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http://hdl.handle.net/10722/1022
2024-03-19T05:28:53ZApplication of silver diamine fluoride (SDF) solution versus atraumatic restorative treatment (ART) restoration in treating dentine caries lesions in primary teeth
http://hdl.handle.net/10722/341606
Title: Application of silver diamine fluoride (SDF) solution versus atraumatic restorative treatment (ART) restoration in treating dentine caries lesions in primary teeth
Authors: Chan, Wai Ling; 陳慧玲
Abstract: OBJECTIVE:
The objective of the randomized clinical trial of the PhD research was to compare the effectiveness and cost of using a non-restorative approach by application of silver diamine fluoride (SDF) solution and a minimally invasive restorative approach by placement of fillings using atraumatic restorative treatment (ART) in treating cavitated caries lesions in the primary teeth of preschool children in Hong Kong.
MATERIAL AND METHODS:
Preschool children with cavitated dentine caries were recruited in kindergartens in Hong Kong and were randomized for treatments for the caries lesion using either biannual application of SDF solution or placement of ART restoration. Questionnaires were completed by parents to assess the oral health related quality of life (OHRQoL) of the children, as well as the parents’ acceptance of the study treatments for their child’s decayed teeth. Biannual follow-ups were carried out to evaluate the success of treatments in both study groups. The short-term and long-term rates of success of the treatment of carious lesions in the primary teeth, defined as no symptoms from the treated tooth, no active caries and no need for further treatment, in the two groups were compared. The OHRQoL of children treated by ART and SDF treatments, and parental acceptance of the two treatments were also compared.
RESULTS:
A total of 426 preschool children, aged 3 to 4 years, were recruited and treated at baseline. There were no significant differences in the socio-demographic background and baseline status, as well as caries experience, OHRQoL, oral hygiene and snacking habits between the two groups at baseline. At the 6-month follow-up, the overall success rate of treatment in the SDF and ART groups were 83.9% and 60.7%, respectively (p<0.001). At the 24-month follow-up, the overall success rate of treatment in the SDF and ART groups were 71.1% and 28.5%, respectively (p<0.001). Moreover, there were no significant differences in the child’s OHRQoL as well as parental acceptance of treatment, between the two study groups at the 24-month follow-up. The cost of providing biannual application of SDF was lower than the placement of ART fillings.
CONCLUSIONS:
It can be concluded that SDF treatment has superior clinical outcomes compared to ART restorations, both in short term and long term, and can be used to effectively manage cavitated dentine caries lesions in the primary teeth of preschool children. Parental acceptance of the two treatments, as well as the OHRQoL of children treated by either of the treatments, do not differ significantly. The cost of treatment is lower for the provision of biannual SDF solution application.2024-01-01T00:00:00ZCreation of virtual dental patients and the use of artificial intelligence in tooth replacement
http://hdl.handle.net/10722/341593
Title: Creation of virtual dental patients and the use of artificial intelligence in tooth replacement
Authors: Lam, Walter Yu Hang; 林宇恒
Abstract: This thesis is composed of 9 chapters exploring 2 research directions. The first one was creating a Virtual Patient Model (VPM), including the determination of the maxilla position within a three-dimensional (3D) face, the hinge axis of the temporomandibular joint, and the ideal camera setting for capturing tooth color. The second direction reviewed the use of Artificial Intelligence (AI) in prosthodontics, developed a protocol for training and validating an AI system, and conducted two preliminary studies investigating the feasibility of the AI system.
Chapter 1 is an introduction and provides a general overview of this thesis. Chapter 2 is a systematic review performed to determine Computer-Aided Design and Computer-Aided Manufacturing (CAD-CAM) techniques for the fabrication of digital complete dentures and their outcomes. From the 39 papers finally reviewed, the occlusal error was commonly seen with no consensus on methods of jaw registration found.
