The use of the Erbium Yttrium Aluminium Garnet (2940 nm) in a laser-assisted apicectomy procedureA. Reyhanian,1 S. Parker2 and J. Moshonov3

If conventional endodontic treatment is not possible or not successful, apical endodontic surgery may be indicated. New techniques, materials and technologies had been implicated to increase the already high success rate of root canal treatment. The purpose of this article is to describe the use of the Erbium:YAG (2940 nm) laser in treatment of apicectomy as a central tool, with the advantages of enhanced patient comfort, better bactericidal and decontamination effects.

INTRODUCTIONSurgical endodontic therapy (apicec-tomy) is a treatment alternative aimed at removing periapical infl ammatory tissue followed by apical resection and retro-fi lling of the root canal.1 Such procedures are performed through a trans-osseous approach.2 The term ‘api-cectomy’ has been well known for more than 200 years and surgical manage-ment is intended to eliminate or block infection originating in the root canal. The root end is customarily sealed to prevent pathogenic products remain-ing in the root canal from reaching the peri-radicular tissue.3,4

Different cases require different treat-ment modes. It is important to emphasise that endodontic treatment remains the primarily preferred therapeutic action.

The optimal way to address endodontic failures is to re-treat the root canal sys-tem fi rst if clinically possible and only then, if no remission is seen, perform surgery with curettage.5-7 Advance-ments in instruments (endodontic

microsurgery), materials and techniques have made endodontic surgery a more predictable procedure.8-10

In a review of randomised controlled trials to establish the relative effective-ness of surgical vs. non-surgical endodon-tic re-treatment, the Cochrane Database System Review11 concluded that there is no apparent difference between either of the treatments, rather that greater criteria were risk of complications, operator skill, technical feasibility and the extent of the presenting lesion.

It is important to recall the principles of endodontic surgery that dictate treat-ment. The prime considerations may be summarised as follows:• A thorough appreciation of surgical

anatomy is of primary importance in order to effect a well-performed procedure and appropriate radio-graphic investigation must precede any surgical approach in order to properly assess the lesion and associated anatomical structures12

• Surgical access – the preferred muco-periosteal access is through a semi-lunar incision, which must always be positioned above the lesion and never through the lesion

• Operator experience and good surgical technique13

• Thorough removal of associated granulation tissue or more organised peri-apical pathology

• Appropriate resection of the root apex, to eradicate the apical tip and any

accessory root canals in this region. Wherever possible, the resection level should be coincident with the buccal or labial alveolar bone level

• Retrograde obturation – it is considered appropriate that a retrograde root canal fi lling should be performed routinely during apical surgery. The purpose of the retrograde fi lling is to seal the exposed root canal and prevent leakage of pathogens into the peri-apical area. Isolation of the root area is vital during this procedure and will enhance the successful outcome.14

An array of potential retrograde fi ll-ing materials have been advocated and such choice has been extensively inves-tigated in vivo and in vitro.15,16

Many studies have been performed to compare the success rates of various root-end fi lling materials, such as Super-EBA™ (Harry J. Bosworth Company), IRM® (Intermediate Restorative Material, Dentsply International), zinc-free high copper amalgam, gold leaf, gutta-percha, calcium hydroxide and silver.17-20

Using the Er:YAG laser in apicectomy surgeryThe Erbium Yttrium Aluminium Garnet (Er:YAG) laser has a wavelength of 2940 nanometres and emits as a free-run-ning pulsed train of photons in the Mid infra-red portion of the electromagnetic

1*General Practitioner, 1 Shaar Haemek Street, Netanya 42292, Israel; 2General Practitioner, 30 East Parade, Harrogate HG1 5LT; 3Clinical Associate Professor and Acting Chairman of the Department of Endodontics, Hebrew University – Hadassah Faculty of Dental Medi-cine, 25 Habanai Street, Jerusalem 96264, Israel*Correspondence to: Dr Avi ReyhanianEmail: avi5000rey@gmail.com

Refereed PaperAccepted 30 May 2008DOI: 10.1038/bdj.??????????©British Dental Journal 200?; 20?:

BRITISH DENTAL JOURNAL VOLUME 20? NO. ? ??? ?? ???? 1

• The apicectomy and retrograde root fi lling procedure must be assessed as a preferred option for treatment.

• Successful surgical outcome will be enhanced through appropriate understanding of causative factors and surgical skill.

• The use of the Erbium:YAG laser in the apicectomy procedure can allow surgical precision, minimise collateral iatrogenic damage to surrounding tissue and achieve signifi cant pathogen reduction within the surgical site.

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spectrum. Successive laser pulses are 100-200 microseconds in width. The prime chromophore of this laser wave-length is water, which makes it appro-priate for ablating both hard and soft oral target tissue. Incident laser energy is absorbed by the chromophore, con-verted into thermal energy which results in expansive vaporisation. Such action causes a dislocation of the tissue struc-ture and ablation; often this is accompa-nied by an audible ‘popping’ sound.

