J. smaN An&. Pract. (1979) 20,691495.
Restoration of an incisor tooth of a Wolfhound: case report D. ADAMS
AND
J. GILLESPIE
School of Dental Surgery, University of Liverpool, and 28 Green Lane, Liverpool 18, England
ABSTRACT A technique is described for the restoration of a fractured upper incisor tooth in an Irish Wolfhound by the provision of a bonded porcelain/gold post crown* and an apicectomy with retrograde amalgam root filling. INTRODUCTION Almost the whole range of dental restorative procedures have been used in veterinary practice on dogs as is shown by the literature. Charnock & Usher (1968) report the replacement of a lower canine in an Alsatian dog with a cobalt chromium alloy post crown which, although undoubtedly functional, would have limited aesthetic appeal. Ross & Myers (1970) describe the procedure for the endodontic treatment of teeth with retrograde amalgam seals which was successfully used on 200 dogs but without restoration of the crown. Sweetman (1973) reports a restorative procedure using an epimine plastic or, alternatively, a quartz-filled composite resin which would be highly aesthetic but of limited functional strength. A similar use of a quartz-filled composite is also described by Bedford & Heaton (1977) for the restoration of dental abrasion. Hamilton & Ridgway (1976) used a cast gold post and a full gold crown for the treatment of a maxillary canine in an Alsatian dog. When trauma to the crown results in exposure of the pulp of the tooth the inflammatory response to the infection of the pulp by oral micro-organisms results in necrosis of the pulp. Extension of this into the periapical tissues produces a periapical abscess. If drainage via the root canal is not possible due to blockage by debris then the infection may track along the path of least resistance * Degudent U gold and porcelain, Panadent, 15 Gt. Dover Street, London SEl47W. 0020-4510/79/1100-0691$02.00
69 1
01979 BSAVA
692
D . ADAMS AND J . GILLESPIE
FIG.1. Pre- and post-operative photographs of traumatized upper right third incisor.
to a point intra- or extra-orally, or it may become chronic with granulomatous or cystic change. Treatment is directed towards removal of infected tissue and obturation of the pulp chamber and root canal. CASE REPORT A lhyear old Irish Wolfhound was brought to the surgery having fractured the upper third incisor by getting it hooked over a door handle. On examination the fracture was found to be through enamel and dentine and to have produced a
RESTORATION OF A N INCISOR TOOTH
693
FIG.2. Pre- and post-operative radiographs of the upper jaw.
pulpal exposure (Fig. 1a). Radiographic examination using standard veterinary jaw views revealed the presence of a periapical lesion associated with the apex of the root (Fig. 2a). The significant radiological feature is the loss of the lamina dura or ‘white line’ around the apex of the involved tooth and not the apparent halo around the contra-lateral tooth which must be considered a radiological artefact as it is not apparent in Fig. 2b. Whilst extraction would have been the most expedient treatment, the owner wished an attempt at conservation to be undertaken, if possible. The first procedure necessary was to extirpate the dental pulp and occlude the pulp chamber in order to prevent a focus of infection with subsequent periapical abscess formation and the necessity for extraction. In the human subject this would normally be done via the crown of the tooth with hand held reamers but it was felt that the length of root canal, assessed from the radiograph, would be too great for the available instruments. The only procedure thus available was that of apicectomy and retrograde root filling, as described by Ross (1977). The animal was sedated with Acepromazine (2 mg/ml) 30 minutes pre-operatively, general anaesthesia being induced by Thiopentone (Pentothal) and maintained with fluothane and oxygen via a cuffed tube. The operative area was then prepared by swabbing with 2% chlorhexidine in an alcoholic solution. Access to the apex was gained via a standard buccal flap, buccal bone being removed with a large round burr in a dental handpiece, normal
694
D. ADAMS AND J . GILLESPIE
Apex removed
Retrograde amolgom filling
Prefo bricoted post
Crown
W FIG.3. Diagram of operative procedure.
saline being used as a coolant. The point of entry, which should lie over the apex of the tooth, was placed a little too far mesially, resulting in the necessity for the removal of more of the apex than would be considered desirable, but which is unlikely to be of any post-operative significance (Fig. 2b). The apical end of the root canal was then occluded with dental silver amalgam. After careful irrigation of the cavity to remove bone fragments and any particles of amalgam the wound was closed with black silk sutures. Attention was now turned to the problems of restoration of the coronal portion of the tooth. Unfortunately the remaining portion of the tooth was too short to provide sufficient retention for a crown. Normally a prefabricated post would be cemented into the root canal, the coronal portion of this thus providing extra length for a crown preparation, but the available posts were too small. A post was fabricated at operation by grinding down a dental burr until it could be inserted approximately 15 mm up the root canal in which position it was cemented with a polycarboxylate cement* (Fig. 3). A crown preparation was then cut onto the remaining portion of tooth and post. An impression tray was fabricated from self-curing polymethylmethacrylate? by moulding the dough over the appropriate teeth separated from them with four dental napkins. An impression was then made using a silicone impression
* Poly-F, Claudius Ash, 10-12 Slade Lane, Longsight, Manchester. Northill Plastics Ltd., London N W 6 .
