Dental plaque part3

Chemical plaque controlPRESENTED BY: ROSHNI MAURYA, 2ND YEAR PGTDEPT. OF PEDODONTICS & PREVENTIVE DENTISTRY, GNIDSR

INTRODUCTIONAdvancement in science & research methodologies has helped us understand the infectious nature of dental diseases better , which in turn has dramatically increased interest in chemical methods of plaque control. In addition, certain patients with dental diseases or medical diseases require additional assistance beyond mechanotherapy to maintain a normal state of oral health. Moreover, some patients are unable , unwilling or untrained to practice effective mechanotherapy. This has resulted in development of chemotherapeutic agents to plaque control.

IDEAL PROPERTIES OF AN ANTI- PLAQUE AGENT

Affects only the target tissue Affects only bacteria known to cause gingivitis or periodontitis or

both Affects only the tooth or root surface and not oral mucosa Affects only the metabolic process of plaque bacteria Remains at the site of action Substantive effect Safe at concentration & dosage recommended Inexpensive Meaningful reduction in gingivitis or periodontitis or both.

CLASSIFICATION OF CHEMICAL PLAQUE CONTROL AGENTS:

First Generation Antiplaque Agent(APA)

capable of reducing plaque scores by about 20-50%.

Exhibits poor retention within mouth.

Ex: antibiotics ; phenols ; quaternary ammonium compounds and sanguanarine.

Second Generation Antiplaque Agent(APA)

Produce an overall plaque reduction of around 70-90%

Are better retained by the oral tissues

Exhibit slow release properties.

Ex: bisbiguanides [Chlorhexidine (CHX)]

Third Generation Antiplaque Agent(APA) :

They block binding of m/o to tooth or to each other.

Compared to CHX , they do not exhibit good retentive properties.

Ex: delmopinol .

ON THE BASIS OF CHEMICAL COMPOSITION

TYPE AGENTS Bis- biguanides CHX ; alexidine

Antiseptics (quaternary cetylpyridinium chlorideAmmonium compounds)

Antibiotics Penicillin;metronidazole;tetracycline; Vancomycin; kanamycin

Enzymes Dextranase; glucose- amylogluosidase

Cont.…… TYPE AGENTSFluorides & SnF2; Chlorine dioxide; H2O2; NaCl; inorganic ions domiphen bromide ; NaHCO3

Organic compounds Sanguanarine ; menthol /thymol

Anticalculus agents Soluble pyrophosphates

CHLORHEXIDINE (CHX) Many advances in the treatment and prevention of dental

caries have been introduced over the past century. The use of chlorhexidine in caries prevention has been

referred to as a non-surgical management of dental caries and has represented the modern medical model of caries treatment.

However, there is a lack of consensus on evidence-based treatment protocols and controversy regarding the role of CHX in caries prevention among dental educators and clinicians.

There is a need to standardize guidelines to optimize evidence-based non-surgical disease management to provide appropriate care

Dental caries is caused by the interplay of caries risk factors leading to demineralization.

Considered as an endogenous multi-bacterial infection. However, the presence of bacteria alone is not sufficient to cause enamel

and dentin demineralization. In the presence of a diet high in sugar, it has been shown that subjects with high levels of S mutans develop more caries than those with low levels of S mutans. [Emilson, C. G. 1994. Potential efficacy of chlorhexidine against mutans streptococci and human dental caries. Journal of Dental Research 73 3:682–691.] 

CHX, an antimicrobial agent that can suppress the growth of mutans streptococci, has been considered as having the potential to prevent dental caries.  

A variety of delivery systems exist, but the only product currently marketed in the US is a mouthrinse containing 0.12 percent chlorhexidine gluconate.

Due to the lack of other delivery systems with higher concentrations of CHX, this mode is still widely recommended for caries prevention in several caries management programs in the US

CHX GLUCONATE

It is a cationic bisbiguanides

Effective against gram +ve, gram –ve organisms, fungi, yeasts and viruses

Exhibit antiplaque & antibacterial properties

MECHANISM OF ACTION

Antiplaque action of chlorhexidine

1. Prevents pellicle formation by blocking acidic groups on salivary glycoproteins thereby reducing glycoprotein adsorption on to the tooth surface

2. Prevents adsorption of bacterial cell wall on to the tooth surface

3. Prevents binding of mature plaques

Antibacterial action of CHXIt shows two actions

1. Bacteriostatic at low concentrations

Bacterial cell wall(-ve charge)

