Medicaments: Aids to success in endodontics. Part 2. Clinical recommendations Paul V. Abbott, BDSc(WA), MDS(Adel), FRACDS(Endo)*
Key words: Endodontics, medicaments. Abstract In order to predictably achieve bacteria-free root canal systems, especially in pulpless teeth, it is necessary to use intracanal medicaments. Medicaments can also be used to influence the peri-radicular response to endodontic treatment. Considerationof a material's therapeutic action must be made when selecting a medicament for any pathologicalcondition. In general, only two commercial preparations satisfy the general requirements for root canal medicaments. Guidelines and the rationale for the use of these preparations are presented. (Received for publication March 1989. Revised December 1989. Accepted January 7990.)
Introduction In Part 1 of this review,' the role of bacteria in the progression of pulp and periapical diseases was discussed. The inter-appointment medication of root canals was shown to be a predictable means of eliminating bacteria from root canal systems and a reliable method for reducing periapical inflammation and stimulating hard tissue formation. However, some medicaments are capable of causing inflammation due to the toxicity of some components.
Based on a lecture presented at the Australian Dental Association 25th Congress, Sydney, 15-20 May 1988. *Visiting Lecturer in Endodontics, The University of Western Australia; Visiting Consultant Endodontist, Perth Dental Hospital, Western Australia. Australian Dental Journal 1990;35(6):491-6.
There are many commercial preparations marketed as endodontic medicaments. In choosing a medicament, the operator must be aware of the full list of the components and their respective concentrations and effects to the pulp and periradicular tissues. The decision should be based on an assessment of the risk versus benefit ratio and only a material that will produce a favourable response should be chosen. Part 1' outlined the various advantages and disadvantages of the common commercial preparations and concluded that more than one medicament was required to achieve all of the aims of medicating canals. Two preparations satisfy the general requirements for medicaments, Lederrnix? paste and Pulpdent$ paste but they require sequential or combined use to achieve the full range of desired therapeutic responses. The following is an outline of the clinical considerations for using medicaments and recommendations for medication regimens for pathological conditions that can be treated by conservative endodontic therapy.
Time of use of medicaments In general, it takes 10-15 days for inflammation to subside or heal.2 The use of anti-inflammatory medicaments such as Lederrnix paste can provide rapid relief of symptoms. However, theabsence of symptoms does not indicate the lack of pathology. Therefore, consideration of total healing time is required prior to completing a root canal filling. Thus, the minimum inter-appointment time interval should be 10 days, unless symptoms are
tLederle Pharmaceuticals, Wolfratshausen, West Germany. $Pulpdent Corporation, Brooklyn, Massachusetts, USA. 491
not subsiding. Leaving a dressing in place for more than 15 days means that the next treatment will be done when the periapical conditions are more favourable. The length of time a medicament will remain effective within the root canal will depend on the following factors. (1) Size of the apical foramen. A wide foramen may be present in immature teeth or canals that have been over-instrumented. A wide foramen allows greater ‘washing out’ of the medicaments due to fluid hence the medicament will not remain effective for as long. ( 2 ) Size of dentinal tubules. Young teeth with little peritubular or secondary dentine will allow greater diffusion of the medicament’s components, hence they will not remain effective within the canal for as long as in older teeth. ( 3 ) Presence of smear layer. A smear layer will initially delay the release of the components. It is an undesirable layer of debris on the canal wall and can have the effect of not allowing the medicaments to reach the regions of infection or inflammation in suitable therapeutic concentration^.^ (4)Absence of cementum. If the cementum is missing from any areas of the root (for example, following root planing, endo-periodontal lesions, external resorption, trauma) then release of the components will be much f a ~ t e r . ~ (5) Presence of pulpal tissue. If pulpal tissue (with its blood supply and its venous and lymphatic drainage) is left in the canal then the medicaments will be dissolved and rapidly cleared from the canal system. This may occur following emergency treatment when insufficient time is available for complete canal preparation, when a canal is not located or when it is not completely cleaned of pulpal tissue. (6) Temporary sealing of the access cavity. If the access cavity is not effectively sealed, then medicaments will not last as long due to dissolution. (7) The medicament being used. The physical consistency and nature of the material being used will affect the rate at which it is dissolved. The ideal material should be in paste form and have low solubility. Therefore, the length of time that a medicament should be left in a root canal will depend on the conditions present in each individual case. Ledermix paste in a prepared root canal can be expected to be effective for approximately 2-3 month^.^ When Ledermix paste is combined with 492
Pulpdent paste it will last longer, up to a maximum of 3-4 months.’ Pulpdent paste used alone has yet to be investigated, however a maximum effective dressing time of 3-6 months could be expected.
