Calculus revisited. A review

Periodontitis and alveolar resorption in human skeletal remains: The relationship between quantitative alveolar bone loss, occlusal wear, antemortem tooth loss, dental calculus and age at death in a low socioeconomic status, modern forensic human collection from Yucatan

OBJECTIVE

This paper assesses the relationship between the distance between the cemento-enamel junction and alveolar crest and risk factors commonly associated with periodontitis.

MATERIALS

Eighty individuals between 28 and 92 years old with known biological sex and age were analyzed from a 20th century forensic human collection from Merida, Yucatan (Mexico).

METHODS

Macroscopic assessment, along with metric analysis, was employed using a probe.

RESULTS

Ante-mortem tooth loss was positively correlated with the distance between the cemento-enamel junction and alveolar crest, as was the presence of root calculus in females.

CONCLUSIONS

Cemento-enamel junction to alveolar crest distance is not a reliable indicator of periodontitis since it is not directly related to periodontitis-causing infectious pathogens, and since ante-mortem tooth loss can affect root exposure.

SIGNIFICANCE

This study demonstrates that a purely quantitative approach to diagnosing periodontitis in archaeological and forensic human remains can be misleading.

LIMITATIONS

The skeletal collection is only representative of the low socioeconomic class of Merida, and its female cohort is underrepresented. In addition, because the Xoclan collection is modern, limitations (particularly with respect to tooth wear) of the applicability of these interpretations to older archaeological remains exist.

SUGGESTION FOR FURTHER RESEARCH

A combination of quantitative and qualitative characteristics of alveolar bone is needed to reliably diagnose periodontitis in skeletal populations.

Effect of salivary urea, pH and ureolytic microflora on dental calculus formation and its correlation with periodontal status

Context

Dental calculus, formed by mineralization of plaque predisposes to the development of periodontal disease.

Aim

To evaluate the influence of salivary urea and the presence of ureolytic bacteria on dental calculus formation and periodontal status in patients with good, fair and poor oral hygiene.

Material and methods

An observational cross-sectional study was carried out on 135 patients, 18–60 years of age. Based on the simplified calculus index, patients were divided into three groups, good oral hygiene, fair oral hygiene and poor oral hygiene. Clinical parameters such as plaque index, gingival index, pocket probing depth and clinical attachment level and salivary pH were recorded for each subject. Saliva samples were collected to evaluate the urea levels using autoanalyzer method. Supragingival calculus samples were collected and presence and quantification of ureolytic bacteria were done by gram staining and bacterial culture and confirmed by biochemical reaction. For statistical analysis, test like Shapiro-Wilk test, Kruskal Wallis and Spearman's rho were used.

Results

Increase in salivary pH was associated with increased odds of higher calculus index score (odds ratio = 2.785). There was a non-significant weak correlation between salivary urea and ureolytic bacteria in dental calculus in all the three groups (p > 0.05). Higher calculus index score was associated with increased odds of presence of ureolytic bacteria (odds ratio>1).

Conclusions

Higher level of ureolytic bacteria with increasing calculus index score may breakdown the salivary urea to ammonia resulting in a ureolytic pH rise that facilitate calcium phosphate saturation leading to more calculus formation.

A re-evaluation of scaling and root planing

BACKGROUND

Extensive reviews on the role of scaling and root planing (SRP) in the treatment of periodontitis have been previously published. This commentary will address the importance of subgingival calculus in the progression and treatment of periodontitis and addresses factors that make the execution of a "definitive" SRP a critical part of therapy.

METHODS

A search for articles, using keywords relevant to the subject , (e.g., periodontitis, dental scaling, root planing, dental calculus, biofilm, inflammation) was conducted using PubMed, Ovid Medline, Cochrane Reviews and the ADA Center for Evidence Based Dentistry data bases. Additionally, references cited in relevant articles were also considered.

RESULTS

Surfaces of subgingival calculus are covered with a biofilm of metabolically active bacteria. Periodontal inflammation is clearly related to the presence of calculus and biofilm. The primary goal of SRP is removal of subgingival calculus and biofilm deposits to create a biologically compatible root surface and reduce the inflammatory burden. Current evidence suggests that inflammation associated with periodontal infections affects both the immediate oral environment and the patient's systemic health.

CONCLUSION

SRP is still critical to the treatment of periodontitis. SRP involving deep probing depths (≥ 5 mm) and root surfaces with anatomical and surface irregularities, regardless of the type of instrumentation, requires time, exceptional skill and perseverance, and patient compliance with periodontal maintenance. Sites with persistent nonresponding probing depths and signs of inflammation following a definitive SRP, should be considered for surgical intervention.

Accuracy of dental calculus detection using digital radiography and image manipulation

BACKGROUND

The aim of this study was to determine if image enhancement improves a clinician's ability to identify the presence of calculus on digital radiographs.

METHODS

Seventy-one hopeless teeth were collected from 34 patients. Teeth were stained with 1% methylene blue, the largest interproximal calculus deposit was scored, and photographs of each interproximal root surface were taken. The surface area of calculus deposit was determined as a percentage of the total interproximal root surface area. Digital radiographs of teeth taken before extraction were modified using the following enhancements: auto-contrast, emboss, invert, and sharpen. Radiographic presence of calculus was determined by two examiners. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each examiner and enhancement. A receiver operating characteristic curve was used to compare differences between the image enhancements in the detection of dental calculus. The kappa statistic was used to compare ratings between examiners.

RESULTS

None of the enhanced images were statistically superior to original images in identifying radiographic calculus (P > 0.05). The average sensitivity of digital radiography was 50%, average specificity was 82.2%, PPV was 94%, and NPV 23.2%. A threshold of >30% of interproximal root surface covered with calculus and increasing size of deposits were associated with improved detection (P < 0.05).

CONCLUSIONS

Digital enhancements do not significantly improve radiographic detection of dental calculus. As area of calculus on the root surface and size of calculus deposits increased, sensitivity of detection also increased.

Analysis of Predisposing Factors for Rapid Dental Calculus Formation

Background: Calculus accumulation varies widely between individuals. Dental calculus has been associated with the principal periodontal diseases. The aim of this study was to analyze individual characteristics, and salivary and microbiological parameters among patients considered to be rapid calculus formers and patients who form calculus slowly. Methods: Individual characteristics were recorded in a sample of 74 patients (age, sex, smoking, periodontal diagnosis, and dental crowding), as well as salivary parameters (unstimulated saliva flow, pH, and biochemical analysis of saliva) and microbiological parameters (by means of semi-quantitative polymerase chain reaction (PCR) analysis). Results: A statistically significant association (p = 0.002) was found between the rate of calculus formation and the diagnosis of periodontal disease. A greater presence of dental crowding was observed among the group of rapid calculus formers. Urea and phosphorus levels were higher among rapid calculus formers. Regarding microbiological parameters, differences were found in Streptococcus mutans, this being higher in the group of slow formers. Conclusions: Rapid calculus formation appears to be linked to patients diagnosed with more severe periodontal diseases. Rapid calculus-forming patients present more dental crowding and a lower proportion of S. mutans.

