Sarbin Ranjitkar

The effect of casein phosphopeptide–amorphous calcium phosphate on erosive enamel and dentine wear by toothbrush abrasion

OBJECTIVE In addition to its role as a remineralizing agent in preventing dental caries, calcium product (CPP-ACP) delivered as a mousse (Tooth Mousse, TM) can reduce erosion of enamel and dentine. The aim of this study was to determine whether CPP-ACP could also reduce erosive tooth wear involving toothbrush abrasion. METHODS Flat, polished enamel and dentine specimens (n=72) were subjected to 10 wear regimes, with each regime involving erosion in 0.3% citric acid (pH 3.2) for 10 min followed by toothbrush abrasion in a slurry of fluoride-free toothpaste and artificial saliva (1:3 ratio by weight) under a load of 2N for 200 cycles. The specimens were immersed in artificial saliva for 2h between wear regimes. In the experimental group 1, TM (containing CPP-ACP) was applied at the beginning of each wear episode for 5 min whereas TM- (without CPP-ACP) was applied in the experimental group 2. No mousse was applied in the control group. RESULTS TM significantly reduced enamel wear (mean+/-S.E., 1.26+/-0.33 microm in the experimental group 1 vs 3.48+/-0.43 microm in the control group) and dentine wear (2.16+/-0.89 microm in the experimental group 1 vs 10.29+/-1.64 microm in the control group), and dentine wear was significantly less in the experimental group 1 than in the experimental group 2 (5.75+/-0.98 microm). CONCLUSION The finding that TM reduced erosive tooth wear involving toothbrush abrasion, probably by remineralizing and lubricating eroded tooth surfaces, may have implications in the management of tooth wear.

An in vitro assessment of the role of Tooth Mousse in preventing wine erosion

BACKGROUND The recommendation that Tooth Mousse (TM), an anticariogenic remineralizing agent, is effective for controlling dental erosion in professional wine tasters is not evidence-based. The aim of this in vitro study was to determine the effectiveness of TM in reducing erosion of coronal enamel and radicular dentine/cementum simulating a typical wine judging session. METHODS Enamel and dentine/cementum from buccal halves (experimental sample) and palatal halves (control sample) of human maxillary premolar teeth were subjected to 1500 one-minute exposures (cycles) to white wine (pH = 3.5). TM was applied every 20 cycles to the experimental sample, but not to the control sample. Paired t-tests were used to determine whether there were significant differences in erosion depths between the experimental and control samples. RESULTS Mean erosion depths were significantly shallower in the experimental sample than the control sample for both enamel (34.4 microm versus 49.2 microm, respectively) (p < 0.05) and dentine/cementum (143.2 microm versus 203.7 microm, respectively) (p < 0.01). CONCLUSIONS TM may have significant role in the management of wine erosion, which is under-recognized as an occupational hazard by the Australian wine industry. Future studies are needed to compare the relative benefits of TM and other remineralizing agents, when used individually or in combination, in preventing dental erosion.

Gastroesophageal Reflux Disease and Tooth Erosion

The increasing prevalence of gastroesophageal reflux disease (GERD) in children and adults, and of “silent refluxers” in particular, increases the responsibility of dentists to be alert to this potentially severe condition when observing unexplained instances of tooth erosion. Although gastroesophageal reflux is a normal physiologic occurrence, excessive gastric and duodenal regurgitation combined with a decrease in normal protective mechanisms, including an adequate production of saliva, may result in many esophageal and extraesophageal adverse conditions. Sleep-related GERD is particularly insidious as the supine position enhances the proximal migration of gastric contents, and normal saliva production is much reduced. Gastric acid will displace saliva easily from tooth surfaces, and proteolytic pepsin will remove protective dental pellicle. Though increasing evidence of associations between GERD and tooth erosion has been shown in both animal and human studies, relatively few clinical studies have been carried out under controlled trial conditions. Suspicion of an endogenous source of acid being associated with observed tooth erosion requires medical referral and management of the patient as the primary method for its prevention and control.

The effect of CPP-ACP on enamel wear under severe erosive conditions.

