ArticlesDental implantation in complicated conditions

Dental implantation in complicated conditions

O. Doroshenko V. Klimentyev

Partial and total loss of teeth is one of the most common pathologies of teeth-jaw system, especially in the elderly patients. Presently, common method of replacement of defects of dentition using traditional methods of prosthetics, namely the manufacture of partial and full removable dentures is not always satisfactory for patients.

From this point, the manufacture of orthopaedic structures supporting upon the dental implants is more prospective.

Very often the tooth loss is accompanied by significant atrophy of alveolar process and complex anatomical topographical conditions, and the installation of dental implants is becoming a rather difficult problem.

At present, there are the following possible options for carrying out dental implantation in complicated anatomical topographical conditions of the lower jaw:

  • the use of implants (subcortical, disk, transosseous), which is accompanied by a considerable number of complications;
  • subperiosteal implantation;
  • the use of methods of circumventing the anatomical obstacles;
  • use of the method of bone regeneration;
  • bone grafting;
  • transposition of the mandibular nerve, which allows to create optimal conditions for the installation of implants, but there is a risk of damage to the sheath of the nerve and its axis.

Recently in the literature appeared the data on the successful functioning of immediately loaded and functioning implants in patients with toothless jaws. Immediate implantation combines two surgical steps in one - tooth removal and implants installation carried out simultaneously and prevents the alveolar bone resorption. In this operation, the implant can be placed in an ideal position, close to the position of the removed tooth in the most favourable for perception of masticatory loads on the supporting bone.

Immediate implantation compensates the patient's negative psychological effect because of the removal of teeth, especially when they are the last teeth in the jaw. In addition, the patient can almost instantly start using dentures, not after the long period after removal of teeth and use of classic implants. The number of visits to a dentist and the cost of treatment are reduced as well.

The stability of the implant and prediction of its functioning is the better the larger the bone-implant contact area.

At present, there is no unified opinion and approved clinical protocol, which defines the length and diameter of the implant to replace a tooth.

Quite often after the atrophy of the alveolar ridge, the position for the installation of implants becomes very problematic because of the thin alveolar crest or nearby anatomical structures, namely the inferior alveolar nerve. Nerve dysfunction can occur with direct trema perforation and trauma during the formation of the implant bed as well as through the compression of the nerve with postoperative swelling or dental implants. These difficulties are manifested in the form of absence or prolonged changes in sensitivity of the tissue in the area of innervation, development of pain of varying intensity, but also accompanied by emotional stress disorders and greatly affects the quality of life of the patient.

The location of the 10 mm implant in the case of atrophy of the alveolar ridge is problematic, and the use of short implants (length: 5 7-8.5 mm) leads to a large number of complications. As for small diameter implants (3.75 mm), their use is limited by specific criteria, but at present there is not sufficient scientific works with long term observation on the efficiency of their use.

Only careful planned surgical intervention with the holding of computed tomography and making surgical templates can provide a lack of complications during surgery in the case of installation in the side area of the dental implants bypassing the mandibular nerve.

A high percentage of complications during dental implantation on the lower jaw with complex anatomical topographical conditions with the aim of making fixed orthopaedic designs indicates insufficient study of the problem and the results of the studies do not have a single evaluation.

Therefore, the aim of our study was conducting the rehabilitation of patients with complicated anatomical topographical conditions of toothless lower jaw by using proposed algorithm of surgical dental implantation.

Patient S., born in 1960, applied to the clinic with complaints of missing teeth on the lower jaw with the aim of establishing a permanent orthopaedic structure with support on implants. Patient's medical history indicated prolonged use of the partial removable denture.

On the opposite jaw – metal-porcelain non-removable prosthetic appliances with support on teeth 1 6, 1 4, 1 3, 1 2, 1 1, 2 1, 2 2, 2 3, 2 4 and 2 7.

In order to determine the possibilities of making removable prosthetic constructions with support on dental implants the computed tomography was carried out (Figure 1).

In EDC Computed tomography of the lateral area of the lower jaw before treatmen Computed tomography of the lateral area of the lower jaw before treatmen

 

Fig. 1. Computed tomography of the lateral area of the lower jaw before treatment

This study demonstrated patient having I type of the bone tissue by Lekholm and Zarb classification.

In the lateral area, where it is planned to install implants, alveolar crest is 10.63 mm wide and 12.60 mm high. The distance from the cortical plate to the mandibular trema is only 4.84 mm.

The decision was made to install non-removable orthopaedic structure supported by 8 implants.