Application of medicaments Following the final flushing of the root canal system, the canals should be dried. This can be rapidly achieved by first aspirating the bulk of the remaining liquid from the canal with the irrigation syringe. Sterile, absorbent paper points of an appropriate size can then be placed into the canals to absorb the remaining fluid. The paper points should not be passed beyond the apical foramen. Root canal medicaments such as Ledermix and Pulpdent are marketed as pastes which allows easy placement into and removal from the root canal. Paste materials can be placed into root canals using either (a) a spiral root filler in a low speed handpiece, (b) a hand reamer, or (c) an injection system. The author favours the use of spiral root fillers if the canal has been enlarged and shaped. An appropriate size spiral is selected and a small amount of paste is placed on the spiral. Once the spiral has been inserted into the canal, the motor is started and run at a low speed in the forward direction. The spiral should be advanced vertically into the canal but it should not reach any further than 3 mm short of the canal working length. T o completely coat the canal walls and fill the canal lumen, the spiral should be moved vertically up and down the canal several times and on the final withdrawal the motor should be kept running. The process should be repeated 2-3 times for each canal. Hand reamers are useful in fine, unprepared canals or in canals with sharp curves. Injection systems are not favoured by the author due to the difficulty in controlling the flow of the paste beyond the desired length or through the apical foramen. Figure 1 demonstrates the relative abilities of spirals and reamers to fill root canals with a radiopaque paste and the potential hazard of using an injection system. If the Ledermix paste/Pulpdent paste combination is being used, the Ledermix paste can be spun into the canal first. Then the Pulpdent paste can be spun in and the pastes will be mixed in the canal by the spiral. An alternative method is to delay the mixing of the pastes until just prior to placing them in the canal. The former method is favoured by the author since, once mixed, these pastes form a coagulated mixture which does not flow as readily as the individual pastes. Australian Dental Journal 1990;35:6.
Fig. 1.-The comparative effectiveness of three different methods of placing radiopaque paste materials into rwt canals. a, A spiral root filler in a low speed handpiece results in the canal being well filled to the apex and in the body of the canal. b, A hand reamer may leave material near the apex but does not adequately fill the canal proper. c, Paste injection systems may result in material being forced through the apical foramen. (Photograph by courtesy of Perth Dental Hospital.)
Recommended medicament regimens A medicament should always be placed within the root canal system between In addition, one-visit endodontic treatment is not encouraged especially in pulpless, infected teeth.s The following is a guide to the use of the medicaments recommended in Part l of this review,' assuming the root canals are thoroughly cleaned and shaped at the first appointment. (1) Vital elective endodontic therapy. Use Ledermix paste for two weeks minimum prior to placing a root canal filling. (2) Vital pulpectomy. Ledermix paste for two weeks minimum prior to placing a root canal filling. (3) Painful tooth. Ledermix paste for two weeks minimum. Then treat according to the diagnosis of the cause of the pain and overall pathology. (4) Asymptomatic pulpless tooth. (Routine with no complications.) Use either Ledermix/Pulpdent 50:50 mixture or Pulpdent alone for two weeks minimum prior to root canal filling. ( 5 ) Pulpless tooth with acute apical patholoo. Ledermix paste 'for two weeks minimum. Then either LederrnbdPulpdent or Pulpdent alone for up to two to three months prior to root canal filling (Fig. 2). I , , '
Australian Dental Journal 1990;35:6.