Reacts with +ve charged CHX molecule

Integrity of cell membrane altered

CHX binds to inner membrane phospholipids & increase permeability

Vital elements leak out & this effect is reversible

2. Bacteriocidal action increased concentration of CHX

Progressive greater damage to membrane

Larger molecular weight compounds lost

Coagulation and precipitation of cytoplasm

Free CHX molecule enter the cell & coagulates proteins

Vital cell activity ceases

cell death(irreversible)

EFFECT OF DIFFERENT MODES IN CARIES PREVENTIONMouthrinses Early studies on the effect of CHX rinses, gels and varnishes on

caries progression were reviewed by Luoma.(Luoma, H. 1992. Chlorhexidine solutions, gels and varnishes in caries prevention. Proceedings of the Finnish Dental Society88 3–4:147–153 )

 After these early studies, conducted more than 20–25 years ago, there are very few published articles that describe evaluations of the effect of chlorhexidine rinse on caries.

One clinical study by Spets-Happonen and others, ( 1991. Effects of a chlorhexidine-fluoride-strontium rinsing program on caries, gingivitis and some salivary bacteria among Finnish school children. Scandinavian Journal of Dental Research 99 )where the use of periodic chlorhexidine mouthwashes was followed over a period of two years and nine months, revealed no significant reduction in caries.

In 1989, a 0.12% solution of CHX gluconate was marketed in the US, and it is currently the only CHX treatment mode available. There are very few clinical studies on this CHX mode that assess the progression of caries.

A clinical study by Wyatt and MacEntee( Caries management for institutionalized elders using fluoride and chlorhexidine mouthrinses. Community Dentistry and Oral Epidemiology, 2004. ) evaluated the effectiveness of either a 0.25% neutral sodium fluoride (NaF) solution or a 0.12 % CHX solution as a daily mouthrinse for controlling caries in a two-year randomized clinical trial among the elderly in long-term care facilities in Canada. The prevalence of caries increased in the CHX and placebo groups, whereas there was a 24% decrease in the NaF group. The investigators concluded that the daily rinse with 0.25% NaF solution was significantly better than with 0.12% CHX rinse. A double-blind clinical trial by Wyatt and others. ( CHX and preservation of sound tooth structure in older adults. A placebo-controlled trial. Caries Research, 2007.)also tested the impact of regular rinsing with a 0.12% CHX solution on caries in low-income elders in Seattle, WA, USA and Vancouver, Canada. The subjects alternated between daily rinsing for one month, followed by weekly rinsing for five months. Regular rinsing with CHX did not have a substantial effect on the preservation of sound tooth structure in older adults.

In a randomized clinical trial by Powell and others,(1999. Caries prevention in a community-dwelling older population.Caries Research ) a weekly rinse with 0.12% chlorhexidine over three years did not reduce caries development significantly in a low-income older subjects population. This study was the only clinical study using 0.12% chlorhexidine rinse that was included in the review by.( 2004. Antimicrobials in future caries control? A review with special reference to CHX treatment. Caries Research ). His review concluded that CHX has substantial antimicrobial properties against caries-causing bacteria, but its use as an anti-caries agent remains controversial.

To be maximally effective, an antimicrobial agent must be used for a sufficient but definite period of time. (Emilson, C. G. 1994. Potential efficacy of CHX against mutans streptococci and human dental caries. Journal of Dental Research ). The lesser effect on mutans streptococci and surfaces at risk probably reflect a re-growth of mutans streptococci, because the reservoirs in the dentition are not sufficiently affected due to the low bio-availability of CHX from the mouthrinse solution. Staining of the teeth, silicate fillings and the tongue, as well as disturbances of taste, raise concerns for maintaining prolonged daily use of 0.12% CHX acetate solution for caries prevention.

Gels Clinical studies of CHX gels have been mainly conducted on children, and

the data are promising, but sparse. Emilson found that studies with CHX gel treatment in high caries-risk

children showed significant reductions in dental decay.  This finding was based on the original study by Zickert and others,(1982. Effect of caries preventive measures in children highly infected with the bacterium Streptococcus mutans. Archives of Oral Biology) which reported a great reduction in caries increment in children with high levels of S mutans in saliva and when treated with 1% CHX gel trays for five minutes daily for 14 days.

After three years, the children in the control group had developed 9.6 new caries lesions, while the treated children only developed 4.2 new caries lesions (a 56% difference).

Emilson's conclusions were also based on the original study by Linquist and others, in which a 52% caries reduction was found in the 1% CHX gel group after two years, compared to the control group. In the CHX group, children with high levels of mutans streptococci in saliva were treated with 1% CHX gel every third month.

