Calculus update: prevalence, pathogenicity and prevention

Epidemiology of plaque-induced gingivitis among 12-15-year-old Chinese schoolchildren: A study based on the 2018 case definition

AIM

To explore the epidemiology of plaque-induced gingivitis and related factors among Chinese adolescents.

MATERIALS AND METHODS

This cross-sectional survey comprised 118,601 schoolchildren in the 12-15-year age group. Data came from the National Oral Health Survey in mainland China. The field investigation was conducted according to the World Health Organization guidelines. The new 2018 case definition for plaque-induced gingivitis was used. Participants underwent clinical examinations and completed a structured questionnaire. Bleeding on probing (BOP) was performed on all teeth. Multinomial logistic regression was used to explore the factors related to the extent of gingivitis.

RESULTS

Nearly half of the study population (47.3%) had plaque-induced gingivitis; 23.9% and 23.3% presented with localised and generalised gingivitis, respectively. The first molars were the most affected by BOP. Well-established factors, such as demographic characteristics, socioeconomic status, local factors and smoking habits, were significantly associated with the extent of gingivitis. Odds ratios for localised and generalised gingivitis increased with the decrease in frequency of toothbrushing with a fluoride dentifrice.

CONCLUSIONS

The study population had high plaque-induced gingivitis prevalence. The extent of gingivitis appeared to have a dose-response relationship with the frequency of toothbrushing with a fluoride dentifrice.

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.

The impact of 0.2% chlorhexidine gel on oral health and the incidence of pneumonia amongst adults with profound complex neurodisability

AIMS

Investigate the effect of toothbrushing with 0.2% chlorhexidine gel on oral health and pneumonia amongst patients with a neurodisability who are fed via percutaneous endoscopic gastrostomy.

METHOD

Forty-nine patients at the Royal Hospital for Neuro-disability were recruited to an observational study. Daily toothbrushing with 0.2% chlorhexidine gel was undertaken for 12 months by trained nursing staff. Plaque and gingival health were assessed every six weeks using the Simplified Debris Index and the Basic Periodontal Examination. The annual incidence and prevalence of episodes of pneumonia experienced by patients whilst using the chlorhexidine gel were compared to rates from the previous year.

RESULTS

Plaque levels and the proportion of patients with periodontal pocketing > 3.5 mm significantly reduced, P < .001, with chlorhexidine toothbrushing. Total number of pneumonia episodes (75-67), antibiotics administered (73-64), and radiographs taken (19 to 16) were lower in the year wherein chlorhexidine was employed, and hospitalisations dropped by 31% (16-11), but these reductions were not statistically significant. No adverse events were reported.

CONCLUSION

Daily toothbrushing with 0.2% chlorhexidine undertaken by a trained and supported nursing staff was effective in improving oral health but did not significantly affect annual rates of pneumonia amongst patients.

Microbial differences between dental plaque and historic dental calculus are related to oral biofilm maturation stage

BACKGROUND

Dental calculus, calcified oral plaque biofilm, contains microbial and host biomolecules that can be used to study historic microbiome communities and host responses. Dental calculus does not typically accumulate as much today as historically, and clinical oral microbiome research studies focus primarily on living dental plaque biofilm. However, plaque and calculus reflect different conditions of the oral biofilm, and the differences in microbial characteristics between the sample types have not yet been systematically explored. Here, we compare the microbial profiles of modern dental plaque, modern dental calculus, and historic dental calculus to establish expected differences between these substrates.

RESULTS

Metagenomic data was generated from modern and historic calculus samples, and dental plaque metagenomic data was downloaded from the Human Microbiome Project. Microbial composition and functional profile were assessed. Metaproteomic data was obtained from a subset of historic calculus samples. Comparisons between microbial, protein, and metabolomic profiles revealed distinct taxonomic and metabolic functional profiles between plaque, modern calculus, and historic calculus, but not between calculus collected from healthy teeth and periodontal disease-affected teeth. Species co-exclusion was related to biofilm environment. Proteomic profiling revealed that healthy tooth samples contain low levels of bacterial virulence proteins and a robust innate immune response. Correlations between proteomic and metabolomic profiles suggest co-preservation of bacterial lipid membranes and membrane-associated proteins.

