Calcium Hydroxide Therapy For Persistent Chronic Apical Periodontitis .
CASE SERIES Calcium Hydroxide Therapy for Persistent Chronic Apical Periodontitis : A Case Series Mithun Jith.K 1 , Jerry J2 Sa th ya n ar a ya n an R 3 ABST RACT : A c om m on s equl a e t o pul p di s ea s e i s de vel opm en t of p er i a pi ca l l esi on s. Chr on i c per i a pi ca l l esi on s m ost l y oc cur wi t h out an y e pi sod e of a cut e pa i n an d ar e di scover ed on r out i n e r a di ogra ph i c exa m in a ti on . It ’s a wel l a cc ept ed fa ct t h at a l l in fl a m ma t or y p er i a pi ca l l esi on s sh oul d be i n i t i al l y t r ea t ed wi t h con ser va t i ve n on sur gi ca l pr ocedur es. St udi es h a ve r epor t ed a succe ss r a t e of up t o 85% a ft er e n dodon t i c tr ea t m en t of t e et h wi t h per i api ca l . l esi on s. Wi t h va ri ous bi ol ogi c pr op er t i es, ca l ci um h ydr oxi de h a s been wi del y us ed i n en dod on t i cs fr om i t s i n t r oduct i on i n 1920. Lar ge si z e of a ch r on i c per i a pi ca l l esi on does n ot a l wa ys m an da t e i t s sur gi ca l r em ova l , an d th a t even c yst -l i ke per i a pi ca l l esi on s h ea l fol l owi n g a con ser va t i ve en dod on t i c th er a py wi t h l on g t erm ca l ci um h ydr oxi de t h er a py. Th i s ca se ser i es h i ghl i gh t s th e im por t an ce of ca l ci um h ydr oxi de bei n g used a s in tra ca na l m edi ca m en t wi th st a n dar d pr oct oc ol s a n d t im e fr a m e an d al so on di ffer en t n on sur gi ca l tr ea t m en t str at egi es for m an a gem ent of ch r on i c a pi ca l per i odod on t i t i s pat i en t s. Ke ywor d s: Ca l ci um h ydr oxi d e, Chr oi n c a pi ca l per i odod on t i t i s, en dodon t i c th er a py, ca l ci um h ydr oxi de t h er a py T placed as an intracanal medicament between he outcome of the endodontic therapy appointments5. depends on reduction or elimination of Apical periodontitis is caused by bacteria bacteria from the root canal space. The major within the canal space6,7. The treatment of factor associated with endodontic failure are apical periodontitis should, therefore, aim at the persistence of microbial infection in the bacterial eradication. Since cleaning and root canal system and/or the periradicular shaping area1,2. The most essential step in aiming at effectively eliminate bacteria8, alone do not completely it and seems complete disinfection of the root canal space is the chemo mechanical preparation. However, total elimination of bacteria is difficult to accomplish3,4,5. For the elimination of the surviving bacteria, calcium hydroxide is Scan the QR code with any smart phone scanner or PC scanner software to download/ share this publication Journal of Scientific Dentistry, 4(1), 2014 24
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l logical to medicate canals with an intracanal suggestive of a chronic lesion. (Fig 1A) antibacterial medicament after biomechanical Conventional retreatment as the first line of preparation. A success rate of 80.8%9 has treatment was planned. Bridge was removed been reported with calcium hydroxide, when and root canal was re entered under cotton roll used for endodontic treatment of teeth with isolation. Mesial canal was intentionally over periradicular lesions. instrumented with 25 no K file. 25 no. K file Calcium hydroxide has been widely used in was extended till approximately the centre of endodontics from the time it was introduced in the lesion which was about 2 mm beyond Endodontics by Herman in 1920. With a pH apex. Upon instrumentation profuse bleeding of approximately 12.5 it is a strong alkaline was present. Copious irrigation was done with substance. In an aqueous solution, calcium normal saline and plain cotton dressing was hydroxide and placed and temporary coronal seal was done hydroxyl ions. Various biological properties with zinc oxide eugenol. One week later, have been attributed to this substance, such as Calcium hydroxide mixed with glycerin was dissociates into 4 calcium tissue-dissolving coated in the canal with lentulo spiral and the ability10, inhibition of tooth resorption11, and access cavity was sealed with reinforced glass repairing ability by hard tissue formation12. At ionomer restorative material, as the patient present, calcium hydroxide is acknowledged was not available for next three months. as one of the most effective antibacterial Temporary intracanal medicament during endodontic cemented with zinc phosphate. (Fig 1B) therapy. Four months later patient reported with no This case series highlights the importance of complaint and the bridge was removed. The calcium hydroxide being