Longitudinal studies, in which the effect of chlorhexidine gel on approximal caries was evaluated, showed significant caries reduction ranging from 26% to 68%.  For example, in a study by Gisselsson and others,(Effect of professional flossing with chlorhexidine gel on approximal caries in 12- to 15-year-old schoolchildren. Caries Research ,1988) a 1% CHX gel was applied four times a year to approximal spaces, followed by dental flossing. After three years, the caries increment reduced significantly (52%) compared to a control group.

A recent study by Petti and Hausen (Caries-preventive effect of chlorhexidine gel applications among high-risk children. Caries Research ,2006) assessed the effect of chlorhexidine gel among three-year old children whose regular fluoride exposure came from tooth-paste. The subjects underwent chlorhexidine gel application for three days at three-month intervals for 15 months. The chlorhexidine gel applications showed a moderate reduction in mutans streptococci levels but no effect on caries prevention. Twetman's conclusion that there is limited evidence on the effectiveness of chlorhexidine gels and rinses in preventing caries seems to still be current.

VarnishesCHX-containing varnishes were developed to increase the substantivity, length of the time of suppression(Clinical trial in adults of an antimicrobial varnish for reducing mutans streptococci. Journal of Dental Research,1991)  and effectiveness of the delivery of chlorhexidine to sites colonized by S mutans.( A preliminary report of long-term elimination of detectable mutans streptococci in man. Journal of Dental Research ,1988)

 Varnish has been shown to reduce the numbers of S mutans in several studies. Suppression of S mutans for periods of up to five months has been achieved by the application of a varnish containing a high concentration of chlorhexidine (40%). (1991. Clinical trial in adults of an antimicrobial varnish for reducing mutans streptococci. Journal of Dental Research)  Twetman stated in his review that clinical data on caries prevention effects remain sparse and that the recent literature was inconclusive for the use of chlorhexidine varnishes for caries prevention in risk groups.  

Studies of the effect of CHX varnishes on caries in young permanent teeth showed no statistically significant effect. For example, Forgie and others assessed the efficacy of chlorzoin, a chlorhexidine varnish containing 10% chlorhexidine acetate and 20% Sumatra benzoin, in reducing caries increment in 1,240 high-risk adolescents aged 11–13 in a three-year clinical trial. In the first year, the varnish was applied weekly for the first month. Patients received a minimum of four and a maximum of six varnish applications in the first year and a minimum of one and a maximum of three applications in each subsequent year. After three years, the results indicated that the use of chlorzoin had an initial effect on S mutans levels, but no long-term reduction in caries increment was documented.

One study by Twetman and Petersson(Interdental caries incidence and progression in relation to mutans streptococci suppression after chlrohexidine thymol varnish treatments in school children. ActaOdontogicScandinavia,1999) evaluated the effect of chlorhexidine varnish treatments on both caries incidence and lesion progression in school children with a high risk for caries. One-hundred and ten children ages 8 to 10 years old with moderate to high counts of salivary S mutans were treated three times within two weeks with interdental spot applications of 1% Cervitec varnish.

After two years, it was found that a reduction in caries incidence and lesion progression was clearly dependent on this antimicrobial treatment. A significantly higher progression score was found among children who exhibited less marked suppression of interdental S mutans levels when compared to those with high suppression and to the children in the reference group. It was suggested that the suppression of S mutans in interdental plaque might be important in preventing and arresting approximal caries development

Rozier (Effectiveness of methods used by dental professionals for the primary prevention of dental caries. Journal of Dental Education,2001)   summarized the evidence for the effectiveness of methods available for caries prevention. The studies in his review provided mixed evidence of the caries-preventive effects of chlorhexidine used as a varnish, and they were judged to provide insufficient evidence of effectiveness.

Combinations of Fluoride and CHX Some clinical trials and in vitro tests have shown that the

combination of chlorhexidine and fluoride was effective against S mutans and that the effect was synergistic (Luoma, et al. . A simultaneous reduction of caries and gingivitis in a group of schoolchildren receiving chlorhexidine-fluoride applications. Results after 2 years. Caries Research,1978 ) & (Ostela et al. Effect of chlorhexidine-sodium fluoride gel applied by tray or by toothbrush on salivary mutans streptococci . Proceedings of the Finnish Dental Society,1990)

Chlorhexidine-fluoride gel has been shown to reduce numbers of S mutans.  It has also been shown that this suppression effect lasts for a longer period of time than after chlorhexidine treatment alone. However, clinical data on the effects of caries prevention continues to remain sparse.

