Endo-perio lesions-the problem and the solutions

INTRODUCTION

A close interrelationship exists between the pulp and periodontium. This relationship of structures influences each other during health, function and disease. The pulp originates from the dental papilla and the periodontal ligament from the dental follicle and is separated by Hertwig’s epithelial root sheath. The relationship between periodontium and pulp was first described by Simring and Goldberg in 1964.¹ Periodontium is anatomically interrelated with the pulp through different pathways like dentinal tubules, lateral and accessory canals and apical foramen.^2,3 Through these pathways an exchange of noxious agents take place when either or both the tissues are diseased. Thus pathologic changes in one tissue affect the other. Factors like bacteria, fungi and also other factors like trauma, root resorption, perforations and malformations result in development and progression of the lesions. The simultaneous existence of pulpal problems and periodontal disease can complicate diagnosis and treatment planning. Pulpal and periodontal problems are responsible for more than 50% of tooth mortality.⁴

According to Louis Grossman, endo-perio lesions are classified based on therapy as

a) Teeth that require endodontic therapy only

b) Teeth that require periodontal therapy

c) Teeth that require endodontic and periodontal therapy

Franklin S Weine classified endo-perio lesions based on aetiology and treatment required as

a) Class I- Tooth that clinically and radiographically simulate periodontal involvement but is truly due to pulpal inflammation and/ or necrosis

b) Class II- Tooth with both pulpal and periodontal disease

c) Class III- Teeth that has no pulpal problems but requires endodontic therapy with root amputation to achieve periodontal healing

d) Class IV-tooth that clinically and radiographically simulate pulpal or peri-radicular disease but in fact has periodontal disease.

Simon’s classification based on aetiology, diagnosis, prognosis and treatment is⁵

a) Primary endodontic involvement

b) Primary endodontic with secondary periodontal involvement

c) Primary periodontal with secondary endodontic involvement

d) True combined lesions

Diagnosis of Endo-Perio Lesions: Accurate diagnosis requires diligent history taking, thorough and proper examination.⁶ Following steps will aid in diagnosis and in arriving at an appropriate treatment plan.

Visual examination: It is usually seen that swelling caused by endodontic infections occur in the muco-buccal fold and that caused by periodontal infections occur in the attached gingiva. Teeth should also be examined for any caries, defective restoration, erosions, abrasions, cracks, fractures and discolorations.

Fistula Tracking: Presence of a sinus tract allows for a proper diagnosis and a radiograph with gutta-percha point within the orifice of the fistula leads us to the source. If the gutta-percha point goes to the apex of the tooth, the fistula is considered to be of endodontic origin and if the point goes to midroot or furcation region, a periodontal problem is diagnosed.

Palpation: Palpation is performed by applying firm digital pressure to the mucosa covering the roots and apices. A positive response to palpation may indicate active peri-radicular inflammatory process.

Percussion: The tooth crown is tapped vertically and horizontally. Although this test does not disclose the condition of the pulp, it indicates the presence of a peri-radicular inflammation.

Probing: It is an important test to differentiate endodontic and periodontal lesions. In periodontal lesions probing defects are usually wide and do not usually extend to the apex of the involved teeth; in contrast probing defects from endodontic lesions are usually narrow and extend to the apices.

Radiographs: Periodontal lesions are usually associated with bone loss extending from cervical region towards the apex. For purposes of differential diagnosis, periapical and bitewing radiographs should be taken from several angles.

Vitality Test: If the patient complains of pain and the vitality test produces a normal reaction indicating a vital pulp, periodontal treatment should be done first. On the other hand, if the test findings are abnormal, with or without pain, endodontic treatment should be done first.

Mobility: Periodontal disease causes mobility due to inflammation and loss of supporting alveolar bone. Mobility can occur as a result of trauma from occlusion. Fractured roots, recently traumatized teeth, periradicular abscess also cause transient mobility.

Treatment : Various treatment modalities have been proposed to address the endo-perio lesions. A treatment concept was developed by Haueisen et al that combines endodontic and periodontal measures in a particular sequence and at specific intervals.7 The initial treatment was followed by endodontic therapy to allow healing, except in conditions where the patient had acute periodontal symptoms.7 Periodontal measures or surgical endodontics would be undertaken on the basis of the clinical and radiographic findings at the recall review at 3-6 months.

