Chemical Plaque Control (Cont) PDF 2023

Prof Dr Hala Yassin Periodontology Dept. AAST 2023 Chemical Plaque Control( cont) Adjunctive aids for subgingival plaque control: a) Sub gingival irrigation b) Controlled-release devices c) Systemic antibiotics a.Sub gingival irrigation: Sub...

Prof Dr Hala Yassin Periodontology Dept. AAST 2023 Chemical Plaque Control( cont) Adjunctive aids for subgingival plaque control: a) Sub gingival irrigation b) Controlled-release devices c) Systemic antibiotics a.Sub gingival irrigation: Subgingival irrigation is capable of delivering solutions to the depth of the pocket via mechanized hand-piece, mechanized irrigators, ultrasonic and handheld syringes. Both a disposable, blunt-end needle and/or a canula attached to hand held syringe are successful in penetrating periodontal pockets. Irrigation with antiseptics as chlorhexidine, stannous fluoride and phenols or with antibiotics was recommended. Tetracycline, was found to be adsorbed by the root surfaces. Therapeutic levels of tetracycline hydrochloride are released for up to one week following subgingival irrigation with a 100mg/ml aqueous solution for 5 minutes. The weak performances of chemotherapeutic agents delivered via sub gingival irrigation is due to:  Inability to sustain adequate concentration for a sufficient period of time.  Continual flow of crevicular fluid from the pocket rapidly clears aqueous agents from the subgingival area. Antimicrobial agents may be delivered by direct placement into the periodontal pocket or via the systemic route. Each method of delivery has specific advantages and disadvantages. Page 1 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023 Local therapy may allow the application of antimicrobial agents at levels that cannot be reached by the systemic route. Local therapy may be particularly successful if the presence of target organisms is confined to the clinically visible lesions. Systemically administered antibiotics may reach widely distributed microorganisms. Disadvantages of systemic antibiotic therapy relate to the fact that the drug is dissolved by diffusion over the whole body, and only a small portion of the total dose actually reaches the subgingival microflora in the periodontal pocket. Adverse drug reactions are likely to occur if drugs are distributed via the systemic route. Local drug delivery systems are means of drug application to confined areas. For the treatment of periodontal disease, local delivery of antimicrobial drugs ranges from simple pocket irrigation, over the placement of drug-containing ointments and gels, to sophisticated devices for sustained release of antibacterial agents. In order to be effective, the drug should not only reach the entire area affected by the disease, including the base of the pocket, but should also be maintained at a sufficiently high local concentration for some time. With a mouth rinse or supragingival irrigation it is not possible to predictably deliver an agent to the deeper parts of a periodontal defect. Agents brought into periodontal pockets by subgingival irrigation are washed out rapidly by the gingival fluid. Even a highly concentrated, highly potent agent would thus be diluted within Page 2 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023 minutes. If an agent can bind to surfaces and be released in active form, a prolonged time of antibacterial activity could be expected. The potential to create a drug reservoir of significant size on the small surface area available in a periodontal pocket is limited. To maintain a high concentration over a prolonged period of time, the flushing action of the crevicular fluid flow has to be counteracted by a steady release of the drug from a larger reservoir. b- Controlled-release devices Site-specific, controlled- release delivery systems allowed the administration of therapeutic levels of drug to the site of infection for prolonged periods of time. Agents available that incorporate the active ingredient into an agent (fibers, gels, chips, collagen film, acrylic strips, and a polymer). The active ingredient is then released over a period of days. A locally delivered product must remain in the pocket long enough to be effective. Considering that the gingival crevicular fluid in a 5 mm pocket is replaced about 40 times per hour, a reservoir that can release the drug continuously to offset this fluid elimination is necessary. The goal of locally delivered products should be to eliminate the pathogenic organisms or alter the inflammatory response, and thereby minimize tissue destruction. The three criteria for achieving these goals are:  Medication must reach the intended site of action;  Must remain at an adequate concentration; Page 3 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023  Must last for a sufficient amount of time. Sustained release device or controlled delivery is a system designed to prolong retention of chemotherapeutic agents in periodontal pockets and ensure a regular and steady release of the agent at therapeutic levels. Controlled-release devices theoretically produce more constant and prolonged concentration profiles when compared to systemic and topical applications. Apparently the concentration in plasma is lower than the systemic route which means controlled delivery minimizes risks of side effects Commercial preparations 1- Actisite: (Tetracycline HCl) 2- PerioChip:(2.5 mg Chlorhexidine Gluconate) 3- Atridox* (doxycycline) 10% 4- Arestin : (minocycline HCl 1mg) 5- Dentomycin : (2% Minocycline ointment and microspheres) 6- Elyzol (Metronidazole 25 % gel) c- Systemic antibiotics Indications Antibiotics are administered after careful case selection and it shouldn't be a substitute for routine treatment regimen. 