Assessment of the capacity of a pyrophosphate-based mouth rinse to inhibit the formation of supragingival dental calculus. A randomized double-blind placebo-controlled clinical trial

Background

This study aimed to analyze the efficacy of an anti-calculus mouth rinse and its possible adverse effects on the mucosa and teeth.

Material and Methods

This randomized double-blind placebo-controlled clinical trial included 40 patients with treated and managed periodontal disease, all with a history of rapid calculus formation. Patients used a pyrophosphate-based test mouth rinse (B) or a placebo (A). A range of parameters were measured for: saliva (saliva flow, pH and chemical composition); calculus (Volpe-Manhold [V-M] index, weight, and volume); adverse effects on mucosa and teeth; and the patients’ subjective perceptive of mouth rinse efficacy.

Results

The test mouth rinse B produced reductions in urea, uric acid, and phosphorous, calcium, saliva flow, and increases in pH. V-M index and calculus weight decreased after using the test mouth rinse. Calculus volume decreased with both mouth rinses. No changes to the mucosa or teeth were observed. Patients perceived that the test mouth rinse was more effective.

Conclusions

The test/B and placebo mouth rinses both modified certain parameters in saliva composition, particularly reductions in urea, uric acid, and phosphorous. Calcium tended to increase after using the test-B mouth rinse. The results did not demonstrate the anticalculus efficacy of the pyrophosphate-based mouth rinse or positive effects on saliva flow or composition. This field requires further research, as no product has been developed that prevents calculus formation completely.

Key words:Dental calculus, anticalculus mouth rinse, Volpe Manhold index.

Validation of Quantitative Light-Induced Fluorescence for Quantifying Calculus on Dogs' Teeth

Periodontal disease is a common disease of dogs and is initiated by the buildup of plaque on the tooth surface. As plaque matures, it becomes mineralized to form calculus, which although not directly involved in the etiology of periodontal disease, provides an irregular surface to which plaque can adhere. Evaluation of the quantity of plaque and calculus on dogs' teeth is therefore essential to enable the efficacy of products, designed to prevent or retard plaque and calculus accumulation, to be evaluated. The objective of this study was to determine whether quantitative light-induced fluorescence (QLF^TM) is a suitable tool to quantify the amount of calculus on the buccal surface of dogs' teeth following the removal of disclosed plaque by tooth brushing. The amount of calculus on the teeth of 26 miniature schnauzers was measured, using QLF and a calculus index method (Warrick-Gorrel), during a 28-day phase crossover study comparing feeding a daily dental chew versus providing no daily chew. Quantification of calculus using the Warrick-Gorrel method showed a 43.8% reduction in calculus buildup, with 95% confidence interval of 27.3 to 60.3 ( P < .001). With QLF, the percentage reduction in calculus accumulation was 65.8% (58.1-73.4, P < .001). A retrospective sample size analysis showed that fewer dogs were required for QLF analysis compared to the Warrick-Gorrel method. This study demonstrated that QLF is a sensitive and precise method for quantification of calculus on dogs' teeth. It removes the subjective element of human examiners and has greater accuracy and reduced variability through the continuous nature of the data.

In vitro performance of DIAGNOdent laser fluorescence device for dental calculus detection on human tooth root surfaces

OBJECTIVE

This study assessed the reproducibility of a red diode laser device, and its capability to detect dental calculus in vitro on human tooth root surfaces.

MATERIAL AND METHODS

On each of 50 extracted teeth, a calculus-positive and calculus-free root surface was evaluated by two independent examiners with a low-power indium gallium arsenide phosphide diode laser (DIAGNOdent) fitted with a periodontal probe-like sapphire tip and emitting visible red light at 655 nm wavelength. Laser autofluorescence intensity readings of examined root surfaces were scored on a 0-99 scale, with duplicate assessments performed using the laser probe tip directed both perpendicular and parallel to evaluated tooth root surfaces. Pearson correlation coefficients of untransformed measurements, and kappa analysis of data dichotomized with a >40 autofluorescence intensity threshold, were calculated to assess intra- and inter-examiner reproducibility of the laser device. Mean autofluorescence intensity scores of calculus-positive and calculus-free root surfaces were evaluated with the Student's t-test.

RESULTS

Excellent intra- and inter-examiner reproducibility was found for DIAGNOdent laser autofluorescence intensity measurements, with Pearson correlation coefficients above 94%, and kappa values ranging between 0.96 and 1.0, for duplicate readings taken with both laser probe tip orientations. Significantly higher autofluorescence intensity values were measured when the laser probe tip was directed perpendicular, rather than parallel, to tooth root surfaces. However, calculus-positive roots, particularly with calculus in markedly-raised ledges, yielded significantly greater mean DIAGNOdent laser autofluorescence intensity scores than calculus-free surfaces, regardless of probe tip orientation. DIAGNOdent autofluorescence intensity values >40 exhibited a stronger association with calculus (36.6 odds ratio) then measurements of ≥5 (20.1 odds ratio) when the laser probe tip was advanced parallel to root surfaces.

CONCLUSIONS

Excellent intra- and inter-examiner reproducibility of autofluorescence intensity measurements was obtained with the DIAGNOdent laser fluorescence device on human tooth roots. Calculus-positive root surfaces exhibited significantly greater DIAGNOdent laser autofluorescence than calculus-free tooth roots, even with the laser probe tip directed parallel to root surfaces. These findings provide further in vitro validation of the potential utility of a DIAGNOdent laser fluorescence device for identifying dental calculus on human tooth root surfaces.

Inhibition of Formation of Calcium Phosphate Deposits on Teeth and Dental Materials: Recent Advances

The inorganic composition of dental calculi from teeth and dentures has been characterized by x-ray diffraction, electron microprobe, and infrared absorption spectroscopy. They consist of carbonated hydroxylapatite (CHA), dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP), and magnesium-substituted beta-tricalcium phosphate (6-TCMP). The calculi on denture surfaces are principally CHA. Formulations have been developed to inhibit formation of these calculi in humans. The active inhibitors are pyrophosphate, pyrophosphate plus polymer, and zinc salts. These agents inhibit calculus formation in humans by preventing the formation of hydroxyapatite crystals. The new formulations include multiple-benefits products containing fluoride and antimicrobial and/or desensitizing agents. These provide not only reduction in calculus formation in humans but also reduced plaque, gingivitis, and/or dentinal hypersensitivity. Recent studies have also indicated a relationship between gingival recession and supragingival calculus in the Thai population, and the use of an anticalculus formulation has shown significant improvement in gingival recession in this population.