When traditional endodontic and periodontal treatments prove insufficient to stabilize an affected tooth, the clinician must consider treatment alternatives. Alternate treatments often consist of resective or regenerative approaches. Resective methods involve removal of affected roots or extraction of involved teeth. Bone replacement grafts using guided tissue and bone regeneration techniques are ways to re-establish biologic structures that were lost during this disease process.

This case series gives an insight into the various treatment procedures that can be applied for the resolution of the endo-perio lesions.

CASE REPORTS

Case 1

A 29 year old male patient reported to Department of Periodontics, D A P M R V Dental College, Bangalore, with a complaint of mobility of his lower right and left posterior teeth. The lower right first molar had grade III mobility and its prognosis was deemed to be poor; however, a decision was taken to make an attempt at salvaging the first molar and a vitality test was advised. The lower left first molar, which showed periradicularradiolucency in relation to the distal root with a pocket depth of 10mm, was also subjected to vitality testing. The lower right first molar was found to be non-vital whereas the lower left first molar responded at +8. Endodontic therapy was performed on both the teeth. 3 months after the commencement of endodontic therapy, the probing depth remained deep and a wide radiolucent lesion was still evident due to the untreated primary periodontal lesion. (fig 1A, fig 2A).

In the lower right first molar area, a full thickness flap was reflected to gain access to the peri-radicular region. After debridement and irrigation with povidone iodine a hemi septal defect not amenable to regenerative therapy was seen (fig 1B). The flap was sutured back and post-operative instructions were given. A radiographic image taken 1 year postoperatively showed remarkable enhancement in the radio-density around the affected region (fig 1C).

In the lower left first molar region, the full thickness flap reflection and debridement revealed that the distal root was completely devoid of bone support (fig 2B). Hemisection was performed and the distal portion of the tooth was removed (fig 2C, 2D). The flap was sutured back and allowed to heal. After 5 weeks, a temporary restoration was inserted. At the end of 1 year following the therapy, permanent splinted crowns were given after assessing the periodontal status (fig 2E) and a regular recall and maintenance was advised.

Case 2

A 36 year old male patient reported to the department with a complaint of pain and swelling in relation to lower right first molar. The tooth had Grade II mobility and showed a positive vitality test (+7) according to the electric pulp test. The probing pocket depth was 10 mm at the distal site. Radiographic image showed a wide and deep radiolucent lesion around the distal root (Fig 3A). Endodontic therapy was carried out as the first step. At 3 months recall, a persistence of the pocket was noted. Regenerative periodontal therapy using Platelet Rich Fibrin (PRF) was performed to fill the remaining defect (fig 3B, 3C). Radiograph at the 6 month follow-up showed increased radio-density in the affected area suggestive of bone regeneration (fig 3D).

Case 3

A 33-year-old male visited the department with a chief complaint of persistent pain and occasional swelling and pus discharge in relation to the lower left first molar. The result of the electric pulp tests indicated that the first molar was vital (+7). The tooth had a Grade III furcation involvement. Endodontic therapy was performed and it relieved the symptoms. A 3 month recall examination showed a persistence of the furcation involvement (fig 4A, 4B) with evident signs of inflammation in the furcation area, indicating an inability to maintain a plaque free zone. Bicuspidisation was performed to eliminate the furcation involvement (fig 4C, 4D) and a functionally efficient tooth form was created by placing crowns of appropriate morphology after a period of 3 months.

Case 4

A 35 year old male patient with a chief complaint of pain and swelling in the lower right first molar region reported to the department. The vitality test showed a negative result suggestive of a necrotic pulp. Endodontic treatment followed by regenerative periodontal treatment was planned. Three months after the endodontic treatment (fig 5C) the guided tissue regeneration using resorbable collagen barrier membrane (HealiguideTM, Advanced Biotech Products (P) limited, Alathur) along with Calciumphospho-silicate putty (Novabone dental putty, Novabone Products, Alchua, FL) (fig 5B, 5D, 5E) was performed for the resolution of the primary periodontal intraosseous lesion. The 6 months recall examination showed a significant reduction in the pocket depth, a remarkable osseous repair and enhanced radio opacity.