In a study by Katz ,a regime of four topical applications of 1.0% NaF-1.0% chlorhexidine digluconate plus daily rinses with a combination of 0.05% NaF-0.2% chlorhexidine solution completely prevented radiation caries. Use of the chlorhexidine-fluoride rinses alone also stopped radiation caries but did not support remineralization.(. The use of fluoride and chlorhexidine for the prevention of radiation caries. Journal of the American Dental Association,1982)

Petersson and others(Effect of semi-annual applications of a chlorhexidine/fluoride varnish mixture on approximal caries incidence in schoolchildren. A three-year radiographic study.European Journal of Oral Sciences,1998)  treated a test group of 12 year-old children (n=115) semi-annually with a mixture of varnish containing 0.1% F (Fluor Protector) and 1.0% CHX (Cervitec). A reference group (n=104) received fluoride varnish semi-annually. Approximal caries was recorded from bitewing radiographs at baseline and after three years. In this study, the differences in caries increments were not significant, and the combination of fluoride and CHX had no additional preventive effect.

In a study by Ogaard and others,(2001. Effects of combined application of antimicrobial and fluoride varnishes in orthodontic patients. American Journal of Orthodontic Dentofacial Orthopedics)   the effect of CHX varnish in combination with a fluoride varnish was compared to a fluoride varnish alone in reducing white spot lesions in orthodontic patients. Patients received one application of 1% CHX varnish every week for three weeks and fluoride varnish at the next visit, six weeks later. The patients were seen every six weeks and each varnish was applied every 12 weeks. During the first 48 weeks of treatment, the combination with a CHX varnish (Cervitec, 1%) significantly reduced the number of S mutans in plaque. However, this effect did not result in significantly less development of white spot lesions compared with the group receiving only fluoride varnish.

RE-COLONIZATION The main clinical problem with the use of CHX is the difficulty in

suppressing or eliminating S mutans for an extended period of time. In many clinical studies, the organisms re-colonized the dentition. However, the re-colonization time varied among subjects.

In cases where S mutans had been decreased to low or undetectable levels by the CHX gel, they generally reached the pre-treatment levels after two to six months . The most likely explanation for the reappearance of S mutans is their regrowth . This suggests that there must be reservoirs or retention sites in the dentition that are hardly affected or not affected at all by this CHX treatment and from which the S mutans re-colonize the dentition after treatment. Patients with more retentive sites, such as faulty restorations, occlusal fissures, enamel cracks, incipient lesions or patients with orthodontic appliances, were more rapidly re-colonized with S mutans

ADVERSE EFFECTS OF CHLORHEXIDINE

Brownish staining of tooth or restorations Loss of taste sensation Rarely hypersensitivity to CHX has been reported Stenosis of parotid duct has also been reported burning sensations of the oral soft tissues, soreness and dryness of the oral tissues, desquamated lesions and ulcerations of the gingival

mucosa.

Triclosan

Triclosan is a chemical that was developed nearly 30 years ago.  It was first introduced into the Health Care Services in 1972 and since then, it is extensively used in deodorants, toothpastes, shaving creams, mouth washes, cleaning products, and is infused in an increasing number of consumer products, such as kitchen utensils, toys, bedding, socks, and trash bags

TRICLOSAN

Phenol derivative Is synthetic and ionic Used as a topical antimicrobial agent Broad spectrum of action including both gram positive

and gram negative bacteria It also includes mycobacterium spores and Candida species IUPAC name Of Triclosan 

5-chloro-2- (2,4-dichlorophenoxy) phenol

MECHANISM OF ACTION

TRICLOSAN

ACT ON CYTOPLASMIC MEMBRANE

INDUCE LEAKAGE OF CELLULAR CONSTITUENTS

BACTERIOLYSIS

Triclosan is included in tooth paste to reduce plaque formation

Used along with Zinc citrate or co-polymer Gantrez to enhance its retention within the oral cavity

Triclosan delay plaque formation

It inhibits formation of prostaglandins & leukotrienes there by reduces the chance of inflammation

Previous studies indicate that triclosan reduces the pain and other symptoms after chemically induced inflammation in the oral mucosa and skin when sodium lauryl sulfate (SLS) is used as an irritant

a dentifrice that contains triclosan/copolymer provides a more effective level of plaque control and periodontal health than a conventional fluoride dentifrice. (Evidence-Based Dentistry (2005) 6, 33).

Dentistry urged to take precautions with triclosan

Following various studies on the use of the antibacterial agent triclosan in consumer products, including oral care, experts are urging companies to remove it from their formulations as a precaution.

