Laurence Walsh | The University of Queensland, Australia (original) (raw)

Papers by Laurence Walsh

Journal of Materials Chemistry B

Surface functionalized MSNs with large radial pores delivered miRNA-26a-5p into rat bone marrow m... more Surface functionalized MSNs with large radial pores delivered miRNA-26a-5p into rat bone marrow mesenchymal stem cells and promote their osteogenic differentiation. Lyophilized dry powder formulation remained functional after 6 months of storage.

Recent Progress in Materials, 2021

Subsurface remineralization can be promoted by the topical application of nanoparticles of casein... more Subsurface remineralization can be promoted by the topical application of nanoparticles of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). To assess changes in enamel white spot lesions, an in situ proof-of-concept investigation was performed using 5 subjects (all of whom were healthy young adults) with a cross-over study design. Custom orthodontic brackets were attached to the buccal surfaces of the maxillary second premolar and first molar teeth. Each bracket had a recess that held a slab of enamel with a standardized 100 μm deep white spot lesion (WSL). Changes in mineral were evaluated in lesion cross sections using backscatter electron imaging (BSE) and electron probe microanalysis (EPMA). The following products were applied twice daily for 2 weeks: GC Tooth Mousse™ (CPP-ACP), Tooth Mousse Plus™ (CPP-ACFP), CPP-ACFP Mineral Enhanced (CPP-ACFP Enh), or the vehicle paste of CPP-ACFP containing 900 ppm fluoride. To ensure blinding, all products had identical flavours ...

Infertility affects approximately 15% of couples worldwide, an estimated 30% of which is related ... more Infertility affects approximately 15% of couples worldwide, an estimated 30% of which is related to male factor infertility. Application of low level laser therapy (LLLT) to improve fertility status is a rapidly growing discipline in medicine. Laser therapy triggers a variety of biological processes through interaction with primary cellular photoacceptors. The present review aims at evaluating the literature available in the MEDLINE/ PubMed on cellular and molecular mechanisms of photobiomodulation in the domains of reproductive and veterinary medicine. We primarily focused on the clinical application of laser treatment on seminal quality, in particular its role in promoting spermatozoa motility, as well as the role of phototherapy in modulating assisted reproduction (ART). Additionally, we investigated the strength of evidence in support of the positive impact of photobiomodulation on facilitating ART.

Clinical and Experimental Dental Research, 2016

The VistaCam® intra-oral camera system (Dürr Dental, Bietigheim-Bissingen, Germany) is a fluoresc... more The VistaCam® intra-oral camera system (Dürr Dental, Bietigheim-Bissingen, Germany) is a fluorescence system using light emitting diodes that produce a 405-nm violet light. This wavelength has potential application for detection of dental calculus based on red emissions from porphyrin molecules. This study assessed the digital scores obtained for both supragingival and subgingival calculus on 60 extracted teeth and compared these with lesions of dental caries. It has also examined the effect of saliva and blood on the fluorescence readings for dental calculus. VistaCam fluorescence scores for both supragingival (1.7-3.3) and subgingival calculus (1.3-2.4) were higher than those for sound root surfaces (0.9-1.1) and dental caries (0.9-2.2) (p < .05). The readings for calculus samples were not affected by the presence of saliva or blood. These results suggest that the use of violet light fluorescence could be a possible adjunct to clinical examination for deposits of dental calculus.

Clinical and Experimental Dental Research, 2015

The objective of this study is to compare the performance of the DIAGNOdent laser fluorescence (L... more The objective of this study is to compare the performance of the DIAGNOdent laser fluorescence (LF) Pen to conventional periodontal probing for detection of subgingival calculus under defined laboratory conditions. Extracted teeth with various levels of subgingival deposits of calculus were mounted anatomically in stone casts, and an impression material was used to replicate periodontal soft tissues. The casts were examined for the presence of subgingival calculus at eight surfaces per tooth (240 sites) using LF and a periodontal probe. Sites were rescored after 1 and 3 weeks. Direct imaging of the root surfaces under magnification was the gold standard. As a result, for an experienced operator, LF was more accurate than tactile assessment (across all sites, 84.0% vs. 59.8%). The performance difference was greater for multi-rooted teeth (85.8% vs. 56.9%) than single-rooted teeth (77.2% vs. 66.7%). The performance of LF in this laboratory trial was influenced strongly by clinician skill and experience. When used by an experienced operator, LF was more sensitive (75.1% vs. 69.2%), specific (92.6% vs. 86.3%), and accurate (84% vs. 77.9%) than for an inexperienced operator. In conclusion, under the defined laboratory conditions used, LF had better performance than tactile examination, particularly for multi-rooted teeth. This method may have value clinically as an adjunct for detecting subgingival deposits of calculus in clinical practice. The usefulness of the method improves with operator experience.