(6) Largeperiapical lesion. Ledermix paste for two weeks. Then LedermixlPulpdent and review at three monthly intervals. Reapply LedermixlPulpdent if required, until healing evident radiographically (see Part 1: Fig. 4). (7) Incompletely deereloped pulpless teeth. If pain or other symptoms exist then use Ledermix paste for two weeks and then change to Pulpdent paste. If symptomless use Pulpdent paste. Review and reapply Pulpdent paste at three monthly intervals until apical closure is evident (see Part 1: Fig. 3). (8) Transverse root fracture. If coronal fragment is pulpless and infected - treat to fracture line. If pain or other symptoms use Ledermix paste for two weeks and then change to Pulpdent. If no symptoms use Pulpdent paste. Review and reapply Pulpdent paste at three monthly intervals until there is evidence of a hard tissue barrier at the fracture end of the coronal segment (see Part 1: Fig. 5). (9) Internal resorption. Ledermix paste for two weeks. Then Pulpdent for two weeks. Reapply Pulpdent paste several times at two weekly intervals until entire lesion treated. (10) Internal apical resorption. As for incompletely developed pulpless teeth. 493
Fig. 2.-The upper right central incisor had an acute exacerbation of a chronic periapical lesion associated with an open apex, an unsatisfactory root canal tilling and a postkore and crown. The crown, postkore and root tilling were removed and drainage was established through the root canal. The tooth was initially dressed with Ledermix paste for 2 weeks followed by a LedermixlPulpdent mixture for 3 months. Then Pulpdent paste was used for 12 months to encourage apexification and periapical bone repair. a, Drainage established via the root canal. b, Pre-operative radiograph. c, The root canal tilling was placed when the apical dome had formed.
(1 1) Internal/external resorption. If pain or other symptoms exist use Ledermix for two weeks then change to Pulpdent. If no symptoms use Pulpdent paste. Review and reapply Pulpdent paste at three monthly intervals until there is evidence of hard tissue repair and bone healing. (12) Perforation. As for internal/external resorption. (13) Luxated and avulsed teeth. Ledermix paste for six weeks. Reapply a Ledermix paste dressing for a further six weeks. Then change to Lederrnix/ Pulpdent or Pulpdent paste if hard tissue formation 494
is required - review and reapply Pulpdent at three monthly intervals until hard tissue formation is evident (see Part 1: Fig. 6 ) . (14) External inflammatory root resorption folIowing trauma. Use Ledermix paste for two months. Reapply a Ledermix paste dressing if resorption is not arrested. Otherwise change to Pulpdent paste for three months. Review and redress at three monthly intervals until hard tissue formation is evident (see Part 1: Fig. 7 ) . (15) Exudation control. Ledermix paste or LedermixlPulpdent for up to two months. Then Australian Dental Journal 1990;35:6.
Fig. 3.-The upper left central incisor o f a 22 year old woman had an unsatisfactory root canal filling and external apical inflammatory root resorption leaving an open apex. The previous root filling was removed and the canal was dressed with Ledermix paste for 5 months. As there was no further evidence of resorption, the canal was then dressed with Pulpdent paste (for apexification) for 9 months. a, Pre-operative radiograph. b, Radiograph taken after 14 months showing the apical dome. c, Radiograph taken at the 6 month review appointment.
Pulpdent paste for two to three months if required (Fig. 2). (16) Apical inflammatory root resorption. Lederrnix paste for two months. Then Pulpdent paste for three months - review and reapply Pulpdent paste at three monthly intervals until hard tissue formation is evident (Fig. 3). (17) Endodontic retreatment. Ledermix paste for two weeks. Reapply a dressing of Ledermix/Pulpdent or Pulpdent paste alone for up to three months. Continue dressings as above if hard tissue formation required (Fig. 2, 3 and Part 1: Fig. 8). Australian Dental Journal 1990;35:6.