1. Severe cases of ANUG Metronidazole is used. Page 4 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023 2. When local infection of periodontal abscess spreads within the tissue planes to cause facial swelling & systemic involvement broad spectrum antibiotics are used to control infection. 3. Multiple abscess & gross periodontal infection (as in diabetic patients) broad spectrum antibiotics are used. 4. HIV positive individuals are at high risk for potential growth of Candida albicans when other antibiotics are used. So metronidazole is given to prevent over growth. 5. Refractory periodontitis (which are advanced or moderate cases of periodontal disease which show breakdown & loss of attachment despite thorough mechanical ttt & good plaque control.) 6. Cases of aggressive periodontitis either in combination with surgical or non surgical therapy. 7. In chronic periodontitis to reduce need for periodontal surgery. Contraindications & Disadvantage Generally the contraindications for use are related to the impaired metabolism & excretion of the drugs. Consequently impaired function of hepatic or renal tracts should warrant caution in prescribing systemic antibiotics. Disadvantage relates to the fact that the drug is dissolved by dispersal over the whole body & only a small portion of the total dose actually reaches the subgingival microflora in periodontal pocket Penicillin Penicillin (benzyl penicillin, penicillin G) is a beta lactam bactericidal compound that acts through inhibition of bacterial cell wall synthesis. Without an adequate cell wall the microorganisms are physiologically incapable of survival. The problem with penicillins, however, is the high rate of hypersensitivity to the drug. Moreover, with its wide spread usage, many organisms have developed resistance to penicillin through the production of beta-lactamases, which destroy the beta-lactam ring of penicillin, making it inactive. Page 5 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023 Amoxicillin It is a semi-synthetic broad spectrum (G-ve & G+ve bacteria) penicillin.It's susceptible to penicillinase & β 3 lactamase.produced by certain bacteria, which breaks penicillin ring structure, therefore rendering it ineffective. Dose: 500 mg tid Augmentin Is a combination of the penicillin derivative amoxicillin (250mg or 500 mg) and clavulanic acid (125mg). Clavulanic acid is an inhibitor of beta-Iactamase and thus overcomes the bacterial resistance to amoxicillin. Thus amoxicillin clavulanic acid combinations are promising in the antibi otic augmentation of mechanical periodontal therapy. Clindamycin (Dalacin C) It's a derivative of Lincomycin. It inhibits protein synthesis (bacteno- static). It's effective against anaerobic bacteria, especially P.gingivalis & Fuso bacterium.It is used in patients with periodontitis refractory to tetracycline. It is limited due to association with pseudomembranous colitis, diagnosed by diarrhea & cramping. Tetracyclines The tetracyclines are bacteriostatic and are effective against rapidly multiplying bacteria. They generally are more effective against gram- positive bacteria than gram-negative bacteria. Pharmacology. Page 6 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023  It acts by inhibiting protein synthesis through binding to bacterial ribosomes. Moreover, it has anticollagenolytic activity.  Tetracycline is absorbed from the GIT & absorption is reduced when drugs are taken with milk & antacids.  Drug concentration in gingival crevicular fluid is 2-10 times that in serum.  It also binds to the tooth surface from where they may be released slowly over time (substantivity).  Tetracyclines have been widely used in the treatment of periodontal diseases. They have been frequently used in treating refractory periodontitis, including localized aggressive periodontitis.  Tetracyclines have the ability to concentrate in the periodontal tissues and inhibit the growth of A.a Clinical use:  In chronic periodontitis tetracycline with root planing, decrease inflammation.  In aggressive periodontitis the A.a is tissue invasive, therefore tetracycline is used in con junction with mechanical therapy to suppress A.a & arrest bone loss with an increase in post- therapy bone level noted. A 2 week course is given to minimize chance of re-colonization with the A.a that might originate from a residual infection of the gingival tissues.  In periodontal abscess.  In Refractory Periodontitis the drug is effective  The drug is used for 14-21 days around the active periodontal therapy & not long term regimen as high frequency of resistant organism occurs. Drug interactions  It is recommended that tetracycline not be taken at the same time with milk and antacids, because they reduce the absorption of the drugs which absorbed in the GIT. Page 7 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023  Tetracycline may enhance the activity of warfarin and result in excessive thinning of the blood, necessitating a reduction in the dose of warfarin.  Phenytoin (Dilantin), Carpamazepine (Tegretol), and barbiturates (such as phenobarbital) can enhance the metabolism of tetracycline. Specific agents 1)Tetracycline Dose: 250 mg q.i.d.as the half life is 6-10 hr. It is inexpensive and shouldn't be given to patients with impaired renal function, as it's excreted in urine. 2) Minocycline Dose: 100 mg twice daily for 1 week, as half life is 16-18 hr, thus it facilitates cooperation. It is broad spectrum & suppresses spirochetes up to 3 months post operatively.  In chronic Periodontitis, It has an effect on resolving gingival inflammation with less renal toxicity, as it is excreted in feces. 3) Doxycycline Dose: 100 mg twice daily in first day then 100 mg once daily (patient is more conformable).  The dose may be 50mg twice daily to decrease stomach upset.  It has same spectrum as minocycline.  