used as a intracanal coronal seal was intact with good marginal medicament in persisting non healing chronic seal. apical periodontitis. evidence of root formation. As the patient was antibacterial activity , bridge Radiograph was fabricated revealed and questionable travelling again for four months, the same calcium hydroxide therapy was planned. This CASE REPORT 1: (Fig 1) time calcium hydroxide was mixed with Patient reported with loose failing bridge on virgin coconut oil (based on unpublished left examination research study by the author) and coated with revealed cantilever bridge with crown in 36 as lentulo spiral and temporary coronal seal was abutment for pontic 35. Radiograph revealed done with reinforced glass ionomer (fuji GC root Type bottom treated condensat ion radiolucency 25 teeth. 36 Clinical with and with deficient huge radio lateral per iapica l opaque Journal of Scientific Dentistry, 4(1), 2014 border IX). The temporary bridge was recemented with zinc phosphate. (Fig 1C) Patient reported after three months. Clinically
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l asymptomatic and radiologically there were condensation technique. some signs of bone formation and reduction in radiograph revealed satisfactory obturation periapical radiolucency (Fig 1D). Patient was with little sealer rescheduled for obturation. Root canals were extending beyond apex of mesial canals. (Fig obturated after three weeks with guttapercha 1E) and zinc oxide eugenol sealer in lateral Patient reported 1A 1B 1C 1D 1E 1F Post operative and questionable GP after three years for Fig– 1: Case report 1 1A: Preoperative status of 36 showing large periapical raiolucency involving apex of 36. 1B: Overinstrumentation beyond the apex towards the centre of the lesion. 1C: Calcium hydroxide dressing with virgin coconut oil. 1D: Three months review showing signs of healing. 1E: Obturation of 36 with mild extrusion of sealer beyond apex. 1F: Five years follow up showing complete healing. Journal of Scientific Dentistry, 4(1), 2014 26
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l maintenance check up. Clinically 36 was 22 respectively (Fig 2B). Powder Calcium normal and radiologically the periapical lesion hydroxide was mixed with glycerin and reduced considerably. There was evidence of coated with lentiulospiral in the root canal. periodontal involvement with furcation and Temporary coronal seal was given with plain inter dental bone loss. Periodontal therapy was cotton seal and thick mix of zinc oxide done. Five years follow up revealed excellent eugenol. Patient was rescheduled after four bone healing with stable periodontal condition weeks for further management. for past two years.(Fig 1F) Patient was reviewed and was asymptomatic. The factors strongly associated for the success Clinical examination revealed sinus in relation of this case would be: to 21. Canals were reentered, irrigated and 1. Deco mpr ess io n of le s io n by redressed with calcium hydroxide. Temporary overinstrumenting to the center of the lesion. coronal seal was given. 2. Calcium hydroxide therapy with virgin Patient cocoanut oil. days .Clinically patient was asymptomatic and 3. Glass ionomer coronal seal. the sinus had disappeared. All there tooth was 4. Unintentional three months interim period obturated with 2% guttapercha with zinc between appointments. oxide sealer and cold lateral condensation was technique. rescheduled Immediate post after ten operative CASE REPORT 2: (Fig 2) radiograph revealed satisfactory obturation in Patient reported with mild discoloration in 21, 11 and sealer beyond apex in 22. (Fig 2C) maxillary front tooth .History revealed that Permanent coronal seal was done with glass root canal treatment was done two year ionomer. Patient declined to go for the crown back .Radiograph revealed improper because of cost and minimal discoloration. and Periapical Patient reported after 15 years with complain radiolucency were seen in relation to 11, 21 for increased discoloration and wanted to and 22. Vitality test with electric and heat know whether the anterior tooth was under gave negative response. 11 was diagnosed as control. Clinical patient was asymptomatic, nonvital tooth and scheduled for root canal with no pathological change in relation to treatment (Fig 2A). Retreatment was planned 11,21 in 21 and 22. satisfactory periapical status in relation to Root canal of 11 was opened without local 11,21 and 22. The obturation in 21 showed anesthesia. Old GP were removed with H files deficient lateral seal and residual very from 21 and 22. Canals were irrigated with minimal periapical radiolucency even after 15 normal saline and shaped till 60/80 and 30 K years suggestive of apical scar. (Fig 2D) The files with hand instrumentation in 11,21 and inference of this follow up confirms the obturation in 21 22. 27 Journal of Scientific Dentistry, 4(1), 2014 and 22. Radiograph revealed