Dental Calculus Stimulates Interleukin-1β Secretion by Activating NLRP3 Inflammasome in Human and Mouse Phagocytes

Dental calculus is a mineralized deposit associated with periodontitis. The bacterial components contained in dental calculus can be recognized by host immune sensors, such as Toll-like receptors (TLRs), and induce transcription of proinflammatory cytokines, such as IL-1β. Studies have shown that cellular uptake of crystalline particles may trigger NLRP3 inflammasome activation, leading to the cleavage of the IL-1β precursor to its mature form. Phagocytosis of dental calculus in the periodontal pocket may therefore lead to the secretion of IL-1β, promoting inflammatory responses in periodontal tissues. However, the capacity of dental calculus to induce IL-1β secretion in human phagocytes has not been explored. To study this, we stimulated human polymorphonuclear leukocytes (PMNs) and peripheral blood mononuclear cells (PBMCs) with dental calculus collected from periodontitis patients, and measured IL-1β secretion by ELISA. We found that calculus induced IL-1β secretion in both human PMNs and PBMCs. Calculus also induced IL-1β in macrophages from wild-type mice, but not in macrophages from NLRP3- and ASC-deficient mice, indicating the involvement of NLRP3 and ASC. IL-1β induction was inhibited by polymyxin B, suggesting that LPS is one of the components of calculus that induces pro-IL-1β transcription. To analyze the effect of the inorganic structure, we baked calculus at 250°C for 1 h. This baked calculus failed to induce pro-IL-1β transcription. However, it did induce IL-1β secretion in lipid A-primed cells, indicating that the crystalline structure of calculus induces inflammasome activation. Furthermore, hydroxyapatite crystals, a component of dental calculus, induced IL-1β in mouse macrophages, and baked calculus induced IL-1β in lipid A-primed human PMNs and PBMCs. These results indicate that dental calculus stimulates IL-1β secretion via NLRP3 inflammasome in human and mouse phagocytes, and that the crystalline structure has a partial role in the activation of NLRP3 inflammasome.

Bacterial Viability within Dental Calculus: An Untrodden, Inquisitive Clinico-Patho- Microbiological Research

INTRODUCTION

Chronic inflammatory periodontal diseases i.e. gingivitis and periodontitis are one of the most common afflictions faced by human beings. Dental plaque, which is a pool of pathogenic microorganisms, remains to be current mainstay in etiopathogenesis. Dental calculus, which is a mineralized product of this plaque remains ignored and is considered merely as an ash heap of minor significance. However, the intriguing array in disease etiopathogenesis bulldozed researchers to suspect the role of calculus in disease chrysalis but still the viability of bacteria inside calculus and thus its pathogenicity remains an intricacy; the answer to which lies in the Pandora's Box.

AIM

The present study was undertaken to investigate the viability of bacteria within dental calculus along with their identification. Also, to classify dental calculus on the basis of mineralization and to observe the variation of viable microflora found in dental calculus with the extent of mineralization and disease severity.

MATERIALS AND METHODS

A total of 60 samples were obtained, by harvesting two samples of supragingival calculus from each patient having chronic inflammatory periodontal disease. These samples were divided into two groups (Group A and Group B). Samples of Group A were kept non-irradiated and samples of Group B were exposed to UV radiation. The samples were categorized into less, moderately and highly mineralized according to the force required for crushing them. All the crushed calculus samples were then divided into three parts. These were used for dark-field microscopy, gram staining and bacterial cultures. Bacterial identification of the cultures obtained was also carried out by performing various biochemical assays.

RESULTS

The present study revealed the presence of motile spirochaetes within the samples under dark-field microscope. Gram staining revealed presence of numerous gram positive cocci and gram negative bacilli. Bacterial cultures showed growth of variety of aerobic and capnophilic microorganisms.

CONCLUSION

The present study concludes the presence of viable aerobic and capnophilic bacteria inside dental calculus which may reside within the lacunae and channels in the calculus.

DIAGNOdent Pen versus tactile sense for detection of subgingival calculus: an in vitro study

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.

Time to shift: from scaling and root planing to root surface debridement

Non-surgical periodontal treatment has traditionally been based on the notion that bacterial plaque (dental biofilm) penetrates and infects dental cementum. Removal of this infected cementum via scaling and root planing (SRP) was considered essential for re-establishing periodontal health. In the 1980s the concept of SRP was questioned because several in vitro studies showed that the biofilm was superficially located on the root surface and its disruption and removal could be relatively easily achieved by ultrasonic instrumentation of the root surface (known as root surface debridement (RSD). Subsequent in vivo studies corroborated the in vitro findings. There is now sufficient clinical evidence to substantiate the concept that the deliberate removal of cementum by SRP is no longer warranted or justified, and that the more gentle and conservative approach of RSD should be implemented in daily periodontal practice.

Dental calculus is associated with death from heart infarction

Objectives. We studied whether the amount of dental calculus is associated with death from heart infarction in the dental infection—atherosclerosis paradigm. Materials. Participants were 1676 healthy young Swedes followed up from 1985 to 2011. At the beginning of the study all subjects underwent oral clinical examination including dental calculus registration scored with calculus index (CI). Outcome measure was cause of death classified according to WHO International Classification of Diseases. Unpaired t-test, Chi-square tests, and multiple logistic regressions were used. Results. Of the 1676 participants, 2.8% had died during follow-up. Women died at a mean age of 61.5 years and men at 61.7 years. The difference in the CI index score between the survivors versus deceased patients was significant by the year 2009 (P < 0.01). In multiple regression analysis of the relationship between death from heart infarction as a dependent variable and CI as independent variable with controlling for age, gender, dental visits, dental plaque, periodontal pockets, education, income, socioeconomic status, and pack-years of smoking, CI score appeared to be associated with 2.3 times the odds ratio for cardiac death. Conclusions. The results confirmed our study hypothesis by showing that dental calculus indeed associated statistically with cardiac death due to infarction.

Evaluation of marginal alveolar bone height for early detection of periodontal disease in pediatric population: clinical and radiographic study

OBJECTIVES

To establish a normal range for the radiographic distance between cementoenamel junction and alveolar bone crest and the factors affecting distances for the early assessment of periodontal disease in Dravidian pediatric population.