Chapter 3 determined the accuracy of transferring a digital scan of maxillary teeth into a 3D face recorded by 3D stereophotogrammetry by using a virtual facebow. This is the first step in the creation of VPM. Forty-seven patients were recruited and the accuracy of the teeth-and-face reference relationship in VPM was found to be relatively small (<2 mm) when compared to that of the cone-beam computed tomography.
n Chapter 4, a study was conducted to predict the hinge axis of casts mounted on an articulator by scanning two different jaw relationships, teeth closed and teeth slightly apart, and from this calculating the rotational center of the hinge axis. The estimated hinge axis discrepancy was found <5 mm when compared with the hinge axis of the articulator.
In Chapter 5, a study was performed to investigate the accuracy of color captured by different settings of a professional Single-lens Reflex (SLR) camera and a smartphone camera. Compared with the spectrophotometer, the SLR camera has better color accuracy than a smartphone camera.
Chapter 6 is a narrative review of the usage of AI in prosthodontics and Chapter 7 aims to develop a protocol for training and validating a novel AI system for designing dental prostheses.
In Chapter 8, two preliminary studies investigated the use of AI in designing biomimetic occlusal surfaces of maxillary first molar dental prostheses by learning the features of adjacent remaining teeth. In the first study, 10 AI-designed dental prostheses were mixed and matched to their original natural teeth. The chance of the correct match was 1/10 for each pair. The result is promising with over 60% correct matching. The second study was a comparison of tooth morphology between dental prostheses designed by CAD software (Control) and by AI. The differences from the original teeth, in terms of median Hausdorff distance, AI-designed dental prostheses was 0.366 mm, while that of CAD-designed dental prostheses was 0.304 mm.2023-01-01T00:00:00ZThe use of sealants and fluoride varnish in preventing early childhood caries
http://hdl.handle.net/10722/341586
Title: The use of sealants and fluoride varnish in preventing early childhood caries
Authors: Lam, Phoebe Pui Ying; 林珮盈
Abstract: Early Childhood Caries (ECC) is a completely preventable disease but still affecting around half of the preschool children worldwide. ECC often results in pain and infections, which significantly depreciate the children’s quality of life and overall wellbeing. The susceptibility of dental caries varies among children and teeth, and more target-specific and cost-effective caries-preventive measures are essential to combat the problem.
Systematic reviews and meta-analyses conducted in this thesis identified children with existing caries, poor oral hygiene and lower parental education attainment being more susceptible to future caries increment in their primary dentition. The consequence of ECC can be profound and lasting as children with ECC were shown to be 3 times more likely to develop caries in their mixed and permanent dentitions.
Among all primary teeth, the primary second molars (PSMs) have the longest service life for around 10 years. However, they are very vulnerable to caries as their occlusal fissures favour plaque accumulation. A meta-evaluation was performed as part of the thesis to evaluate different fissure sealants and preventive interventions to prevent occlusal caries in molars. Resin-based sealant (RBS) was found to be an effective and cost-saving preventive measure for permanent molars, but a clinically- and cost-effective treatment for the primary molars among preschool children is yet to be identified.
A randomised controlled trial was conducted to compare the clinical efficacies of 5% sodium fluoride varnish (NaFV) and glass-ionomer sealant (GIS) in preventing occlusal caries at PSMs. The cost effectiveness, children behaviours and acceptance towards these two preventive interventions were also evaluated. A total of 736 children were recruited from 18 kindergartens and randomised into either Group 1- receiving NaFV quarterly, or Group 2 - single placement of GIS at baseline. Interventions were performed on 1431 and 1264 PSMs, respectively. The primary outcome was the prevalence of dentinal caries developed at the occlusal surfaces of PSMs over time. By 18 months, 542 children with 1664 PSMs were reviewed. Despite a low GIS retention rate of 5.2% by 18 months, only 12.1% of PSM in GIS group developed dentinal occlusal caries. No significant difference was identified when compared to the proportion of occlusal dentinal decay among PSMs in the NaFV group (15.2%). Regression analysis with GEE revealed that only household income, baseline caries dft scores and plaque levels had a significant influence in the caries progression.
