Comparing cytocompatibility of two fluoridecontaining solutions and two resin-based restorative m... more Comparing cytocompatibility of two fluoridecontaining solutions and two resin-based restorative materials-a pilot study.
Zenodo (CERN European Organization for Nuclear Research), Jun 26, 2019
Background: The Powder/Liquid Ratio (PLR) influence, and the literature regarding the handling an... more Background: The Powder/Liquid Ratio (PLR) influence, and the literature regarding the handling and physical properties of Glass Ionomer restorative materials (GIC) were investigated.
Zenodo (CERN European Organization for Nuclear Research), Jun 26, 2019
Background and Objective: Literature suggests the use of thinner indirect partial coverage restor... more Background and Objective: Literature suggests the use of thinner indirect partial coverage restorations. The purpose of this in vitro study was to evaluate the influence of cavity design optimisation and biosubstitution with various cuspal and fissure designs, for indirect lithium disilicate partial coverage restorations. The influence on the initial crack formation and subsequently the catastrophic fracture force were evaluated. Method: Forty molars were prepared and randomly divided into four test groups (A, B, C and D). Indirect partial coverage restorations were milled with different cuspal and fissure thicknesses of lithium disilicate ceramic. Group A (cusp 1; fissure 0.7 mm thickness) and group B (cusp 0.8; fissure 0.5 mm) received a composite restoration in the class I preparation additionally. Group C (cusp 1; fissure 1.7 mm) and group D (cusp 0.8; fissure 1.5 mm) had ceramic included in the class I cavity. The restored specimens were thermo-cycled and force application was completed with a Universal testing machine in two phases. Phase one was the determination of initial first crack formation with various pre-set forces. Phase two was the maximum catastrophic fracture force. Statistical analysis was completed with the Kruskal-Wallis test and confirmed by the Dunn-Sidak multiple comparison test (p < 0.05). Results: The catastrophic fracture force in group A (2460N) was significantly greater than group B (1523N), with no difference between group C (3142N) and group D (2591N). Conclusion: The cuspal thicknesses of 1 mm for indirect partial coverage restorations were advisable, with or without composite in the class I cavity.
Objectives: To compare the precision of two cephalometric landmark identification methods, namely... more Objectives: To compare the precision of two cephalometric landmark identification methods, namely a computer-assisted human examination software and an artificial intelligence program, based on South African data. Methods: This retrospective quantitative cross-sectional analytical study utilized a data set consisting of 409 cephalograms obtained from a South African population. 19 landmarks were identified in each of the 409 cephalograms by the primary researcher using the two programs [(409 cephalograms x 19 landmarks) x 2 methods = 15,542 landmarks)]. Each landmark generated two coordinate values (x, y), making a total of 31,084 landmarks. Euclidean distances between corresponding pairs of observations was calculated. Precision was determined by using the standard deviation and standard error of the mean. Results: The primary researcher acted as the gold-standard and was calibrated prior to data collection. The inter- and intrareliability tests yielded acceptable results. Variatio...
Gingival pigmentation, whether focal or diffuse, may be of aesthetic concern to patients and esta... more Gingival pigmentation, whether focal or diffuse, may be of aesthetic concern to patients and establishing the underlying aetiology of the pigmentation is essential to ensure that the correct management is performed.
The purpose of this in vitro study was to evaluate the influence of cavity design optimisation an... more The purpose of this in vitro study was to evaluate the influence of cavity design optimisation and biosubstitution with various cuspal and fissure designs, for indirect lithium disilicate partial coverage restorations.
Six methods were assessed to determine the extent of surface hardness improvement. The methods we... more Six methods were assessed to determine the extent of surface hardness improvement. The methods were: standard set as the control, pressure, high frequency, low frequency, heat and high frequency/heat. Surface microhardness was tested with a Vickers hardness tester (Zwick-Roell durometer, ZHV1/2 Micro-Vickers, Italy) at HV0.5 (500gf) load with a dwell time of 10 seconds. The glass ionomer used to assess the six methods was Chemfil Rock (DeTrey, Dentsply, Konstanz, Germany).
Journal of Dental Health, Oral Disorders & Therapy, 2017
Fissure sealants are recommended to be applied soon after the tooth eruption, mainly at the level... more Fissure sealants are recommended to be applied soon after the tooth eruption, mainly at the level of the first permanent molars. The additional benefits of the application of bioactive fissure sealant materials lies in the build-in functionality of these materials to chemical attack in oral cavity as well as additional antibacterial action.