DISCUSSION

The relationship between pulpal and periodontal disease can be traced to embryological development, since the pulp and the periodontium are derived from a common mesodermal source. Appropriate diagnosis and treatment planning are essential to achieve a complete resolution of the lesion and to arrive at functional stability.

In the various cases presented here, endodontic therapy was performed prior to the periodontal therapy. Except in two instances, the endodontic therapy was intentional in nature. This may be justified by the fact that partial necrosis of the pulp may render a positive pulp testing value despite the existence of a combined lesion, especially in a multi-rooted tooth.⁸ Recently, in a series of studies, potential effect of tooth with necrotic pulp has been described as a risk factor in the initiation and progression of periodontal disease and in the impairment of resolution of periodontal pockets.^9-13 The clinical consequences suggested by the above mentioned series of studies are; significantly deeper probing depths, more bone loss, impaired periodontal healing following nonsurgical periodontal treatment, and enhanced progression of periodontal disease, suggesting that endodontic therapy should be completed before periodontal therapy. However, Sanders et al.¹⁴ reported in 1983 that, after the use of freeeze dried bone allograft, 65% of the teeth that did not have root canal treatment showed complete or greater than 50% bone-fill in periodontal osseous defects, while only 33% of the teeth which had root canal treatmentprior to the periodontal surgical procedure had complete or greater than 50% bonefill.

In our case series periodontal treatment was scheduled to address the remaining intraosseous defect only after osseous healing was induced sufficiently by initial endodontic treatment. A period of at least 3 months elapsed between the endodontic therapy and the commencement of the periodontal therapy. A similar healing period was seen in a case report by Kwon et al.¹⁵

The success rate of the endo-perio combined lesion without a concomitant regenerative procedure has been reported to range from 27% to 37%.¹⁶ This result demonstrates the notably low success rate and explains why regenerative periodontal surgery should be performed following endodontic treatment in combined endo-perio lesions.¹⁵ Platelet rich fibrin(PRF) and Calcium-phospho-silicate putty(Novabone dental putty, Novabone Products, Alchua, FL) along with resorbable collagen membrane (HealiguideTM, Advanced Biotech Products (P) limited, Alathur) have been used in the regenerative techniques employed in this case series. All the regenerative procedures employed showed a vast improvement in the clinical parameters including an increased radio-density in the affected areas. In a case report by Murali et al, the use of PRF in an endo-perio lesion resulted in a successful outcome, indicating that it is an effective regenerative material in the treatment of endo-perio lesions.¹⁷ The other graft material used in this case series is a pre-mixed composite of bioactive calcium-phospho-silicate particulate and a synthetic, absorbable binder. The bioactive glasses have been used extensively in medicine for middle ear surgery and have been applied to dentistry in the treatment of bone defects, ridge preservation and periodontal bone defects.¹⁸ Guided tissue regeneration (GTR) barrier prevents contact of connective tissue with the osseous walls of the defect, protecting the underlying blood clot and stabilizing the wound.¹⁹ Britain et al. showed that use of bio-absorbable collagen membranes alone or in combination with anorganic bovine bone matrix resulted in enhanced regeneration when compared to open flap debridement alone.²⁰

Open flap debridement without the placement of a graft material had been successfully attempted in one of the described cases where the site was not amenable to regenerative procedures. This suggested that a thorough treatment of the endodontic and periodontal component of the lesion, without a concomitant regenerative procedure also resulted in resolution of the endoperio lesion. Hemisection and bicuspidisation have also been used as alternate treatment modalities when regeneration was not a viable option for the treatment of the endo-perio lesions. The treated teeth were subsequently restored and on reevaluation were functionally stable. In a case report by Haueisen et al hemisection has been used successfully in the treatment of an advanced endo-perio lesion.⁷

CONCLUSION

Endodontic and periodontic lesions result from the close interrelationship of pulp tissue and the periodontium. When examining and treating the combined or individual lesion in endodontics and periodontics, the clinician must bear in mind that successful treatment depends on a correct diagnosis. Proper diagnosis of the various disorders affecting the periodontium and the pulp is important to exclude unnecessary and even detrimental treatment. So, the clinician should therefore be well acquainted with the pathogenesis as well as with available diagnostic measures aimed at identifying disease conditions of these tissues and the possible inter-relationships between disease process of the dental pulp and the periodontium.