OBJECTIVE In addition to its role as a remineralizing agent in preventing dental caries, recent evidence has shown that casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) can protect teeth against erosion. The aim of this study was to determine whether CPP-ACP could reduce enamel wear rates under severe erosive conditions simulating heavy attrition and gastric regurgitation. DESIGN Enamel specimens were subjected to 10,000 wear cycles at a load of 100 N and pH 1.2 in a tooth wear machine. The machine was stopped every 2 min (160 cycles), and CPP-ACP in the form of a paste was applied for 5 min in experimental group 1. A paste with the same formulation but without CPP-ACP was applied in experimental group 2. No paste was applied in the control group. RESULTS A linear mixed model analysis indicated that the mean wear rates in experimental group 1 (0.44+/-0.05 mm(3) per 1000 cycles) and in experimental group 2 (0.63+/-0.06 mm(3) per 1000 cycles) were significantly lower than that in the control group (0.92+/-0.11 mm(3) per 1000 cycles) (p<0.05). The mean wear rate in experimental group 1 was also lower than that in experimental group 2 (p<0.05). Wear facets in experimental groups 1 and 2 were noted to be smoother and more polished than those in the control group. CONCLUSIONS Both remineralizing and lubricating properties of the paste containing CPP-ACP appear to contribute to wear reduction in enamel. These findings may lead to new strategies for the clinical management of tooth wear.

Oral manifestations of gastroesophageal reflux disease

Numerous case‐control and other studies involving confirmation of gastroesophageal reflux disease (GERD) by esophageal pH‐metry and the assessment of dental erosions have shown significant associations between the two conditions in both adults and children. By contrast, when asked to vote on whether GERD may cause dental erosions, only 42% of physicians strongly agreed that such an association existed in adults, and just 12.5% strongly agreed for children, respectively in two global consensus reports. Part of this divergence between the perceptions of physicians and the findings of research publications may reflect a general lack of oral health education during medical training, and cursory oral examinations being made under less‐than‐ideal conditions. Adequate salivary secretions are essential for the protection of the teeth and the oropharyngeal and esophageal mucosa. The quantity and quality of the saliva require monitoring as many drugs, including several of the proton pump inhibitors (PPIs), can cause hyposalivation. In addition, PPIs do not always result in adequate acid suppression. Therefore, collaboration between physicians and dentists is strongly advocated to prevent or ameliorate possible adverse oral effects from both endogenous and exogenous acids, and to promote adequate saliva production in patients with GERD.

The effect of casein phosphopeptide‐amorphous calcium phosphate on erosive dentine wear

BACKGROUND Erosive tooth wear is a growing concern in clinical dentistry. Our aims were to assess the effect of Tooth Mousse (TM) in managing erosive dentine wear in vitro. METHODS Opposing enamel and dentine specimens from 36 third molar teeth were worn under a load of 100 N for 75 000 cycles in electromechanical tooth wear machines. In experiment 1, TM was applied continuously at the wear interface and the mean dentine wear rate was compared with those of specimens subjected to continuous application of hydrochloric acid (HCl, pH 3.0) and deionized water (DW, pH 6.1) as lubricants. In experiment 2, specimens were subjected to TM application every 1600 cycles at both pH 3.0 and 6.1, and the mean dentine wear rates were compared with those of specimens worn with continuous application of HCl and DW lubricants. RESULTS Dentine wear was reduced significantly with continuous application of TM compared with HCl and DW lubricants. Specimens prepared with continuous TM application displayed smooth wear facets, whereas more pronounced microwear details were observed with HCl and DW lubricants. CONCLUSIONS Both remineralization and lubrication seem to contribute to reduction in dentine wear associated with TM application, although lubrication appears to have a more pronounced effect.

Application of three‐dimensional computed tomography in craniofacial clinical practice and research

Following the invention of the first computed tomography (CT) scanner in the early 1970s, many innovations in three-dimensional (3D) diagnostic imaging technology have occurred, leading to a wide range of applications in craniofacial clinical practice and research. Three-dimensional image analysis provides superior and more detailed information compared with conventional plain two-dimensional (2D) radiography, with the added benefit of 3D printing for preoperative treatment planning and regenerative therapy. Current state-of-the-art multidetector CT (MDCT), also known as medical CT, has an important role in the diagnosis and management of craniofacial injuries and pathology. Three-dimensional cone beam CT (CBCT), pioneered in the 1990s, is gaining increasing popularity in dental and craniofacial clinical practice because of its faster image acquisition at a lower radiation dose, but sound guidelines are needed to ensure its optimal clinical use. Recent innovations in micro-computed tomography (micro-CT) have revolutionized craniofacial biology research by enabling higher resolution scanning of teeth beyond the capabilities of MDCT and CBCT, presenting new prospects for translational clinical research. Even after four decades of refinement, CT technology continues to advance and broaden the horizons of craniofacial clinical practice and phenomics research.