(18) Endo-Perio lesions. Ledermix paste for two to three months. Then use Ledermix/Pulpdent for two to three months. Review and reapply dressings until hard tissue repair is evident and periodontal Prognosis determined (see Part 1: Fig- 8)Sealing the medicament The root canal system must be sealed between all appointments to prevent contamination of the canal by oral microflora and leakage of the medicament from the canal into the mouth. The material chosen to seal the tooth will depend on the 495
presenting status of the tooth. It may also be necessary to build up a temporary restoration to allow rubber dam placement for tooth isolation and to protect the remaining tooth structure from fracture. Before placing a temporary restoration, it is advisable to place a thin layer of cotton wool over the canal orifices - this will prevent particles of the temporary restoration from lodging in the canals and will make it easier to remove the temporary restoration at subsequent appointments. One material that has consistently shown good sealing ability is Cavits. There are three forms of this material available - Cavit, Cavit G and Cavit W. T h e author prefers Cavit, which, according to the manufacturer, is stronger and provides the best seal. Cavit has been reported to provide an effective seal as long as there is a thickness of at least 3.5 mm of material placed in the access Other materials that provide effective seals are IRM, 1 glass ionomers (for example, Ketac Fills) and glass ionomer with metal reinforcement (for example, Ketac Silvers). T h e latter two materials are generally expensive and technique sensitive, but they are very useful in the temporary restoration of broken down teeth and they can also be used in conjunction with stainless steel bands for this purpose. In some situations a ‘double seal’ will be required - especially where occlusal forces are encountered or where wearing of the temporary restoration may occur and in long-term dressing situations. T h e simplest method of providing a double seal is to place a layer of Cavit over the cotton pellet and then a layer of IRM. I R M is a zinc oxide-eugenol material reinforced with plastic resins. These resins improve the strength of the material and make it less soluble. Alternatively, a layer of glass ionomer could be placed over the Cavit. Following the placement of all temporary restorations and removal of the rubber dam the occlusion should be checked with thin articulating paper and adjusted to relieve occlusal contact. Summary Bacteria play a major role in the progression of pulpal and periapical disease. One of the major aims
SEspe GmbH, Seefeld, Oberbay, West Germany
IIL-D Caulk Co., Milford, Delaware, USA.
496
of endodontic treatment is to remove all bacteria from the root canal system. T h e root canal system can be very complex and medicaments are required to predictably achieve a bacteria-free system prior to completing a root canal filling. Various medicaments are available and the choice of which drug to use must be based on the therapeutic properties and the toxicity potential of the material. Ledermix paste and Pulpdent paste appear to be appropriate commercial preparations that can be used as root canal medicaments. T h e rationale and recommendations for the clinical use of these two medicaments in the conservative endodontic treatment of various pathological conditions have been discussed. References 1. Abbott PV. Medicaments: Aids to success in endodontics. Part 1. A review of the literature. Aust Dent J 1990;35:438-48. 2. Stanley HR. Pulpal responses. In: Cohen S, Burns RC, eds. Pathways of the pulp. 3rd edn. St Louis: CV Mosby, 1984:465. 3. Abbott PV, Heithersay GS, Hume WR. Release and diffusion through human tooth roots in vitro of corticosteroid and tetracycline trace molecules from Ledermix paste. Endod Dent Traumatol 1989;4:55-62. 4. Abbott PV, Hume WR, Heithersay GS. Barriers of diffusion of Ledermix paste in radicular dentine. Endod Dent Traumatol 1989;5:98-104. 5. Abbott PV, Hume WR, Heithersay GS. Effects of combining Ledermix and calcium hydroxide pastes on the diffusion of corticosteroid and tetracycline through human tooth roots in vitro. Endod Dent Traumatol 1989;5:188-92. 6. Bystrom A, Sundqvist G. The antibacterial action ofsodium hypochlorite and EDTA in 60 cases ofendodontic therapy. Int Endod J 1985;18:35-40. 7. Sjogren U, Sundqvist G. Bacteriologic evaluation of ultrasonic root canal instrumentation. Oral Surg Oral Med Oral Path 1987;63:366-70. 8. Langeland K. Tissue response to dental caries. Endod Dent Traumatol 1987;3:149-71. 9. Widerman F, Eames W, Serene T. The physical and biological properties of Cavit. J Am Dent Assoc 1971;82:379-82. 10. Tamse A, Ben-Amar A, Gover A. Sealing properties of temporary filling materials used in endodontics. J Endod 1982;8:322-5. 11. Teplitsky PE, Meimaris IT. Sealing ability of Cavit and T E R M as intermediate restorative materials. J Endod 1988;14:278-82.
Address for correspondencedreprints: Suite 19, T h e Perth Surgicentre, 38 Ranelagh Crescent, South Perth, Western Australia, 6 151.
