Implant Placement Through Impacted Teeth: A Report of Two Clinical Cases

INTRODUCTION

Impacted teeth are commonly found, with the highest incidence in third molars, followed by canines. For younger individuals, orthodontic alignment of impacted teeth is recommended; if not feasible, extraction is indicated. In adults, more predictable treatments like surgical removal followed by grafting are preferred.^[1] Surgical removal of the impacted tooth involves extensive damage to the implant site that has to be then rehabilitated and grafted, followed by a healing period before implant placement. This would delay the implant restoration insertion by at least 6 months.^[2] Ferguson et al. have reported that unless the impacted teeth are symptomatic, there is no need for surgical removal.^[3]

Davarpanah and Szmukler-Moncler suggested a treatment modality that avoids traumatic removal of impacted teeth. They reported that insertion of the implant through the impacted tooth itself may be done to facilitate prosthetic rehabilitation.^[4]

Clinical stability was not compromised when implants were placed through impacted teeth, and interfaces other than the implant-bone interface were created. This resulted in uneventful hard tissue repair.^[1,4] Since its introduction by Davarpanah and Szmukler-Moncler, several reports support this treatment method.

Recent in vitro and animal studies have demonstrated that the hydrophilic surface of SLA (Sand blasted, Acid etched) titanium implants significantly enhances cell differentiation and growth factor production, affecting both soft and hard tissue integration.^[5,6]

This manuscript presents two cases where implants with having hydrophilic SLA surface were placed through impacted teeth without surgical removal, offering a less invasive alternative to traditional surgery.

CASE REPORT

Case 1

A 45-year-old male presented with a missing upper left central incisor [Figure 1] and an impacted canine on radiographic examination. Initially offered extraction of the canine and delayed implant placement, but the patient declined. Instead, an alternative plan was proposed of placing an implant through the impacted canine, followed by prosthetic rehabilitation.

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Figure 1:

Missing left central incisor.

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DICOM data from CBCT and STL data from an intraoral scan (Carestream Dental LLC, Atlanta, USA) were merged for implant planning using an implant planning software (coDiagnostiX®, Dental Wings Inc., Canada) [Figures 2 and 3]. A surgical guide was prepared, and using guided surgery, a BLX implant (Institute Straumann AG, Basel, Switzerland) of 10 mm length and 4.0 mm diameter [Figure 4] was inserted with high primary stability (45 Ncm). There was a slight variation in the drilling protocol as compared to conventional drilling, wherein the speed of the drill was increased to 1200 rpm with copious saline irrigation. The peri-implant buccal bone defect was grafted with a 50:50 mixture of autogenous bone chips and Cerabone® (Botiss biomaterials GmbH; Zossen, Germany), and an interim fixed provisional was delivered to the patient. The implant site was allowed a healing period of four months.

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Figure 2:

CBCT images of the patient (1). CBCT: Cone beam computed tomography.

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Figure 3:

CBCT image of the patient (1). CBCT: Cone beam computed tomography.

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Figure 4:

Implant placed at the central incisor site.

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After six weeks of healing, a provisional was placed. Soft tissue contours were developed with a provisional restoration, and after four weeks of its placement, an intraoral scan was recorded. The final restoration-a multi-layered Zirconia crown (IPS E.max ZirCAD Prime (Ivoclar Vivadent, Schaan, Liechtenstein) [Figure 5] bonded to a titanium base abutment (Variobase, Institut Straumann AG, Basel, Switzerland) was delivered. The patient was satisfied with the treatment outcome.

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Figure 5:

Final restoration of the missing (impacted) central.

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Case 2

A 50-year-old male presented with missing teeth 31, 41, and 42. Radiographs revealed an impacted mandibular canine in the 43 region [Figures 6, 7, and 8]. The patient had a previous implant with 3 mm bone loss and declined orthodontic or surgical extraction of the impacted tooth.

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Figure 6:

OPG of the patient with impacted mandibular canine. OPG: Orthopantomogram.

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Figure 7:

CBCT images of the patient (2) with impacted canine. CBCT: Cone beam computed tomography.

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Figure 8:

CBCT image of the patient (2). CBCT: Cone beam computed tomography.

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An alternative treatment involving placing an implant through the impacted tooth, followed by a fixed dental prosthesis (FDP), was discussed with the patient and met his approval. Using a standard drilling sequence, a 12 mm length, 3.5 mm diameter Straumann BLX implant (Institute Straumann AG, Basel, Switzerland) was placed through the impacted canine [Figure 9] and allowed to heal for 2 months.

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Figure 9:

Implant placed through the impacted canine.

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A provisional restoration was used to develop soft tissue contours. After healing, an intraoral scan (Carestream Dental LLC, Atlanta, USA) was taken for fabrication of a multilayered Zirconia (IPS E.max ZirCAD Prime (Ivoclar Vivadent, Schaan, Liechtenstein) [Figure 10], which was then cemented.

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Figure 10:

Final restoration of the missing (impacted) canine.

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The patient received post-care instructions, and follow-up visits showed he was satisfied with the treatment outcome.

DISCUSSION

The third molar is the most commonly impacted tooth in the oral cavity, followed by the canine.^[7] Mazor et al. have reported that the impaction rate for mandibular canines is in the range of 0.07% to 1.3%, and for maxillary canines it ranges from 1% to 3%.^[2]

Maxillary canine impaction is common because it travels the longest distance to reach occlusion. Once the root apex closes, the tooth loses its ability to erupt.^[7] One rehabilitation method of impacted teeth is extraction, but if the tooth is deeply impacted, surgical removal can create a large defect requiring reconstruction.^[4]

Surgical removal of impacted teeth in adults, though the gold standard, is invasive, time-consuming, and often has low patient acceptance. Placing dental implants through the impacted teeth is suggested as a reasonable alternative.^[3,4]

A 2021 systematic review by Pérez-González et al. analysed ten studies on implants placed through impacted teeth, reporting a 90.32% overall implant survival rate, 97.56% success for implants through impacted teeth, and 76.19% through residual roots.^[8]

Nevins et al. reported that placing implants through impacted teeth is more successful than through root fragments, as impacted teeth are free from oral environment exposure and infection risks.^[9]

Davarpanah et al. reported several advantages of this protocol: avoiding extensive surgery and grafting, preserving bone architecture for more predictable results, shortening treatment time, and increasing patient acceptance.^[1]

Ideal conditions for placing implants through impacted teeth would include fully impacted teeth covered by at least 5mm of bone and soft tissue with an absence of associated pathology. Also, the operator should avoid the pulp of the impacted tooth during placement.^[9]

In the case series documented here, the implants used had an active thread design with a hydrophilic implant surface, known to promote faster osseointegration.⁵ Additionally, they have been found to be of benefit in areas where cortical bone present is minimal or not of the best quality.^[5,6,10,11] The use of implants with these features can potentially further increase the possibility of successful outcomes in these situations. The patient cases presented here have been followed up every six months following treatment, with no adverse effects so far.

The limitation of the case series is the limited number of cases (only two) in the present report.

A randomised study with a higher sample size, longer follow-up should be carried out to get better insight into the placement of the implant.

CONCLUSION

This protocol shows promise for restoring teeth in areas with impacted teeth, despite limited documentation. There are not many articles on the subject, and clinicians are frequently faced with a puzzle of an impacted tooth present in a future implant site. Further well-designed clinical trials are needed better to understand its effectiveness in edentulous sites with impacted teeth.