Dental phenomics: advancing genotype to phenotype correlations in craniofacial research

The field of dental phenomics provides many opportunities to elucidate the roles of genetic, epigenetic and environmental factors in craniofacial development. To date, research findings have helped to clarify the pathogenesis of many conditions, aiding diagnosis and clinical management. This paper provides an overview of dental phenomics research in some commonly encountered oral diseases in everyday clinical practice, as well as research relating to craniofacial growth and development. Clinically, advances in cariology and periodontology have led to better diagnostic capabilities and treatment provision. In the study of growth and development, important information regarding the varying clinical presentation and pathogenesis of many disorders is now apparent through the accurate quantification of phenotypes. Improvements in two-dimensional (2D) and three-dimensional (3D) imaging and analytical techniques have allowed for accurate dental phenotyping, and efforts are ongoing to apply these in vitro techniques to the in vivo setting. The field of dental phenomics represents an exciting avenue that links research findings to practical application, and collaboration between researcher and clinicians will help advance the field further.

A qualitative assessment of non‐carious cervical lesions in extracted human teeth

BACKGROUND Opinions vary about the causes of non-carious cervical lesions (NCCLs). They have been attributed to toothbrush abrasion, acid corrosion (commonly termed dental erosion), and abfraction. The purpose of this study was to examine the microwear details of NCCLs in a collection of extracted human teeth using scanning election microscopy (SEM). METHODS Negative replicas of large NCCLs in 24 extracted human teeth were obtained in polyvinylsiloxane impression material (Light Body Imprint II, 3M ESPE) and viewed under SEM. RESULTS All NCCLs extended from the cemento-enamel junction to the root surface and they displayed a variety of wedge-shaped appearances. There was evidence of both abrasion and corrosion in 18 of the 24 teeth (75.0 per cent), abrasion only in one tooth (4.2 per cent) and corrosion only in five teeth (20.8 per cent). Horizontal furrows with smooth edges and minor scratch marks, characteristic of abrasion and corrosion, were noted in 13 teeth (54.2 per cent). CONCLUSIONS Based on microscopic assessment of a sample of extracted teeth, it appears that abrasion and corrosion are common associated aetiological factors in the formation of NCCLs.

The teeth and faces of twins: providing insights into dentofacial development and oral health for practising oral health professionals.

The continuing studies of the teeth and faces of Australian twins and their families in the Craniofacial Biology Research Group in the School of Dentistry at the University of Adelaide began 30 years ago. Three main cohorts of twins have been recruited, enabling various objectives and specific hypotheses to be addressed about the roles of genetic, epigenetic and environmental influences on human dentofacial growth and development, as well as oral health. This paper highlights some key findings arising from these studies, emphasizing those of direct relevance to practising oral health professionals. We also draw on published literature to review the significant developments in relation to the use of precision 2D and 3D imaging equipment, the application of modern molecular techniques, and the development of sophisticated computer software for analysing genetic relationships and comparing complex shapes. Such developments are valuable for current and future work. Apart from the classical or traditional twin model, there are several other twin models that can be used in research to clarify the relative contributions of genetic, epigenetic and environmental contributions to phenotypic variation. The monozygotic (MZ) co-twin model is one particularly valuable method, given that examination of only one pair of MZ twins can provide considerable insights into underlying causes of observed variation. This model can be used in a dental practice environment, with oral health professionals having the opportunity to explore differences in orofacial structures between MZ co-twins who are attending as patients. As researchers have become more aware of the complexities of the interactions between the genome, the epigenome and the environment during development, there is the need to collect more phenotypic data and define new phenotypes that will better characterize variations in growth processes and health status. When coupled with powerful new genetic approaches, including genome-wide association studies and linkage analyses, exciting opportunities are opening up to unravel the causes of problems in craniofacial growth and common oral diseases in human populations.