CONCLUSIONS

Overall, we find that there are systematic microbial differences between plaque and calculus related to biofilm physiology, and recognizing these differences is important for accurate data interpretation in studies comparing dental plaque and calculus.

Association between incisor irregularity and coronal caries: A population-based study

INTRODUCTION

The objective of this study was to investigate the association between incisor irregularity and anterior coronal caries by means of an arch-specific analysis among the U.S. population in the National Health and Nutritional Examination Survey (NHANES III) 1988-1994.

METHODS

This study analyzed data from 9049 participants who were surveyed from 1988 to 1994 as a part of the NHANES III. Participants with a complete set of fully erupted permanent anterior teeth in the maxillary and mandibular segments (ie, canine to canine), who completed an examination of occlusal characteristics and anterior dental caries, and who reported no previous orthodontic treatment were included in the study. Incisor irregularity per arch was determined with the use of the Little irregularity index. Anterior coronal caries per arch was defined as ≥1 surface with decayed or filled surface (CDFS ≥1). Analyses were conducted with the use of chi-square test and logistic regression modeling taking into account the complex sampling design of the survey.

RESULTS

In the maxillary arch, 25.1% of the study population had maxillary anterior coronal caries experience (CDFS ≥1), whereas only 5.5% of the study population had mandibular anterior coronal caries experience (CDFS ≥1). In both arches, no statistically significant association between incisor irregularity and anterior coronal caries experience was found.

CONCLUSIONS

Maxillary and mandibular incisor irregularity is not associated with anterior dental caries prevalence in a subset of NHANES III data that included mostly highly educated adult participants who were white, of medium socioeconomic status, and with high oral health compliance and oral self-care. Future well designed prospective cohort studies are needed to confirm these results. Clinicians are still encouraged to continue providing oral health education to their patients about the well established effect of incisor irregularity on plaque retention.

Incisor malalignment and the risk of periodontal disease progression

INTRODUCTION

The objective of this study was to investigate the association between incisor crowding, irregularity, and periodontal disease progression in the anterior teeth.

METHODS

Data collected over 35 years from men enrolled in the Veterans Affairs Dental Longitudinal Study included information concerning pocket depth and alveolar bone loss. Plaster casts of the maxillary (n = 400) and mandibular (n = 408) arches were available for baseline measurements. Periodontal disease in the anterior teeth was defined as per arch sum of pathologic pocket depth and sum of teeth with any alveolar bone loss in the anterior sextants. Incisor malalignment status was defined by the anterior tooth size-arch length discrepancy index and Little's Irregularity Index. Adjusted mixed effects linear models computed the beta (β) estimates and 95% confidence intervals (95% CI) of the amounts of change in periodontal disease outcomes by the level of malalignment.

RESULTS

In the anterior maxillary arch, crowding and spacing were significantly associated with an increased per-arch sum of pathologic pocket depth (β, 0.70 mm; 95% CI, 0.20-1.21, and β, 0.49 mm; 95% CI, 0.06-0.91, respectively). In the anterior mandibular arch, incisor crowding and irregularity were significantly associated with an increased per-arch sum of pathologic pocket depth (mild crowding: β, 0.47 mm; 95% CI, 0.01-0.93; severe irregularity: β, 0.94 mm; 95% CI, 0.50-1.38), and the sum number of teeth with alveolar bone loss (mild and moderate-to-severe crowding: β, 0.45 teeth; 95% CI, 0.08-0.82; and β, 0.45 teeth; 95% CI, 0.13-0.83, respectively; moderate irregularity: β, 0.34 teeth; 95% CI, 0.06-0.62).

CONCLUSIONS

Certain incisor malalignment traits (ie, maxillary incisor crowding, maxillary incisor spacing, mandibular incisor mild crowding, mandibular incisor moderate-to-severe crowding, mandibular incisor moderate irregularity, and mandibular incisor severe irregularity) are associated with significant periodontal disease progression.

