The effect of platelet-rich plasma on osteoblast and periodontal ligament cell migration, proliferation and differentiation

BACKGROUND AND OBJECTIVE

Platelet-rich plasma is used to deliver growth factors, in a safe and convenient manner, for enhancing bone and periodontal regeneration. However, conflicting reports regarding its effectiveness suggest that further study of the relevant cellular mechanisms is required. The aim of this study was to investigate the in vitro effect of platelet-rich plasma on osteoblasts and periodontal ligament cell function.

MATERIAL AND METHODS

Various concentrations of platelet-rich plasma (100, 50, 20 and 10%) and platelet-poor plasma, obtained from human donors, were applied to primary cultures of human osteoblasts and periodontal ligament cells. [(3)H]-Thymidine incorporation, crystal violet staining and MTT assays were utilized to assess DNA synthesis and proliferation. Migration was determined by assessing the cell response to a concentration gradient, while differentiation was assessed using Alazarin Red staining.

RESULTS

Platelet-rich plasma and platelet-poor plasma had stimulatory effects on the migration of both human osteoblasts and periodontal ligament cells. At 24 h, DNA synthesis was suppressed by the application of the various concentrations of platelet-rich plasma, but over a 5-d period, a beneficial effect on proliferation was observed, especially in response to 50% platelet-rich plasma. Platelet-poor plasma resulted in the greatest enhancement of cellular proliferation for both cell types. At a concentration of 50%, platelet-rich plasma and platelet-poor plasma facilitated differentiation of both cell types.

CONCLUSION

Platelet-rich plasma can exert a positive effect on osteoblast and periodontal ligament cell function, but this effect is concentration specific with maximal concentrations not necessarily resulting in optimal outcomes. Platelet-poor plasma also appears to have the ability to promote wound healing-associated cell function.

Periodontitis and rheumatoid arthritis: a review

Periodontitis and rheumatoid arthritis (RA) appear to share many pathologic features. In this review, the common pathologic mechanisms of these two common chronic conditions are explored. Emerging evidence now suggests a strong relationship between the extent and severity of periodontal disease and RA. While this relationship is unlikely to be causal, it is clear that individuals with advanced RA are more likely to experience more significant periodontal problems compared to their non-RA counterparts, and vice versa. A case is made that these two diseases could be very closely related through common underlying dysfunction of fundamental inflammatory mechanisms. The nature of such dysfunction is still unknown. Nonetheless, there is accruing evidence to support the notion that both conditions manifest as a result of an imbalance between proinflammatory and anti-inflammatory cytokines. As a result, new treatment strategies are expected to emerge for both diseases that may target the inhibition of proinflammatory cytokines and destructive proteases. The clinical implications of the current data dictate that patients with RA should be carefully screened for their periodontal status.

Use of the Vectortm scaling unit in supportive periodontal therapy: a subjective patient evaluation

BACKGROUND

Patient discomfort is one reason for poor compliance with supportive periodontal therapy (SPT). The aim of this study was to compare the levels of discomfort during SPT, using the Vector system and treatment with a conventional ultrasonic scaler.

METHODS

Forty-six patients with an SPT programme were debrided using both the Vector system and a conventional piezo-electric scaler (Sirona) in a split mouth design. A visual analogue scale was used to evaluate of pain scores upon completion of treatment. A verbal response scale(VRS) was used to assess discomfort, vibration and noise associated with the scaling system, as well as the volume and taste of the coolant used by these systems.

RESULTS

Patients instrumented with the Vector system experienced approximately half the amount of pain compared with the conventional ultrasonic scaling system. The VRS showed that the Vector system caused less discomfort than the conventional ultrasonic scaling system when assessed for pain, vibration, noise and volume of coolant. These findings were all statistically significant. There was, however, no statistically significant difference between the two systems when assessed for taste.

CONCLUSION

During SPT the Vector system caused reduced discomforting sensations compared with conventional methods and may be useful in improving compliance with SPT programmes.

Prevalence of systemic diseases in Brisbane general and periodontal practice patients

BACKGROUND

Periodontitis has been associated with a number of systemic diseases such as atherosclerosis, coronary heart diseases, and respiratory diseases. This study aimed to determine whether there is a significant difference in the prevalence of systemic diseases (a) in patients referred for periodontal care compared to the general practice population, (b) in patients attending a public hospital and private practices, (c) in patients attending public and private periodontal practices, and (d) among patients with periodontitis of varying severity.

