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7 July 2010
Primary pulp organ1. 2. 3.
Time : 8.3 years Pulp organ growth- 1yr Pulp maturation-3yr 9 m Pulp regression- 3yr 6m
Maximum life 9.6 years
INTRODUCTION IRRIGATING MATERIALS INTRACANAL DISINFECTING MATERIALS ROOTCANAL FILLING MATERIALS
Definition:temporary placement of medicaments with good biocompatibility into root canals for the purpose of inhibiting coronal invasion of bacteria from the oral cavity.Nobuyuki Kawashima, International Dental Journal (2009) 59, 5-11 Use of intracanal medicaments (Chong and Pittford -1992)1. 2.
3. 4. 5.
Eliminate remaining bacteria after canal instrumentation Reduce inflammation of periapical tissues and pulp remnants Neutralize tissue debris and render canal contents inert Act as a barrier against leakage from the temporary filling Help to dry persistently wet canals06
Requirements of an ideal intra canal medicament5
Chong and Pittford -1992 1. Non irritant to periapical tissues 2. Able to eliminate bacterial flora of the canal 3. Prevent pain 4. Reduce periapical inflammation 5. Stimulate perapical repair 6. Effective rapidly and active for long periods 7. Capable of diffusion and penetration into dentin 8. Effective in the presence of pus and organic debris 9. Long shelf life 10. Non staining
Rationale for use of intracanal medicaments6
Reduce root canal microflora following cleaning of the canal - minimal effect on normal host tissue Reduce post instrumentation pain Antimicrobial effect :Tissue toxicity directly related to this effect Potent antibacterial medications most irritating Diluted ineffective Host tissue responses Universally accepted means of canal disinfection canal instrumentation + chemomechanical preparation
Aim : removal of pulp remnants and dentin debris
Ideal properties of Irrigating materials8
4. 5. 6. 7. 8.
Walten and Torabinajed 1989 Tissue and debris dissolution Low surface tension - promote the flow of irrigant into inaccessible areas Lubricant property enables instrument to readily slide down the canal Sterilization Removal of smear layer Cost Adequate shelf life Ease of storage
Classification of irrigating materials9
1. 2. 3. 1. 2. 3. 4. 5. 6.
Chemically non active solutions Water Saline Local anesthetic Chemically active materials Acids: 30% HCl, 50% Sulphuric acid, citric acid Alkalis: NaOCl, NaOH, Chelating agents: EDTA Oxidizing agents Antibacterial agents : chlorhexidine Detergents : sodium lauryl sulphate
Classification of irrigating materials Acc to Cohen:10
1. 2. 3.
Proteolytic materials Detergents Decalcifying materials
Proteolytic materials - NaOCl11
Early 20th century : treating wounds Clear,straw coloured reducing agent 5% chlorine Actions : Dissolves necrotic tissues and debris - Availability of free chlorine Higher temperature Concentration : 0.5% - Dakin 5.25% 1% - antimicrobial effect The concentration rise is directly proportional to the antimicrobial effect and tissue dissolution capacity and inversely proportional to biologic compatibility.
Destruction of bacteria : biosynthetic alterations in cellular metabolism and phospholipid destruction, formation of chloramines that interfere in cellular metabolism, oxidative action with irreversible enzymatic inactivation in bacteria, and lipid and fatty acid degradation
Does not effectively wet dentin Canal extensions poorly irrigated Deplete dentin of organic compounds Pure NaOCl 5.25% NaOCl Toxic Commercial NaOCl buffered pH 12 to13 caustic Diluted limited shelf life Stored for 1-2 weeks
Clinical complications : Accidental injection to periradicular tissues Pain Bleeding Swelling Release oxygen free radicals Reduce bonding of resin to dentin
Broad spectrum antimicrobial agent Antimicrobial mechanism: Cationic bisbiguanide molecular structure At low concentrations bacteriostatic At high concentrations bactericidal Property of substantivity 2% and 12% - residual antimicrobial activity -72hrs
Lin et al compared the use of CHX irrigant and slow releasing device against E.faecalis Viable bacteria reduced 0.2% CHX CHX impregnated GP points Combination with NaOCl Causes stainingEndodontic solutions online,volume 10,issue 1,spring 2004
Remove fatty tissue residues Quaternary ammonium compounds Used in water solutions at 0.1 to 1% Zepheran chloride : Toxic Low antimicrobial effectiveness Iodophores Wescodyne and iodopax Effective at low concentrations Mixed with Ca(OH)2
DECALCIFYING MATERIALS EDTA18
Smear layer EDTA : Chelates and removes mineralized portion of smear layer Decalcify 50m layer Concentration :17% Time : less than 1 min 15 minutes Limited value in root canal preparation Beltz et al -Added with NaOCl remove organic component of smear layer Eg : endodilator N EDTA + Ammonium Compounds Smear clear EDTA +centrimide + anionic surfactants
SmearClear was able to remove the smear layer from the root canals of primary teeth as effectively as ethylenediaminetetraacetic acid, suggesting that both solutions may be indicated for such purpose
Nelson Filho P Efficacy of SmearClear and ethylenediaminetetraacetic acid for smear layer removal in primary teeth J Dent Child (Chic). 2009 JanApr;76(1):74-7
Intracanal disinfection materials20 1. 2. 3.