The Journal of Contemporary Dental Practice, 2015

Aim Tetracycline-stained tooth structure is difficult to bleach using nightguard tray methods. Th... more Aim Tetracycline-stained tooth structure is difficult to bleach using nightguard tray methods. The possible benefits of in-office light-accelerated bleaching systems based on the photo-Fenton reaction are of interest as possible adjunctive treatments. This study was a proof of concept for possible benefits of this approach, using dentine slabs from human tooth roots stained in a reproducible manner with the tetracycline antibiotic demeclocycline hydrochloride. Materials and methods Color changes overtime in tetracycline stained roots from single rooted teeth treated using gel (Zoom! WhiteSpeed®) alone, blue LED light alone, or gel plus light in combination were tracked using standardized digital photography. Controls received no treatment. Changes in color channel data were tracked overtime, for each treatment group (N = 20 per group). Results Dentin was lighter after bleaching, with significant improvements in the dentin color for the blue channel (yellow shade) followed by the gre...

Lasers in Medical Science, 2014

In some well-established laser applications where large spot sizes are used, an array of high-int... more In some well-established laser applications where large spot sizes are used, an array of high-intensity light emitting diodes (LED) emitting at similar wavelength could potentially replace the laser. This situation applies for the photodynamic bleaching of stains in teeth. This study compared the relative efficacy of an array of visible green LED (535 nm ± 15 nm) with a KTP laser in photodynamic bleaching of tetracycline-stained dentine in human tooth roots. After establishing consistent staining in 96 roots using a validated method, the roots were sectioned into 2-3-mm thick horizontal slices that were treated with gels containing rhodamine B (Smartbleach® or Smartbleach® 3LT). Colour changes were tracked up to 1 month after treatment. While both systems were effective in bleaching the tetracycline-stained dentine, KTP laser activation gave greater bleaching efficacy than LED activation, enhancing the action of the gel. Use of the KTP laser would be preferable over an LED system when confronted with tetracycline staining. Use of this photodynamic bleaching method offers valuable means to reduce the severity of tetracycline staining.

Critical Reviews in Oral Biology & Medicine, 2002

Both antigen-specific and non-specific mechanisms may be involved in the pathogenesis of oral lic... more Both antigen-specific and non-specific mechanisms may be involved in the pathogenesis of oral lichen planus (OLP). Antigen-specific mechanisms in OLP include antigen presentation by basal keratinocytes and antigen-specific keratinocyte killing by CD8+ cytotoxic T-cells. Non-specific mechanisms include mast cell degranulation and matrix metalloproteinase (MMP) activation in OLP lesions. These mechanisms may combine to cause T-cell accumulation in the superficial lamina propria, basement membrane disruption, intra-epithelial T-cell migration, and keratinocyte apoptosis in OLP. OLP chronicity may be due, in part, to deficient antigen-specific TGF-β1-mediated immunosuppression. The normal oral mucosa may be an immune privileged site (similar to the eye, testis, and placenta), and breakdown of immune privilege could result in OLP and possibly other autoimmune oral mucosal diseases. Recent findings in mucocutaneous graft- versus-host disease, a clinical and histological correlate of liche...

Journal of Cutaneous Pathology, 1992

Adhesion molecules are critical for leukocytes migration to the skin. Leukocytes mustˆrst be capt... more Adhesion molecules are critical for leukocytes migration to the skin. Leukocytes mustˆrst be captured or tethered from the ‰owing blood allowing them to roll along the skin vessels. Leukocytes are activated by chemoattractants, which results inˆrm adhesion and arrest and ultimately transendothelial migration into the tissue. Selectin family which consists of L selectin, P selectin, E selectin is critical for capture and rolling. Deˆciency of these molecules leads to the diminution of cutaneous in‰ammation. Firm adhesion is governed by b2 integrin and a4 integrin. Inhibition of b2 integrin and its ligand ICAM 1 also reduce cutaneous in‰ammation. Similarly, blocking of a4 integrin and its ligand VCAM 1 alleviate in‰ammation of the skin. Transmigration and diapedesis are mediated by various molecules such as PECAM 1, CD99, and JAM, whose inhibition also leads to amelioration of skin in‰ammation. Manipulating adhesion molecules might lead to novel therapy to treat dermatitis by controlling leukocytes migration into cutaneous sites of in-‰ammation.

