J. Vet. Med. A 45, 137-144 (1998) 0 1998 Blackwell Wissenschafts-Verlag,Berlin ISSN 0931-184X

Department and Clinic

Veterinay Sutgey, Wmdaw, Pokand

Lateral Condensation in Treatment of Pulpitis and Pulp Gangrene: Studies on Dog Canine Teeth K. RATAJCZAK'and J. GAWOR* Addresses of the authors: 'Department and Clinic of Veterinary Surgery, Faculty of Veterinary Medicine, The Agricultural University, Plac Grunwaldzki 51,50-366 Wroclaw and 'Small Animals Hospital, Gersona st. 2a, 30-818 Krakow, Poland Wtb 3 figures and ? tabks

(ReceivedforpublicationMarch ZS, 1997)

Summary The clinical investigation, carried out in dogs, comprises selected cases of chronic pulpitis and pulpal gangrene of canine teeth resulting from injuries. A group of 20 teeth (group 1) underwent extirpation of pulp, as well as elaboration of a root canal and its filling with Endomethasone paste, under general anaesthesia during a one-stage procedure. The second group of 20 teeth differed from the first in an additional concentrationof the paste, due to an introduction of gutta-percha points (lateral condensation). This sealing modification proved to diminish the risk of leaving empty spaces after pulp removal in the pulpitis state. However, in teeth where gangrenous pulp extirpation was performed, lateral condensation was endangered by pushing the paste through beyond the apex. Both anomalies were likely to predispose to the development of apical periodontitis.

Introduction In dogs contusion or fraction of the crown is the main cause of canine tooth pulp disease. First of all diagnosis must rule out irreversible changes within the pulpa dentis. Typically, the whole process begins with pulpitis accompanied by short-lasting pain, usually not even noticed by the owner. Pulp remaining without any treatment immediately after an accident is affected by pulpitis initially and followed by degeneration and pulp necrosis. Pulpal gangrene, in its painless course, develops inside a tooth. After some time the disease spreads outside the root canal. Then, in the region of the apex, granulomas or cysts occur as an evidence of complicated gangrene. These changes can be seen o n a radiograph as periapical radiolucency. The following stage of the disease may affect periodontal tissues as well as cranial bones. Its clinical symptoms involve periapical abscess with gingival fistula (HARVEY,1985; EMILY,1990; VAN FOREEST, 1991; HARVEY and ORR, 1992). Because of the aforementioned consequences of pulpitis chronica or gangraena pulpae simplex, medical support is necessary. It may consist of extraction or endodontic therapy. In humans, the latter, the conservative solution, is usually the first choice. It allows metabolism and tooth functions to be maintained as well as averting, temporarily or permanently, the danger of losing a tooth. Endodontic therapy consists of extirpation o f pulp followed by preparation o f the root canal and its filling. Apart from its contents and qualities, sealing paste should be able to penetrate a tooth canal cavity. It is known that empty spaces left after processing diminish the therapeutic effects. In human stomatology the way to improve obturation is condensation U.S. copyright ciez-ce

center ccdCstatement:

0931-1 84X/98/4503-0137 $14.00/0

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through use o f ptta-percha points. It can be applied by several methods, among which the lateral o n e is regarded as the simplest (PAHNCKE,1994). Considering the facts mentioned above, it was decided to present these experiences connected with the total root canal therapy of canine teeth in dogs performed as a one-stage procedure. T h e purpose of the work was to determine the influence o f the lateral condensation of sealer (Endomethasone) o n the procedure and the healing effects in the early post-operation period. Comparative studies aimed at estimating the results of the chosen therapy in the cases of pulpitis and pulpal gangrene.

Materials and Methods Animals The subjects of investigation were 37 dogs of various breeds and ages. In each case diagnosis had stated irreversible pulp d x a s e of either one or two canine teeth. The animals were divided into two groups (gr.) according to the chagnosis. There were 19 dogs in the first group with pulpitis identified in 20 teeth. The second group consisted of 18 dogs with 20 teeth affected by simple gangrene. The animals in the two groups consisted of individuals with a wide range of body weights and ages. The mean values did not vary markedly from one group to another. Both groups were dominated by males and pedigree dogs Fable 1). The groups were divided into two subgroups (sgr.). Each subgroup (sgr. a, sgr. b) had 10 canine teeth chosen for therapy.