Journal of Dentistry, Oral Disorders & Therapy, 2015
In any repair of a tooth with permanent restorative materials, the interface is always a sensitiv... more In any repair of a tooth with permanent restorative materials, the interface is always a sensitive region. The appearance of adhesive materials was a great step forward in dealing with the problems of this region and improving the overall performance of the restorations. However, contemporary adhesive materials do have a major disadvantage, namely that their durability is limited, a limitation which often arises due to their inadequate marginal adaptation. Restorative materials in the new era aim to be "bio-active" and longlasting.
International Journal of Dentistry and Oral Science, 2015
Nanodiamonds were first synthesized by Soviet scientists [13] in 1962 through the detonation of t... more Nanodiamonds were first synthesized by Soviet scientists [13] in 1962 through the detonation of trinitrotoluene (TNT) with hexogen (RDX) in a closed chamber. Today it can be prepared at room
R. MULDER, Restorative Dentistry, University of Western Cape, Cape Town, South Africa Objectives:... more R. MULDER, Restorative Dentistry, University of Western Cape, Cape Town, South Africa Objectives: To determine the total volumetric change and the relative speed of shrinkage of newly developed bulk fill flowable composites during polymerization. The possible effects of the different organic matrices and inorganic fillers on the polymerization shrinkage were also discussed. Methods: A specially designed electronic mercury dilatometer was used to determine the polymerization shrinkage. The mercury dilatometer has a computer that measures and stores the polymerization readings every 0.5 seconds for the full length of the polymerization process. The Teflon test specimen holder has a hole with a specimen volume of 49.087mm3. The materials tested were the composite Z250 (3M ESPE) as a control and four bulk fill flowable composites: SDR (Dentsply/Caulk), Venus bulk fill (Haraeus Kulzer), Filtek bulk fill flow (3M ESPE) and Xtra base bulk fill flow (Voco). Results: The Tukey-Kramer Multipl...
Background: The use of SEM-EDS line scan analysis to evaluate the movement of ions from dental ma... more Background: The use of SEM-EDS line scan analysis to evaluate the movement of ions from dental materials towards the tooth structure and the concept of ion movement is well established. This analysis technique was used to determine the ion movement of two commercially available silver-and fluoride-containing products. Methods: This study aimed to compare the elemental analysis of primary molar teeth treated with silver diamine fluoride (SDF) and water-based silver fluoride (AgF) and to analyse the penetration of SDF and AgF from the infected dentine towards the healthy dentine. The teeth were cleaned from debris and contaminants off the roots and stored until use. A total of 15 primary molars with large active cavitated lesions, not extending into the pulp (specimens), were divided into three test groups: silver diamine fluoride (SDF) (n = 5), water-based silver fluoride (AgF) (n = 5), and deionised water (W) (n = 5) as the control group. The teeth were sectioned, embedded, and received SEM-EDS line scans. The line scan had a total length of 82.65 μm. The visible end of the infected dentine and the start of the more affected dentine were chosen as the starting point to ensure that the infected caries' line distribution towards the affected dentine's transition area was as standardized as possible. Therefore, the infected dentine length of the scan was 22.80 μm (8 scan points of 2.85 μm apart), and the affected dentine, including the healthy dentine, was 59.8 μm (21 scan points). The SEM-EDS line scan from each specimen determined the average fluoride, iodide, and silver weight percentage for that specimen. Results: The 15 sample SEM-EDS line scans were used to determine the average ion movement in wt%. The Kruskall-Wallis test and Tukey's HSD test were completed at a p < 0.05. SDF and AgF presented no significant fluoride movement in terms of the weight percentage. There was, however, significantly more fluoride movement from infected caries to the healthy dentine with SDF and AgF (p = 0.0010053) compared to the control specimens treated with deionised water. There was no significant difference between SDF and AgF for the movement of the iodide (p = 0.5953) and silver (p = 0.3708) from infected caries to the healthy dentine. Conclusion: SDF and AgF easily penetrated through infected caries and affected tooth structure to the healthy dentine for the line scan of 82.65 μm. There was no significant difference between SDF and AgF for the movement of ions within the infected dentine nor in the affected/healthy dentine.