The Journal of Clinical Endocrinology & Metabolism, 1998

abstractThe insulin-like growth factor (IGF)-binding proteins (IGFBPs) carry IGFs in serum and re... more abstractThe insulin-like growth factor (IGF)-binding proteins (IGFBPs) carry IGFs in serum and regulate their activity and bioavailability. The main IGFBP in serum, IGFBP-3, is known to form a 150-kDa complex with IGFs and the acid-labile subunit (ALS).We investigated the binding of IGFBP-3 to additional association proteins in human serum (IGFBP-3 APs). Ligand blots, column chromatography, and affinity cross-linking experiments revealed the specific binding of IGFBP-3 to at least three novel serum proteins. These techniques demonstrated the presence of proteins with molecular masses of 70, 100, and 150 kDa that bind IGFBP-3 with high affinity. Serum ALS migrated separately (at 88 kDa) from the novel IGFBP-3 APs (as evident by Western immunoblot), and bound IGFBP-3 weakly (by reverse ligand blots). We also demonstrated that large amounts of one of the IGFBP-3 APs and small amounts of ALS were coimmunoprecipitated with IGFBP-3 from human serum. Similar to ALS, these IGFBP-3 APs are a...

Aktuelle Neurologie, 2006

Background: Matrix metalloproteinases (MMPs) are a family of extracellular endopeptidases that de... more Background: Matrix metalloproteinases (MMPs) are a family of extracellular endopeptidases that degrade the extracellular matrix and other extracellular proteins. Studies in experimental animals demonstrate that MMPs play a number of roles in the detrimental as well as in the beneficial events after spinal cord injury (SCI). In the present correlative investigation, the expression pattern of several MMPs and their inhibitors has been investigated in the human spinal cord. Methods: An immunohistochemical investigation in post mortem samples of control and lesioned human spinal cords was performed. All patients with traumatic SCI had been clinically diagnosed as having "complete" injuries and presented lesions of the maceration type. Results: In the unlesioned human spinal cord, MMP and TIMP immunoreactivity was scarce. After traumatic SCI, a lesion-induced bi-phasic pattern of raised MMP-1 levels could be found with an early up-regulation in macrophages within the lesion epicentre and a later induction in peri-lesional activated astrocytes. There was an early and brief induction of MMP-2 at the lesion core in macrophages. MMP-9 and-12 expression peaked at 24 days after injury and both molecules were mostly expressed in macrophages at the lesion epicentre. Whereas MMP-9 levels rose progressively from 1 week to 3 weeks, there was an isolated peak of MMP-12 expression at 24 days. The post-traumatic distribution of the MMP inhibitors TIMP-1,-2 and-3 was limited. Only occasional TIMP immuno-positive macrophages could be detected at short survival times. The only clear induction was detected for TIMP-3 at survival times of 8 months and 1 year in peri-lesional activated astrocytes. Conclusion: The involvement of MMP-1,-2,-9 and-12 has been demonstrated in the post-traumatic events after human SCI. With an expression pattern corresponding largely to prior experimental studies, they were mainly expressed during the first weeks after injury and were most likely involved in the destructive inflammatory events of protein breakdown and phagocytosis carried out by infiltrating neutrophils and macrophages, as well as being involved in enhanced permeability of the blood spinal cord barrier. Similar to animal investigations, the strong induction of MMPs was not accompanied by an expression of their inhibitors, allowing these proteins to exert their effects in the lesioned spinal cord.

Australian and New Zealand journal of public health, Jan 16, 2017

To estimate the incidence of dog bite-related injuries requiring public sector hospitalisation in... more To estimate the incidence of dog bite-related injuries requiring public sector hospitalisation in Australia during the period 2001-13. Summary data on public sector hospitalisations due to dog bite-related injuries with an ICD 10-AM W54.0 coding were sourced from the Australian Institute of Health and Welfare for the study period 2001-2013. In Australia, on average, 2,061 persons were hospitalised each year for treatment for dog bite injuries at an annual rate of 12.39 (95%CI 12.25-12.53) per 100,000 during 2001-13. The highest annual rates of 25.95 (95%CI 25.16-26.72) and 18.42 (95%CI 17.75-19.07) per 100,000 were for age groups 0-4 and 5-9 years respectively. Rates of recorded events increased over the study period and reached 16.15 (95%CI 15.78-16.52) per 100,000 during 2011-13. Dog bites are a largely unrecognised and growing public health problem in Australia. Implications for public health: There is an increasing public sector burden of hospitalisations for injuries from dog b...

Periodontology and Dental Implantology

The performance of clinicians undertaking periodontal assessment or periodontal therapy can be im... more The performance of clinicians undertaking periodontal assessment or periodontal therapy can be improved by using optical methods as adjuncts to visual inspection and periodontal probing. Subtle changes that occur over time in periodontal tissues that are below the detection limit of visual examination or periodontal probing can be found and tracked accurately over time using 3D imaging, fluorescence spectroscopy, and optical coherence tomography. During debridement of teeth and dental implants, the effective removal of subgingival microbial biofilms and dental calculus deposits can be enhanced using magnifying loupes and operating microscopes and by novel methods based on the interactions of light with bacterial deposits, such as differential reflectometry and light-induced fluorescence. While such techniques can also be used using initial case assessment, their primary purpose is for checking debridement procedures, since the point when bacterial deposits are no longer present represents an endpoint for treatment. The concept of realtime feedback has been developed, using fluorescence readings to control the removal of deposits. Overall, optical methods can support traditional periodontal diagnosis and improve treatment planning and clinical periodontal care.