METHODS

Fifty children aged 6 to 8 years were selected based on inclusion and exclusion criteria. Clinical and radiographic examination was performed. All the surfaces were examined starting from the distal surface of primary canine to the mesial surface of first permanent molar. The various risk factors like plaque, calculus, proximal caries, restoration and bleeding on probing were recorded. A pair of bitewing radiographs was taken for each child. Bitewing radiographs were traced and analyzed.

RESULTS

It showed that CEJ-ABC distance in primary teeth is about 1 ± 0.5 mm. In the permanent teeth, it was found to be 0.6 ± 0.5 mm in 6 to 8 years age group. CEJ-ABC distance was also affected by different variables like physiologic (eruption and exfoliation) and pathologic factors (plaque, calculus, dental caries, restorations, stainless steel crowns, bleeding on probing and probing depth).

CONCLUSION

CEJ-ABC distances greater than 2.5 mm should be considered under recall and follow-up. Children and adolescents susceptible to periodontal disease should be identified by radiographic means as early as possible in order to prevent the advance of an otherwise possibly destructive disease. The concept of oral health examination and treatment must include examination of the periodontal status of the patient.

Viability of bacteria in dental calculus - A microbiological study

Aim:

The aim of this study was (1) To investigate the viability of bacteria within supragingival and subgingival calculus, (2) To examine motility of bacteria, and (3) To identify bacterial morphotypes in calculus.

Materials and Methods:

Supra and subgingival calculus were harvested from 30 subjects having clinical evidence of chronic inflammatory periodontal disease and were divided into two groups. Samples from both groups were immediately transported to the Department of Microbiology for gram staining, acridine orange staining, bacterial culture and to the Department of Oral Pathology for dark field microscopy.

Results:

Gram staining revealed presence of bacteria within the samples.Dark field microscopic examination revealed presence of filamentous organisms, spirochetes, and motile short bacilli. Acridine orange fluorescent stain showed that the viable bacteria appeared apple green. Bacterial culture revealed presence of a variety of aerobic organisms.

Conclusion:

From the results, it appeared that viable bacteria were present within calculus especially within internal channels and lacunae.

A survey on misunderstanding of dental scaling in Hong Kong

There is no information on the misunderstanding of dental scaling; on whether the misunderstanding affects the general public to go for scaling or not; on complaints about dental scaling and suggestion of who should educate the public in the existing literature. This study gives the information from the general public in Hong Kong.

METHODS

A cross-sectional survey by telephone interview on a random sample of 1412 subjects aged 13 years and above in Hong Kong was conducted from 3rd January to 15th February 2006.

RESULTS

More females had received scaling (adjusted OR = 1.73, 95%CI 1.31-2.29 P < 0.001), 51-60 years age group had the highest scaling experience (adjusted OR = 2.69, 95% CI 1.55-4.68, P < 0.001). Higher education was related to scaling experience (P < 0.001). Of the subjects with complete data, 22.5% (307/1364) had never received dental scaling, 17.9% (55/307) did not understand the purpose, 12.1% (37/307) replied that it would make the teeth thinner, 11.4% (35/307) replied that the gum space would become wider, and 11.4% (35/307) stated that scaling would damage the gum. In all, 45.9% (298/649) of the subject reported bleeding, 33.7% (139/413) sensitivity, 40.5% (62/153) smaller teeth and 23.9% (84/351) widened gum space because of mistakes made during the procedure; 8.6% (56/649) of those who experienced bleeding, 17.8% (27/152) of those who reported the teeth became smaller and 12% (42/350) of those who stated that the gum space became wider intended to reduce the frequency, delay or not go for scaling. A total of 79.6% (841/1057) experienced one of the perceived problems; 27.8% (234/841) had complained about scaling.

CONCLUSION

This study shows a common lack of knowledge of dental scaling in the Hong Kong population. Patients should be better informed about the aim before the procedure.

Is there any relation of nanobacteria with periodontal diseases?

Periodontal diseases, including gingivitis and periodontitis, have been described as inflammation of the supporting tissues of the teeth. The main cause of periodontal disease is dental plaque. If dental plaque is not eliminated of dental surface, mineralized dental plaque (calculus) occur. The mineralization process of calculus is similar to that of other ectopic calcifications, such as kidney stones and gallstones. The presence of a certain type of microorganism discovered during the last decade in various pathogenic calcification such as renal stones, atherosclerotic plaques. This microorganism is nanobacterium that has unique characteristics in different regards. Nanobacteria appear as self-propagating calcifying macro-molecular complexes found in bovine and human blood and blood products. The fact that nanobacteria is present in various pathogenic calcification incidences in the body and that it is responsible for the formation of calcification may remind us the hypothesis that it may be present in dental calculus which has a similar mineralization formation process and that it may play an efficient role in the calcification of dental calculus. Thus, nanobacteria may be considered to be a risk factor for the periodontal diseases providing that it has effect on the formation of dental calculus. The nucleating role of the microorganisms in the formation of dental calculus show similarities to that of nanobacteria in calcification. What is more significant is that the presence of an alkali environment is essential for nanobacteria to cause calcification as is the case for dental calculus to occur. These significant conditions support the idea that nanobacteria may be present in the formation and in the contents of dental calculus. Unfortunately, there are only few studies on nanobacteria conducted in the field of dentistry. It is not known whether or not dental plaque is associated with nanobacteria. A study may reveal the fact whether nanobactera are really a new bacteria species or they were the bacteria previously found and given a different name, but not yet proved to be involved in calcification. Nanobacteria may be proved to be a helpful criterion in explaining the relation of nanobacteria with periodontal disease formation.

An in vitro study of the effect of some dietary components on calculus formation: regulation of calcium phosphate precipitation

OBJECTIVE

We studied the effects of food components on the in vitro formation of calcium phosphate precipitates.

MATERIALS AND METHODS

The effects of food components, such as starch, soybean flour, fish meal, rapeseed oil, and coconut oil, on calcium phosphate precipitation were studied using a pH drop method.

RESULTS

Although the addition of starch had no effect on the rate of precipitation of amorphous calcium phosphate (ACP), it increased both the rate of transformation of ACP to hydroxyapatite (HAP) and the induction time (i.e. time for the initiation of transformation of ACP to HAP to occur); this was irrespective of the heat treatment of the starch. Amylopectin (insoluble constituent of starch) was effective in increasing the rate of HAP transformation, but amylose (soluble constituent of starch) was not. Oil specimen obtained from rapeseed (400 microl ml(-1)) increased the entire reaction of calcium phosphate precipitation, but that from coconut did not. Protein food, such as soybean flour and fish meal, decreased the rate of transformation of ACP to HAP and increased the induction time, while they had no effect on the rate of ACP precipitation.

