Magister Scientiae Dentium - MSc(Dent) (Restorative Dentistry)

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Fracture resistance of endodontically treated maxillary premolars restored with horizontal glass fiber post: An in vitro and finite element analysis
(University of the Western Cape, 2022) Abdulrab, Saleem; Geerts, Greta
Maxillary premolars are subjected to a combination of vertical and lateral occlusal forces. Furthermore, premolars present with an anatomical shape and unfavorable crown to root ratio, making them more prone to fractures than other posterior teeth. When endodontic treatment is combined with mesio-occluso-distal (MOD) cavities, the susceptibility to fracture increases.
Comparison between immediate and conventional implant loading for fixed and removable prosthesis
(University of the Western Cape, 2022) Palanyandi, Celeste; Khan, Saadika
Literature states that different loading systems have been explored; and are used depending on the clinical situation. The success with each of these systems also differs with regards to quality of bone, the length and diameter of an implant, whether the implant is placed anteriorly or posteriorly, as well as number of implants inserted. This thesis will focus on these aspects to better guide clinical decision makers and practitioners on deciding which loading system can be best suited for the patient. Different types of loading systems include immediate, early, and conventional dental loading. Immediate loading refers to a prosthesis being attached to an implant within 24 hours.
Accuracy in reproduction of bounded edentulous saddle areas using different cast fabrication methods: A comparison
(University of the Western Cape, 2022) Essa, Ameera Yusuf; Farao, Warren
A common patient-request when presenting to restorative clinicians is replacement of missing teeth either by means of a fixed partial denture (FPD) or a removable partial denture (RPD). For decades, dental casts have been fabricated via the conventional cast fabrication technique which presents with its own set of disadvantages. To address these disadvantages, digital cast fabrication has been presented as an alternative. This is done via intraoral scanning and subsequent three-dimensional (3D) printing of dental models. However, the stitching process in intraoral scanning can be inadequate for areas lacking adequate geometry, such as edentulous saddle areas.
The effect of different types of smoking on teeth and nanocomposites
(University of the Western Cape, 2022) Ibrahim, Yasmin; Khan, Saadika
Tobacco is one of the most notoriously misused psychoactive substances among the world's rural and urban populations (Omare et al., 2021). WHO reported that more than eight million individuals die every year from tobacco use (WHO, 2019). This number is predicted to rise to ten million deaths by 2031 (Nidhi and Singh, 2019). Smoking tobacco has increased, and new consumption methods become a trend amongst young people (Pisinger and Døssing, 2014).
A laboratory evaluation of conventional chemically activated and microfilled light activated composite restorative resins
(University of the Western Cape, 1986) Joseph, Vincent Phillip; Retief, Hugo
The purpose of this study was to evaluate in vitro, the tensile bond strengths of some conventional and light cured resins, to study the effects of etchants on polished and ground enamel using the scanning electron microscope, and to the resin/etched enamel examlne electron interface by scanning microscopy This study was divided into: 1) laboratory tensile bond strength study of 'four composite resin materials. 2) a scanning electron microscopic study of the effect of four etchants on enamel. 3) the S.E.M. examination of the interfacial zone after the application of a demineralizing agent. The tensile bond strength study consisted of testing the bond strengths of two macrofilled and two microfilled resins in common use. These resins were applied directly to the etched enamel surfaces of extracted human teeth by utilizing newly developed perpex stubs which allowed a uniform surface area and for light curing of the resin. In this laboratory study the extracted teeth and the composite filled stubs were stressed to failure of the material bond to tooth in an Instron Machine. Bond strengths were recorded and tabulated in Newtons/mm2. The application of statistical analysis by Analysis of Variance and Duncans Multiple Range Test showed that there was a significant difference in the bond strengths of some of the four materials. The scanning electron microscope study consisted of an examination of etched enamel, either polished or ground using the etchants supplied by the two manufacturers i.e. 3 M Dental Company and J&J Dental Company. The interfacial zones of the resin/tooth interface systems were examined, using the two macrofilled and the two microfilled resijs in the stUdY.! Differences were found to exis.t at this zone.