METHODS

Charts of 1000 adult patients were selected from four clinics (University of Queensland (UQ) School of Dentistry Admissions Clinic, UQ School of Dentistry Periodontics Clinic, Private Periodontal Practice, and Private General Dental Practice). The prevalence of medical conditions was evaluated using validated self-reported health questionnaires. The periodontal condition was assessed from the most recent relevant radiographs in the files.

RESULTS

Periodontal patients had a higher prevalence of systemic diseases compared to the general practice population. Public patients had a greater prevalence of systemic diseases compared to patients in private practice for both general practice and periodontal patients. In patients with advanced periodontitis, bronchitis, hepatitis and rheumatoid arthritis were most prevalent. Patients with periodontitis also took more medications and were more likely to suffer from multiple conditions compared to the general dental population.

CONCLUSIONS

Patients attending public dental facilities have an increased prevalence of systemic disease compared to those attending private practices. Furthermore periodontal patients have a greater prevalence of diseases compared to general practice patients. Patients with moderate or advanced periodontitis show an increase in the prevalence of some systemic diseases previously reported to be risk factors for periodontal disease.

Inter-relationships between rheumatoid arthritis and periodontal disease. A review

This review considers the considerable similarities between periodontal disease and rheumatoid arthritis (RA). While the etiology of these two diseases may differ, the underlying pathogenic mechanisms are remarkably similar and it is possible that individuals manifesting both periodontitis and RA may suffer from a unifying underlying systemic dysregulation of the inflammatory response. In light of these findings, the implications for the use of disease-modifying medications in the management of these two chronic inflammatory conditions is apparent. Further longitudinal studies and medication-based intervention studies are required to determine just how closely these two conditions are allied.

Applicability of a computer-assisted image analysis system for the evaluation of gingival status in subjects from Asian and Caucasian backgrounds

We have recently developed a computer program to allow the automatic evaluation of the degree of gingival inflammation. The aim of the present study was to determine the efficiency of our system, which consisted of a digital camera, computer and our original program, in a sample population of various ethnic backgrounds. Digital images of frontal views of maxillary incisors were taken for 141 subjects and then subjected to computer-assisted analysis to determine the degree of redness (colorimetric assessment) and swelling (morphometric assessment) and was compared with the visual assessment of the PMA gingival score. The age of subjects ranged from 19 to 65 (Mean 33.9 SD12.8), and consisted of slightly more females (81) than males (60). Within the study group 78% of subjects classified themselves as Caucasian (European, South American, Middle Eastern), 21% were Asian or Pacific Islander, and 1% was African. The subjects were separated into 9 groups according to their PMA score. In addition, colorimetric and morphometric score were plotted against each other. The colorimetric scores ranged between 55.1 to 64.8 (arbitrary units) and morphometric scores ranged between 0.175 to 0.313 (arbitrary units). There were no ethnic differences with respect to colour and contour when two groups of European (90) and Asian (17), who were scored as 000 using the PMA index, were compared. There was no significant correlation between PMA score and morphometric score (P = 0.0711), but the correlation coefficient between PMA score and colorimetric score was 0.130 (P = 0.0122). Comparison of the highly scored image samples and the lower scored images with the visual assessment codes showed very good correlation. These preliminary findings suggest that the developed computer-assisted image analysis system shows promise for assessing gingival inflammation via an automated method.

Relationship between rheumatoid arthritis and periodontitis

BACKGROUND

Because of several similar features in the pathobiology of periodontitis and rheumatoid arthritis, in a previous study we proposed a possible relationship between the two diseases. Therefore, the aims of this study were to study a population of rheumatoid arthritis patients and determine the extent of their periodontal disease and correlate this with various indicators of rheumatoid arthritis.

METHODS

Sixty-five consecutive patients attending a rheumatology clinic were examined for their levels of periodontitis and rheumatoid arthritis. A control group consisted of age- and gender-matched individuals without rheumatoid arthritis. Specific measures for periodontitis included probing depths, attachment loss, bleeding scores, plaque scores, and radiographic bone loss scores. Measures of rheumatoid arthritis included tender joint analysis, swollen joint analysis, pain index, physician's global assessment on a visual analogue scale, health assessment questionnaire, levels of C-reactive protein, and erythrocyte sedimentation rate. The relationship between periodontal bone loss and rheumatological findings as well as the relationship between bone loss in the rheumatoid arthritis and control groups were analyzed.