Chlorhexidine Loaded Cyclodextrin Containing PMMA Nanogels as Antimicrobial Coating and Delivery Systems

Antimicrobial nanogels, aggregates, and films are prepared by complexation of the antiseptic and bacteriostatic agent chlorhexidine (CHX) for medical and dental applications. A series of α-, β-, and γ-cyclodextrin methacrylate (CD-MA) containing hydrophobic poly(methyl methacrylate) (PMMA) based nanogels are loaded quantitatively with CHX in aqueous dispersion. The results show that CHX is enhancedly complexed by the use of CD-MA domains in the particles structure. β-CD-MA nanogels present the highest uptake of CHX. Furthermore, it is observed that the uptake of CHX in nanogels is influenced by the hydrophobic PMMA structure. CHX acts as external cross-linker of nanogels by formation of 1:2 (CHX:CD-MA) inclusion complexes of two β-CD-MA units on the surfaces of two different nanogels. The nanogels adsorb easily onto glass surfaces by physical self-bonding and formation of a dense crosslinked nanogel film. Biological tests of the applied CHX nanogels with regard to antimicrobial efficiency are successfully performed against Staphylococcus aureus.

A randomized controlled clinical study of the effect of daily intake of Ascophyllum nodosum alga on calculus, plaque, and gingivitis

OBJECTIVE

The aim of this study is to evaluate, in a randomized controlled cross-over study, the effect of daily intake of the alga Ascophyllum nodosum on supragingival calculus, plaque formation, and gingival health over a 6-month period.

MATERIAL AND METHODS

Sixty-one adults with moderate to heavy calculus formation since their last yearly recall visit participated. In a randomized order over two 6-month periods, they swallowed two capsules daily, comprising a total of 500 mg dried marine alga powder (Ascophyllum nodosum, ProDen PlaqueOff®) or two negative control tablets. During the study, the participants maintained their regular oral habits. Their teeth were professionally cleaned at the start of each period and after the 6-month registrations. A wash out period of 1 month separated the two 6-month periods. Supragingival calculus (Volpe Manhold), gingivitis (Löe and Silness), gingival bleeding (Ainamo and Bay), and plaque (Quigley-Hein) were registered at screening and at the end of the two periods. Differences in oral health between the test and control periods were analyzed using a paired t test and Wilcoxon signed rank test.

RESULTS

Fifty-five participants completed the study. After the alga intake, the mean calculus reduction was 52% compared to the control (p < 0.0001). Fifty-two participants showed less calculus formation in the alga group than in the control group. Plaque (p = 0.008) and gingival bleeding (p = 0.02) were also significantly less in the alga group. However, no significant difference was found between the groups for gingivitis (p = 0.13).

CONCLUSIONS

The alga intake significantly reduced the formation of supragingival calculus and plaque and occurrence of gingival bleeding. The alga has a systemic effect on oral health.

CLINICAL RELEVANCE

Daily intake of the alga Ascophyllum nodosum as an adjunct to customary oral hygiene showed a major reduction of supragingival calculus formation and reduced plaque formation. In addition, the calculus in the alga group was characterized by a more porous and less solid structure and was easier to remove than the calculus in the control group.

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.

Salivary bacteria and oral health status in children with disabilities fed through gastrostomy

OBJECTIVES

This study examined caries level, amount of calculus, and oral microbial environment in gastrostomy tube (GT)-fed children compared with healthy children and children with disabilities orally fed (PO).

STUDY DESIGN

The study group consisted of 12 GT-fed children and the two control groups consisted of 16 children with disabilities orally fed and 17 healthy children. DMF-T/dmf-t index, calculus index, Mutans Streptococci (MS), Lactobacilli (LB) levels and salivary buffer capacity were examined.

RESULTS

DMF-T/dmf-t index was significantly lower in the tube-fed group. Calculus index was highest in the tube-fed group. MS and LB levels were the lowest in the tube-fed children. Correlation was found between MS and DMF-T/dmf-t.

CONCLUSIONS

Tube-fed children demonstrated significantly higher calculus levels and less caries, MS, and LB levels then healthy children or children with disabilities eating PO.

Social factors and periodontitis in an older population

OBJECTIVES

We assessed the prevalences of periodontitis by education and income levels among US adults with data from the third National Health and Nutrition Examination Survey.

METHODS

The study was limited to non-Hispanic Blacks, Mexican Americans, and non-Hispanic Whites 50 years of age or older with a complete periodontal assessment during the dental examination.

RESULTS

Blacks with higher education and income levels had a significantly higher prevalence of periodontitis than their White and Mexican-American counterparts. The relationship between income level and periodontitis was modified by race/ethnicity. High-income Blacks exhibited a higher prevalence of periodontitis than did low-income Blacks and high-income Whites.