Comparing cytocompatibility of two fluoridecontaining solutions and two resin-based restorative m... more Comparing cytocompatibility of two fluoridecontaining solutions and two resin-based restorative materials-a pilot study.
Zenodo (CERN European Organization for Nuclear Research), Jun 26, 2019
Background: The Powder/Liquid Ratio (PLR) influence, and the literature regarding the handling an... more Background: The Powder/Liquid Ratio (PLR) influence, and the literature regarding the handling and physical properties of Glass Ionomer restorative materials (GIC) were investigated.
Zenodo (CERN European Organization for Nuclear Research), Jun 26, 2019
Background and Objective: Literature suggests the use of thinner indirect partial coverage restor... more Background and Objective: Literature suggests the use of thinner indirect partial coverage restorations. The purpose of this in vitro study was to evaluate the influence of cavity design optimisation and biosubstitution with various cuspal and fissure designs, for indirect lithium disilicate partial coverage restorations. The influence on the initial crack formation and subsequently the catastrophic fracture force were evaluated. Method: Forty molars were prepared and randomly divided into four test groups (A, B, C and D). Indirect partial coverage restorations were milled with different cuspal and fissure thicknesses of lithium disilicate ceramic. Group A (cusp 1; fissure 0.7 mm thickness) and group B (cusp 0.8; fissure 0.5 mm) received a composite restoration in the class I preparation additionally. Group C (cusp 1; fissure 1.7 mm) and group D (cusp 0.8; fissure 1.5 mm) had ceramic included in the class I cavity. The restored specimens were thermo-cycled and force application was completed with a Universal testing machine in two phases. Phase one was the determination of initial first crack formation with various pre-set forces. Phase two was the maximum catastrophic fracture force. Statistical analysis was completed with the Kruskal-Wallis test and confirmed by the Dunn-Sidak multiple comparison test (p < 0.05). Results: The catastrophic fracture force in group A (2460N) was significantly greater than group B (1523N), with no difference between group C (3142N) and group D (2591N). Conclusion: The cuspal thicknesses of 1 mm for indirect partial coverage restorations were advisable, with or without composite in the class I cavity.
Objectives: To compare the precision of two cephalometric landmark identification methods, namely... more Objectives: To compare the precision of two cephalometric landmark identification methods, namely a computer-assisted human examination software and an artificial intelligence program, based on South African data. Methods: This retrospective quantitative cross-sectional analytical study utilized a data set consisting of 409 cephalograms obtained from a South African population. 19 landmarks were identified in each of the 409 cephalograms by the primary researcher using the two programs [(409 cephalograms x 19 landmarks) x 2 methods = 15,542 landmarks)]. Each landmark generated two coordinate values (x, y), making a total of 31,084 landmarks. Euclidean distances between corresponding pairs of observations was calculated. Precision was determined by using the standard deviation and standard error of the mean. Results: The primary researcher acted as the gold-standard and was calibrated prior to data collection. The inter- and intrareliability tests yielded acceptable results. Variatio...
Gingival pigmentation, whether focal or diffuse, may be of aesthetic concern to patients and esta... more Gingival pigmentation, whether focal or diffuse, may be of aesthetic concern to patients and establishing the underlying aetiology of the pigmentation is essential to ensure that the correct management is performed.
The purpose of this in vitro study was to evaluate the influence of cavity design optimisation an... more The purpose of this in vitro study was to evaluate the influence of cavity design optimisation and biosubstitution with various cuspal and fissure designs, for indirect lithium disilicate partial coverage restorations.
Six methods were assessed to determine the extent of surface hardness improvement. The methods we... more Six methods were assessed to determine the extent of surface hardness improvement. The methods were: standard set as the control, pressure, high frequency, low frequency, heat and high frequency/heat. Surface microhardness was tested with a Vickers hardness tester (Zwick-Roell durometer, ZHV1/2 Micro-Vickers, Italy) at HV0.5 (500gf) load with a dwell time of 10 seconds. The glass ionomer used to assess the six methods was Chemfil Rock (DeTrey, Dentsply, Konstanz, Germany).
Journal of Dental Health, Oral Disorders & Therapy, 2017
Fissure sealants are recommended to be applied soon after the tooth eruption, mainly at the level... more Fissure sealants are recommended to be applied soon after the tooth eruption, mainly at the level of the first permanent molars. The additional benefits of the application of bioactive fissure sealant materials lies in the build-in functionality of these materials to chemical attack in oral cavity as well as additional antibacterial action.