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l importance of cleaning and shaping and the shaped till no.80 at the estimated working long term intracanal medicament with calcium length. hydroxide. glycerin was loaded with lentiulospiral in the Calcium hydroxide mixed with root canal. As there was no apical stop, the CASE REPORT 3: (Fig 3) calcium hydroxide extruded into the periapical Patient reported with pain in relation to the lesion. Temporary coronal seal was given with upper right front tooth with evidence of pus plain cotton seal and thick mix of zinc oxide discharge in relation to the same. Clinical eugenol. Patient was rescheduled after three examination revealed discolored 11 with sinus weeks for further management. (Fig 3B) opening in relation to 11. Radiograph revealed Patient was reviewed and was asymptomatic. root treated 11 with deficient lateral and apical Clinically patient was asymptomatic but the seal and a large periapical radiolucency tenderness on percussion still persisted . around the open apex of 11. (Fig 3A) Canals were reentered, irrigated and redressed Old GP were removed with H files from 11. with calcium hydroxide. Temporary coronal Canals were irrigated with normal saline and seal was given. Patient was rescheduled after 1A 1B 1C 1D Fig– 2: Case report 2 2A: Preoperative status of 11, 21 and 22. 2B: Complete GP retrieval and working length assessment. 2C: Satisfactory obturation of 11, 21 and 22. 2D: 15 years follow up showing complete healing. Journal of Scientific Dentistry, 4(1), 2014 28
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l three weeks for further management. revealed satisfactory obturation in 11. (Fig Patient was reviewed and was clinically 3E) Permanent coronal seal was done with asymptomatic. There was no tenderness on glass ionomer and post endodontic restoration percussion. was was given after a week. Patient was reviewed complete resolution of the periapical lesion after 18 months, Clinically 11 was normal and with the concomitant resorption of the radiologically the periapical lesion reduced calcium hydroxide placed periapically. (Fig considerably with fully formed apex. (Fig 3F) Radiographically, there 3C)Temporary coronal seal was removed and the master cone was checked and obturation CASE REPORT 4: (Fig 4) was done using an inverted cone technique Patient reported with pain in relation to the (Fig 3D) using zinc oxide as sealer and cold upper left front tooth with diffuse swelling lateral condensation technique with accessory intraorally cones. Immediate post operative radiograph examination revealed discolored 21,22 with 4A Fig– 4: Case report 4 4A: Preoperative status of 21, 22. 4B: Completed BMP and matercone fit assessment. 4C: Metapex intracanal medicament. 4D: Immediate post obturation radiograph. 4E: Eight months follow up. 29 Journal of Scientific Dentistry, 4(1), 2014 21 4C 4B 4D relation 4E region. Clinical
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l an opened access in 21. Radiograph revealed upper right front tooth. Clinical examination root canal attempted in 21 with deficient root revealed discolored 12, filling. The root canal treatment was left revealed a large periapical radiolucency incomplete as the patient has discontinued around the apex of 12 and 13 with mild treatment dentist. displacement of 13. The radiolucency was periapical well circumscribed with corticated margins. Radiograph from the revealed previous a large 13. Radiograph radiolucency around the apex of 21 and 22 (Fig 5A). with an opened access cavity in 22. (Fig 4A) Non surgical management was first planned Root canal of 21, 22 was opened without local and the access was opened. The canal was anesthesia. Canals were irrigated with normal intentionally over instrumented with 25 no K saline and shaped till 80 and 60 K files with file. 25 no. K file was extended till hand 22 approximately the centre of the lesion which respectively and the master cone was selected was about 2 mm beyond apex. Upon (Fig 4B). Calcium hydroxide in propylene instrumentation profuse pus discharge was glycol base (metapex) was loaded with evident through the canal and the active non lentiulospiral in the root canal. Temporary surgical decompression was done through the coronal seal was given with plain cotton seal canal using a canal aspirator and a high and thick mix of zinc oxide eugenol. Patient volume