Forensic science international, 2017

The objective of this study was to compare the fluorescence properties of dry and wet samples of ... more The objective of this study was to compare the fluorescence properties of dry and wet samples of contemporary tooth-coloured restorative materials using a fluorescence based DSLR camera and a variety of LEDs emitting different wavelengths of visible light as excitation sources. The materials examined included resin composites; ceramics and hybrid restorative materials such as ormocers, Vita Enamic™ and resin reinforced glass-ionomer cements. The levels of fluorescence for each sample under different combinations of incident light wavelengths and filters was analysed by using histogram data for colour channels from Adobe Photoshop software. Fluorescence patterns were influenced by water sorption of the materials. UV-A/Violet light (405±nm) produced the greatest range of luminosity values (10-204) amongst the tooth-coloured restorative materials, and showed the greatest differences between restorations and tooth structure. The best filter combinations with violet light were orange or ...

The laser-induced fluorescence can be used to detect and diagnose dental caries, calculus and bac... more The laser-induced fluorescence can be used to detect and diagnose dental caries, calculus and bacterial biofilms in dental applications. As such the molecular fluorescence phenomenon has been illustrated scientifically and the literatures relating the fluorescence properties of dental tissues have been explored till the literature reviews ultimately led up to the development of the current Laser Fluorescence (LF) devices. These LF devices have been introduced clinically for dental caries, calculus and bacterial detection to replace inaccurate contemporary detection tools. The future for LF technologies in diagnostic dentistry has been indicated as accurate and potentially applicable in a wide range in restorative dentistry, periodontology and endodontics.

Background Workplace non-sharps injuries are a common occurrence in a dental school setting. In d... more Background Workplace non-sharps injuries are a common occurrence in a dental school setting. In dentistry, the importance of preventing non-sharps injuries is often overlooked due to emphasis on sharps-related injuries in clinical and laboratory settings. To analyse the incidences of non-sharps injuries over a 10 year period in a dental school to identify trends and the possible causative factors for these injuries. Methods Injury reports lodged with the UQ Workplace Health and Safety databases between 2009 and 2019 were categorised and analysed. Results Of 1156 incidents reported, 35.7% (n = 413) were non-sharps injuries, the most common type of non-sharps injury was general incidents (48.4%, n = 200). The most common body site for injury was the hands (19.4%, n = 80) and the most common location where an injury occurred was when working in clinical patient care (53.8%, n = 222). The personnel type most at risk of a non-sharps injury fluctuated between students and staff throughout...

The Diagnodent device is based on principles of caries detection by laser fluorescence which were... more The Diagnodent device is based on principles of caries detection by laser fluorescence which were developed in Sweden in the mid-1980s. Since that time, several lasers have been employed for caries detection (such as the argon, carbon dioxide, and excimer lasers). These systems are however more complex to use and more expensive than the visible red diode laser system upon which Diagnodent® is based, and for this reason they have not been used in clinical practice to any significant extent.

Clinical and Experimental Dental Research, 2015

The VistaCam® system (Durr Dental, Bietigheim-Bissingen, Germany) has been suggested as an adjunc... more The VistaCam® system (Durr Dental, Bietigheim-Bissingen, Germany) has been suggested as an adjunct to clinical examination for dental caries. This study assessed whether the digital scores obtained for tooth surfaces were affected by the colour of the carious lesions present and by the presence of saliva or blood on the tooth surface. The VistaCam intra-oral ries, or with sound enamel and root surfaces, with or without overlying dental plaque biofilm. Teeth that had undergone root treatment or were stained by tetracycline were also assessed. Readings were taken in the dry state and after application of human stimulated saliva or venous blood onto the surface of the samples. VistaCam fluorescence scores for all samples were similar in the dry state, and when covered with saliva (P > 0.05), however a coating of dilute blood elevated the readings for most samples to a high level (P < 0.01), other than tetracycline stained teeth and dental caries (P > 0.05). Readings for healthy enamel were 0.9-1.1, and these increased up to 2.8 in the presence of blood. VistaCam fluorescence scores are not affected by dryness or moisture from the presence of saliva but increase when traces of blood are present. This problem needs to be taken into account when the device is used clinically, because blood from the gingival crevice is a common contaminant of tooth surfaces when patients have widespread gingival inflammation. There are also issues with elevated scores from background fluorescence from tetracyclines, which need to be considered when the system is in clinical use.