RESULTS

No differences were noted for the plaque and bleeding indices between the control and rheumatoid arthritis groups. The rheumatoid arthritis group did, however, have more missing teeth than the control group and a higher percentage of these subjects had deeper pocketing. When the percentage of bone loss was compared with various indicators of rheumatoid arthritis disease activity, it was found that swollen joints, health assessment questionnaire scores, levels of C-reactive protein, and erythrocyte sedimentation rate were the principal parameters which could be associated with periodontal bone loss.

CONCLUSIONS

The results of this study provide further evidence of a significant association between periodontitis and rheumatoid arthritis. This association may be a reflection of a common underlying disregulation of the inflammatory response in these individuals.

Nitric oxide and tissue destruction

Nitric oxide (NO) is a free radical which has complex roles in both health and disease. It is now recognized that NO is essential for a vast spectrum of intracellular and extracellular events in a wide variety of tissues. NO has also been implicated in the pathogenesis of numerous inflammatory and autoimmune diseases. In this review we consider the roles of NO generally and in particular the implications for periodontal diseases.

Australian dentists' views on toothbrush wear and renewal

The purpose of this study was to survey the views of Australian dentists on toothbrush wear, toothbrush renewal periods and recommendations to patients and to investigate the relationship between dentists' views on patients' toothbrush renewal intervals and dentists' own renewal habits. Questionnaires were mailed to 5,596 Australian general dental practitioners and replies received from 3,406 (61 per cent response rate). The majority of respondents (85.7 per cent) felt patients should renew their toothbrushes more often. However, only 45.3 per cent usually made a recommendation to their patients as to when they should renew their toothbrush and only 41.7 per cent thought patients actually followed such recommendations. Most respondents (56.6 per cent) thought the average adult patient should renew a toothbrush every two-three months. A renewal period of one month or earlier was recommended by 23.8 per cent of dentists; four-five months by 8 per cent; and six months or longer by 11.5 per cent. A highly significant correlation was found between the renewal periods recommended for patients and the intervals selected by the dentists for their personal brushes (p < 0.001; chi-square test). Bending and splaying of bristles was the sign identified by the majority of dentists (70 per cent) as indicating the need for a new brush. The findings suggest dentists' recommendations concerning toothbrush renewal intervals may be based on their own toothbrush renewal habits. It is also concluded that dentists think patients comply poorly with their recommendations on toothbrush renewal.

Periodontal implications of immunodeficient states: manifestations and management

The importance of the immune system in modulating the host response to plaque is well recognised, and in this context the immune system is clearly a risk/modifying factor for human periodontal disease. This review examines the periodontal manifestations of subjects with immunodeficiencies and considers potential preventive protocols for the periodontal management of these patients.

Is there a relationship between rheumatoid arthritis and periodontal disease?

AIM

The aim of this study was to determine whether there is a relationship between disease experience of rheumatoid arthritis and periodontal disease.

METHODS

1,412 individuals attending the University of Queensland's School of Dentistry were assessed for the prevalence of periodontal disease and rheumatoid arthritis. Analysis of data obtained from a self-reported health questionnaire and dental records was carried out and included: number of individuals referred for advanced periodontal care (test group); number of individuals attending for routine dentistry; determination of rheumatoid arthritis, cardiovascular disease and diabetes mellitus through self-reporting and assessment of prescription medications; assessment of periodontal disease through assessment of existing oral radiographs.

RESULTS

In patients referred for periodontal treatment, the prevalence of self-reported rheumatoid arthritis was 3.95% which is significantly higher than that seen in patients not referred for periodontal treatment (0.66%) and also that reported in the general population (1%). Of those referred patients with rheumatoid arthritis, 62.5% had advanced forms of periodontal disease. These results were mirrored in the results of the self-reported prevalence of cardiovascular disease and diabetes mellitus which was consistent with the published higher prevalence in periodontal patients.