I’reliminary quah$cation Anamnesis and physical examination identified a diseased tooth and determined the cause and form of pulp disease. Isometric rachograms were made in the occlusive projection with the use of Chirac-70; Dental DX 3 X 4 film (Dental X-Ray Film, Foton S.A., Warszawa, Poland). They helped to control the periodontal structure and hard body tissue, which is imperceptible for a physical examination. Animals with good general health were qualified for the treatment. The canine tooth with pulp disease was firmly attached to an alveolar socket. The teeth did not undergo therapy in the case of periapical radiolucency, advanced destruction of periodontal tissues o r when root fracture had been observed.

Anaesfhesia

Before treatment, the animals underwent starvation for 12 h with free access to water. Atropine and xylazine were administered as premedication. Induction and maintenance of general anaesthesia were achieved with the use of an anaesthetic mixture applied intravenously according to the method by UTAJCZAK and SKRZYPCZAK(1993). Roof canal therapy technique (gc /a, IIa) Access to the root canal was obtained at the fracture spot. Keeping the crown structure untouched, access to the cavity was on the labial tooth surface above the edge of the gingiva, with a round bur. Pulp

Table 1. Division into groups and characteristics of animals with diseased pulp o f canine teeth qualified to root canal therapy

*€F Group

Number Sex of animals Male Female

Body weight

0

(years) x

f

i

x

Breed

Mongrels Pedigeedogs

~

I I1

19 18

15 11

4 7

6.6 8.5

2.87 3.53

30.8 3.72 32.4 3.56

~

5 7

14 11

Group I, animals with pulpitis; Group 11, animals with simple pulp gangrene; x, mean value, f, standard deviation

Lateral Condensation in Treatment of Canine Pulpitis and Pulp Gangrene

139

was withdrawn from the canal with a barbed broach. After extirpation a small diameter file was gently inserted into the root canal until a certain resistance occurred. Then a radlograph was taken. It helped to determine proper working length, i.e. the distance from the rim of the access cavity to the natural constriction of the root canal within the apical region called the physiological foramen. Each subsequent file was marked to penetrate the exact radiographically confirmed depth of the root canal. The canal was filed clean by a Hedstrom file that was manipulated by a circular up-and-down motion. Once that file was being inserted easily, the next, bigger instrument was used. After this instrument had been used, the root canal was flushed with 3 Yo hydrogen peroxide solution. Preparation of the root canal continued unul clean dentinal shavings had occurred. The prepared canal as finally irrigated with sterile water several times and then dried. Endomethasone paste was prepared according to the producer’s instruction (Septodont endomethasone (root canal sealer, Speciahties Septodont, Saint-Maur, France)) and it was inserted into the root canal with the use of a lentdo spiral filler. Before the access was filled, the fitness of obturation was checked by taking the next radlogram. In sgr. Ib and IIb, in addltion to the above stages, the lateral condensation as applied. For that purpose, gutta-percha points were inserted into the root canal filled up with the sealer. The first point was the thickest and it was introduced with the use of a plugger. The empty space needed for each following point was obtained by a spreader. The following points, with successively diminished diameters, were applied until they had filled up the root canal densely and no more space could be created for additional points. Excessive gutta-percha, reachrng beyond the edge of access, was burnt by a heated excavator. In all subgroups, the process was finished by fihng the access cavity with phosphatic cement as a base, covered by GlasIonomer Cement (Shofu GlasIonomer Cement (cement for filling, Shofu Inc., Kyoto 605, Japan)). Post-operationcontrol

The clinical and radiographical examinations, carried out on the 40th day after the process, aimed to estimate the degree of the canal obturation and the state of the root apex and periodontal tissues.

