FIBER REINFORCED COMPOSITE AND METHODS OF FORMING THE SAME

EP1590150B1Granted Paten

Graphic Processing Units (GPUs)-Based Haptic Simulator for Dental Implant Surgery

This paper presents a haptics-based training simulator for dental implant surgery. Most of the previously developed dental simulators are targeted for exploring and drilling purpose only. The penalty-based contact force models with spherical-shaped dental tools are often adopted for simplicity and computational efficiency. In contrast, our simulator is equipped with a more precise force model adapted from the Voxmap-PointShell (VPS) method to capture the essential features of the drilling procedure, with no limitations on drill shape. In addition, a real-time torque model is proposed to simulate the torque resistance in the implant insertion procedure, based on patient-specific tissue properties and implant geometry. To achieve better anatomical accuracy, our oral model is reconstructed from cone beam computed tomography (CBCT) images with a voxel-based method. To enhance the real-time response, the parallel computing power of GPUs is exploited through extra efforts in data structure design, algorithms parallelization, and graphic memory utilization. Results show that the developed system can produce appropriate force feedback at different tissue layers during pilot drilling and can create proper resistance torque responses during implant insertion

A Study of Success Rate of Miniscrew Implants as Temporary Anchorage Devices in Singapore

Objective. To find out the success rate of miniscrew implants in the National Dental Centre of Singapore (NDCS) and the impact of patient-related, location-related, and miniscrew implant-related factors. Materials and Methods. Two hundred and eighty-five orthodontic miniscrew implants were examined from NDCS patient records. Eleven variables were analysed to see if there is any association with success. Outcome was measured twice, immediately after surgery prior to orthodontic loading (T1) and 12 months after surgery (T2). The outcome at T2 was assessed 12 months after the miniscrew’s insertion date or after its use as a temporary anchorage device has ceased. Results. Overall success rate was 94.7% at T1 and 83.3% at T2. Multivariate analysis revealed only the length of miniscrew implant to be significantly associated with success at both T1 (P=0.002) and T2 (P=0.030). Miniscrew implants with lengths of 10–12 mm had the highest success rate (98.0%) compared to other lengths, and this is statistically significant (P=0.035). At T2, lengths of 10–12 mm had significantly (P=0.013) higher success rates (93.5%) compared to 6-7 mm (76.7%) and 8 mm (82.1%) miniscrew implants. Conclusion. Multivariate statistical analyses of 11 variables demonstrate that length of miniscrew implant is significant in determining success

A Study of Success Rate of Miniscrew Implants as Temporary Anchorage Devices in Singapore

Objective. To find out the success rate of miniscrew implants in the National Dental Centre of Singapore (NDCS) and the impact of patient-related, location-related, and miniscrew implant-related factors. Materials and Methods. Two hundred and eighty-five orthodontic miniscrew implants were examined from NDCS patient records. Eleven variables were analysed to see if there is any association with success. Outcome was measured twice, immediately after surgery prior to orthodontic loading (T1) and 12 months after surgery (T2). The outcome at T2 was assessed 12 months after the miniscrew's insertion date or after its use as a temporary anchorage device has ceased. Results. Overall success rate was 94.7% at T1 and 83.3% at T2. Multivariate analysis revealed only the length of miniscrew implant to be significantly associated with success at both T1 ( = 0.002) and T2 ( = 0.030). Miniscrew implants with lengths of 10-12 mm had the highest success rate (98.0%) compared to other lengths, and this is statistically significant ( = 0.035). At T2, lengths of 10-12 mm had significantly ( = 0.013) higher success rates (93.5%) compared to 6-7 mm (76.7%) and 8 mm (82.1%) miniscrew implants. Conclusion. Multivariate statistical analyses of 11 variables demonstrate that length of miniscrew implant is significant in determining success