CONCLUSION

These results suggest that carbohydrate and oil (both are staple diets for the humans) enhance oral calcification (dental calculus formation or re-mineralization of tooth enamel), while side dishes of protein food would decrease it.

Real-time detection of dental calculus by blue-LED-induced fluorescence spectroscopy

Successful periodontal therapy requires sensitive techniques to discriminate dental calculus from healthy teeth. The aim of the present study was to develop a fluorescence-based procedure to enable real-time detection and quantification of dental calculus. Thirty human teeth--15 teeth with sub- and supragingival calculus and 15 healthy teeth--covered with a layer of physiological saline solution or blood were illuminated by a focused blue LED light source of 405 nm. Autofluorescence spectra recorded along a randomly selected line stretching over the crown-neck-root area of each tooth were utilized to evaluate a so called calculus parameter R, which was selected to define a relationship between the integrated intensities specific for healthy teeth and for calculus in the 477-497 nm (S(A)) and 628-685 nm (S(B)) wavelength regions, respectively. Statistical analysis was performed and a cut-off threshold of R=0.2 was found to distinguish dental calculus from healthy teeth with 100% sensitivity and specificity under various experimental conditions. The results of the spectral evaluation were confirmed by clinical and histological findings. Automated real-time detection and diagnostics for clinical use were implemented by a corresponding software program written in Visual Basic language. The method enables cost-effective and reliable calculus detection, and can be further developed for imaging applications.

A new system to detect residual subgingival calculus: in vitro detection limits

AIM

We recently introduced an experimental surface detection system based on a conventional dental ultrasonic scaler. This device automatically discriminates cementum and dental calculus, which is the prerequisite for complete and thorough calculus removal. In the present study, the detection limits of this device were tested in vitro.

MATERIAL AND METHODS

From 50 extracted teeth, subgingival calculus was gradually removed using a Gracey curette. During this stepwise procedure, detection properties of the surface detection system were continuously monitored and systematically verified until the system stopped discriminating calculus from the root surface. By measuring the diameter, circumference and area of the smallest, yet recognizable deposit, and of the no longer recognizable deposit, the cut-off point of the discriminative capability of the detection device was determined.

RESULTS

The cut-off points for the correct classification of residual deposits averaged on a diameter of 219 microm, an area of 21,600 microm2, and a circumference of 748 microm. This means a sensitivity of 73% and a specificity of 80% in this critical area.

CONCLUSIONS

This calculus detection system was able to detect small deposits. In clinical practice, this device may support dentists in deciding whether to stop or to continue the debridement.

Scanning electron microscopic and profilometric study of different sharpening stones

Scaling and root planing contribute to the recovery of periodontal health. All periodontal instruments loose their fine cutting angle after use. To maintain this angle, correct sharpening is required using specifically designed stones. The characteristics of sharpening stones can be compared to the blade of the instruments and also transported to root surface during instrumentation. Root smoothness is related to the quality of the blade. Therefore, the purpose of this study was to evaluate the characteristics of 9 sharpening stones by scanning electron microscopic and profilometric analyses. Ceramic and Neumar stones were very fine and both may be recommended to maintain the sharpness of the instruments. Arkansas, Thompson and CE stones presented greater roughness with very regular and round particles, and are suitable for maintenance of the cutting angle. In addition, these stones may be indicated for the routine sharpening of the instruments that are partly dull. Oxide Aluminum, Carborundum and JON stones were the coarsest with large irregular particles and may be indicated for initial sharpening of totally dull instruments with completion of sharpening with finer stones.

Detection of Subgingival Calculus With a Novel LED-Based Optical Probe

BACKGROUND

A recently introduced detection device is designed for objective subgingival calculus diagnosis. The aim of the present study was to assess the possibility of detecting subgingival calculus with this novel LED-based optical probe in vitro.

METHODS

Twenty extracted human teeth with calculus on the root surface were fixed on a translation stage. Measurements on the root surface were carried out in increments of 0.25 mm with an angulation of 0 to 10 degrees , 45 degrees , or 90 degrees to the optical fiber. Teeth were covered either with sodium chloride (NaCl) or blood in order to determine the influence of ambient fluids. Successional areas of positive measurements were defined as "length of positive values" (LPV). The results were compared to the clinical and histological findings.

RESULTS

Clinically and histologically apparent calculus on the root surface was accompanied by positive measurement values. A reduction of the angulation between probe and root surface resulted in shorter LPV when measurements were performed in blood (P <0.05) and longer LPV employing NaCl as the ambient fluid (P <0.05). For both blood and NaCl, sensitivity and/or specificity values decreased when using lower angulations.

CONCLUSION

The optical probe offers the possibility of subgingival calculus detection and may, therefore, be suited to determine the endpoint of root surface instrumentation during non-surgical periodontal therapy.

Efficiency of subgingival calculus removal with the Vectortm-system compared to ultrasonic scaling and hand instrumentation in vitro

OBJECTIVE

The recently introduced Vector-system (Duerr Dental, Bietigheim-Bissingen, Germany) is recommended to be used in conjunction with different insert tips and irrigation fluids. The aim of the study was to assess subgingival calculus removal depending on the mode of operation and to compare the results to conventional methods for root debridement.

METHODS

Sixty extracted human teeth with calculus on the root surface were treated in an artificial periodontal pocket model using six methods: Vector-system with metal probe insert (VPP) or metal curette insert (VPC), both used with polishing fluid, Vector-system with metal probe insert (VAP) or metal curette insert (VAC), both used with abrasive fluid, EMS-ultrasonic system (U) and hand instrument (Gracey curette). Photographs of the root surface were taken at intervals of 10 s and calculus removal was assessed using a surface analysis software until the root surfaces were cleaned completely. Analysis of variances (ANOVA) of the ranks with subsequent comparison of mean ranks and calculation of homogeneous groups (Scheffe) were used for statistical analysis.

RESULTS

Employing the hand instrument, highest efficiency could be observed (0.340 mm2/s). Calculus removal with the Vector-system and metal probe insert (VPP: 0.036 mm2/s; VAP: 0.067 mm2/s) was less effective (p < 0.05) than using the system with metal curette inserts (VPC: 0.122 mm2/s; VAC: 0.209 mm2/s). Employing the abrasive fluid, removal of deposits with the metal curette insert was as efficient as with the conventional ultrasonic system (U: 0.199 mm2/s, p > 0.05).

CONCLUSION

The present in vitro study indicates that the efficiency of calculus removal with the Vector-system is significantly dependent on the selection of inserts and irrigation fluids.

A preliminary investigation into the ultrastructure of dental calculus and associated bacteria

INTRODUCTION

Though dental calculus is generally recognised as comprising mineralised bacteria, areas of non-mineralised bacteria may be present.