CONCLUSIONS

Our findings call attention to the importance of recognizing socioeconomic status-related health differences across racial/ethnic groups within the social, political, and historical context.

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.

Social factors and periodontitis in an older population

OBJECTIVES

We assessed the prevalences of periodontitis by education and income levels among US adults with data from the third National Health and Nutrition Examination Survey.

METHODS

The study was limited to non-Hispanic Blacks, Mexican Americans, and non-Hispanic Whites 50 years of age or older with a complete periodontal assessment during the dental examination.

RESULTS

Blacks with higher education and income levels had a significantly higher prevalence of periodontitis than their White and Mexican-American counterparts. The relationship between income level and periodontitis was modified by race/ethnicity. High-income Blacks exhibited a higher prevalence of periodontitis than did low-income Blacks and high-income Whites.

CONCLUSIONS

Our findings call attention to the importance of recognizing socioeconomic status-related health differences across racial/ethnic groups within the social, political, and historical context.

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.

Supragingival calculus: formation and control

Dental calculus is composed of inorganic components and organic matrix. Brushite, dicalcium phosphate dihydrate, octacalcium phosphate, hydroxyapatite, and whitlockite form the mineral part of dental calculus. Salivary proteins selectively adsorb on the tooth surface to form an acquired pellicle. It is followed by the adherence of various oral micro-organisms. Fimbriae, flagella, and some other surface proteins are essential for microbial adherence. Microbial co-aggregation and co-adhesion enable some micro-organisms, which are incapable of adhering, to adhere to the pellicle-coated tooth surface. Once organisms attach to the tooth surface, new genes could be expressed so that mature dental plaque can form and biofilm bacteria assume increased resistance to antimicrobial agents. Supersaturation of saliva and plaque fluid with respect to calcium phosphates is the driving force for plaque mineralization. Both salivary flow rate and plaque pH appear to influence the saturation degree of calcium phosphates. Acidic phospholipids and specific proteolipids present in cell membranes play a key role in microbial mineralization. The roles of crystal growth inhibitors, promoters, and organic acids in calculus formation are discussed. Application of biofilm culture systems in plaque mineralization is concisely reviewed. Anti-calculus agents used--centering on triclosan plus polyvinyl methyl ether/maleic acid copolymer, pyrophosphate plus polyvinyl methyl ether/maleic acid copolymer, and zinc ion-in commercial dentifrices are also discussed in this paper.

Periodontal disease as a specific, albeit chronic, infection: diagnosis and treatment

Periodontal disease is perhaps the most common chronic infection in adults. Evidence has been accumulating for the past 30 years which indicates that almost all forms of periodontal disease are chronic but specific bacterial infections due to the overgrowth in the dental plaque of a finite number of mostly anaerobic species such as Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola. The success of traditional debridement procedures and/or antimicrobial agents in improving periodontal health can be associated with the reduction in levels of these anaerobes in the dental plaque. These findings suggest that patients and clinicians have a choice in the treatment of this overgrowth, either a debridement and surgery approach or a debridement and antimicrobial treatment approach. However, the antimicrobial approach, while supported by a wealth of scientific evidence, goes contrary to centuries of dental teaching that states that periodontal disease results from a "dirty mouth." If periodontal disease is demonstrated to be a risk factor for cardiovascular disease and stroke, it will be a modifiable risk factor since periodontal disease can be prevented and treated. Since the antimicrobial approach may be as effective as a surgical approach in the restoration and maintenance of a periodontally healthy dentition, this would give a cardiac or stroke patient and his or her physician a choice in the implementation of treatment seeking to improve the patient's periodontal condition so as to reduce and/or delay future cardiovascular events.