A Clinical Study to Determine the Factors That May Influence Results in Non-Surgical Endodontic Retreatments
(University of the Western Cape, 2010) Zolty, Gary; Saayman, Charlene
When faced with a failing or failed root treatment, the dentist must decide whether the tooth can be retreated and saved or extracted. The dentist's decision to retreat is often based on the x-ray presenting a failing root treatment. The dentist must be aware that there might be a number of factors that have contributed to the failure and which may preclude, following retreatment, a successful long term clinical function. The current study has been made to determine those factors that may influence the prognosis in order to assist the clinician in advising the patient of the best course of treatment. A literature review was made to determine and identify these factors and explain their relevance and influence on the healing process. The current study included identifying the factors described in the literature review and noting their influence on the prognosis following non-surgical retreatment. Retreatment of failed root treated teeth requires special knowledge and skill from the clinician in order to correct and manage the case. The current study was made in a clinical setting and compared results of retreatment with two types of rotary files on the market: progressive or variable taper (Pro Taper) with constant non-ISO 06 taper (K3). Clinical signs and symptoms were noted at the patient's presentation and following recalls at 1, 4 months and 1 year. The results were recorded and statistically analysed and the results were discussed. The results showed that out of 81 patients 10cases of retreatment were considered to have failed and 68 cases were considered to have been successful. Three patients did not return for their assessments and were therefore not considered in further results. There was a statistically significant (p<0.1 0) recording of deep periodontal pockets associated with teeth with failing root treatments (40%) and (13%) in the "Success" group. The two estimated proportions of "Sinus" present (60%) in the "Failure" group and 10% in the 'Success' group were significantly different (p<0.01). "Sinus present" in the "Success group" means in the initial clinical assessment before retreatment was initiated. The presence of a sinus at the One Year follow up signified a failure of the root retreatment (p<0.001). The two estimated proportions of "Occlusion" present (80% and 99%) in the "Failure" and "Success" group were significantly different (p<0.05). Therefore, teeth in "occlusion" were more within the "Success" group. 70% of those teeth that failed had pretreatment apical rarefactions of greater than 6mm diameter; whereas 76.5% of successful retreatments had areas less than 6mm diameter. The differences were significant according to Fisher's Exact Test (p<0.01). 44% of failed cases had areas of rarefaction described as "diffuse"; and 56% of failed cases had areas that were described as "well-defined". 95% of cases that were successful had areas described as "diffuse" and the rest were "welldefined". The differences between the success and failure categories were statistically significant (p<0.0 1). The two estimated proportions of "Post present" (0% and 31%) in the "Failure" and "Success" groups were significantly different (p<0.1 0). Therefore, the "Post was present" in many more cases within the "Success" group than in the "Failure" group. There was no difference between the Median "Crown/Root" ratios of the "Failure" (Median = 0.595) or "Success" groups (Median = 0.662) (Wilcoxon Test, p>O.10). Teeth with longer roots tend to lead to failure, however there was a considerable overlap between the distributions. Therefore the finding is that the Median length of the roots of the "Failures" is longer than that of the "Successes". (Wilcoxon Rank Sum Test, p-value = 0.0628). The results also indicated that previous short root filling preparation contributes to the final success of retreatment (Fisher Exact Test, p<0.05). There was a significant difference between the distribution of the "Failure" and "Success" (88.2%) groups (Fisher Exact Test, p
The restoration of the endodontically treated tooth: A review of the Literature. Supplemented by drawings and photographs of clinical cases taken by the author during operative procedures
(University of Stellenbosch, 1978) Orkin, Darel Alan; Orkin, Darel Alan
Many books, articles and reviews of this aspect of restorative dentistry have been published. An attempt has been made to correlate all the relevant material in order that a comprehensive review of most of the published literature could be presented under one cover. It is possible that certain aspects have been omitted, this would not have been deliberate but in a review of this nature every published article may not have been attainable.
Current prevalence and preferences for immediate loading of fixed completearch implant-supported prostheses: A survey among South African Prosthodontists
(University of Western Cape, 2021) Julyan, Jennifer; Maart, Ronel
Edentulism negatively impacts patients􀂶 quality of life. A fixed complete-arch implant-supported prosthesis is proven to restore function and aesthetics and is associated with high patient satisfaction. An immediate loading protocol can provide patient satisfaction in a shorter period, as the time between surgical implant placement and connection of a prosthesis is lessened. The many considerations involved in this type of treatment are either based on available evidence or the preferences of the clinicians themselves.