Journal of Dentistry, Oral Disorders & Therapy, 2015
In any repair of a tooth with permanent restorative materials, the interface is always a sensitiv... more In any repair of a tooth with permanent restorative materials, the interface is always a sensitive region. The appearance of adhesive materials was a great step forward in dealing with the problems of this region and improving the overall performance of the restorations. However, contemporary adhesive materials do have a major disadvantage, namely that their durability is limited, a limitation which often arises due to their inadequate marginal adaptation. Restorative materials in the new era aim to be "bio-active" and longlasting.
International Journal of Dentistry and Oral Science, 2015
Nanodiamonds were first synthesized by Soviet scientists [13] in 1962 through the detonation of t... more Nanodiamonds were first synthesized by Soviet scientists [13] in 1962 through the detonation of trinitrotoluene (TNT) with hexogen (RDX) in a closed chamber. Today it can be prepared at room
R. MULDER, Restorative Dentistry, University of Western Cape, Cape Town, South Africa Objectives:... more R. MULDER, Restorative Dentistry, University of Western Cape, Cape Town, South Africa Objectives: To determine the total volumetric change and the relative speed of shrinkage of newly developed bulk fill flowable composites during polymerization. The possible effects of the different organic matrices and inorganic fillers on the polymerization shrinkage were also discussed. Methods: A specially designed electronic mercury dilatometer was used to determine the polymerization shrinkage. The mercury dilatometer has a computer that measures and stores the polymerization readings every 0.5 seconds for the full length of the polymerization process. The Teflon test specimen holder has a hole with a specimen volume of 49.087mm3. The materials tested were the composite Z250 (3M ESPE) as a control and four bulk fill flowable composites: SDR (Dentsply/Caulk), Venus bulk fill (Haraeus Kulzer), Filtek bulk fill flow (3M ESPE) and Xtra base bulk fill flow (Voco). Results: The Tukey-Kramer Multipl...
Background: The use of SEM-EDS line scan analysis to evaluate the movement of ions from dental ma... more Background: The use of SEM-EDS line scan analysis to evaluate the movement of ions from dental materials towards the tooth structure and the concept of ion movement is well established. This analysis technique was used to determine the ion movement of two commercially available silver-and fluoride-containing products. Methods: This study aimed to compare the elemental analysis of primary molar teeth treated with silver diamine fluoride (SDF) and water-based silver fluoride (AgF) and to analyse the penetration of SDF and AgF from the infected dentine towards the healthy dentine. The teeth were cleaned from debris and contaminants off the roots and stored until use. A total of 15 primary molars with large active cavitated lesions, not extending into the pulp (specimens), were divided into three test groups: silver diamine fluoride (SDF) (n = 5), water-based silver fluoride (AgF) (n = 5), and deionised water (W) (n = 5) as the control group. The teeth were sectioned, embedded, and received SEM-EDS line scans. The line scan had a total length of 82.65 μm. The visible end of the infected dentine and the start of the more affected dentine were chosen as the starting point to ensure that the infected caries' line distribution towards the affected dentine's transition area was as standardized as possible. Therefore, the infected dentine length of the scan was 22.80 μm (8 scan points of 2.85 μm apart), and the affected dentine, including the healthy dentine, was 59.8 μm (21 scan points). The SEM-EDS line scan from each specimen determined the average fluoride, iodide, and silver weight percentage for that specimen. Results: The 15 sample SEM-EDS line scans were used to determine the average ion movement in wt%. The Kruskall-Wallis test and Tukey's HSD test were completed at a p < 0.05. SDF and AgF presented no significant fluoride movement in terms of the weight percentage. There was, however, significantly more fluoride movement from infected caries to the healthy dentine with SDF and AgF (p = 0.0010053) compared to the control specimens treated with deionised water. There was no significant difference between SDF and AgF for the movement of the iodide (p = 0.5953) and silver (p = 0.3708) from infected caries to the healthy dentine. Conclusion: SDF and AgF easily penetrated through infected caries and affected tooth structure to the healthy dentine for the line scan of 82.65 μm. There was no significant difference between SDF and AgF for the movement of ions within the infected dentine nor in the affected/healthy dentine.
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