suction. was rescheduled after two weeks for further Canals were irrigated with normal saline and management. (Fig 4C). shaped Patient was reviewed and was clinically instrumentation in 12 and 13 respectively and asymptomatic. Radiograph shows complete the master cone was selected (Fig 5B). resorption of the calcium hydroxide which Calcium hydroxide in propylene glycol base was periapex. was mixed with glycerin and coated with Obturation was done with lateral condensation lentiulospiral in the root canal. Temporary and with zinc oxide as sealer. Immediate coronal seal was given with plain cotton seal postoperative shows satisfactory obturation. and thick mix of zinc oxide eugenol. Patient (Fig 4D). Permanent coronal seal was given was rescheduled after two weeks for further with GIC. management. Patient was reviewed after eight months, T he Clinically 21, 22 was normal and there was a radiographically there were signs of healing, complete resolution of the periapical lesion. but still weeping was persistent, Canals were (Fig 4E). re-entered, CASE REPORT 5: (Fig 5) calcium hydroxide. Temporary coronal seal Patient reported with pain in relation to the was given (Fig 5C). Patient was rescheduled instrumentation extruded in int o 21 t he and till 60 p at ie nt K files was irrigated and with r e v ie w ed redressed hand a nd with Journal of Scientific Dentistry, 4(1), 2014 30
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l after eight weeks for further management. Patient reported with dull pain in relation to The patient was reviewed and when the the lower left back tooth for the past two criteria’s of obturation was met which months. Patient gave prior history of root includes getting a dry canal, obturation was canal being performed by a general dentist a done with lateral condensation and with zinc year back. oxide eugenol as sealer. (Fig 5D). Clinical examination revealed intact metal Patient was reviewed after 6 months, ceramic crown with revealed a leaky margins. large periapical Clinically 12, 13 was normal and there was a Radiograph drastic reduction of the periapical lesion. (Fig radiolucency around the apex of the mesial 5E). root of 36 with silver points obturation with poor apical and lateral seal. (Fig 6A) Conventional non surgical retreatment was CASE REPORT 6: (Fig 6) 5A 5D Fig– 5: Case report 5 5A: Preoperative status of 12, 13. 5B: Over instrumentation beyobnd apex and master cone selection. 5C: Calicun hydroxide intracanal medicament. 5D: Immediate post obturation follow up. 5E: Six months review. 31 Journal of Scientific Dentistry, 4(1), 2014 5C 5B 5E
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l planned , crown was removed and the silver Patient was reviewed after 6 months, where points ultrasonics. patient was completely asymptomatic and done with Radiograph revealed complete healing of the intentional working beyond the apex with lesion. Core build up was done using fiber small sized K files. Copious irrigation was post in the distal canal and all ceramic full done with 5.2% sodium hypochlorite and final coverage restoration was given. (Fig 6C) was Cleaning and removed using shaping was rinse was done with 2% chlorhexidine. Two week calcium hydroxide dressing was given DISCUSSION: and when all criteria for obturation was Antibacterial activity of calcium hydroxide is achieved, obturation was done with protaper directly proportional to gutta percha points and zinc oxide eugenol hydroxyl ions in an aqueous environment. sealer condensation Hydroxyl ions being highly oxidant free technique. Excess calcium hydroxide extruded radicals shows extreme reactivity, reacting through the apex was left behind for healing. with several other biomolecules (Fig 6B). bactericidal effect of calcium hydroxide on using cold lateral the release 13 of . The 6B 6A 6C Fig– 6: Case report 6 6A: Preoperative status of 36. 6B: Immediate post obturartion with extruded calcium hydroxide beyond apex. 6C: Six months follow up with complete healing with post endodontic restoration. Journal of Scientific Dentistry, 4(1), 2014 32