The antimicrobial treatment of periodontal disease: changing the treatment paradigm

Over the last 100 years, methods of surgical periodontal treatment have enjoyed a history of success in improving oral health. The paradigm of care is based on the "non-specific plaque hypothesis"--that is, the overgrowth of bacterial plaques cause periodontal disease, and the suppression of this overgrowth reduces disease risk. The central feature of this approach to care is the removal of inflamed gingival tissue around the teeth to reduce periodontal pocket depth, thereby facilitating plaque removal by the dentist and by the patient at home. Over the last 30 years, with the recognition that periodontal disease(s) is caused by specific bacteria and that specific antimicrobial agents can reduce or eliminate the infection, a second paradigm has developed. This new paradigm, the "specific plaque hypothesis", focuses on reducing the specific bacteria that cause periodontal attachment loss. The contrast between the two paradigms can be succinctly stated as follows: The antimicrobial therapy reduces the cause, while the surgical therapy reduces the result of the periodontal infection. The specific plaque hypothesis has two important implications. First, with the increasing attention to evidence-based models for prevention, treatment, outcome assessment, and reimbursement of care, increasing attention and financial effort will be channeled into effective preventive and treatment methods. Second, the recent observations that periodontal infections increase the risk of specific systemic health problems, such as cardiovascular disease, argue for the prevention and elimination of these periodontal infections. This review highlights some of the evidence for the specific plaque hypothesis, and the questions that should be addressed if antimicrobial agents are to be used responsively and effectively.

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.

The history of oral hygiene products: how far have we come in 6000 years?

How far have we come in the past six millennia? Numerous dental epidemiological studies indicate that people are keeping their teeth longer than over before in this century. Agents and devices have evolved, by custom and by research, to enable people, with professional assistance, to maintain good oral health. Our diets, our lifestyles and our professional colleagues have "conspired" as pathogenic influences on oral health. The profession has met the challenge by developing and perfecting a myriad of devices and agents to thwart these pathogenic factors. Patient motivation and professional acceptance of preventive dentistry procedures still remain challenges. We certainly eat well, speak well, look fine and "smell fresh"--but we also have plaque, gingivitis and dental caries. The reader can determine how much progress has been made by reflecting on his or her personal oral health status!

Dental calculus: recent insights into occurrence, formation, prevention, removal and oral health effects of supragingival and subgingival deposits

Dental calculus, both supra- and subgingival occurs in the majority of adults worldwide. Dental calculus is calcified dental plaque, composed primarily of calcium phosphate mineral salts deposited between and within remnants of formerly viable microorganisms. A viable dental plaque covers mineralized calculus deposits. Levels of calculus and location of formation are population specific and are affected by oral hygiene habits, access to professional care, diet, age, ethnic origin, time since last dental cleaning, systemic disease and the use of prescription medications. In populations that practice regular oral hygiene and with access to regular professional care, supragingival dental calculus formation is restricted to tooth surfaces adjacent to the salivary ducts. Levels of supragingival calculus in these populations is minor and the calculus has little if any impact on oral-health. Subgingival calculus formation in these populations occurs coincident with periodontal disease (although the calculus itself appears to have little impact on attachment loss), the latter being correlated with dental plaque. In populations that do not practice regular hygiene and that do not have access to professional care, supragingival calculus occurs throughout the dentition and the extent of calculus formation can be extreme. In these populations, supragingival calculus is associated with the promotion of gingival recession. Subgingival calculus, in "low hygiene" populations, is extensive and is directly correlated with enhanced periodontal attachment loss. Despite extensive research, a complete understanding of the etiologic significance of subgingival calculus to periodontal disease remains elusive, due to inability to clearly differentiate effects of calculus versus "plaque on calculus". As a result, we are not entirely sure whether subgingival calculus is the cause or result of periodontal inflammation. Research suggests that subgingival calculus, at a minimum, may expand the radius of plaque induced periodontal injury. Removal of subgingival plaque and calculus remains the cornerstone of periodontal therapy. Calculus formation is the result of petrification of dental plaque biofilm, with mineral ions provided by bathing saliva or crevicular fluids. Supragingival calculus formation can be controlled by chemical mineralization inhibitors, applied in toothpastes or mouthrinses. These agents act to delay plaque calcification, keeping deposits in an amorphous non-hardened state to facilitate removal with regular hygiene. Clinical efficacy for these agents is typically assessed as the reduction in tartar area coverage on the teeth between dental cleaning. Research shows that topically applied mineralization inhibitors can also influence adhesion and hardness of calculus deposits on the tooth surface, facilitating removal. Future research in calculus may include the development of improved supragingival tartar control formulations, the development of treatments for the prevention of subgingival calculus formation, the development of improved methods for root detoxification and debridement and the development and application of sensitive diagnostic methods to assess subgingival debridement efficacy.