t-test (p>0.05). For precision, there was a significant difference between TRIOS4 and I500, I500 and COMFORT+ in the Inlay model (respectively p=0.027, p<0.001). In the Onlay and three-unit Bridge models, a significant difference was found between COMFORT+ and the remaining two intraoral scanners (TRIOS4, I500). Trueness and precision are lowered if the optimal distance between the scanner and the model is not maintained due to the narrow and deep part such as a three-unit bridge or the insufficient space between the units. Thus, errors tend to accumulate when the scan range increases. This study provides accuracy information on intraoral scanners, contributing to decision making it offer a view on which intraoral scanners is appropriate for use.본 연구에서는 최근 소개된 구강스캐너의 진실도 (trueness) 및 정밀도 (precision) 비교를 통해 스캐너 자체 정확도 (accuracy) 등의 성능에 대하여 평가하고 검증하고자 하였다. ISO 5725를 참고하여 구강스캐너의 정확도 비교를 위해 진실도 및 정밀도를 평가하였다. 진실도는 모델스캐너로 측정한 참조 데이터에 대하여 구강스캐너로 측정한 비교 데이터 간의 차이를 나타내는 값이며, 정밀도는 3 종류의 구강스캐너를 이용해 반복하여 얻은 데이터를 서로 중첩하여 얻은 오차 값이다. CAD 소프트웨어인 Solidworks 2016TM (Dassault Systèmes SolidWorks Corp., Waltham, MA, USA) 으로 모델을 설계하였고, NextDent C&B MFH (3D Systems, RockHill, SC, USA) 3D 프린팅 레진으로 NextDent 5100 (3D Systems, RockHill, SC, USA) 3D 프린터를 이용하여 모델로 제작하였다. 임상에서 자주 쓰이는 깊고 좁은 형태 등을 재현하여 인레이, 온레이 및 3본-브릿지 모델을 제작하였으며, 모든 실험군에서 동일한 레진 모델을 사용하여 제품 비교 평가에 용이하였다. 또한, 본 논문에서는 TRIOS4 (3 Shape, Copenhagen, Denmark), I500 (Medit Co, Seoul, South Korea), COMFORT+ (DDS, Seoul, South Korea) 3가지 종류의 구강스캐너를 평가하였는데, 일관성을 위해 숙련된 동일한 연구자에 의해 각각 5개의 스캔 데이터를 채득하였다. 채득된 데이터는 Geomagic Control XTM (3D Systems, RockHill, SC, USA) 소프트웨어의 최적 적합 중첩법(베스트-핏 정렬)을 통해 참조 데이터와 중첩하였고, 3D 비교 시 허용범위는 ±30μm으로 설정하여 RMS (Root Mean Square) 를 산출하였다. 진실도와 정밀도 비교를 위해 유의수준 0.05를 기준으로 일원분산분석, Bonferroni test로 통계 분석하였다. 진실도의 경우, 인레이 모델에서 RMS 값은 36.32μm~37.22μm에 걸쳐 TRIOS4, COMFORT+, I500 순으로 커지며 진실도가 낮아지는 경향을 보였다. 온레이와 3본-브릿지 모델에서 RMS 값은 각각 35.98μm~37.22μm와 52.24μm~56.64μm를 보였으나, 일원분산분석 후 다중비교분석 Bonferroni t-test에서 모든 모델에 있어 구강스캐너 종류에 따른 진실도 값의 유의한 차이는 발견되지 않았다. 정밀도의 경우, 인레이 모델에서 TRIOS4와 I500, I500과 COMFORT+간 유의한 차이가 있었으며 (각각 p=0.027, p<0.001), 온레이와 3본-브릿지 모델에서는 COMFORT+와 나머지 두 종류의 구강스캐너 (TRIOS4, I500) 사이에서 유의한 차이를 발견하였다. 결론적으로, 3본-브릿지와 같이 폭이 좁고 깊은 부분을 포함하고, 구성 단위(unit) 사이 간격이 좁아 스캐너와 모델 간의 최적의 거리가 확보되지 않을 경우 진실도와 정밀도는 낮아진다. 더하여, 스캔의 범위가 넓어질수록 오차는 축적되어 정확도는 감소하게 된다. 본 연구를 통해 구축된 실험 데이터를 기반으로 임상에서 적절한 구강스캐너의 선택 및 스캔 전략에 도움되고자 하였다.Ⅰ. INTRODUCTION 1 Ⅱ. MATERIALS AND METHODS 10 Ⅲ. RESULTS 16 Ⅳ. DISCUSSION 22 Ⅴ. CONCLUSIONS 30석

Assessment of 3D Facial Scan Integration in 3D Digital Workflow Using Radiographic Markers and Iterative Closest Point Algorithm

Introduction: Integration of 3 dimensional (3D) facial scanning into digital smile design workflows has been made available in multiple commercially available systems. Limited data exists on the accuracy of facial scans and accuracy of various methods of merging facial scans with cone beam computed tomography (CBCT) scans.Objective: The purpose of this prospective clinical study was to evaluate the accuracy of 2 methods used to integrate soft tissue facial scans with CBCT scans. It would allow proposal of a novel approach for integrating a 3D facial scan using facial radio-opaque markers in a 3D digital workflow.Material and methods: Fifteen CBCT and 3D face scans were obtained from patients who were undergoing treatment at MUSoD. A DICOM with RO markers and 3 STL data files from the facial scans were obtained for each patient. These files were superimposed using Exocad software. Accuracy of superimpositions was evaluated by measuring distances between RO markers on DICOM and STL data. The obtained dataset was analyzed using the paired t-test. Results: The results showed that the mean values for the 6 subsets, merging through the ICP algorithm, were 1.47-2mm. However, when merged by RO markers, the mean valuewas 0.14mm. Using a paired t-test, the novel RO points method was statistically more accurate than ICP algorithm method (