Australian Dental Journal 1990;35:6.
Key words: Endodontics, medicaments. Abstract In order to predictably achieve bacteria-free root canal systems, especially in pulpless teeth, it is necessary to use intracanal medicaments. Medicaments can also be used to influence the peri-radicular response to endodontic treatment. Considerationof a material's therapeutic action must be made when selecting a medicament for any pathologicalcondition. In general, only two commercial preparations satisfy the general requirements for root canal medicaments. Guidelines and the rationale for the use of these preparations are presented. (Received for publication March 1989. Revised December 1989. Accepted January 7990.)
Introduction In Part 1 of this review,' the role of bacteria in the progression of pulp and periapical diseases was discussed. The inter-appointment medication of root canals was shown to be a predictable means of eliminating bacteria from root canal systems and a reliable method for reducing periapical inflammation and stimulating hard tissue formation. However, some medicaments are capable of causing inflammation due to the toxicity of some components.
Based on a lecture presented at the Australian Dental Association 25th Congress, Sydney, 15-20 May 1988. *Visiting Lecturer in Endodontics, The University of Western Australia; Visiting Consultant Endodontist, Perth Dental Hospital, Western Australia. Australian Dental Journal 1990;35(6):491-6.
There are many commercial preparations marketed as endodontic medicaments. In choosing a medicament, the operator must be aware of the full list of the components and their respective concentrations and effects to the pulp and periradicular tissues. The decision should be based on an assessment of the risk versus benefit ratio and only a material that will produce a favourable response should be chosen. Part 1' outlined the various advantages and disadvantages of the common commercial preparations and concluded that more than one medicament was required to achieve all of the aims of medicating canals. Two preparations satisfy the general requirements for medicaments, Lederrnix? paste and Pulpdent$ paste but they require sequential or combined use to achieve the full range of desired therapeutic responses. The following is an outline of the clinical considerations for using medicaments and recommendations for medication regimens for pathological conditions that can be treated by conservative endodontic therapy.
Time of use of medicaments In general, it takes 10-15 days for inflammation to subside or heal.2 The use of anti-inflammatory medicaments such as Lederrnix paste can provide rapid relief of symptoms. However, theabsence of symptoms does not indicate the lack of pathology. Therefore, consideration of total healing time is required prior to completing a root canal filling. Thus, the minimum inter-appointment time interval should be 10 days, unless symptoms are
tLederle Pharmaceuticals, Wolfratshausen, West Germany. $Pulpdent Corporation, Brooklyn, Massachusetts, USA. 491
not subsiding. Leaving a dressing in place for more than 15 days means that the next treatment will be done when the periapical conditions are more favourable. The length of time a medicament will remain effective within the root canal will depend on the following factors. (1) Size of the apical foramen. A wide foramen may be present in immature teeth or canals that have been over-instrumented. A wide foramen allows greater ‘washing out’ of the medicaments due to fluid hence the medicament will not remain effective for as long. ( 2 ) Size of dentinal tubules. Young teeth with little peritubular or secondary dentine will allow greater diffusion of the medicament’s components, hence they will not remain effective within the canal for as long as in older teeth. ( 3 ) Presence of smear layer. A smear layer will initially delay the release of the components. It is an undesirable layer of debris on the canal wall and can have the effect of not allowing the medicaments to reach the regions of infection or inflammation in suitable therapeutic concentration^.^ (4)Absence of cementum. If the cementum is missing from any areas of the root (for example, following root planing, endo-periodontal lesions, external resorption, trauma) then release of the components will be much f a ~ t e r . ~ (5) Presence of pulpal tissue. If pulpal tissue (with its blood supply and its venous and lymphatic drainage) is left in the canal then the medicaments will be dissolved and rapidly cleared from the canal system. This may occur following emergency treatment when insufficient time is available for complete canal preparation, when a canal is not located or when it is not completely cleaned of pulpal tissue. (6) Temporary sealing of the access cavity. If the access cavity is not effectively sealed, then medicaments will not last as long due to dissolution. (7) The medicament being used. The physical consistency and nature of the material being used will affect the rate at which it is dissolved. The ideal material should be in paste form and have low solubility. Therefore, the length of time that a medicament should be left in a root canal will depend on the conditions present in each individual case. Ledermix paste in a prepared root canal can be expected to be effective for approximately 2-3 month^.^ When Ledermix paste is combined with 492
Pulpdent paste it will last longer, up to a maximum of 3-4 months.’ Pulpdent paste used alone has yet to be investigated, however a maximum effective dressing time of 3-6 months could be expected.