Antifungal and cytotoxic potential of green synthesized silver nanoparticles
(University of Western Cape, 2021) Klein, Widadh; Adam, Razia Z
The rate at which the population is ageing is much faster than in the past. An increase in age results in an increase in oral diseases. One of the most common types of oral diseases in the elderly are fungal infections caused by Candida albicans. It has been noted that drug resistance to fungal pathogens is developing into a serious threat to public health and healthcare systems worldwide. This has consequently led to the need to develop effective and innocuous treatment modalities. The purpose of this study was to explore the antimicrobial and cytotoxic potential of silver nanoparticles (AgNPs) synthesised from Berzelia lanuginose, Helichrysum cymosum, and Searsia crenata.
Ability of 5th year Students to Detect Early Interproximal Caries
(2021) Muzan, Abdalla; Khan, Saadika
Objective: The objectives of this study were to evaluate the diagnostic capability of 5th year students using digital imaging, conventional bitewing radiographs (BW), printed film on paper and to compare the results with the observers’ experience level to detect early interproximal caries lesions on radiographs. To map the literature in regards to different diagnostic methods that students use globally in dental clinics by conducting a scoping review. Methods: A cross-sectional study was conducted with senior dental students (Reg No: BM 19/9/8). Three digital radiographs were shown individually to the students on a screen, 3 bitewing radiographs and 3 printed films on paper were passed on individually to all students with a questionnaire; with a viewing time of 2 mins per radiograph; thus 9 radiographs in total were viewed. A control group consisting of specialists from both the Restorative and Radiology Departments had finalized the answers prior to conducting the study regarding the presence/absence of caries and its depth on all 3 different radiographic images. The answers recorded by students were divided into 5 categories, R0: Intact surface, R1: Radiolucency in outer half of enamel, R2: Radiolucency in inner half of enamel, R3: Radiolucency in outer half of dentin, and R4: Radiolucency in inner half of dentin. A protocol specific for the objectives of this study was developed according to the criteria for a scoping reviews. Relevant databases (Pubmed, Scopus, Ebscohost, Science Direct, Wiley Online Library and Cochrane Library) were searched to identify evidence which was restricted to the English language for the period 2015–2021. Results: Comparison using an Anova test on the 3 different diagnostic methods showed that the type of method used affects the presence detection and size measuring accuracy, where the P-value confirms a significant difference. The Prisma flow diagram showed a result of the most common methods for diagnosing interproximal caries happen to be visual examination and bitewing radiography. Conclusions: Senior dental students have shown good accuracy in detecting the presence of interproximal caries. Although the accuracy in detecting the size of carious lesions was poor.
Clinical evaluation of shade improvement after in-office vital bleaching
(University of the Western Cape, 2010) Salem, Yousef; Osman, Y. I.
Tooth discoloration has increased the demand by patients to pursue aesthetic treatment options. Bleaching is considered a conservative approach in performing an aesthetic treatment for discolored teeth; however colour rebound and post-operative sensitivity are among the adverse effects associated with vital bleaching. In-office bleaching systems employ the use of high hydrogen peroxide concentrations. The effects of in-office bleaching agents on the degree of colour change and the gender differences in relation to bleaching outcomes are questionable. Post-operative sensitivity can be considered a bleaching side effect and the number of patients that experience it is unknown. Aim: The aim of this study was to assess the outcome of an in-office vital bleaching technique. Objectives: The objectives of this study were to evaluate the degree of colour change after vital tooth bleaching using a 35% hydrogen peroxide gel (Yotuel® Special, Biocosmetics Laboratories, Spain), using a spectrophotometer (CM-2600d Konica, Minolta) to measure the colour change at each intervention during the bleaching process, to assess the post operative sensitivity during the first week of the intervention, to evaluate the patients' perception of the colour change and to compare it to the colour change (~E) expressed in numeric values and to investigate whether gender differences exist in relation to the outcome of the bleaching procedure. Materials and Methods: The maxillary anterior teeth of 22 patients comprising of 11 males and 11 females were. bleached with a 35% hydrogen peroxide gel (Yotuel® Special, Biocosmetics Laboratories, Spain). Pre-treatment readings of the two maxillary central incisors using a spectrophotometer (CM-2600d Konica, Minolta) were obtained. Subsequent readings were obtained after scaling and polishing, before bleaching (which was used as a baseline reading), immediately after bleaching, one week and one month postoperatively. Patients were requested to complete a form regarding postoperative tooth sensitivity and their colour perception toward the bleaching treatment. Results: The quantitative effect of the bleaching material on tooth colour showed an increase in L * values and a decrease in a* and b* values, the changes were significant (p values- 0.05) except for the mean value of b* one month after bleaching which was only significant between five and ten percent.