AIM

To investigate the ultrastructure of non-decalcified young and mature supragingival calculus and subgingival calculus, and the possible presence of internal viable bacteria.

MATERIALS AND METHODS

Supragingival calculus was harvested from five patients, 9-10 weeks after scaling and root debridement. Five samples of mature supragingival and subgingival calculus were taken from patients presenting with adult periodontitis. Specimens were fixed and embedded for transmission electron microscopy.

RESULTS

The ultrastructure of young and mature supragingival calculus was similar with various large and small crystal types. Non-mineralised channels were observed extending into the calculus, often joining extensive lacunae, both containing intact non-mineralised coccoid and rod-shaped microorganisms. Subgingival calculus possessed more uniform mineralisation without non-mineralised channels and lacunae.

CONCLUSION

Supragingival calculus contains non-mineralised areas which contain bacteria and other debris. The viability of the bacteria, and their identification could not be determined in this preliminary investigation. As viable bacteria within these lacunae may provide a source of re-infection, further work needs to be done to identify the bacteria in the lacunae, and to determine their viability.

Inhibitory Effect of a Novel Bisphosphonate, TRK-530, on Dental Calculus Formation in Rats

BACKGROUND

A newly developed bisphosphonate, TRK-530 (disodium dihydrogen[4-(methylthio)phenylthio]methanebisphosphonate), has recently been reported to show anti-inflammatory and anti-bone-resorbing activity. Since bisphosphonates have been shown to inhibit the formation of calcium-phosphate crystals in vitro, TRK-530 may inhibit the formation of dental calculus. Therefore, the present study was performed to examine whether this compound has such an effect.

METHODS

Three groups of Wistar rats fed a calculogenic diet (RC16) were treated with TRK-530 in drinking water at concentrations of 0 (control group), 0.75, and 1.5 mM. Another group received a daily subcutaneous injection of TRK-530 at a dose of 2.25 micromoles/rat, which was assumed to correspond to the maximum amount of this compound absorbed from the intestine when rats received 1.5 mM TRK-530 in drinking water. Rat dental calculus formation was evaluated. The crystalline nature of dental calculus was studied by x-ray diffraction analysis. Finally, the effects of TRK-530 on the precipitation of calcium-phosphate from solution were tested in vitro.

RESULTS

TRK-530 in drinking water inhibited dental calculus formation dose-dependently. However, subcutaneous injection of TRK-530 did not have any significant effect, suggesting that the anticalculus effect of TRK-530 in drinking water was topical, not systemic. The calculus that formed in both the control and experimental groups was primarily hydroxyapatite, a main constituent of human dental calculus. TRK-530 inhibited the precipitation of calcium-phosphate from solution in vitro.

CONCLUSIONS

TRK-530 inhibited the formation of dental calculus in a dose-dependent fashion via a local effect. Inhibition of the precipitation of calcium-phosphate from solution might be involved in the anticalculogenic mechanism of this drug.

Study of Bacterial Viability within Human Supragingival Dental Calculus

BACKGROUND

There is evidence that supragingival calculus contains unmineralized channels and lacunae. The purpose of this study was to investigate the viability of bacteria within these areas.

METHODS

Supragingival calculus harvested from patients with moderate to severe chronic periodontitis was immediately frozen to -70 degrees C. Six samples were cryosectioned, stained with a bacterial viability kit, and examined with fluorescence microscopy. Controls comprised heat treatment of cryosections prior to staining. Four additional samples were stained and examined whole in a confocal laser scanning microscope (CLSM). Nine additional samples were prepared for bacterial culture, after initial irradiation with ultraviolet light to kill viable organisms on the covering plaque layer. Test samples were crushed to expose internal bacteria, while two controls were used without crushing.

RESULTS

Viable bacteria, as identified using the bacterial viability stain, were found within cavities/lacunae in supragingival calculus cryosections. Similar results were obtained from whole calculus samples using CLSM. Of the nine experimental samples where bacterial culture was attempted, five provided positive bacterial culture under both aerobic and anaerobic conditions; one showed positive growth under aerobic conditions only; while one showed no bacterial growth. The controls showed no bacterial growth.

CONCLUSIONS

From this study, it appears that viable aerobic and anaerobic bacteria may be present within supragingival calculus, specifically within the internal channels and lacunae. Clinically, this may be important, since incomplete removal of supragingival calculus may expose these reservoirs of possible pathogenic bacteria and be a factor in the recurrence of periodontal diseases after treatment.

Calcium phosphate deposition in human dental plaque microcosm biofilms induced by a ureolytic pH-rise procedure

The objectives were to develop and characterize a procedure based on a ureolytic pH rise to deposit calcium phosphate into microcosm dental plaque biofilms and to test the importance of the plaque pH range. Plaque biofilms were cultured in a multiplaque culture system ('artificial mouth') with a continuous supply of a simulated oral fluid (basal medium mucin; BMM) with 146 mmol/l (5% w/v) sucrose periodically applied over 6 min every 8h. After initial plaque growth, the biofilms were periodically exposed for up to 16 days to 6-min applications of calcium phosphate monofluorophosphate urea (CPMU) solution containing 20 mmol/l CaCl(2), 12 mmol/l NaH(2)PO(4), 5 mmol/l monofluorophosphate and 500 mmol/l urea (pH 5.0). Three application regimes were examined, one included a sucrose-induced acidic pH fluctuation. Plaque hydrolysis of the urea in CPMU caused the pH to rise to between 8.2 and 8.8, depositing fluoridated and carbonated calcium phosphates, and possibly some calcium carbonate, into the plaque. Calcium, phosphate and fluoride deposition was rapid for about 4 days and then slowed. After 10 days' treatment under standard conditions (BMM containing 1 mmol/l urea and 1 mmol/l arginine), plaque calcium and phosphate concentrations had increased up to 50-fold and 10-fold to approximately 2-4 and 1-2 mmol/g plaque protein, respectively. The calcium, phosphate and fluoride content increased steadily. Calcium phosphate deposition was proportional to the plaque resting pH, increasing over four-fold when the BMM urea concentration was increased from 0 to 20 mmol/l, which raised the resting pH from 6.4 to 7.2 and yielded a mean plaque calcium concentration of 14.3 mmol/g protein, one subsample reaching 20.8 mmol/g protein. Supplementation of BMM with 20% human serum inhibited deposition. These results support the hypothesis that an alkaline pH in plaque is critical in promoting plaque mineralization and that mineral deposition is modulated by serum. These factors are likely to be important in regulating calculus formation.

Glycemic control of type 2 diabetes and severe periodontal disease in the US adult population

OBJECTIVE

We investigated the association between glycemic control of type 2 diabetes mellitus (type 2 DM) and severe periodontal disease in the US adult population ages 45 years and older.