Application of medicaments Following the final flushing of the root canal system, the canals should be dried. This can be rapidly achieved by first aspirating the bulk of the remaining liquid from the canal with the irrigation syringe. Sterile, absorbent paper points of an appropriate size can then be placed into the canals to absorb the remaining fluid. The paper points should not be passed beyond the apical foramen. Root canal medicaments such as Ledermix and Pulpdent are marketed as pastes which allows easy placement into and removal from the root canal. Paste materials can be placed into root canals using either (a) a spiral root filler in a low speed handpiece, (b) a hand reamer, or (c) an injection system. The author favours the use of spiral root fillers if the canal has been enlarged and shaped. An appropriate size spiral is selected and a small amount of paste is placed on the spiral. Once the spiral has been inserted into the canal, the motor is started and run at a low speed in the forward direction. The spiral should be advanced vertically into the canal but it should not reach any further than 3 mm short of the canal working length. T o completely coat the canal walls and fill the canal lumen, the spiral should be moved vertically up and down the canal several times and on the final withdrawal the motor should be kept running. The process should be repeated 2-3 times for each canal. Hand reamers are useful in fine, unprepared canals or in canals with sharp curves. Injection systems are not favoured by the author due to the difficulty in controlling the flow of the paste beyond the desired length or through the apical foramen. Figure 1 demonstrates the relative abilities of spirals and reamers to fill root canals with a radiopaque paste and the potential hazard of using an injection system. If the Ledermix paste/Pulpdent paste combination is being used, the Ledermix paste can be spun into the canal first. Then the Pulpdent paste can be spun in and the pastes will be mixed in the canal by the spiral. An alternative method is to delay the mixing of the pastes until just prior to placing them in the canal. The former method is favoured by the author since, once mixed, these pastes form a coagulated mixture which does not flow as readily as the individual pastes. Australian Dental Journal 1990;35:6.
Fig. 1.-The comparative effectiveness of three different methods of placing radiopaque paste materials into rwt canals. a, A spiral root filler in a low speed handpiece results in the canal being well filled to the apex and in the body of the canal. b, A hand reamer may leave material near the apex but does not adequately fill the canal proper. c, Paste injection systems may result in material being forced through the apical foramen. (Photograph by courtesy of Perth Dental Hospital.)
Recommended medicament regimens A medicament should always be placed within the root canal system between In addition, one-visit endodontic treatment is not encouraged especially in pulpless, infected teeth.s The following is a guide to the use of the medicaments recommended in Part l of this review,' assuming the root canals are thoroughly cleaned and shaped at the first appointment. (1) Vital elective endodontic therapy. Use Ledermix paste for two weeks minimum prior to placing a root canal filling. (2) Vital pulpectomy. Ledermix paste for two weeks minimum prior to placing a root canal filling. (3) Painful tooth. Ledermix paste for two weeks minimum. Then treat according to the diagnosis of the cause of the pain and overall pathology. (4) Asymptomatic pulpless tooth. (Routine with no complications.) Use either Ledermix/Pulpdent 50:50 mixture or Pulpdent alone for two weeks minimum prior to root canal filling. ( 5 ) Pulpless tooth with acute apical patholoo. Ledermix paste 'for two weeks minimum. Then either LederrnbdPulpdent or Pulpdent alone for up to two to three months prior to root canal filling (Fig. 2). I , , '
Australian Dental Journal 1990;35:6.