1. 2. 3.
Phenolic compounds Antiseptics with chlorine and iodine base Phenol/carbolic acids: Paramonochlorophenol Thymol Cresol Phenol : non specific protoplasm poison Optimal antibacterial effect:1 -2% High conc: lower antibacterial effect Camphoration less toxic compound Disadvantages : Ineffective antimicrobials Intracanal dressing ineffective Induce inflammatory changes at low conc.
1. 2. 3.
Formocresol- 19 to 37% formaldehyde Tricresol formalin : Tricresol 10% + formaldehyde 90% Volatile releases antimicrobial vapors Antimicrobial effectiveness lower than its toxicity Disadvantages : Toxicity Tissue destruction Mutagenic and carcinogenic potential
Introduced by Buckley J P IN 1904 Equal parts of formalin and tricresol Effective bacteriocide Buckleys formula Tricresol (35%) Acqeous formaldehyde(19%) Glycerin(15%) Water(31%) Formocresol pulpotomy: vital primary teeth with carious exposures Sweet 1930
Preparation : 3 parts glycerin + 1 part water diluent solution 1 part formocresol + 4 parts diluent 1/5 th conc.
Mechanism of action: Prevents tissue autolysis bonding to proteins(peptide group of side chain aminoacids) Reversible process- no change in basic structure of proteins Emmerson (1959) : Action on pulp tissue Varied with length of time of contact 5minutes : surface fixation of normal tissue 3 days : calcific degeration Vital /nonvital pulpotomy : depends on duration
Acc to Mass and Zilbermann1933 Massler and Mansokhani 1959 Immediate: 7 14 days 1. Broad eosinophilic zone of fixation 2. Broad pale staining zone of atrophy with poor cellular definition 3. Broad zone of inflammation extending apically After 1 year: progressive apical movement of the zones with only acidophilic zone left at the end of 1 year
Jacob Daniel 1959: distinct zones 1. Superficial debris along with dentinal chips at the amputation site 2. Eosinophilic stained and compressed tissue 3. Palely stained zone with loss of cellular definition 4. An area of fibrotic and inflammatory activity 5. An area of normal appearing pulp tissue considered to be vital
Sweet 1930- multivisit technique Doyle 1962 complete devitalization 2 sitting procedure Spedding 1965 5 minute protocol partial devitalization Venham 1967 15 min procedure Current concept 4 min application
Rolling and Thylstrup 3 year follow up 91% -3months 83% - 12 months 78% - 24 months 70% - 36 months Fuks, Garcia- Godoy (1983) hard tissue deposition or calcification of root canal walls following formocresol pulpotomy
Concerns regarding Formocresol28
Lewis 1981, Ranly 1984, Garcia- Godoy 1986
Toxicity: formaldehyde- cytotoxic, mutagenic and carcinogenic in experimental formaldehyde- cytotoxic, animals Systemic distribution
Myers et al 1978 demonstrated systemic distribution of radio isotope labelled formaldehyde Nongentini et al 1980- mutations occurred following a 6 minute application of formocresolInternational agency for research on cancer (2004) formaldehyde human carcinogen Other alternatives Ferric suphate MTAMichael J Casas Do we still need formocresol In pediatric dentistry? J Can Dent Assoc 2005; 71:749-51
Devitalizing paste Andrew 1955 Objective: seal in place for 1-2 weeks Disadvantage : incomplete devitalization of pulp Hannah and Rowe -1971 5% PFD - ineffective Recommended : Uncooperative child and time factor in single visit Child does not accept local analgesia
EASLICKS PARAFORMALDEHYDE PASTE30
Paraformaldehyde Procaine base Powdered asbestos Petroleum jelly
Paraform devitalizing paste31
Paraformaldehyde Lignocaine Propylene glycol Carbowax Carmine to color
Tricresol Cresol Glycerin Paraformaldehyde ZOE
Dankert J, Gravemade and Wemes -1976 2 to 4% - rapid fixation of pulp tissue Limited penetration Underlying Pulp vital , free of inflamma