Effect of different resin cements on shear bond strength of CAD-CAM crowns fabricated from hybrid materials.
(University of the Western Cape, 2021) Zayed, Mona; Mpungose, Sandile
CAD/CAM crowns have become popular due to the many advantages associated with this technology. Optimal bonding adhesion is crucial for the durability of these indirect restorations and many factors influence this crucial step. Currently, there is no consensus or evidence-based guidelines on the best adhesion protocol for CAD/CAM crowns fabricated from hybrid materials. This study was aimed at investigating the influence of three types of resin cements on the shear bond strength of a hybrid CAD/CAM material in vitro.
In vitro antibacterial activity of three root canal sealers against Enterococcus Faecalis
(University of the Western Cape, 2020) Mukorera, Tafadzwa Fraderick; Ahmed, S
The goal of root canal treatment is to eradicate microorganisms in the root canal system of the tooth. However; it has been found that no method of tooth preparation is efficient in eliminating all microorganisms present in root canals. Therefore, obturation materials with anti-microbial properties are advantageous, so that any residual microorganisms in the root system of the tooth can be eliminated. Therefore, the aim of the study was to assess the antimicrobial effect of 3 endodontic sealers: Sealapex™, EndoREZ™ and Guttaflow bioseal™ against Enterococcus faecalis. The Direct Contact test was used to assess the antibacterial effect of the 3 sealers against E. Faecalis. Sample size was n=50 per sealer. The survival of bacteria was assessed by culturing aliquots of 100 μL onto Tryptic Soy Agar plates after 10-fold serial dilutions. After incubation for 24 hours at 37⁰C, colonies on the plates were counted, and the CFU/mL was calculated. The experiments were performed in triplicates. Testing after setting enabled the assessment of the antimicrobial activity of aged sealers after 7 days, 14 days, 21 days and 28 days. All 3 sealers displayed evidence of antibacterial activity against E. Faecalis with various degrees of antibacterial activity at day 0, 7, 14, 21 and 28. Antibacterial activity was displayed by all 3 sealers against E. Faecalis which will have an effect on entombed bacteria.
Retreatability of root canals obturated using a bioceramic sealer and gutta percha
(University of the Western Cape, 2020) Maronga, Godfrey Obaigwa; Saayman, C M
Statement of problem: Although bioceramic endodontic sealer cements offer various advantages over conventional zinc oxide-based and resin-based cements, questions have been raised about the ability to retreat root canals that have been sealed using these cements. Aims and Objectives: The aim of the study was to determine the retreatability of root canals sealed using a bioceramic calcium silicate-based sealer cement. The objectives were to determine the possibility of achieving working length and apical patency when obturation is done with the master GP placed at working length and when it is short by 3mm. The time it took to achieve these parameters when it was possible to achieve them was also determined. The role of XP Endo Finisher R, a supplementary retreatment file, in achieving working length and apical patency was also to be evaluated. However, this latter aspect was eliminated after the pilot study, when it was found not to have an effect in regaining working length and apical patency.
Green synthesised Zinc Oxide Nanoparticles and their antifungal effect on Candida albicans Biofilms
(University of Western Cape, 2020) Lyimo, Germana Vincent; Ajayi, Fanelwa
Candida albicans is a clinical fungal isolate that is most frequently isolated from different host niches, and is implicated in the pathogenesis of several fungal infections, including oral candidiasis. The pathogenesis and antifungal resistance mechanisms of Candida species are complex and involve several pathways and genes. Oral candidiasis incidence rates are rapidly increasing, and the increase in resistance to conventional antifungals has led to the need to develop innocuous and more efficacious treatment modalities. The purpose of this study was to explore a single pot process for phytosynthesis of zinc oxide nanoparticles (GZnO NPs) and to assess their antifungal potential.