Journal of Materials Chemistry B

Surface functionalized MSNs with large radial pores delivered miRNA-26a-5p into rat bone marrow m... more Surface functionalized MSNs with large radial pores delivered miRNA-26a-5p into rat bone marrow mesenchymal stem cells and promote their osteogenic differentiation. Lyophilized dry powder formulation remained functional after 6 months of storage.

Recent Progress in Materials, 2021

Subsurface remineralization can be promoted by the topical application of nanoparticles of casein... more Subsurface remineralization can be promoted by the topical application of nanoparticles of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). To assess changes in enamel white spot lesions, an in situ proof-of-concept investigation was performed using 5 subjects (all of whom were healthy young adults) with a cross-over study design. Custom orthodontic brackets were attached to the buccal surfaces of the maxillary second premolar and first molar teeth. Each bracket had a recess that held a slab of enamel with a standardized 100 μm deep white spot lesion (WSL). Changes in mineral were evaluated in lesion cross sections using backscatter electron imaging (BSE) and electron probe microanalysis (EPMA). The following products were applied twice daily for 2 weeks: GC Tooth Mousse™ (CPP-ACP), Tooth Mousse Plus™ (CPP-ACFP), CPP-ACFP Mineral Enhanced (CPP-ACFP Enh), or the vehicle paste of CPP-ACFP containing 900 ppm fluoride. To ensure blinding, all products had identical flavours ...

Infertility affects approximately 15% of couples worldwide, an estimated 30% of which is related ... more Infertility affects approximately 15% of couples worldwide, an estimated 30% of which is related to male factor infertility. Application of low level laser therapy (LLLT) to improve fertility status is a rapidly growing discipline in medicine. Laser therapy triggers a variety of biological processes through interaction with primary cellular photoacceptors. The present review aims at evaluating the literature available in the MEDLINE/ PubMed on cellular and molecular mechanisms of photobiomodulation in the domains of reproductive and veterinary medicine. We primarily focused on the clinical application of laser treatment on seminal quality, in particular its role in promoting spermatozoa motility, as well as the role of phototherapy in modulating assisted reproduction (ART). Additionally, we investigated the strength of evidence in support of the positive impact of photobiomodulation on facilitating ART.

Clinical and Experimental Dental Research, 2016

The VistaCam® intra-oral camera system (Dürr Dental, Bietigheim-Bissingen, Germany) is a fluoresc... more The VistaCam® intra-oral camera system (Dürr Dental, Bietigheim-Bissingen, Germany) is a fluorescence system using light emitting diodes that produce a 405-nm violet light. This wavelength has potential application for detection of dental calculus based on red emissions from porphyrin molecules. This study assessed the digital scores obtained for both supragingival and subgingival calculus on 60 extracted teeth and compared these with lesions of dental caries. It has also examined the effect of saliva and blood on the fluorescence readings for dental calculus. VistaCam fluorescence scores for both supragingival (1.7-3.3) and subgingival calculus (1.3-2.4) were higher than those for sound root surfaces (0.9-1.1) and dental caries (0.9-2.2) (p < .05). The readings for calculus samples were not affected by the presence of saliva or blood. These results suggest that the use of violet light fluorescence could be a possible adjunct to clinical examination for deposits of dental calculus.

Clinical and Experimental Dental Research, 2015

The objective of this study is to compare the performance of the DIAGNOdent laser fluorescence (L... more The objective of this study is to compare the performance of the DIAGNOdent laser fluorescence (LF) Pen to conventional periodontal probing for detection of subgingival calculus under defined laboratory conditions. Extracted teeth with various levels of subgingival deposits of calculus were mounted anatomically in stone casts, and an impression material was used to replicate periodontal soft tissues. The casts were examined for the presence of subgingival calculus at eight surfaces per tooth (240 sites) using LF and a periodontal probe. Sites were rescored after 1 and 3 weeks. Direct imaging of the root surfaces under magnification was the gold standard. As a result, for an experienced operator, LF was more accurate than tactile assessment (across all sites, 84.0% vs. 59.8%). The performance difference was greater for multi-rooted teeth (85.8% vs. 56.9%) than single-rooted teeth (77.2% vs. 66.7%). The performance of LF in this laboratory trial was influenced strongly by clinician skill and experience. When used by an experienced operator, LF was more sensitive (75.1% vs. 69.2%), specific (92.6% vs. 86.3%), and accurate (84% vs. 77.9%) than for an inexperienced operator. In conclusion, under the defined laboratory conditions used, LF had better performance than tactile examination, particularly for multi-rooted teeth. This method may have value clinically as an adjunct for detecting subgingival deposits of calculus in clinical practice. The usefulness of the method improves with operator experience.