RESTORATION OF AN INCISOR TOOTH
695
material*, the impression being extended sufficiently to include the contralateral tooth so that the technician could copy its anatomy. It was found that at maximum intercuspidation the third incisor was not in occlusion thus impressions of the opposite jaw were unnecessary. As the tooth was non-vital, no temporary crown was considered necessary, the only precaution deemed necessary being to request the owner to keep the animal on a soft diet until the next visit which was arranged for 1 week later. At the subsequent visit the sutures were removed and the crown cemented on with a fluoride containing polycarboxylate cement (Fig. 2b). DISCUSSION The final result was such that close inspection was required to ascertain which was the restored tooth and it is still functionally satisfactory 10 months after its construction, with no tooth mobility. The use of porcelain fused to gold would seem to be the ideal restorative material in that the strength of the gold is complemented by the excellent aesthetics of dental porcelains. Theoretically, there is no reason why any dental procedure cannot be applied to veterinary practice, indeed it is suspected that some considerable amount of veterinary dentistry is practical as many dentists will tell stories from orthodontics on poodles to inlays on crib biting horses. This case is reported not only for its inherent interest but also to show the interdisciplinary relationship which may be of mutual benefit to the veterinary and dental surgeon. ACKNOWLEDGMENTS
We would like to thank Mr G. Williams for his surgical assistance, Mr A. Cross for his technical expertise, and Mr J. S. Baillie, Medical Illustration Department, University of Liverpool, School of Dental Surgery. REFERENCES BEDFORD, P.G.C. & HEATON,M.G. (1977) A repair technique for dental abrasion in the dog. Vet. Rec. 101,327. CHARNOCK, M. & USHER, F.J. (1968) Fitting a prosthetic crown to a canine tooth in a police dog. Vet. Rec. 83,464. HAMILTON, C.J. & RIDGWAY, R.L. (1976) Dowel and core preparation and full gold coverage of maxillary canine teeth in a German Shepherd. Vet. Med./Small Animal Clin. 71, 176. Ross, D.L. (1977) The Oral Cavity. In: Current Veterinary Therapy (Ed. R.W. Kirk), pp. 921. V 1, W.B. Saunders Co., Philadelphia. Ross,D.L. & MYERS, J.W. (1970) Endodontic Therapy for Canine Teeth in the Dog. J. Am. Vet. Med. Ass. 157, 1713. SWEETMAN, A.J.P. (1973) Traumatic incisor injuries in small animals. J.small Anim. Pract. 14,715.
* Coltex medium, Coltine CH9450 Altstaetten, Switzerland Heberlein Co.
Restoration of an incisor tooth of a Wolfhound: case report D. ADAMS
AND
J. GILLESPIE
School of Dental Surgery, University of Liverpool, and 28 Green Lane, Liverpool 18, England
ABSTRACT A technique is described for the restoration of a fractured upper incisor tooth in an Irish Wolfhound by the provision of a bonded porcelain/gold post crown* and an apicectomy with retrograde amalgam root filling. INTRODUCTION Almost the whole range of dental restorative procedures have been used in veterinary practice on dogs as is shown by the literature. Charnock & Usher (1968) report the replacement of a lower canine in an Alsatian dog with a cobalt chromium alloy post crown which, although undoubtedly functional, would have limited aesthetic appeal. Ross & Myers (1970) describe the procedure for the endodontic treatment of teeth with retrograde amalgam seals which was successfully used on 200 dogs but without restoration of the crown. Sweetman (1973) reports a restorative procedure using an epimine plastic or, alternatively, a quartz-filled composite resin which would be highly aesthetic but of limited functional strength. A similar use of a quartz-filled composite is also described by Bedford & Heaton (1977) for the restoration of dental abrasion. Hamilton & Ridgway (1976) used a cast gold post and a full gold crown for the treatment of a maxillary canine in an Alsatian dog. When trauma to the crown results in exposure of the pulp of the tooth the inflammatory response to the infection of the pulp by oral micro-organisms results in necrosis of the pulp. Extension of this into the periapical tissues produces a periapical abscess. If drainage via the root canal is not possible due to blockage by debris then the infection may track along the path of least resistance * Degudent U gold and porcelain, Panadent, 15 Gt. Dover Street, London SEl47W. 0020-4510/79/1100-0691$02.00
69 1
01979 BSAVA
692
D . ADAMS AND J . GILLESPIE
FIG.1. Pre- and post-operative photographs of traumatized upper right third incisor.
to a point intra- or extra-orally, or it may become chronic with granulomatous or cystic change. Treatment is directed towards removal of infected tissue and obturation of the pulp chamber and root canal. CASE REPORT A lhyear old Irish Wolfhound was brought to the surgery having fractured the upper third incisor by getting it hooked over a door handle. On examination the fracture was found to be through enamel and dentine and to have produced a
RESTORATION OF A N INCISOR TOOTH
693
FIG.2. Pre- and post-operative radiographs of the upper jaw.