The colour stability of various glass ionomer cements
(University of the Western Cape, 2019) Karjiker, Farzana; Moodley, Desigar; Khan, Saadika
Introduction: Together with bonding to both enamel and dentine, an ideal restorative material would display physical properties similar to that of natural tooth tissue and would not be prone to degradation as a result of the oral environment. This includes changes in colour. Glass ionomer technology has undergone many changes to its original chemistry since it was developed in the early 1970’s. In 1988 resin-modified glass ionomers were introduced and in 2008, nano-ionomers were introduced. As a result of the progression in material sciences and the use of more sophisticated techniques and methods in restorative dentistry, it is possible to accomplish much improved aesthetics and functional durability of a restoration, both anteriorly and posteriorly. However, for as long as aesthetic restorations have been available, and in spite of advances in material structure and performance, one of the greatest challenges facing clinicians still remains that aesthetic restorations have to be replaced relatively frequently as staining and discolouration is a common problem. Aim of the study: The aim of this study was to determine the stainability of four resin-modified glass ionomers and one glass ionomer cement when exposed to a staining broth. Objectives: To record any change in colour before and after exposing the sample with the staining broth using a spectrophotometer, to compare the stainability, to examine the depth of staining using a light microscope and to observe the particle size of the powder and the surface texture using Scanning Electron Microscopy of the four resin- modified glass ionomer cements and one glass ionomer cement. Materials and Methods: Four resin-modified glass ionomers (one nano-ionomer) and one glass ionomer (zinc-reinforced ionomer) were selected. All were shade A2, except for Vitremer™ which was not available in A2. 15 discs of each material were prepared. The discs were 15 mm in diameter and 2 mm in thickness. All the materials were handled and cured according to the manufacturers’ instructions. After curing, only one side of each disc was polished using Sof-Lex™ discs (3M ESPE, USA). The unpolished side of each disc was designated as a matrix finish. The specimens were all immersed in distilled water at 37 °C for one week. They were then immersed in a staining broth for a period of one week and readings were taken after a period of 2 hours, 4 hours, 8 hours, 24 hours and one week. Colour was read on each side of each disc at the indicated intervals with a spectrophotometer. The colour difference was calculated using the CIELAB colour co-ordinates. Sample discs were then sectioned to determine the depth of staining. An additional sample disc of each material was made for observation with the SEM and was therefore not stained. Also, an unmixed sample of each material was prepared for examination with the SEM. Results: In general, for all materials there was an increase in staining when assessed with the colour difference between the baseline colour and the 7 day reading. Ketac™ N100, showed the highest total colour change of 43.84 for the unpolished surface followed by Riva™ which showed the total colour change of 28.55 for the unpolished surface. This was similar to Fuji II LC® which had a total colour change of 28.16 for the unpolished surface. For Vitremer™, the total colour change increased to 18.07 for the unpolished surface. For the unpolished surfaces, ChemFil™ Rock showed the least colour difference from baseline to 7 days (ΔE*ab = 10.45), followed by Vitremer™ (ΔE*ab = 18.07). Both Fuji II LC® and Riva™ Light Cure showed similar colour change from baseline to 7 days for unpolished surfaces (ΔE*ab of 28.16 and 28.55 respectively). Ketac™ N100 showed the highest staining after 7 days in the staining broth with a colour difference of 43.84. For the polished surfaces, the colour change for Fuji II LC® was 25.72 which was similar to Riva™ Light Cure which was 22.44 and Ketac™ N100 which showed a colour change of 22.79 on the polished surface. ChemFil™ Rock showed the least colour change of 17.69 for the polished surface followed by Vitremer™ which showed a colour change of 23.63 for the polished surface. Thus, for both the unpolished and polished surfaces there was a similar staining pattern. Conclusion: In this study it was demonstrated that all products evaluated in this study showed some degree of staining when exposed to a staining broth when evaluated using the ΔE*ab CIELAB colour evaluation. Ketac™ N100 showed the highest colour change compared to the other materials, but the reason for this was not explored. Both Vitremer™ and ChemFil™ Rock showed similar patterns of staining.