The Er:YAG laser can make an incision for fl ap lifting, such as a crestal inci-sion, an intrasulcular or vertical release incision or semilunar incision. The laser produces a wet incision (some bleeding) as opposed to a dry incision (no bleed-ing) produced by current CO2 lasers.21-23

Vaporisation of granulation tissue24,25 (if any exists) after raising a fl ap is effi -cient with the Er:YAG laser, offering a lower risk of overheating the bone26,30,31 than that posed by the current diode or CO2 lasers.

Detoxifi cation of the infected site by lasing directly on the bone – stud-ies have shown that Er:YAG laser energy effects on bone include bacterial reduction.27,28,32

Ablation of alveolar bone tissue with the Er:YAG laser can be used for remodelling, shaping and ablation of necrotic bone.29,30

Root apex resection using the Er:YAG laser in contact mode and preparation of the apex cavity for retrograde.

CASE REPORTThis case describes the use of an Er:YAG laser for apicectomy treatment and the advantages of this laser wavelength in performing apicectomy versus conven-tional methods.

A 28-year-old female presented com-plaining of pain and swelling of the gingival tissue associated with the upper right central incisor tooth (Fig. 1). This condition had been present for some time, with episodes of associated discharge from the area. On examina-tion, the tooth had been restored at some time with full-veneer porcelain fused to metal crown. The general level of oral health was considered good, with evidence of adequate oral hygiene; the periodontal condition was good

with no pocketing or bleeding on prob-ing. The patient’s general medical his-tory was uneventful and she was taking no medication. The patient – after being referred to our clinic for laser surgery by her permanent dentist – was informed of the treatment possibilities and chose the laser surgery route.

Panoramic and periapical fi lm showed a radiolucent area around the apical por-tion of the tooth and root canal (Fig. 2). A diagnosis of peri-apical granuloma, suggestive of failure of the orthograde root fi lling was made and treatment indicated surgical curettage of the area and apicectomy procedure.

Treatment would involve the use of an Er:YAG laser to perform:• The fl ap incision30

• Expansion of the entrance to the defect

• Ablation of granulation tissue around the apex

• Remodelling, shaping and ablating of the bone

• Resection of the apex• Preparing the apex cavity for

retrograde (root fi lling) • An associated osteogenic (GBR) pro-

cedure to prevent soft tissue in-growth and maintain the form of the alveolus.

Treatment alternatives could consist of traditional scalpel, curettes, and rotary instruments.

TreatmentA dual-wave laser system with operating wavelengths of 2940 nm and 10600 nm (OpusDuo™ AquaLite™, Lumenis, Ltd. Yokneam, Israel) was employed for this procedure.

The laser operating parameters employed for the various surgical stages were as shown in Table 1.

A semilunar incision was made (after anaesthesia).32,33 The incision extended from a point approximate to the distal area of the upper right lateral incisor to the distal of the upper left central inci-sor (Figs 3-4) and a buccal fl ap was lifted (Fig. 5). Care was taken to minimise soft tissue trauma. A small fenestration of the labial bone was discovered and sur-rounding bone was ablated in order to expand the entrance to the defect (Fig. 6).

Table 1. XXXX

Flap access Wavelength: 2940 nm (Er:YAG), 200-micron sapphire tip, in contact mode; 450 mJ per pulse at 20 Hz. Total power: 9 Watts.

Granulation tissue removal

Wavelength: 2940 nm (Er:YAG), 1300-micron sap-phire tip, in non-contact mode; 700 mJ per pulse at 12 Hz. Total power: 8.4 Watts.

Bone surgery Wavelength: 2940 nm (Er:YAG), 1300-micron sap-phire tip, in non-contact mode; 450 mJ per pulse at 20 Hz. Total power: 9 Watts.

Resection of tooth apex

Wavelength: 2940 nm (Er:YAG), 800-micron sapphire tip, in contact mode; 850 mJ per pulse at 12 Hz. Total power: 10.2 W.

Retrograde root cavity

Wavelength: 2940 nm (Er:YAG), 800-micron sapphire tip, in contact mode; 850 mJ per pulse at 12 Hz. Total power: 10.2 Watts.

Fig. 1 At presentation - radiolucency area at the location of apex #8

Fig. 2 X-ray at presentation

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A large quantity of granulation tissue was removed with a curette (Fig. 7) and the granulation tissue left behind was ablated with the Er:YAG laser (Fig. 8).

Following surgical exposure, the root apex was sectioned (Fig. 9); the Er:YAG laser energy produced a smooth, clean resection without visible signs of ther-mal damage, which was in accordance with reported fi ndings.34 At the same power setting the cavity of the apex was prepared for retrograde obturation (Fig. 10). Finally the bone defect was shaped and remodelled.