In this clinical case installation of implants in the lateral are bypassing the mandibular trema is only possible under conditions of computed tomography with the establishment of the precise location of the trema and the subsequent production of surgical navigation template.

Dental implantation operation was virtually planned in the DDS-Pro programme for CT, with models scan and wax-up. In the distal parts of the lower jaw spiral one-stage implants were installed with cortical fixation bypassing the mandibular trema, and the front section underwent root-like implantation with intraosseus screw part. The length of the intraosseous part of all implants – 10 mm, thickness – 3.0 mm.

After installing the implants, the computed tomography was carried out in order to confirm the correct placement of implants (Fig. 2, 3).

In EDC CT after installing the implants - right side CT after installing the implants - right side In EDC CT after installing the implants – left side CT after installing the implants – left side

А

B

 

CT after installing the implants (A - right side, B – left side)

In EDC CT after installing the implants - central area

 

CT after installing the implants - central area

Right side CT after installing the implants

Right side CT after installing the implants in EDC

А

B

Fig. 3. CT after installing the implants (A - central area, B – right side)

Conducted surgical step of dental implantation involved the immediate functional loading of temporary non-removable combined denture with plastic coating, which the patient was able to use within 3 days after the performed surgery. A sufficient number of implants of significant length, practical compliance of the denture axes and implants virtually eliminates the occurrence of such risks as decreasing reliability of the denture retention, fracture of the implant and inadequate functional load on them.

The effectiveness of the treatment was determined by clinical and radiographic criteria (Albrektsson and coll).

Postoperative period proceeded without complications, the mucous membrane condition around the implant is satisfactory. No complaints were submitted by the patient.

The patient was clinically determined the stability of implants, the lack of negative manifestations at percussion, lack of pain infectious syndrome around the implants and the absence of paraesthesia.

The clinical picture on the second day after the implantation in EDC

The picture on the second day after the implantation in EDC

Fig. 4. The clinical picture of the mouth on the second day after the implantation

 

Immediate prosthesis on the third day after the surgery

With temporarily non-removable metal and plastic structure
Fig. 4.1. Immediate prosthesis on the third day after the surgery with temporarily non-removable metal and plastic structures.

 

Radiologically, during the entire period of observation, the lack of bone resorption and a minimum loss of bone tissue during the functioning of the implant around intraosseous part of implant were determined (Fig. 5)

 

OPG before dental implantation

OPG before dental implantation

OPG 3 days after the implantation

OPG 6 months after the installation of implants

OPG 3 days after the implantation

OPG 6 months after the installation of implants

 

Fig. 5. Radiological studies before and at the set time after the performed dental implantation

Similar data were obtained during the conduct of a CT in 6 months

CT scan after 6 months сentral area in EDC Central area CT scan after 6 months

CT scan after 6 months - right areaa

A Central area

B Right area

Left area CT scan after 6 months

C Left area

Fig. 6. CT 6 months after implant installation (A - central area, B - right lateral side, C - left lateral side of the alveolar ridge)

 

After 6 months of using the temporary structure, the patient received the fixed permanent non-removable combined structure with the support on dental implants.

Therefore, careful planning of surgical intervention with the computed tomography carried out has ensured the lack of complications during surgery in the installation of one-stage root-like implants: in the lateral area - bypassing the mandibular nerve, and in the central area - in the wells of the deleted teeth.

This minimally invasive technique may be applied in patients who seek to reduce the number of surgical interventions, reduce the number of visits to a dentist and the duration of treatment with the possibility to use non-removable orthopaedic structure immediately after installation of dental implants.

Bibliography:

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  2. Gracheva O. V. Differential Approach to the Treatment of Dental Implant Complications Associated with Dysfunction of the Inferior Alveolar Nerve / O. V. Gracheva, O. M. Panin, O.N. Moskovets // Clinical Dentistry - М., 2009. - No. 4(52) p. 24- 26
  3. Frank Renouard Risk Factors in Dental Implantology / Renoir Frank, Rangert Bo // M. – 2004, 182 p.
  4. Albrektsson T. A New Approach to Demonstrate Cellular Activity in Bone Formation Adjacent to Implants / T. Albrektsson // J. Biomed. Mater. Res. – 2000. – N. 51. – P. 280 – 291.
  5. Hegedus F. ; Trigeminal Nerve Injuries after Mandibular Implant Placement - Practical Knowledge for Clinicists / F. Hegedus, R. Diecidue // Int. J. Oral Maxillofae Implants. - 2006. – N. 21 (1). - P. 111 – 116.