In refractory periodontitis this dose for two weeks produces a significant reduction in A.a. up to 12th month in association with surgery as well as reducing probing depth and gain of clinical attachment. Page 8 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023 Metronidazole It is a bactericidal to anaerobic G-ve & G+ve organisms, with inability to develop resistance, and to obligate anaerobes (Porphyromonous gingivalis, prevotella intermidia).It disrupts the bacterial DNA synthesis. Clinical Usage.  Metronidazole has been used clinically to treat gingivitis, acute necrotizing ulcerative gingivitis, chronic periodontitis, and aggressive periodontitis. It has been used as monotherapy and also in combination with both root planing and surgery or with other antibiotics.  Dose: 250 mg qid for 2 weeks Limitation of use  The trademark name for disulfiram is Antabuse—it is the most commonly used medication for the treatment of ALCOHOLISM  Disulfiram is used to deter drinking by causing an unpleasant reaction if a medicated person drinks ALCOHOL(ethanol).  This reaction is called the disulfiram-ethanol reaction (DER); the symptoms include flushing, dizziness, rapid heartbeat, nausea, vomiting, and headache.  Disulfiram should not be given to patients who are taking metronidazole (Flagyl) as these drugs will produce a DER.  patients undergoing anticoagulant therapy should avoid metrondazole  Avoided in severe hepatic disease Page 9 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023 Marcolides It's bacteriostatic, but can be bactericidal if high concentration is achieved. It inhibits bacterial protein synthesis. It acts against G+ve & G-ve. It is used in patients with history of hypersensitivity to penicillin, or had penicillin resistant organism in mouth. 1) Erythromycin It doesn't concentrate in the gingival crevicular fluid and not effective against ppp, therefore, it is not recommended in periodontal therapy. 2) Spiramycin It acts against G+ve, excreted in high concentration in saliva and it can be detected for at least seven days in the gingiva. It is twice as effective as erythromycin. It is beneficial in advanced periodontal disease. It is safe and nontoxic. Serial and combination therapy Rational They are being considered because of the potential of reaching a broader spectrum of microorganism. Since periodontal infections include aerobic microairophilic, anaerobic G+ve and G-ve therefore more than one antibiotic is needed. The dosage of each antibiotic is decreased and duration of administration is less. Clinical use Caution must be exercised to insure negative interactions between the recommended combinations. Bacteriostatic antibiotics require rapidly dividing microorganisms to be effective (tetracycline) do not function well with bactericidal antibiotics (Amoxicillin or Page 10 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023 metronidazol) so should be given serially if both types are required. Metronidazole & Amoxicillin and metronidozole & augmentin combination produces A.a. suppression and excellent elimination of many organisms which are refractory to tetrarycline and root planing. Metronidazole & ciprofloxacin is effective on A.a., and it is a powerful combination in refractory and recurrent periodontitis as metronidazol targets obligate anaerobes and ciprofloxacin targets facultative anaerobes. In addition to the use of antiseptic mouths and antibiotics, drugs which modulate the host response have been recently introduced for management of periodonta! disease, this approach of therapy is termed host modulatory therapy. In the past, mouth washes that control the inflammatory changes were widely used such as benzydamine hydrochloride (tantum verde), however, the systemic administration of drugs that modulate the host response was currently proposed. Host modulatory therapy HMT Non-steroidal anti-inflammatory drugs (NSAIDs) They decrease bone loss by modifying host inflammatory response to bacteria. Bacteria activate inflammatory cells in the periodontium. Phospholipids in the plasma membranes of the cells become available for phospholipase action releasing free arachidonic acids in the area which is metabolized through: 1. cyclooxygenase pathway into prostaglandin, thromboxanes, prostocycline by cyclooxygenase enzyme 2. Lipooxygenase pathway leukotrienes Action Page 11 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023 1. NSAIDs interfere with arachidonic acid metabolism, so it inhibits inflammatory process. 2. Some NSAIDs affect response of PMNLs to inflammation not related to prostaglandin inhibition Prostaglandin are important mediators in bone resorption, therefore, NSAIDs decrease severity of periodontal diseases. Drugs include Flubiprofen, Ibuprofen, Mefenamic acid. II) Chemically modified tetracycline & subantimicrobial dose of doxycycline (periostat): Research has shown that even though bacteria initiate the periodontal disease process, periodontal tissue destruction is caused not by the bacteria, but by endogenous enzymes produced by the host in response to the presence of bacteria. Tetracyclines in low doses decrease rate of collagen break down i.e. inhibit tissue destruction by its Anti-collagenase effect (collagenase is secreted from PHNLs). Tetracycline is able to chelate metal ions. Collagenases are Ca++ dependant enzymes. Thus tetracyclines are capable to inhibit collagenase enzyme by chelation with Ca++. These effects inhibit bone loss & enhance bone regeneration, which may be of benefit in future therapy related to new attachment procedures i.e. Bone graft & guided tissue regenerationGTR. III) Bisphosphonates: They are chemical analogues of pyrophosphate that are known to inhibit osteoclastic bone resorption. Page 12 of 13 Prof Dr Hala Yassin Periodontology Dept. AAST 2023 Systemic use of bisphosphonate was found to inhibit alveolar bone loss in periodontitis and following periodontal surgery. Page 13 of 13