Relationship of TMD diagnosis and self-reported biopsychosocial status of patients attending the TMD clinic
(University of the Western Cape, 2018) Ahmed, Omer Abdelrahim Sidig; Geerts, Greta
Background: This study aimed to investigate a possible relationship between the diagnosis of TMD and biographical, psychological and social status of patients. Materials and Method: All records of patients who attended the TMD clinic in the Mitchells Plain Oral Health Centre in the period from January 2015 to July 2018, and who were examined according to the DC/TMD protocol, were collected. All diagnostic observations, as well as their biographical, psychological and social data were recorded. Statistical analysis was performed by means of comparisons and association analysis among data to evaluate if there were any statistically relevant associations or differences.
An in-vitro evaluation of the efficacy of oral devices to remove dental biofilm from three prosthodontic materials
(University of the Western Cape, 2019) Ahmed, Omnia Abdelmoneim Khidir; Moodley, Desi
Introduction: The evolution of Dentistry witnessed an increase in fixed prostheses as opposed to removable ones. Zirconia (ZrO2) and Lithium disilicate (LDS) are becoming the material of choice in implant or tooth retained prostheses. Polyetheretherketone (PEEK) is a recent alternative as it is lighter and causes less wear of opposing retained teeth. Biofilm formation is a permanent daily struggle for patients as it can be found in nearly all surfaces exposed to the natural environment. Therefore, the interest in a new device capable of removing or reducing oral biofilm from fixed prostheses is increasing. Aquaflosser (AQ) and Waterpik (WP) are examples of these oral irrigating devices that were introduced to the dental market recently. They can be effective in removing dental biofilm from different surfaces. Purpose of study: The purpose of this study is to evaluate biofilm formation on three fixed dental substructures and to evaluate the efficacy of two oral irrigating devices on biofilm removal from these three substructures.
Influence of variations in ceramic thickness and bonding substrate on the fracture resistance of lithium disilicate restorations
(University of the Western Cape, 2017) van Lierop, Jean; Moodley, Desi
Restorative dentistry aims to replace lost or damaged tooth structure with durable and life-like alternatives. To accommodate the inherent limitations and weakness of the restorative materials, preparation techniques often require the sacrifice of healthy tooth structure to create enough restorative space. This can lead to weakening of the remaining tooth structure, with subsequent damage or catastrophic failure. When using indirect restoratives, the development of adhesive luting agents (adhesive cements) and stronger allporcelain restorations (lithium disilicate) has contributed to the development of “minimally invasive” preparation techniques and concepts such as cavity design optimization (CDO) and bio-substitution. With these techniques, resin materials are combined with ceramic restoratives in an attempt to not only produce strong restorations, but also increase the longevity of the remaining tooth. The clinician needs to therefore find the ideal preparation design that combine such materials to produces a clinically performing restoration while increasing the strength and longevity of the underlying tooth.
Nanoparticles as advanced treatment modalities to disinfect the root canal system
(University of the Western Cape, 2019) Ibrahim, Amir I.O.; Moodley, Desigar
Persistent root canal pathogens are one of the main causes of endodontic treatment failure. These pathogens are usually isolated in areas within the root canals that are inaccessible to mechanical instrumentation, chemical irrigants and medicaments resulting in incomplete sterilization of the root canal system. Furthermore, the development of resistant microbial species renders it difficult to disinfect the root canal system using commonly available root canal irrigants and intra-canal medicaments. Intra-canal medicaments are antimicrobial agents that are placed inside the root canal system in order to eliminate the remaining microorganisms that persist after mechanical instrumentation and irrigation. However, their antimicrobial efficacy is effective only against some of the root canal pathogens. Furthermore, the presence of tissue inhibitory factors such as dentine powder and serum albumine within the root canal system inhibits their antimicrobial activity. The use of nanoparticles as antimicrobial agents has recently attracted considerable attention especially in the medical field as a result of their unique antibacterial properties. These properties include their ability to use multiple mechanisms to eradicate microbial cells and their low potentiality to produce microbial resistance. Polymeric nanoparticles such as chitosan nanoparticles (Ch-Np) gained significant interest as a result of their biocompatible and antimicrobial properties. In medicine, several vehicles were designed to carry these antibacterial nanoparticles. Zeolites (Ze) are microporous crystalline hydrated sodium aluminosilicate material that is utilized in the chemical sciences as a carrier for various nanoparticles.

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