1) Elizabeth Salter Green, director of ChemTrust, a health and environmental body, explained that on a precautionary basis the chemical might not be safe to use at any level. “If one eats the right foods and maintains correct dental hygiene, then triclosan, or other antibacterial agents are not needed,” explained by Salter Green.

2)  The negative effects of triclosan on the environment and its questionable benefits in toothpastes has led to the Swedish Naturskyddsföreningen to recommend not using triclosan in toothpaste.

Removed from GSK’s oral products Oral care giant, GlaxoSmithKline, has removed triclosan from its Aquafresh and Sensodyne toothpastes, as well as its Corsodyl mouthwash, according to the University of Florida which has performed a study on the ingredient in sheep.

ESSENTIAL OIL M.W.

Contains thymol;eucalyptol;menthol;and methyl salicylate.

They are effective to a lesser degree than Chlorhexidine in plaque reduction

Causes an initial burning sensation & bitter taste in mouth

MOA: cell wall disruption & inhibition of bacterial enzymes The most used form is Listerine.

These products also contain alcohol.

A supplement provides clear evidence that EO mouthrinses can be a beneficial, safe component of daily oral health routines, and a key component in oral health management.(. Claffey N. Essential oil mouthwashes: a key component in oral health management. J Clin Periodontol. 2003)

The combination of fluoride and essential oils in a mouthrinse may provide anticaries efficacy, in addition to EO’s established anti gingivitis efficacy. There is evidence that an essential oil mouthrinse with 100 parts per million fluoride is effective in promoting enamel remineralization and fluoride uptake.(The remineralizing effect of an essential oil fluoride mouthrinse in an intraoral caries test. J Am Dent Assoc)

3.QUARTERNARY AMMONIUM COMPOUNDS

Cationic antiseptics & surface active agents Effective against gram positive organisms

MECHANISM OF ACTION

Positively charged molecule reacts with negatively charged cell membrane phosphates and thereby disrupts the bacterial cell wall structure

Eg: Cetylpyridinium chloride(0.05%)

Adverse effects

Produces a yellow brownish discoloration of tongue & around ging. Margin of tooth.

Burning sensation

Occasional desquamation has also been reported

SANGUINARINE

It is a benzophenanthredine alkaloid,an extract from bloodroot plant- Sanguinalia canadenses

Contains extract at 0.03% & 0.2% ZnCl2 It is most effective against gram –ve organisms Used in mouth rinse & toothpaste 17-42%: plaque reduction; 18-57% : gingivitis

reduction Causes a burning sensation when used initially

ENZYMES

Employed as active agents in antiplaque preparations as they would be able to breakdown already formed matrix of plaque & calculus.

Certain proteolytic enzyme are bactericidal to m/o & would be effective when applied topically in mouth.

Ex: Dextranase; glucose- amylogluosidase

DELMOPINOL Is a morpholinoethanol derivative. Has shown to inhibit plaque growth & reduces gingivitis MOA: interferes with plaque matrix formation Reduces bacterial adherence Causes weak binding of plaque to tooth surface , aiding in easy

removal of plaque by mechanical procedures. hence, indicated as a prebrushing mouthrinse

Has been reputed to be effective in both rapid & slow plaque formers; dissolves formed plaque in absence of mechanical plaque control.

Adverse effects

Transient tooth ,tongue staining Taste disturbance Sometimes mucosal soreness & erosion

ANTICALCULUS AGENTS Dentifrices containing either soluble pyrophosphatase & zinc

compounds have demonstrated 10-50% reduction in calculus. MOA: They produce their effects by absorbing onto small

hydroxyapatite crystals, thus inhibiting growth of larger & more organized crystals

Mainly designed to inhibit the mineralization of so called “ petrified plaque”

Ex: pyrophosphates; zinc citrate,zncl2 ; Gantrez ( a copolymer of methyl vinyl & malice anhydride)

Sugar alcohols

Most widely used ; xylitol; sorbitol ; mannitol;maltitol; lacitol; their products Lycasin & Palatinit

It is often claimed that xylitol is superior to other sugar alcohols for caries control

Chewing of sugar –free chewing gum 3 or more times daily for prolonged periods of time may reduce caries incidence irrespective of type of sugar added.

Xylitol gum chewing decreased MS levels during a 13-month intervention, while no changes were detected in the control group. A subgroup of subjects within the xylitol group (10/43) showed low MS levels also during the post intervention period, demonstrating a carryover effect of long-term xylitol use. Ishihara; Caries Res 2012;46

5/24/2011

Thank u