(6) Largeperiapical lesion. Ledermix paste for two weeks. Then LedermixlPulpdent and review at three monthly intervals. Reapply LedermixlPulpdent if required, until healing evident radiographically (see Part 1: Fig. 4). (7) Incompletely deereloped pulpless teeth. If pain or other symptoms exist then use Ledermix paste for two weeks and then change to Pulpdent paste. If symptomless use Pulpdent paste. Review and reapply Pulpdent paste at three monthly intervals until apical closure is evident (see Part 1: Fig. 3). (8) Transverse root fracture. If coronal fragment is pulpless and infected - treat to fracture line. If pain or other symptoms use Ledermix paste for two weeks and then change to Pulpdent. If no symptoms use Pulpdent paste. Review and reapply Pulpdent paste at three monthly intervals until there is evidence of a hard tissue barrier at the fracture end of the coronal segment (see Part 1: Fig. 5). (9) Internal resorption. Ledermix paste for two weeks. Then Pulpdent for two weeks. Reapply Pulpdent paste several times at two weekly intervals until entire lesion treated. (10) Internal apical resorption. As for incompletely developed pulpless teeth. 493
Fig. 2.-The upper right central incisor had an acute exacerbation of a chronic periapical lesion associated with an open apex, an unsatisfactory root canal tilling and a postkore and crown. The crown, postkore and root tilling were removed and drainage was established through the root canal. The tooth was initially dressed with Ledermix paste for 2 weeks followed by a LedermixlPulpdent mixture for 3 months. Then Pulpdent paste was used for 12 months to encourage apexification and periapical bone repair. a, Drainage established via the root canal. b, Pre-operative radiograph. c, The root canal tilling was placed when the apical dome had formed.
(1 1) Internal/external resorption. If pain or other symptoms exist use Ledermix for two weeks then change to Pulpdent. If no symptoms use Pulpdent paste. Review and reapply Pulpdent paste at three monthly intervals until there is evidence of hard tissue repair and bone healing. (12) Perforation. As for internal/external resorption. (13) Luxated and avulsed teeth. Ledermix paste for six weeks. Reapply a Ledermix paste dressing for a further six weeks. Then change to Lederrnix/ Pulpdent or Pulpdent paste if hard tissue formation 494
is required - review and reapply Pulpdent at three monthly intervals until hard tissue formation is evident (see Part 1: Fig. 6 ) . (14) External inflammatory root resorption folIowing trauma. Use Ledermix paste for two months. Reapply a Ledermix paste dressing if resorption is not arrested. Otherwise change to Pulpdent paste for three months. Review and redress at three monthly intervals until hard tissue formation is evident (see Part 1: Fig. 7 ) . (15) Exudation control. Ledermix paste or LedermixlPulpdent for up to two months. Then Australian Dental Journal 1990;35:6.
Fig. 3.-The upper left central incisor o f a 22 year old woman had an unsatisfactory root canal filling and external apical inflammatory root resorption leaving an open apex. The previous root filling was removed and the canal was dressed with Ledermix paste for 5 months. As there was no further evidence of resorption, the canal was then dressed with Pulpdent paste (for apexification) for 9 months. a, Pre-operative radiograph. b, Radiograph taken after 14 months showing the apical dome. c, Radiograph taken at the 6 month review appointment.
Pulpdent paste for two to three months if required (Fig. 2). (16) Apical inflammatory root resorption. Lederrnix paste for two months. Then Pulpdent paste for three months - review and reapply Pulpdent paste at three monthly intervals until hard tissue formation is evident (Fig. 3). (17) Endodontic retreatment. Ledermix paste for two weeks. Reapply a dressing of Ledermix/Pulpdent or Pulpdent paste alone for up to three months. Continue dressings as above if hard tissue formation required (Fig. 2, 3 and Part 1: Fig. 8). Australian Dental Journal 1990;35:6.