METHODS

Data on 4343 persons ages 45-90 years from the National Health and Nutrition Examination Study III were analyzed using weighted multivariable logistic regression. Severe periodontal disease was defined as 2 + sites with 6 + mm loss of attachment and at least one site with probing pocket depth of 5 + mm. Individuals with fasting plasma glucose > 126 mg/dL were classified as having diabetes; those with poorly controlled diabetes (PCDM) had glycosylated hemoglobin > 9% and those with better-controlled diabetes (BCDM) had glycosylated hemoglobin <or= 9%. Additional variables evaluated in multivariable modeling included age, ethnicity, education, gender, smoking status, and other factors derived from the interview, medical and dental examination, and laboratory assays.

RESULTS

Individuals with PCDM had a significantly higher prevalence of severe periodontitis than those without diabetes (odds ratio = 2.90; 95% CI: 1.40, 6.03), after controlling for age, education, smoking status, and calculus. For the BCDM subjects, there was a tendency for a higher prevalence of severe periodontitis (odds ratio = 1.56; 95% CI: 0.90, 2.68).

CONCLUSION

These results provide population-based evidence to support an association between poorly controlled type 2 diabetes mellitus and severe periodontitis.

Periodontal disease status of an indigenous population of Guatemala, Central America

OBJECTIVES

This study was designed to determine the periodontal disease status of an indigenous Indian community of rural Central America (San Juan La Laguna, Guatemala), for comparison with results of similar studies in other populations, and with a view to performing future studies to address familial clustering of adult periodontitis.

METHODS & RESULTS

An initial screen of 239 subjects aged 12-75 years from extended families suggested a high disease prevalence according to full-mouth pocket probing depths (PPDs), with more than 75% of subjects with one or more pockets of PPD > or =5 mm. A more detailed study was performed in 125 unrelated subjects > or =18 years, recording full-mouth PPDs and clinical attachment levels (CALs). The high prevalence of pocketing was confirmed and 90% of adults > or =35 years had at least one site with CAL > or =6 mm. However, extensive disease was restricted to a small minority, with only 10% of adults > or =35 years having 20% or more sites with CAL > or =6 mm.

CONCLUSION

The study results highlight the importance of performing a detailed examination and appropriate analysis. In both studies, tooth retention was high (mean number of teeth recorded was 26.4 and 28.0 respectively), smoking unusual, and families large and localised to the village. This community thus affords several advantages over populations in developed countries when considering familial studies of adult periodontitis.

Morphology and elemental composition of subgingival calculus in two ethnic groups

BACKGROUND

The aim of the present study was to compare the morphology and elemental composition of subgingival calculus between Indo-Pakistani and Caucasian patient groups.

METHODS

Extracted teeth from 14 Indo-Pakistani and 19 Caucasian subjects were collected. Of these, 12 Indo-Pakistani and 10 Caucasian teeth had sufficient subgingival calculus for analysis. Subgingival calculus present on the 22 teeth was classified into six morphological types: 1) crusty/spiny/nodular; 2) ledge/ ring; 3) thin, smooth veneers; 4) finger/fern-like; 5) individual islands/spots; or 6) supramarginal on submarginal. Subgingival calculus was zoned: coronal, mid, and apical. A sample obtained from each zone was subdivided to allow 3 separate analyses: transmission electron microscopic (TEM) x-ray microanalysis for elemental composition, fluoride analysis, and carbonate analysis.

RESULTS

Crusty/spiny/nodular, ledge/ring, and thin, smooth veneers were more commonly found in the Indo-Pakistani group; individual islands were more prevalent in the Caucasian subjects. Supramarginal on submarginal calculus was found only in the Indo-Pakistani group. No finger/fern-like deposits were found. No differences within or between the two ethnic groups were found with regard to calcium:phosphate ratios, fluoride, or carbonate content. However, the Indo-Pakistani group showed significantly lower levels of sodium in apical samples than in coronal samples (ANOVA, F1,16 = 5.98, P= 0.03), and significantly lower levels of sodium (ANOVA, F1,12 = 4.75, P= 0.05) and magnesium (ANOVA, F1,12 = 5.16, P= 0.04) in apical samples than in those from Caucasians. After adjusting for smoking, the magnesium results remained significant (ANOVA, F2,11 = 4.64, P= 0.05).

CONCLUSIONS

Subgingival calculus demonstrated differences in morphology between these two ethnic groups and differences in elemental composition, which may influence its overall solubility and contribute to its greater accretion in the Indo-Pakistani subjects.

Subgingival calculus: where are we now? A comparative review

OBJECTIVE

To critically analyse the formation, composition, ethnic variations and pathogenic potential of subgingival calculus in comparison with supragingival calculus.

DATA SOURCES

Using CD-ROM and index medicus, scientific papers relating to subgingival calculus or subgingival and supragingival calculus written in the English language since 1960 were considered, with the emphasis on more recent articles.

STUDY SELECTION

Studies were selected for their relevance and contemporary nature re:composition and formation of dental calculus and comparisons of ethnic groups with regard to dental calculus, especially subgingival calculus. Some similar studies were not included.

DATA EXTRACTION

Abstracts of studies were kept brief unless particularly important to the review. Population, methodology, statistics and accurate conclusions were used as important guides to the quality and validity of studies.

DATA SYNTHESIS

Similarities and differences between supragingival and subgingival calculus in composition and formation were shown. Different morphological types of subgingival calculus were demonstrated. There was evidence for an association between calculus formation and ethnicity with regard to supragingival and subgingival calculus, and an association between subgingival calculus composition and ethnicity was indicated.

CONCLUSIONS

An association between ethnicity and subgingival calculus formation and composition was found. Further research into the reasons for these ethnic differences in dental calculus and the role of the mineral constituents especially of subgingival calculus would be valuable.