CONCLUSIONS

Based on data derived from self-reported health conditions, and not withstanding the limitations of such a study, we conclude that there is good evidence to suggest that individuals with moderate to severe periodontal disease are at higher risk of suffering from rheumatoid arthritis and vice versa.

Changes in the periodontal status of patients undergoing bone marrow transplantation

BACKGROUND

Patients receiving an HLA-matched bone marrow transplant (BMT) from a relative or unrelated donor undergo a permanent alteration of their immune system, followed by a prolonged period of immunodeficiency. This study aimed to examine alterations in the periodontal status of patients over 6 months post-bone marrow transplantation.

METHODS

Thirty-seven patients scheduled for bone marrow transplantation participated in this study. One calibrated examiner carried out periodontal examinations (clinical and radiographic) immediately prior to and at 3 and 6 months after transplantation. All patients followed an intense oral care program. Subgingival plaque samples were analyzed by enzyme-linked immunosorbent assay (ELISA) for the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Prevotella intermedia. Data were subjected to statistical analyses to determine the relationships between the frequency distribution of the radiographic and clinical variables over time.

RESULTS

Gains in clinical attachment level (CAL) of > or =2 mm at 4 or more sites from baseline to 6 months post-BMT were noted in 9/16 patients (56%), while 6/16 (38%) patients experienced a loss of CAL > or =2 mm at 4 or more sites in the same period. At a site level, 4.8% of sites exhibited a gain in CAL > or =2 mm between baseline and 3 months post-BMT while 2.3% of sites showed a loss of CAL > or =2 mm in the same period. From baseline to 6 months, a gain in CAL of > or =2 mm was recorded at 3.1% of sites, and 2.4% of sites experienced a loss of > or =2 mm. A significant improvement in the gingival index occurred between all sequential time periods when assessed at a site level. At a patient level, 11/18 (61%) patients showed a significant change in gingival index between baseline and 3 months and 10/16 (63%) between baseline and 6 months. There was no significant relationship between clinical changes and the prevalence of the periodontal pathogens at the various time periods.

CONCLUSIONS

An improvement in periodontal health was recorded between baseline and 6 months post-transplantation. Most of the improvement in periodontal status was noted in the first 3 months after BMT, with a slight decline in periodontal health between 3 and 6 months post-transplant. No significant alteration was noted in the prevalence of periodontal pathogens during the study period.

A clinical review of drug-induced gingival overgrowths

There is an increasing number of medications associated with gingival overgrowth. These medications are used to treat a number of common conditions in the Australian population and as such dentists can expect to manage a number of patients with medication-related gingival overgrowth. This review highlights the clinical features and management of the common overgrowths associated with anticonvulsants, immunosuppressants and the calcium channel blockers.

Medication induced gingival overgrowth

A number of idiopathic, pathological and pharmacological reactions may result in an overgrowth of the gingiva. This review concentrates on those overgrowths associated with various pharmacological agents. The pharmaco-kinetics and side effects of each drug associated with gingival overgrowth are discussed along with the clinical and histological features and treatment. By examining the possible pathogeneses for these overgrowths we propose a unifying hypothesis for the causation based around inhibition of apoptosis and decreased collagenase activity modulated by cytoplasmic calcium.

Occlusal Movements of the Brushtail Possum, Trichosurus-Vulpecula, From Microwear on the Teeth

This study characterises the jaw movements of the brushtail possum, Trichosurus vulpecula, from an analysis of microwear on the premolar and molar teeth. From 10 skulls of T, vulpecula, micrographs of tooth replicas which exhibitied progressive degrees of dental wear were examined for the location of wear facets and the orientation of striae on them. These data were transferred to transparencies overlying occlusal photographs of the jaws. Two movements, a vertical sectorial movement in the premolars segment and an anteromedial shearing and grinding stroke in the molar segment, were inferred. The directions of wear striations with respect to the sagittal plane supported the concept that the mandible rotates around the contralateral condyle from the working side. No evidence of balancing contact facets were found on the teeth of the contralateral side, in agreement with an anisognathous jaw movement. Videoradiographic observations of the chewing cycle of one brush-tailed possum confirmed that puncture crushing is employed early in the chewing cycle, followed by an anisognathous labiolingual transit of the mandibular molars. However, the resolution of the condyle by videoradiography was insufficient to determine the point of rotation of the jaw movements.