Further cost minimisation analysis suggested that single-placement of GIS is more cost-effective than quarterly-applied NaFV in prevention of occlusal caries. The children’s behaviours changed markedly within and between groups. Bivariate analyses at the 3 review timepoints consistently identified the child past anxiety and cooperation levels being the sole factors influencing their behaviours and cooperation towards upcoming dental examination and preventive treatments.
Quarterly-applied NaFV and single-placement of GIS demonstrated similar clinical efficacies in occlusal caries prevention among preschool children. However, GIS had a lower direct cost and thus being more cost-effective. Further research is required to forage a clinically- and cost-effective treatment to prevent occlusal caries among preschool children, and enhance children’s cooperation and behaviours.2024-01-01T00:00:00ZThe role of neurovascular formation in dental pulp regeneration
http://hdl.handle.net/10722/341575
Title: The role of neurovascular formation in dental pulp regeneration
Authors: Basabrain, Mohammed Sameer M
Abstract: The dental pulp is a highly vascularized and innervated connective tissue located within the root canal space, encased by impermeable root canal walls. These walls restrict blood supply via a single apical opening. In cases where pulp infection or inflammation arises due to caries, dental trauma, or operative procedures, it could develop into irreversible pulpitis or pulp necrosis. Traditionally, damaged pulp is removed and replaced with synthetic materials. Recently, regenerative endodontic procedures (REPs) have been implemented clinically with a high success rate. However, histological assessments reveal that the newly formed tissue primarily comprises cellular cementum, osseous-like, and periodontal-like tissues rather than actual dentin/pulp complex. Pursuing innovative regenerative strategies to reproduce natural functional pulp-like tissue is crucial in endodontic research. Recognizing that neurovascular niches can incite mesenchymal stem cell (MSC) proliferation and differentiation and encourage their involvement in pulp tissue repair and regeneration, integrating angiogenesis/vasculogenesis and neurogenesis is advantageous for dental pulp regeneration. Stem cells from the apical papilla (SCAPs) are recognized for their multipotency and ability to differentiate into neuronal, endothelial, and smooth muscle cells. These attributes make them a potential singular source of cells for pulp angiogenesis and neurogenesis. Therefore, the objectives of this project are to: (1) optimize methods for neuronal cell differentiation from SCAPs; (2) evaluate the neuroregenerative potential of neuronally induced SCAP (iSCAP) spheroids under various microenvironments in a pulp-on-chip system; (3) explore iSCAP spheres, human umbilical vascular endothelial cells (HUVECs), and SCAPs interactions on neurogenesis and vasculogenesis.
Three studies, accompanied by a scoping review, have been concluded. The initial study assessed whether forming 3D spheres could enhance SCAP neurogenic potential. The subsequent research used a pulp-on-chip system to explore the neuroregenerative potential of SCAP-derived neuronal cell spheroids under various microenvironments. The final study investigated the interactions between neuronally induced SCAP (iSCAP) spheres, SCAPs, and HUVECs, focusing on vasculogenesis and neurogenesis.
From the scoping review, several conclusions were drawn: dental spheres possess great potential in neural regeneration; using multiple assays and associated characterizations provides a better understanding of the mechanism of sphere enhancement on dental stem cell neural differentiation; in vivo, studies are essential for validating the treatment for neurodegenerative diseases. Our in vitro studies concluded that the formation of 3D spheres enhances the neurogenic potential of SCAPs, illustrating the benefits of using 3D SCAP spheres for treating neural diseases. Furthermore, local microenvironments play a critical role in regulating the neuroregenerative potential of SCAP-derived neuronal spheroids. Lastly, spheres formed by iSCAP interact with SCAPs and HUVECs, facilitating vasculogenesis and neurogenesis.
In conclusion, SCAPs are a valuable source for neural regeneration. SCAP neural potentials could be enhanced by sphere formation and are meticulously regulated by the surrounding local microenvironments. Co-culturing iSCAP spheres with SCAPs and HUVECs could promote vasculogenesis and neurogenesis, which holds a promising potential for advancements in regenerative endodontics.2023-01-01T00:00:00Z