Results The examination dealt with the canine teeth which showed irreversible pulp disease as the result of an external trauma, i.e. accidents, catching stones or biting hard objects. The tooth discoloration as regarded as the main symptom of the disease. All teeth underwent that change. The crown was fractured in 34 teeth, and six canine teeth showed pulp disease developed without obvious disconnection of tooth hard tissue. Only the cases recognized by pathological processes not earlier than 2 days after contusion became the subject of this therapy. In the teeth with crown fractures, at the beginning of the process, the gap was widened to the size which allowed penetration of the instruments. Once the tooth cavity was reached, pulp extirpation took place. It required several penetrations with the barbed broach when the tissues were still alive. In the teeth with pulpitis intensive haemorrhage occurred. It was controlled by a few minutes’ pressure upon the root canal bottom using a paper point soaked with 0.35% ephedrine. The gangrenous pulp, however, was of a jelly-like consistency, not firmly connected, and therefore easier to withdraw. Moreover, a broader root canal was found in those cases. Haemorrhage seldom occurred in that form of the disease; it only happened after intensive instrumentation which damaged the tooth apex. While preparing a canine tooth, all the instruments were bent into the shape of an arc which made them similar to the shape of the long axis of the tooth. Mechanical elaboration had to be carried out with regard to depth, curvature and a section of the root canal. Marking the radiographic length o n each inserted instrument limited the risk of pushing infected tissues through the apex. Therefore it was also important to broaden the root canal with the use of the ‘step-back‘ technique, i.e. increasing the file size successively with gradual simultaneous decrease of the penetrated depth. Endomethasone diluted with eugenole became a sern-liquid paste that was administered to the root canal slowly clockwise by lentulo spiral run. However, the lateral condensation, applied to sgr. Ib and IIb, showed its routine course in small canine teeth. In the canine teeth of big dogs gutta-percha points of 25 mm, commonly used in stomatology, could not reach a physiological foramen. In those cases it was necessary to place gutta-percha in a distant part of the root canal first, using a long plugger, and then permanently seal remaining space close to the access. The teeth condensated in that separated, two-stage way showed a proper range of

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obturation and density of the Endomethasone paste in most cases. Canine teeth with the longest root canal required 7-10 points of various thickness. The teeth in which the paste filled up the root canal to its physiological foramen were regarded as properly sealed. If the shadow of the paste could be seen beyond the apex on the radiograph, the case was qualified as pushing the paste through. This happened when the root canal was not widened carefully enough or during its sealing (Fig. 1). Insufficient filling up was recorded when the shadow of the paste did not reach the physiological foramen (too shallow) or if within its range air bubbles caused ball-shaped radiolucency (Figs 2 and 3). If insufficient filling was of the first type, elaboration and sealing were repeated. The presence of too-shallow filling was especially noticed in the teeth sealed exclusively with the Endomethasone paste (sgr. Ia, Ha). The processing was not repeated in the second type (air bubbles) indicating unexact paste density, and the range of canal infiltration as satisfactory. Intra-operation data are presented in Table 2. Generally speaking, the root canal therapy of 40 teeth remained without complications in 23 cases, which made up 57.5% of material subjected to the endodontic processing. Intensive haemorrhage that came from the apex was the complication of nine teeth (five plus four), and it involved mainly those with pulpitis, gr. I. In gr. 11, teeth with pulp gangrene, only two cases of haemorrhage took place after the apex had been pushed through. The total number of teeth with insufficient filling was seven (three plus four), all of them being teeth filled up exclusively with the sealer (sgr. Ia, sgr. Ira). Of these cases, four dealt with intensive bleeding that had taken place previously. Another type of complication, pushing the paste beyond the root canal, was observed in five cases: the majority occurred in sgr. IIb (teeth with pulp gangrene) after their condensation. Table 3 presents the results of examination 40 days after processing. Recorded control determined the proper state of 30 teeth. That made up 75 ?4n of satisfactory therapeutic results. The teeth without inflammatory reactions of tooth apex and parodontium were qualified to

Fig. 1. The apex pushed through (sgr. 1Ib).