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l bacterial cells are probably due to the antibacterial action. Çalişkan and Türkün17 in following mechanisms: his case report demonstrated success with 1. Damage to the bacterial cytoplasmic apical closure and simultaneous periapical membrane. healing in a large cyst-like periapical lesion 2. Protein denaturation. following non-surgical treatment with calcium 3. Damage to the DNA. hydroxide The bactericidal effects of calcium hydroxide containing root canal sealer. In our case series, were observed only when the substance was in case II showed remarkable healing inspite of direct contact with bacteria in suspension. calcium hydroxide being extruded beyond Because of the high availability of hydroxyl apex. and a calcium hydroxide– ions, the survival of the bacteria would be nearly impossible. Clinically, this direct Active non surgical decompression of large contact of the calcium hydroxide with the periapical lesions can be done using a bacteria present in the canal is not always commercially available Endo-eze vacuum possible. Apart from the antibacterial effects system (Ultradent, Salt Lake, Utah) or any of hydroxyl ions, rendering a high pH values other micro syringe with a high vacuum in the environment is a prerequisite to destroy suction to create a negative pressure, which microorganisms. Complete elimination or would result in the decompression of large killing of bacteria depend solely on the periapical lesions. The high volume suction availability of hydroxyl ions in solution, aspirator is connected to a micro gauge which is much higher where the paste is needle, which is inserted in the root canal and applied. The antibacterial effects exerted in when activated creates a negative pressure, the root canal will be continuous as long as which results in aspiration of the exudates/ calcium hydroxide retain a very high pH. If contents of the cystic cavity. The extudate is calcium hydroxide diffuses to tissues and the aspirated till the weeping stops through the hydroxyl concentration is decreased as a result canal and an intracanal medicament of of agents calcium hydroxide is given which usually (bicarbonate and phosphate), proteins, acids helps in reducing the bacterial load. Unlike its antibacterial effectiveness gets declined or the surgical decompression technique, which impaired . 14, 15 involves placing drains directly into the the contact Souza et al 33 16 with buffering suggested that the action of lesions through the labial mucosa, this calcium hydroxide beyond the apex may be technique is minimally invasive as the entire four-fold: (a) anti-inflammatory activity, (b) procedure is done through the root canal and neutralization of acid products, (c) activation has good patient compliance and causes less of discomfort for the patient 18. In our case series, the alkaline phosphatase, Journal of Scientific Dentistry, 4(1), 2014 and (d)
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l case V was managed by non surgical The vehicles with which the calcium decompression through the canal followed by hydroxide powder is mixed/ used have an the calcium hydroxide therapy. important role in the overall dissociation of hydroxyl ions. Its only the vehicle in which Bhaskar has suggested that whenever a calcium hydroxide is delivered determine the periapical lesion persisted on a radiograph velocity of ionic dissociation causing the paste instrumentation should be carried 1 mm to be highly soluble and resorbable at various beyond the apical foramen . This may result in rates by the periapical tissues or from within transient ulceration/ the root canal. The viscosity is indirectly disruption of the epithelial lining resulting in proportional to degree of ionic dissociation. resolution of the lesion.19 Bender on Bhaskar’s The calcium hydroxide when used in these hypothesis added that penetration of the apical viscous vehicles tends to remain in place for a area to the center of the lesion would result in longer period time as these vehicles are high drainage and relieving pressure accumulated molecular weight substances. 22 within the lesion. Fibroblasts begin to There are three main types of vehicles: proliferate once the drainage stops and starts 1. Water-soluble substances such as saline, depositing collagen; which would compresses water, the capillary network. methylcellulose, inflammation and Thus the epithelial car bo xymet hylc e llu lo se, Ringers solution and cells gets completely deprives of nutrition and anaesthetic solutions they undergo degeneration, which are finally 2. Viscous vehicles such as propylene glycol , 20 engulfed by the macrophages. In our case glycerin, and polyethylene glycol (PEG) series, case I, case IV was managed by 3. Oil-based vehicles such as silicone oil, intentionally working beyond the apex to olive oil, camphor (the oil of camphorated puncture at the centre of the lesion to relieve parachlorophenol), some fatty acids (including pressure and to obtain drainage followed by linoleic, oleic, and isostearic acids), & two week calcium hydroxide therapy. metacresylacetate 25 Healing of large cysts like well-defined radiolucencies following conservative root Calcium hydroxide should be always be canal treatment has been reported. Although combined with a liquid vehicle as using dry the cystic fluid contains cholesterol crystals, calcium hydroxide powder alone is difficult to weekly debridement and drying of the canals deliver and to handle, and for the release of over a period of two to three weeks with long hydroxyl ions an aqueous medium becomes term calcium hydroxide therapy , followed by mandatory for calcium hydroxide. The most obturation has led to a complete resolution of commonly used carriers are sterile water or lesions by 12 to 15 months 21. saline. Though dental local anaesthetic Journal of Scientific Dentistry, 4(1), 2014 34