The Journal of Contemporary Dental Practice, 2015

Aim Tetracycline-stained tooth structure is difficult to bleach using nightguard tray methods. Th... more Aim Tetracycline-stained tooth structure is difficult to bleach using nightguard tray methods. The possible benefits of in-office light-accelerated bleaching systems based on the photo-Fenton reaction are of interest as possible adjunctive treatments. This study was a proof of concept for possible benefits of this approach, using dentine slabs from human tooth roots stained in a reproducible manner with the tetracycline antibiotic demeclocycline hydrochloride. Materials and methods Color changes overtime in tetracycline stained roots from single rooted teeth treated using gel (Zoom! WhiteSpeed®) alone, blue LED light alone, or gel plus light in combination were tracked using standardized digital photography. Controls received no treatment. Changes in color channel data were tracked overtime, for each treatment group (N = 20 per group). Results Dentin was lighter after bleaching, with significant improvements in the dentin color for the blue channel (yellow shade) followed by the gre...

Lasers in Medical Science, 2014

In some well-established laser applications where large spot sizes are used, an array of high-int... more In some well-established laser applications where large spot sizes are used, an array of high-intensity light emitting diodes (LED) emitting at similar wavelength could potentially replace the laser. This situation applies for the photodynamic bleaching of stains in teeth. This study compared the relative efficacy of an array of visible green LED (535 nm ± 15 nm) with a KTP laser in photodynamic bleaching of tetracycline-stained dentine in human tooth roots. After establishing consistent staining in 96 roots using a validated method, the roots were sectioned into 2-3-mm thick horizontal slices that were treated with gels containing rhodamine B (Smartbleach® or Smartbleach® 3LT). Colour changes were tracked up to 1 month after treatment. While both systems were effective in bleaching the tetracycline-stained dentine, KTP laser activation gave greater bleaching efficacy than LED activation, enhancing the action of the gel. Use of the KTP laser would be preferable over an LED system when confronted with tetracycline staining. Use of this photodynamic bleaching method offers valuable means to reduce the severity of tetracycline staining.

Critical Reviews in Oral Biology & Medicine, 2002

Both antigen-specific and non-specific mechanisms may be involved in the pathogenesis of oral lic... more Both antigen-specific and non-specific mechanisms may be involved in the pathogenesis of oral lichen planus (OLP). Antigen-specific mechanisms in OLP include antigen presentation by basal keratinocytes and antigen-specific keratinocyte killing by CD8+ cytotoxic T-cells. Non-specific mechanisms include mast cell degranulation and matrix metalloproteinase (MMP) activation in OLP lesions. These mechanisms may combine to cause T-cell accumulation in the superficial lamina propria, basement membrane disruption, intra-epithelial T-cell migration, and keratinocyte apoptosis in OLP. OLP chronicity may be due, in part, to deficient antigen-specific TGF-β1-mediated immunosuppression. The normal oral mucosa may be an immune privileged site (similar to the eye, testis, and placenta), and breakdown of immune privilege could result in OLP and possibly other autoimmune oral mucosal diseases. Recent findings in mucocutaneous graft- versus-host disease, a clinical and histological correlate of liche...

Journal of Cutaneous Pathology, 1992

Adhesion molecules are critical for leukocytes migration to the skin. Leukocytes mustˆrst be capt... more Adhesion molecules are critical for leukocytes migration to the skin. Leukocytes mustˆrst be captured or tethered from the ‰owing blood allowing them to roll along the skin vessels. Leukocytes are activated by chemoattractants, which results inˆrm adhesion and arrest and ultimately transendothelial migration into the tissue. Selectin family which consists of L selectin, P selectin, E selectin is critical for capture and rolling. Deˆciency of these molecules leads to the diminution of cutaneous in‰ammation. Firm adhesion is governed by b2 integrin and a4 integrin. Inhibition of b2 integrin and its ligand ICAM 1 also reduce cutaneous in‰ammation. Similarly, blocking of a4 integrin and its ligand VCAM 1 alleviate in‰ammation of the skin. Transmigration and diapedesis are mediated by various molecules such as PECAM 1, CD99, and JAM, whose inhibition also leads to amelioration of skin in‰ammation. Manipulating adhesion molecules might lead to novel therapy to treat dermatitis by controlling leukocytes migration into cutaneous sites of in-‰ammation.