Lateral Condensation in Treatment of Canine Pulpitis and Pulp Gangrene

141

Fig. 2. Radolucency in apical parodontium observed in canine tooth with insufficient filling (sgr. Ia).

Fig. 3. Air bubbles in sealer (sgr. IIa).

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RATAJ(.ZAKand GAU'OR

Table 2. Intra-operation results o f root canal therapy Total Course of processing

Sgr. Ia

Sgr. Ib

n

Yo

(4

(4

No complications Haemorrhage Pushing through Insufficient fiIling Insufficient filling after haemorrhage Total

23 5 5 3 4 40

57.5 12.5 12.5 7.5 10.0 100

5 1

6 3 1

1 3 10

10

Sgr. IIa (4

Sgr.IIb (4

6

6 1 3

1 2 1 10

10

Sgr. Ia, canine teeth with pulpitis sealed with Endomethasone; sgr. Ib, canine teeth with pulpitis sealed with Endomethasone+condensation; sgr. IIa, canine teeth with simple pulp gangrene sealed with Endomethasone; sgr. IIb, canine teeth with pulp gangrene sealed with Endomethasone+condensation; n, number of teeth; '/a, percentage in n = 40

Table 3. Post-operation results of root canal therapy Total

40 days after processing

n

%

Proper Radiolucency Insufficient filling Radiolucency with insufficient filling Pushing through Radiolucency with pushing through Total

30 1 1 3 2 3 40

75.0 2.5 2.5 7.5 5.0 7.5 100

Sgr. Ia (n)

Sgr. Ib

(4

Sgr. IIa (4

7

9

8

Sgr. IIb

(4 6

1 1 2

1 1

10

10

1 10

1 2 10

For definitions, see Table 2

that group. At the same time cases regarded as healed had to be strongly attached showing n o pain reaction and keeping characteristic gingival colour and consistency. The highest effectiveness was found in sgr. Ib, where nine out of 10 teeth remained without complications. The worst effects were presented in sgr. IIb where complications were seen in four teeth.

Discussion Numerous techniques of endodontic treatment have been described in human stomatology (GRUSZEWSKA-LEWCZUK and HUBERT, 1982; PIATKOWSKAet al., 1982; CALURAet al., 1984; KRUPINSKIet al., 1993; PAHNCKE, 1994). This investigation in dogs was a trial to determine the effects of lateral condensation applied to canine teeth. The observations made proved the relationship between the form of pulp disease and the complications during processing as well as the condition of teeth after treatment. The cases where pushing through the apex occurred most often took place in the teeth with pulp gangrene. It was suspected that a certain predisposition to that form of complication resulted from the broader root canal lumen which was observed in the cases of pulp gangrene. O n the other hand, long-lasting processes of maceration, caused by gangrene and activity of bacterial toxins, were also noticed. Investigations carried out by KRUPINSKIet al. (1990, 1991) proved that the factors mentioned above led to the destruction of tissues building the tooth apex. In these patients, the sealing material beyond the teeth was found in cases with applied condensation. Since the root canal