(18) Endo-Perio lesions. Ledermix paste for two to three months. Then use Ledermix/Pulpdent for two to three months. Review and reapply dressings until hard tissue repair is evident and periodontal Prognosis determined (see Part 1: Fig- 8)Sealing the medicament The root canal system must be sealed between all appointments to prevent contamination of the canal by oral microflora and leakage of the medicament from the canal into the mouth. The material chosen to seal the tooth will depend on the 495
presenting status of the tooth. It may also be necessary to build up a temporary restoration to allow rubber dam placement for tooth isolation and to protect the remaining tooth structure from fracture. Before placing a temporary restoration, it is advisable to place a thin layer of cotton wool over the canal orifices - this will prevent particles of the temporary restoration from lodging in the canals and will make it easier to remove the temporary restoration at subsequent appointments. One material that has consistently shown good sealing ability is Cavits. There are three forms of this material available - Cavit, Cavit G and Cavit W. T h e author prefers Cavit, which, according to the manufacturer, is stronger and provides the best seal. Cavit has been reported to provide an effective seal as long as there is a thickness of at least 3.5 mm of material placed in the access Other materials that provide effective seals are IRM, 1 glass ionomers (for example, Ketac Fills) and glass ionomer with metal reinforcement (for example, Ketac Silvers). T h e latter two materials are generally expensive and technique sensitive, but they are very useful in the temporary restoration of broken down teeth and they can also be used in conjunction with stainless steel bands for this purpose. In some situations a ‘double seal’ will be required - especially where occlusal forces are encountered or where wearing of the temporary restoration may occur and in long-term dressing situations. T h e simplest method of providing a double seal is to place a layer of Cavit over the cotton pellet and then a layer of IRM. I R M is a zinc oxide-eugenol material reinforced with plastic resins. These resins improve the strength of the material and make it less soluble. Alternatively, a layer of glass ionomer could be placed over the Cavit. Following the placement of all temporary restorations and removal of the rubber dam the occlusion should be checked with thin articulating paper and adjusted to relieve occlusal contact. Summary Bacteria play a major role in the progression of pulpal and periapical disease. One of the major aims
SEspe GmbH, Seefeld, Oberbay, West Germany
IIL-D Caulk Co., Milford, Delaware, USA.
496
of endodontic treatment is to remove all bacteria from the root canal system. T h e root canal system can be very complex and medicaments are required to predictably achieve a bacteria-free system prior to completing a root canal filling. Various medicaments are available and the choice of which drug to use must be based on the therapeutic properties and the toxicity potential of the material. Ledermix paste and Pulpdent paste appear to be appropriate commercial preparations that can be used as root canal medicaments. T h e rationale and recommendations for the clinical use of these two medicaments in the conservative endodontic treatment of various pathological conditions have been discussed. References 1. Abbott PV. Medicaments: Aids to success in endodontics. Part 1. A review of the literature. Aust Dent J 1990;35:438-48. 2. Stanley HR. Pulpal responses. In: Cohen S, Burns RC, eds. Pathways of the pulp. 3rd edn. St Louis: CV Mosby, 1984:465. 3. Abbott PV, Heithersay GS, Hume WR. Release and diffusion through human tooth roots in vitro of corticosteroid and tetracycline trace molecules from Ledermix paste. Endod Dent Traumatol 1989;4:55-62. 4. Abbott PV, Hume WR, Heithersay GS. Barriers of diffusion of Ledermix paste in radicular dentine. Endod Dent Traumatol 1989;5:98-104. 5. Abbott PV, Hume WR, Heithersay GS. Effects of combining Ledermix and calcium hydroxide pastes on the diffusion of corticosteroid and tetracycline through human tooth roots in vitro. Endod Dent Traumatol 1989;5:188-92. 6. Bystrom A, Sundqvist G. The antibacterial action ofsodium hypochlorite and EDTA in 60 cases ofendodontic therapy. Int Endod J 1985;18:35-40. 7. Sjogren U, Sundqvist G. Bacteriologic evaluation of ultrasonic root canal instrumentation. Oral Surg Oral Med Oral Path 1987;63:366-70. 8. Langeland K. Tissue response to dental caries. Endod Dent Traumatol 1987;3:149-71. 9. Widerman F, Eames W, Serene T. The physical and biological properties of Cavit. J Am Dent Assoc 1971;82:379-82. 10. Tamse A, Ben-Amar A, Gover A. Sealing properties of temporary filling materials used in endodontics. J Endod 1982;8:322-5. 11. Teplitsky PE, Meimaris IT. Sealing ability of Cavit and T E R M as intermediate restorative materials. J Endod 1988;14:278-82.
Address for correspondencedreprints: Suite 19, T h e Perth Surgicentre, 38 Ranelagh Crescent, South Perth, Western Australia, 6 151.
Australian Dental Journal 1990;35:6.