The Journal of Clinical Endocrinology & Metabolism, 1998

abstractThe insulin-like growth factor (IGF)-binding proteins (IGFBPs) carry IGFs in serum and re... more abstractThe insulin-like growth factor (IGF)-binding proteins (IGFBPs) carry IGFs in serum and regulate their activity and bioavailability. The main IGFBP in serum, IGFBP-3, is known to form a 150-kDa complex with IGFs and the acid-labile subunit (ALS).We investigated the binding of IGFBP-3 to additional association proteins in human serum (IGFBP-3 APs). Ligand blots, column chromatography, and affinity cross-linking experiments revealed the specific binding of IGFBP-3 to at least three novel serum proteins. These techniques demonstrated the presence of proteins with molecular masses of 70, 100, and 150 kDa that bind IGFBP-3 with high affinity. Serum ALS migrated separately (at 88 kDa) from the novel IGFBP-3 APs (as evident by Western immunoblot), and bound IGFBP-3 weakly (by reverse ligand blots). We also demonstrated that large amounts of one of the IGFBP-3 APs and small amounts of ALS were coimmunoprecipitated with IGFBP-3 from human serum. Similar to ALS, these IGFBP-3 APs are a...

Aktuelle Neurologie, 2006

Background: Matrix metalloproteinases (MMPs) are a family of extracellular endopeptidases that de... more Background: Matrix metalloproteinases (MMPs) are a family of extracellular endopeptidases that degrade the extracellular matrix and other extracellular proteins. Studies in experimental animals demonstrate that MMPs play a number of roles in the detrimental as well as in the beneficial events after spinal cord injury (SCI). In the present correlative investigation, the expression pattern of several MMPs and their inhibitors has been investigated in the human spinal cord. Methods: An immunohistochemical investigation in post mortem samples of control and lesioned human spinal cords was performed. All patients with traumatic SCI had been clinically diagnosed as having "complete" injuries and presented lesions of the maceration type. Results: In the unlesioned human spinal cord, MMP and TIMP immunoreactivity was scarce. After traumatic SCI, a lesion-induced bi-phasic pattern of raised MMP-1 levels could be found with an early up-regulation in macrophages within the lesion epicentre and a later induction in peri-lesional activated astrocytes. There was an early and brief induction of MMP-2 at the lesion core in macrophages. MMP-9 and-12 expression peaked at 24 days after injury and both molecules were mostly expressed in macrophages at the lesion epicentre. Whereas MMP-9 levels rose progressively from 1 week to 3 weeks, there was an isolated peak of MMP-12 expression at 24 days. The post-traumatic distribution of the MMP inhibitors TIMP-1,-2 and-3 was limited. Only occasional TIMP immuno-positive macrophages could be detected at short survival times. The only clear induction was detected for TIMP-3 at survival times of 8 months and 1 year in peri-lesional activated astrocytes. Conclusion: The involvement of MMP-1,-2,-9 and-12 has been demonstrated in the post-traumatic events after human SCI. With an expression pattern corresponding largely to prior experimental studies, they were mainly expressed during the first weeks after injury and were most likely involved in the destructive inflammatory events of protein breakdown and phagocytosis carried out by infiltrating neutrophils and macrophages, as well as being involved in enhanced permeability of the blood spinal cord barrier. Similar to animal investigations, the strong induction of MMPs was not accompanied by an expression of their inhibitors, allowing these proteins to exert their effects in the lesioned spinal cord.

Australian and New Zealand journal of public health, Jan 16, 2017

To estimate the incidence of dog bite-related injuries requiring public sector hospitalisation in... more To estimate the incidence of dog bite-related injuries requiring public sector hospitalisation in Australia during the period 2001-13. Summary data on public sector hospitalisations due to dog bite-related injuries with an ICD 10-AM W54.0 coding were sourced from the Australian Institute of Health and Welfare for the study period 2001-2013. In Australia, on average, 2,061 persons were hospitalised each year for treatment for dog bite injuries at an annual rate of 12.39 (95%CI 12.25-12.53) per 100,000 during 2001-13. The highest annual rates of 25.95 (95%CI 25.16-26.72) and 18.42 (95%CI 17.75-19.07) per 100,000 were for age groups 0-4 and 5-9 years respectively. Rates of recorded events increased over the study period and reached 16.15 (95%CI 15.78-16.52) per 100,000 during 2011-13. Dog bites are a largely unrecognised and growing public health problem in Australia. Implications for public health: There is an increasing public sector burden of hospitalisations for injuries from dog b...

Periodontology and Dental Implantology

The performance of clinicians undertaking periodontal assessment or periodontal therapy can be im... more The performance of clinicians undertaking periodontal assessment or periodontal therapy can be improved by using optical methods as adjuncts to visual inspection and periodontal probing. Subtle changes that occur over time in periodontal tissues that are below the detection limit of visual examination or periodontal probing can be found and tracked accurately over time using 3D imaging, fluorescence spectroscopy, and optical coherence tomography. During debridement of teeth and dental implants, the effective removal of subgingival microbial biofilms and dental calculus deposits can be enhanced using magnifying loupes and operating microscopes and by novel methods based on the interactions of light with bacterial deposits, such as differential reflectometry and light-induced fluorescence. While such techniques can also be used using initial case assessment, their primary purpose is for checking debridement procedures, since the point when bacterial deposits are no longer present represents an endpoint for treatment. The concept of realtime feedback has been developed, using fluorescence readings to control the removal of deposits. Overall, optical methods can support traditional periodontal diagnosis and improve treatment planning and clinical periodontal care.