Ca l c i um H y d r o xi d e Th e r a p y solutions have an acidic pH (between 4 and residue on the canal walls. Leaving remnants 5), they are used as adequate vehicle because of oil on the canal walls will adversely affect calcium hydroxide is a strong base with a pH the adherence of sealer or other materials used of around 12.5 which is affected minimally by to obturate the canal 25. acidic nature of the local anesthesia . Rapid Extrusion of calcium hydroxide beyond the ionic dissociation occurs only with the apex was suggested as a factor for the lack of aqueous medium whereas ionic dissociation early healing of periapical lesions initially. 26 will be slower in viscous and oil based However, many researchers advocated that mediums. when calcium hydroxide comes in direct The effects of glycerin and propylene glycol contact with the periapical tissues it is vehicles on the pH of calcium hydroxide were beneficial for the inductive action of the investigated using conductivity testing 23. They calcium hydroxide.27,28 Many authors have reported that a concentration of the vehicles reported high degree of success by using was inversely proportional to the effectiveness calcium hydroxide beyond the apex and into of calcium hydroxide as a root canal the lesions medicament. As the concentration of the lesions vehicle increases the effectiveness or efficacy resorbs and its the barium sulphate that is of calcium hydroxide decreases.23 But the added to the calcium hydroxide paste for availability of hydroxyl ions would drastically radiopacity, which is not readily resorbed reduce in a aqueous medium wherein the when the paste extrudes beyond the apex. availability of hydroxyl ions would be long Several lasting if its used in a viscous vehicle24. As in importance of a long observation time for the our cases, since most of the lesions were large teeth treated with large periapical lesions31, 32. sized and availability of hydroxyl ions for a In longer period of time was required viscous examination ranged from two to ten years. 32. vehicle was selected rather than a aqueous Shah one. A viscous vehicle may remain within recalled at periodic intervals of three months, root canals for several months, and hence the six months, one year, and two years, to assess number of appointments required to change the healing of periapical lesions. There is 25 29,30 . Calcium hydroxide readily authors review 33 in cases with large periapical by have stressed Çalişkan, a on the follow-up suggested that patients should be . In our case always a chance for the quiescent epithelial series propylene glycol and glycerin based cells to be stimulated by instrumentation in vehicles were used . the apical area, with resultant proliferation and Oily vehicles have restricted applications as cyst recurrence/ formation. Hence, follow-up intracanal medicaments as they are difficult to becomes extremely essential and mandatory remove from the canal space and leave a for a period of at least two years to assess the the dressing will be reduced 35 M i t h u n J it h . K e t a l Journal of Scientific Dentistry, 4(1), 2014
Ca l c i um H y d r o xi d e Th e r a p y M i t h u n J it h . K e t a l success of the treatment. intracanal medicament even large sized periapical lesions can heal satisfactorily CONCLUSION: without any surgical intervention. Periodic Non surgical management of periapical follow-up examinations are essential and lesions have shown high success rate. With various assessment tools can be used to employing correct treatment strategy and with monitor the healing of periapical lesions. the use of long term calcium hydroxide as an instrumentation. Journal of Endodontics 1998;24:763– REFERENCES: 1. Lin LM, Skribner JE, Gaengler P. Factors associated with endodontic 2. 7. treatment failures. Journal Endodontics 1992;18:625–7. long-term study. Endod Dent Traumatol 1996;12:215- Nair PNR, Sjögren U, Krey G, Kahnberg K-E, 21. 