pulpal exposure (Fig. 1a). Radiographic examination using standard veterinary jaw views revealed the presence of a periapical lesion associated with the apex of the root (Fig. 2a). The significant radiological feature is the loss of the lamina dura or ‘white line’ around the apex of the involved tooth and not the apparent halo around the contra-lateral tooth which must be considered a radiological artefact as it is not apparent in Fig. 2b. Whilst extraction would have been the most expedient treatment, the owner wished an attempt at conservation to be undertaken, if possible. The first procedure necessary was to extirpate the dental pulp and occlude the pulp chamber in order to prevent a focus of infection with subsequent periapical abscess formation and the necessity for extraction. In the human subject this would normally be done via the crown of the tooth with hand held reamers but it was felt that the length of root canal, assessed from the radiograph, would be too great for the available instruments. The only procedure thus available was that of apicectomy and retrograde root filling, as described by Ross (1977). The animal was sedated with Acepromazine (2 mg/ml) 30 minutes pre-operatively, general anaesthesia being induced by Thiopentone (Pentothal) and maintained with fluothane and oxygen via a cuffed tube. The operative area was then prepared by swabbing with 2% chlorhexidine in an alcoholic solution. Access to the apex was gained via a standard buccal flap, buccal bone being removed with a large round burr in a dental handpiece, normal
694
D. ADAMS AND J . GILLESPIE
Apex removed
Retrograde amolgom filling
Prefo bricoted post
Crown
W FIG.3. Diagram of operative procedure.
saline being used as a coolant. The point of entry, which should lie over the apex of the tooth, was placed a little too far mesially, resulting in the necessity for the removal of more of the apex than would be considered desirable, but which is unlikely to be of any post-operative significance (Fig. 2b). The apical end of the root canal was then occluded with dental silver amalgam. After careful irrigation of the cavity to remove bone fragments and any particles of amalgam the wound was closed with black silk sutures. Attention was now turned to the problems of restoration of the coronal portion of the tooth. Unfortunately the remaining portion of the tooth was too short to provide sufficient retention for a crown. Normally a prefabricated post would be cemented into the root canal, the coronal portion of this thus providing extra length for a crown preparation, but the available posts were too small. A post was fabricated at operation by grinding down a dental burr until it could be inserted approximately 15 mm up the root canal in which position it was cemented with a polycarboxylate cement* (Fig. 3). A crown preparation was then cut onto the remaining portion of tooth and post. An impression tray was fabricated from self-curing polymethylmethacrylate? by moulding the dough over the appropriate teeth separated from them with four dental napkins. An impression was then made using a silicone impression
* Poly-F, Claudius Ash, 10-12 Slade Lane, Longsight, Manchester. Northill Plastics Ltd., London N W 6 .
RESTORATION OF AN INCISOR TOOTH
695
material*, the impression being extended sufficiently to include the contralateral tooth so that the technician could copy its anatomy. It was found that at maximum intercuspidation the third incisor was not in occlusion thus impressions of the opposite jaw were unnecessary. As the tooth was non-vital, no temporary crown was considered necessary, the only precaution deemed necessary being to request the owner to keep the animal on a soft diet until the next visit which was arranged for 1 week later. At the subsequent visit the sutures were removed and the crown cemented on with a fluoride containing polycarboxylate cement (Fig. 2b). DISCUSSION The final result was such that close inspection was required to ascertain which was the restored tooth and it is still functionally satisfactory 10 months after its construction, with no tooth mobility. The use of porcelain fused to gold would seem to be the ideal restorative material in that the strength of the gold is complemented by the excellent aesthetics of dental porcelains. Theoretically, there is no reason why any dental procedure cannot be applied to veterinary practice, indeed it is suspected that some considerable amount of veterinary dentistry is practical as many dentists will tell stories from orthodontics on poodles to inlays on crib biting horses. This case is reported not only for its inherent interest but also to show the interdisciplinary relationship which may be of mutual benefit to the veterinary and dental surgeon. ACKNOWLEDGMENTS
We would like to thank Mr G. Williams for his surgical assistance, Mr A. Cross for his technical expertise, and Mr J. S. Baillie, Medical Illustration Department, University of Liverpool, School of Dental Surgery. REFERENCES BEDFORD, P.G.C. & HEATON,M.G. (1977) A repair technique for dental abrasion in the dog. Vet. Rec. 101,327. CHARNOCK, M. & USHER, F.J. (1968) Fitting a prosthetic crown to a canine tooth in a police dog. Vet. Rec. 83,464. HAMILTON, C.J. & RIDGWAY, R.L. (1976) Dowel and core preparation and full gold coverage of maxillary canine teeth in a German Shepherd. Vet. Med./Small Animal Clin. 71, 176. Ross, D.L. (1977) The Oral Cavity. In: Current Veterinary Therapy (Ed. R.W. Kirk), pp. 921. V 1, W.B. Saunders Co., Philadelphia. Ross,D.L. & MYERS, J.W. (1970) Endodontic Therapy for Canine Teeth in the Dog. J. Am. Vet. Med. Ass. 157, 1713. SWEETMAN, A.J.P. (1973) Traumatic incisor injuries in small animals. J.small Anim. Pract. 14,715.
* Coltex medium, Coltine CH9450 Altstaetten, Switzerland Heberlein Co.