The retrograde cavity was sealed with IRM® (Fig. 11). IRM has been recom-mended for root-end fi lling during endo-dontic therapy and presents advantages such as ease of placement, decreased set-ting time, toxicity, and solubility.34 Due to the fact that biocompatibility is in

today’s forefront, time-tested materials such as silver and amalgam are clearly being used less.28 The success rate of IRM stands at 91%.29

The defect was fi lled with BioOss® (Geistlich Pharma AG, Wolhusen, Swit-zerland, Fig. 12). The purpose of GBR is to provide a matrix for new bone for-mation and prevent soft tissue migra-tion into the surgical defect. The fl ap was sutured with 3-0 silk with careful attention being paid to good primary closure (Fig. 13). After suturing, the CO2 laser was used at a power setting of 4W in continuous wave mode and a focused beam to ablate excess soft tissue (Figs 14-16).

The patient was prescribed antibiotics to avoid infection. She was also given Motrin (800 mg x 15 tablets) for pain. She was instructed to rinse with chlo-

rhexidine 0.2% the next day and for two more weeks, three times a day and was advised to maintain good oral hygiene.

At ten days post-op the patient returned for inspection and sutures removal (Fig. 17). The swelling had resolved, there were no signs of fi stula and healing was progressing well. The patient came in for a scheduled three-week follow-up; the healing progression was satisfactory with fi stula or scar tissue (Figs 18-19). After six weeks the soft tissue was com-pletely healed without complications. The soft tissue was healing over the bone and there were no bony projections observed under the soft tissue (Figs 20-21). The prognosis was considered excellent.

DISCUSSIONThe rate of success with the apicectomy procedure is over 91%.36 Apicectomy

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Fig. 3 Semilunar incision with the Er:YAG laser, 200-micron sapphire tip in contact mode

Fig. 4 Semilunar incision

Fig. 5 Raising the fl ap

Fig. 6 Expanding the entrance to the lesion with the Er:YAG laser, 1300-micron sapphire tip in non-contact mode (700mJ/12 Hz, 8.4W)

Fig. 7 Granulation tissue

Fig. 8 Ablating soft tissue with the Er:YAG laser

Fig. 9 Using the Er:YAG laser to cut the apex and to prepare the apex cavity for retrograde fi lling (800-micron tip in contact mode)

Fig. 10 The apex cavity is prepared for retrograde fi lling

Fig. 11 The retrograde fi lling with IRM®

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failure is generally related to inappropri-ate marginal sealing of the retro-cavity, which allows percolation of micro-organ-isms and their products from the root canal system into the peri-apical tissue.37

The majority of periapical lesions har-bour a variety of fl ora which cannot be eradicated despite a thorough apicec-tomy procedure.38 Surgical re-treatment of teeth previously treated with surgery is a valid alternative to extraction.39

Apicectomy and retro-seal procedures should continue to be a mainstay of den-tal treatment because not all root canal therapy is successful.40 As practitioners have increased their knowledge and skills in the art of saving teeth, peri-radicular surgery has increased in importance.41 With bright illumination and magnifi ca-tion under the operating microscope and the added benefi t of many micro instru-ments, endodontic surgery has evolved into microsurgery.8,9

The use of the Erbium YAG 2940 nm laser has been demonstrated to be effec-tive in the surgical ablation of tooth tissue and bone. Advantages of this modality

over conventional rotary instrumenta-tion may include precision, bacterial decontamination, less collateral dam-age and tactile stimulation. In addition, although studies have been equivocal, the use of this laser in surgical proce-dures may result in less operator fatigue and greater patient acceptance. What has been demonstrated is the enhanced early healing response in bone tis-sue and a lesser level of post-operative

Fig. 13 Primary closure

Fig. 14 Ablating soft tissue with the CO2 laser

Fig. 15 Final result - immediately post-op

Fig. 16 X-ray immediately post-op

Fig. 17 Ten days post-op

Fig. 18 Three weeks post-op

Fig. 19 X-ray three weeks post-op

Fig. 20 X-Ray; six weeks post-op: no radiolucency area

Fig. 21 Six weeks post-op: no scar tissue

Fig. 12 The bone defect is fi lled with BioOss® for GBR procedure

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complications. Although studies into the use of the Er:YAG laser in clinical bone surgery procedures have reported incon-clusive subjective advantages in terms of time required, post-operative pain levels or ease of access, histological investiga-tions have demonstrated better levels of early healing of the bone when the laser is compared to the surgical bur, piezo-saw or carbon dioxide lasers.42,43

CONCLUSIONThe outcome of this clinical case indi-cates that the use of the Er:YAG laser should be considered an alternative, suitable and useful method for perform-ing apicectomy and has been shown to be effective and safe.44-46

A case of surgical resection of a root apex associated with peri-apical pathol-ogy, using the Er:YAG laser has been demonstrated, with evidence of good post-operative healing.47,48

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