Periodontal status of adult Sudanese habitual users of miswak chewing sticks or toothbrushes

Miswak chewing sticks are prepared from the roots or twigs of Salvadora persica plants. They are widely used as a traditional oral hygiene tool in several African and Middle Eastern countries. The aim of this study was to assess and compare the periodontal status of adult Sudanese habitual miswak and toothbrush users. The study population comprised male miswak users (n = 109) and toothbrush users (n = 104) with age range 20-65 years (mean 36.6 years) having 18 or more teeth present. They were recruited among employees and students at the Medical Sciences Campus in Khartoum, Sudan. One examiner used the Community Periodontal Index (CPI) to score gingival bleeding, supragingival dental calculus, and probing pocket depth of the index teeth of each sextant. In addition, the attachment level was measured, which, along with the CPI, was used to assess the periodontal status of the two test groups. Gingival bleeding and dental calculus were highly prevalent in the study population. Approximately 10% of the subjects had > or =4 mm probing depth and 51% had > or =4 mm attachment loss in one or more sextants. Subjects in the age group 40-65 years had a significantly (p < 0.05) higher number of sextants with gingival bleeding and with > or =4 mm probing depth and attachment loss than the 30-39 years group. Miswak users had significantly (p < 0.05) lower dental calculus and > or =4 mm probing depth and higher > or =4 mm attachment loss as well as a tendency (p = 0.09) to lower gingival bleeding in the posterior sextants than did toothbrush users. These differences were not significant in the anterior sextants. It is concluded that the periodontal status of miswak users in this Sudanese population is better than that of toothbrush users, suggesting that the efficacy of miswak use for oral hygiene in this group is comparable or slightly better than a toothbrush. Given the availability and low cost of miswak, it should be recommended for use in motivated persons in developing countries.

Gingival recession, gingival bleeding, and dental calculus in adults 30 years of age and older in the United States, 1988-1994

BACKGROUND

The aim of this study was to assess the prevalence and extent of gingival recession, gingival bleeding, and dental calculus in United States adults, using data collected in the third National Health and Nutrition Examination Survey (NHANES III).

METHODS

The study group consisted of 9,689 persons 30 to 90 years of age obtained by a stratified, multi-stage probability sampling method in 1988 to 1994. The weighted sample is representative of U.S. adults 30 years or older and represents approximately 105.8 million civilian, non-institutionalized Americans. Gingival recession, gingival bleeding, and dental calculus were assessed at the mesio-buccal and mid-buccal surfaces in 2 randomly selected quadrants, one maxillary and one mandibular. Data analysis accounted for the complex sampling design used.

RESULTS

We estimate that 23.8 million persons have one or more tooth surfaces with > or = 3 mm gingival recession; 53.2 million have gingival bleeding; 97.1 million have calculus; and 58.3 million have subgingival calculus; and the corresponding percentages are 22.5%, 50.3%, 91.8%, and 55.1% of persons, respectively. The prevalence, extent, and severity of gingival recession increased with age, as did the prevalence of subgingival calculus and the extent of teeth with calculus and gingival bleeding. Males had significantly more gingival recession, gingival bleeding, subgingival calculus, and more teeth with total calculus than females. Of the 3 race/ethnic groups studied, non-Hispanic blacks had the highest prevalence and extent of gingival recession and dental calculus, whereas Mexican Americans had the highest prevalence and extent of gingival bleeding. Mexican Americans had similar prevalence and extent of gingival recession compared with non-Hispanic whites. Gingival recession was much more prevalent and also more severe at the buccal than the mesial surfaces of teeth. Gingival bleeding also was more prevalent at the buccal than mesial surfaces, whereas calculus was most often present at the mesial than buccal surfaces.

CONCLUSIONS

Dental calculus, gingival bleeding, and gingival recession are common in the U.S. adult population. In addition to their unfavorable effect on esthetics and self-esteem, these conditions also are associated with destructive periodontal diseases and root caries. Appropriate measures to prevent or control these conditions are desirable, and this may also be effective in improving the oral health of the U.S. adult population.

Calculus deposits and bone loss on the teeth of Romano-British and eighteenth-century Londoners

The relation between dental calculus and periodontal disease is not clear but it is generally recognized that calculus is a significant pathogenetic factor. Skeletal material has previously been used to study some aspects of chronic adult periodontitis but few studies have quantified the extent of calculus in ancient populations and its relation to changes in alveolar bone height. This study records the presence and extent of calculus and its relation to alveolar bone loss in a Romano-British and eighteenth-century London population. There were significant differences in calculus deposition in the two populations but this appeared to have little effect on changes in alveolar bone contour. It is suggested that the amount of calculus may be related to diet but that changes in alveolar bone height seem to be independently controlled.

The relationship of dental calculus to caries, gingivitis, and selected salivary factors in 11- to 13-year-old children in Chiang Mai, Thailand

Thai children have been shown to accumulate large amounts of dental calculus. The purpose of this study was to examine the relationship of calculus to caries and gingivitis, and salivary conditions which may contribute to calculus accumulation. Four-hundred and thirty-nine (439) children from 18 schools in Chiang Mai were selected for this study. The children were given oral examinations to determine calculus index (CI); decayed, missing, and filled surfaces (DMFS); decayed, missing, and filled teeth (DMFT); gingival index (GI); and plaque index (PI). Children with mean CI scores > or =1 (206) were assigned to the calculus group; the 233 children with mean CI scores of <1 to the noncalculus group. Saliva was collected from 60 randomly-selected children in each group. Unstimulated and stimulated whole saliva and stimulated parotid saliva were assessed for flow rate, pH, and buffer capacity using 2 methods. Results showed that calculus status was not significantly associated with caries, but that there was a high association between gingivitis and plaque status with calculus accumulation (P < 0.001). There were no significant differences in saliva flow rate, pH, or buffer capacity between calculus and noncalculus groups. The lack of association between calculus status and caries indicated these 2 conditions have different etiologies and suggests the importance of plaque and calculus prevention programs, in addition to caries control efforts, to maintain oral health of Thai children.

The effectiveness of a magnetized water oral irrigator (Hydro Floss) on plaque, calculus and gingival health

The purpose of this study was to evaluate the effects of a magnetized water oral irrigator on plaque, calculus and gingival health. 29 patients completed this double-blind crossover study. Each patient was brought to baseline via an oral prophylaxis with a plaque index < or = 1 and a gingival index < or = 1. Subjects used the irrigator for a period of 3 months with the magnet and 3 months without the magnet. After each 3 month interval, data were collected using the plaque index, gingival index, and accretions index. The repeated measures analysis on plaque, gingival and calculus indices yielded a statistically-significant period effect for PlI (p=0.0343), GI (p=0.0091), and approached significance for calculus (p=0.0593). This meant that the effect of irrigation resulted in a decrease of all indices over time. Therefore, the treatment effect on each index was evaluated using only the measurements obtained at the end of the first period (i.e., assuming a parallel design). Irrigation with magnetized water resulted in 64% less calculus compared to the control group. The reduction was statistically significant (p< or =0.02). The reduction by 27% in gingival index was not statistically significant. The reduction in plaque was minimal (2.2%). A strong positive correlation between the plaque index and the Watt accretion index was observed. The magnetized water oral irrigator could be a useful adjunct in the prevention of calculus accumulation in periodontal patients, but appears to have minimal effect on plaque reduction. The results indicated a clinical improvement in the gingival index, but this was not a statistically significant finding.