Tobacco Mosaic Virus as a Gene Editing Platform

Plant viruses can be engineered and utilized as transient tools for foreign gene overexpression studies and large-scale production of high value proteins. Tobacco mosaic virus (TMV) has been widely used for these purposes. One such example is the efficient agroinfiltratable TMV-based overexpression (TRBO) vector, a coat protein deletion mutant of TMV. The CRISPR/Cas9 gene editing system involves two main components, a single guide RNA (sgRNA) and a Cas9 endonuclease that, as a complex, creates double-stranded breaks to a complementary DNA sequence. Previously, our group used the TRBO vector to express both a green fluorescent protein (GFP) and a biologically active sgRNA (TRBO-G-3′gGFP) in Nicotiana benthamiana. Here, TRBO-based delivery tools were further developed as gene-editing platforms and as a transient approach to study plant gene expression and function. First, two separate TRBO vectors were utilized to transiently express high levels of Cas9, and for delivery of a sgRNA which targets the mgfp5 gene (gGFP) in the N. benthamiana GFP-expressing line 16c. The engineered Cas9-expressing TRBO vector (TRBO-HcoCas9) was able to express a biologically functional protein, despite the large insert size (~4.2 kb). The addition of P19, an RNA silencing suppressor protein of Tomato bushy stunt virus, to the co-delivery of TRBO-HcoCas9 and TRBO-G-3'gGFP resulted in higher levels of Cas9 protein and increased indel (insertions and deletions) percentages in planta. Additionally, Cas9 protein levels were improved by the RNA silencing suppressor activity of the TMV P126 replicase complex. This study also revealed an age-related resistance phenomenon in plants influencing the performance of P19 in the RNA silencing machinery, whereby P19 works more efficiently in older plants. Lastly, I combined both Cas9 and the gGFP in a single delivery vector that resulted in gene editing events. My system demonstrates the potential of virus vectors to rapidly create non-transgenic knockout plants for functional plant genomics and proteomics

Tobacco Mosaic Virus as a Gene Editing Platform

Plant viruses can be engineered and utilized as transient tools for foreign gene overexpression studies and large-scale production of high value proteins. Tobacco mosaic virus (TMV) has been widely used for these purposes. One such example is the efficient agroinfiltratable TMV-based overexpression (TRBO) vector, a coat protein deletion mutant of TMV. The CRISPR/Cas9 gene editing system involves two main components, a single guide RNA (sgRNA) and a Cas9 endonuclease that, as a complex, creates double-stranded breaks to a complementary DNA sequence. Previously, our group used the TRBO vector to express both a green fluorescent protein (GFP) and a biologically active sgRNA (TRBO-G-3′gGFP) in Nicotiana benthamiana. Here, TRBO-based delivery tools were further developed as gene-editing platforms and as a transient approach to study plant gene expression and function. First, two separate TRBO vectors were utilized to transiently express high levels of Cas9, and for delivery of a sgRNA which targets the mgfp5 gene (gGFP) in the N. benthamiana GFP-expressing line 16c. The engineered Cas9-expressing TRBO vector (TRBO-HcoCas9) was able to express a biologically functional protein, despite the large insert size (~4.2 kb). The addition of P19, an RNA silencing suppressor protein of Tomato bushy stunt virus, to the co-delivery of TRBO-HcoCas9 and TRBO-G-3'gGFP resulted in higher levels of Cas9 protein and increased indel (insertions and deletions) percentages in planta. Additionally, Cas9 protein levels were improved by the RNA silencing suppressor activity of the TMV P126 replicase complex. This study also revealed an age-related resistance phenomenon in plants influencing the performance of P19 in the RNA silencing machinery, whereby P19 works more efficiently in older plants. Lastly, I combined both Cas9 and the gGFP in a single delivery vector that resulted in gene editing events. My system demonstrates the potential of virus vectors to rapidly create non-transgenic knockout plants for functional plant genomics and proteomics

Early palatal shape change in infants with complete unilateral cleft lip and palate

Ph.DDOCTOR OF PHILOSOPH

3D printed twin block: A feasibility study

Aims: Twin blocks are appliances used for Class II skeletal discrepancies, where the lower jaw is positioned more posteriorly compared to the upper. The conventional method of fabrication of this appliance is tedious and labour-intensive; hence this study intends to explore the feasibility of a digital workflow to three-dimensionally (3D) print them. Methods: Three sets of twin blocks, identical except for amount of offset (0.0 mm, 0.1 mm and 0.2 mm), were designed and 3D printed for 5 anonymized scans of patients with Class II skeletal discrepancies. The intaglio surfaces of the 0.0 mm offset twin blocks were scanned and superimposed onto their original computer-aided-design files. The resultant colour maps, root mean square (RMS) deviations, and percentage in-tolerance values at thresholds of 0.1 mm and 0.2 mm were assessed. The fit and retention of all twin blocks were assessed on their 3D printed models via a fit and retention score (FRS). Results: The median RMS deviation was 0.10 mm; percentage in-tolerance values at thresholds of 0.1 mm and 0.2 mm were 79.90%, and 94.51%. Printing deviations occurred most often at labial and incisal edges anteriorly, and buccal and occlusal surfaces posteriorly. There was no significant difference between the total FRS for the three groups (p = 0.076). However, the frequency of satisfactory scores for upper fit (p = 0.049), lower fit (p = 0.018), upper retention (p = 0.038) and lower retention (p = 0.015) differed significantly between the three groups. Conclusion: This study demonstrated the viability of a digital workflow to 3D print twin blocks. Print accuracy was satisfactory, with 0.1 mm offset providing the best fit and retention