Lateral Condensation in Treatment of Canine Pulpitis and Pulp Gangrene

143

was always made patent within its radiologic length, it should be assumed that introducing gutta-percha points was the cause of pushing the root canal through. Pressure on the tooth and parodontium was sometimes higher than current mechanical resistance of connective tissues. In dogs’ teeth with pulpitis intensive haemorrhage in the root canal took place. It occurred after pulp extirpation. Numerous authors record that haemorrhage makes surgery difficult, 1990; PAHNCKE, 1994). In the opinion (HARVEY,1985;KRUPINSKIet al., 1988,1993; EMILY, of the authors, this complication also contributed considerably to insufficient infiltration of the root canal with sealer. Filling which was too shallow was observed mainly after haemorrhage in the teeth which were not supplied with gutta-percha points. Radiographical diagnosis before permanent filing of the access enabled correction of obturation and proper distribution of the paste within the root canal. It was characteristic that 40 days after processing in teeth filled properly up to their physiological foramen (and after improvement of previous filling) lack of sealer was noticed in the apical part of the root canal. However those were only the teeth diagnosed during an operation as insufficiently filled after haemorrhage. Correlation between such disorders as haemorrhage and insufficient obturation may lead to the conclusion that lack of sealer after a longer period resulted from rinsing or pushing it out with stream of blood. According to KRUPINSKI et al. (1983) after processing a slight amount of pulp tissue remains in the apical part of the root. Therefore it is suggested that they could stay congested for a longer period of time because of processing trauma. These examinations have proved that to avoid insufficient filling after haemorrhage the routine condensation of sealing paste should be introduced. That procedure could be justified by no record of insufficient filling in teeth after haemorrhage while simultaneously the condensation of the sealer took place. Among complications connected with root canal therapy in humans, the pain that accompanies biting, dental fistula and radiographically noticeable radiolucency is mentioned (GRUSZEWSKA-LEWCZUK and HUBERT,1982; KRUPINSKI et al., 1988,1990,1991,1993). As is known from the literature, pulp excision is a kind of mechanical trauma which leads to acute periodontitis (PIATKOWSKA et al., 1982; KAMII;ISKA-LITWIN and WASZKIEL, 1983; KRUPINSKIet al., 1988, 1993). Hence the sealing material should possess proper pharmacological qualities. It is required to be immunosuppressive, particularly when it is used immediately after patency of the root canal (GORA and KACZMARCZYK, 1982; GRUSZEWSKA-LEWCZUK and HUBERT,1982; KRUPINSKI et a]., 1983; LIMANOWSKA, 1985,1988). In the dogs’ canine teeth therapy Endomethasone, which contains dexamethasone and hydrocortisone, was used. An earlier examination had proved that that multi-element remedy is marked by high antibacterial activity and very low cytotoxicity (PASS1et al., 1983; P u p 0 et al., 1983; CALURAet al., 1984; MERYONand BROOK,1990; WAGNERand TRYKOWSKI,1993).Therefore it is unlikely that the prolipheratic symptoms in the apical parodontium which occurred in these experiments might be the result of an irritating effect of Endomethasone. KRUPINSW et al. (1988) stated that blood and lymph, accumulated in empty spaces of the insufficiently filled root canal, stimulated productive processes. In the case of pushing through, infected tissues of pulp, forced together with the paste beyond the apex, acted in a similar way. In this investigation, 40 days after processing three out of five cases where the root canal had been pushed through were accompanied by radiolucency. It was found that four teeth were filled insufficiently and three of them had periapical radiolucency as well. It proved that in canine teeth incorrectly sealed inflammation tended to spread on to periapical tissues. These clinical experiments show the importance of filling the root canal properly. The procedure chosen should depend on the degree of alteration. In the cases with pulpitis, the lateral condensation proved preferable since its haemostatic effects protected the root canal from insufficient filling. Sealing paste, pressed in lateral directions, entered dentine tubules while the gutta-percha points firmly stuck to the walls of the root canal and pressed towards its bottom. In the cases where incidental haemorrhage occurred, the exclusive use of the sealer did not cause insufficient filling. Therefore the lateral condensation became useless in teeth with removed gangrenous pulp. These experiences prove that such teeth should be sealed only with the paste because additional insertion of gutta-percha carries the danger of pushing the apex through. Preservation of the tooth in its alveolus was the main task for functional and cosmetic

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FUTA~CZAK and GAWOR

reasons. Because o f their anatomical and topographical conditions, the canine teeth tended t o suffer from traumagenic factors. They were affected by pulp disease more than the other teeth. Pulp disease is regarded as pathology of the oral cavity which is still too frequently solved by an extraction. T h e number o f extractions can be diminished by the suggested root canal therapy. Its effectiveness is conditioned by a diagnosis o f the pulp disease form and followed by the choice o f a proper root-sealing technique.

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