Forensic science international, 2017

The objective of this study was to compare the fluorescence properties of dry and wet samples of ... more The objective of this study was to compare the fluorescence properties of dry and wet samples of contemporary tooth-coloured restorative materials using a fluorescence based DSLR camera and a variety of LEDs emitting different wavelengths of visible light as excitation sources. The materials examined included resin composites; ceramics and hybrid restorative materials such as ormocers, Vita Enamic™ and resin reinforced glass-ionomer cements. The levels of fluorescence for each sample under different combinations of incident light wavelengths and filters was analysed by using histogram data for colour channels from Adobe Photoshop software. Fluorescence patterns were influenced by water sorption of the materials. UV-A/Violet light (405±nm) produced the greatest range of luminosity values (10-204) amongst the tooth-coloured restorative materials, and showed the greatest differences between restorations and tooth structure. The best filter combinations with violet light were orange or ...

The laser-induced fluorescence can be used to detect and diagnose dental caries, calculus and bac... more The laser-induced fluorescence can be used to detect and diagnose dental caries, calculus and bacterial biofilms in dental applications. As such the molecular fluorescence phenomenon has been illustrated scientifically and the literatures relating the fluorescence properties of dental tissues have been explored till the literature reviews ultimately led up to the development of the current Laser Fluorescence (LF) devices. These LF devices have been introduced clinically for dental caries, calculus and bacterial detection to replace inaccurate contemporary detection tools. The future for LF technologies in diagnostic dentistry has been indicated as accurate and potentially applicable in a wide range in restorative dentistry, periodontology and endodontics.

Background Workplace non-sharps injuries are a common occurrence in a dental school setting. In d... more Background Workplace non-sharps injuries are a common occurrence in a dental school setting. In dentistry, the importance of preventing non-sharps injuries is often overlooked due to emphasis on sharps-related injuries in clinical and laboratory settings. To analyse the incidences of non-sharps injuries over a 10 year period in a dental school to identify trends and the possible causative factors for these injuries. Methods Injury reports lodged with the UQ Workplace Health and Safety databases between 2009 and 2019 were categorised and analysed. Results Of 1156 incidents reported, 35.7% (n = 413) were non-sharps injuries, the most common type of non-sharps injury was general incidents (48.4%, n = 200). The most common body site for injury was the hands (19.4%, n = 80) and the most common location where an injury occurred was when working in clinical patient care (53.8%, n = 222). The personnel type most at risk of a non-sharps injury fluctuated between students and staff throughout...

The Diagnodent device is based on principles of caries detection by laser fluorescence which were... more The Diagnodent device is based on principles of caries detection by laser fluorescence which were developed in Sweden in the mid-1980s. Since that time, several lasers have been employed for caries detection (such as the argon, carbon dioxide, and excimer lasers). These systems are however more complex to use and more expensive than the visible red diode laser system upon which Diagnodent® is based, and for this reason they have not been used in clinical practice to any significant extent.

Clinical and Experimental Dental Research, 2015

The VistaCam® system (Durr Dental, Bietigheim-Bissingen, Germany) has been suggested as an adjunc... more The VistaCam® system (Durr Dental, Bietigheim-Bissingen, Germany) has been suggested as an adjunct to clinical examination for dental caries. This study assessed whether the digital scores obtained for tooth surfaces were affected by the colour of the carious lesions present and by the presence of saliva or blood on the tooth surface. The VistaCam intra-oral ries, or with sound enamel and root surfaces, with or without overlying dental plaque biofilm. Teeth that had undergone root treatment or were stained by tetracycline were also assessed. Readings were taken in the dry state and after application of human stimulated saliva or venous blood onto the surface of the samples. VistaCam fluorescence scores for all samples were similar in the dry state, and when covered with saliva (P > 0.05), however a coating of dilute blood elevated the readings for most samples to a high level (P < 0.01), other than tetracycline stained teeth and dental caries (P > 0.05). Readings for healthy enamel were 0.9-1.1, and these increased up to 2.8 in the presence of blood. VistaCam fluorescence scores are not affected by dryness or moisture from the presence of saliva but increase when traces of blood are present. This problem needs to be taken into account when the device is used clinically, because blood from the gingival crevice is a common contaminant of tooth surfaces when patients have widespread gingival inflammation. There are also issues with elevated scores from background fluorescence from tetracyclines, which need to be considered when the system is in clinical use.