6. resistant periapical lesions: a long-term light and calcium electron microscopic follow-up study. Journal of Endodontics and Dental Traumatolology 1992; 8:104- Endodontics 1990;16:580–8. 8. Bystrom A, Sundqvist G.Bacteriologic evaluation of and in endodontic therapy. Scandinavian Journal of Dental Traumatology 1988; 4:241-52. 12. manifestations. hydroxide. effect 1990;23:283-97. camphorated paramonochlorophenol, 13. hypochlorite. Endodontics and Dental Foreman PC, Barnes F .A review of calcium Bystrom A, Claesson R, Sundqvist G .The antibacterial of sodium Tronstad L.Root resorption etiology, terminology and clinical International Endodontic Journal Freeman BA, Crapo JD . Biology of disease. Free treatment of infected root canals. Endodontics and radicals and tissue injury. Laboratory Investigation Dental Traumatology 1985;1: 170-5. 1982; 47, 412-24. Siqueira JF Jr, Uzeda M. Intracanal medicaments: 14. Siqueira JF Jr, Lopes HP, Uzeda M . Recontamination evaluation of the antibacterial effects of chlorhexidine, of coronally unsealed root canals medicated with metronidazole, and calcium hydroxide associated with camphorated three vehicles. Journal of Endodontics 1997; 23: 167-9. hydroxide pastes after saliva challenge. Journal of Moller AJ, Fabricius L, Dahlen G, Ohman AE, Heyden Endodontics 1998; 24:11-4. 15. paramonochlorophenol or calcium Siqueira JF Jr, Uzeda M .Influence of different bacteria and necrotic pulp tissue in monkeys. vehicles on the antibacterial effects of calcium Scandinavian Journal of Dental Research 1981; 89: hydroxide. Journal of Endodontics 1998;24:663-5. 475–84. 16. Souza V, Bernabe PF, Holland R, Nery MJ, Mello W, Kakehashi S, Stanley H, Fitzgerald R .The effect of Otoboni Fiho JA. Tratament
been reported with calcium hydroxide, when used for endodontic treatment of teeth with periradicular lesions. Calcium hydroxide has been widely used in endodontics from the time it was introduced in Endodontics by Herman in 1920. With a pH of approximately 12.5 it is a strong alkaline substance. In an aqueous solution, calcium
properties and clinical applications of calcium hydroxide in dentistry. INTRODUCTION In 1920, Hermann introduced calcium hydroxide to dentistry as a pulp-capping material but today it is used widely in the field of endodontics.1 Calcium hydroxide is a white odourless powder with the chemical formula Ca(OH) 2
2. Calcium hydroxide is a solid granular product commonly called hydrated lime or slaked lime. It is commonly mixed with soil, and then sprayed with water used to raise the pH of soil and water to act as an activator of sodium persulfate. When added to water, calcium hydroxide dissociates into calcium ions and hydroxide ions. 3.
with calcium hydroxide was slower than that of MTA, both materials were successful for pulp capping in human teeth. (J Endod 2008;34:1-6) Key Words Biocompatibility, calcium hydroxide, human pulp, min-eral trioxide aggregate, pulp capping, pulp therapy T he aim of conservative pulp therapy is to maintain the coronal and radicular pulp
clocycline calcium (equivalent to 30mg demeclocycline hydrochloride) 10mg triamcinolone acetonide. Excipients: 3mg sodium sulphite anhydrous. Calcium hydroxide has been used by dentists in clinical practice for over a century (Baker and Fotos, 1994). Calcium hydroxide is a white odourless powder
2815.20.00 potasium hydroxide in solid 2815.30.00 peroxide of sodium or potasium 2816 hydroxide and peroxide of magnesium, oxides ,hydroxide and peroxides of stontium or barium 2816.10.00 hydroxide and peroxide of magnesium 2816.20.00 oxide,peroxide and hydroxide of stontium 2816.30.00 oxide,peroxide and hydroxide of barium.
PESSE EASEMENT CORROSION AND MATERIAL SELECTION GUIDE TD/2600T/CORROSION-EN REV C 5 Material AISI 316L stainless steel Hastelloy C Monel Tantalum PTFE Elastomer (Viton) Calcium carbonate B B A A A A Calcium chlorate B A A A A Calcium chloride NR A B A A A Calcium fluoride A A A NR A Calcium hydroxide A A A A A 71 (160) Calcium hypochlorite 6 % NR NR NR A A 71 (160)
This report addresses the safety of the inorganic hydroxides calcium hydroxide (also known as calcium hydrate or slaked lime), magnesium hydroxide, potassium hydroxide (potassium hydrate or potash), and sodium hydroxide (sodium hydrate, lye, or caustic soda). These ingredients are all alkaline salts and are reported in the
America’s criminal justice system. Racial and ethnic disparity foster public mistrust of the criminal jus-tice system and this impedes our ability to promote public safety. Many people working within the criminal justice system are acutely aware of the problem of racial disparity and would like to counteract it. The pur-pose of this manual is to present information on the causes of disparity .
