Vitallium endodontic implants: a scanning electron microscope, electron microprobe, and histologic study

A 22-year follow-up of an endodontic implant

Root fractures in the middle and apical thirds of the root are treated by repositioning and for approximately 6 weeks of immobilization while those in the cervical third are immobilized for 3 months. Even though the results are good, some root-fractured teeth are lost and replaced by dental implants or fixed partial dentures. One historic but effective treatment option for those root fractures with unfavorable crown to root ratios is an endodontic implant in middle and apical third root fractures. This method offers immediate stable fixation of a crown and its coronal root segment to the underlying alveolar bone. This report documents the long-term survival of a tooth treated with an endodontic implant. A 25-year-old male patient presented following a bicycle accident with a dislocated unfavorable root fracture in the middle third. The crown with the coronal root segment was secured to the bone using a commercially available endodontic implant. The apical part of the root was removed. Although the clinical and radiological follow-up results of the endodontic implant demonstrated a good clinical function and little bone loss, the implant ultimately had to be removed after 22 years of service due to pain and increasing mobility.

Histological response to titanium endodontic endosseous implants in dogs

Endodontic endosseous implants stabilize teeth that have crown-root ratios compromised by periodontal disease, trauma, or apical resorption. By increasing the crown-root ratio, the implant improves the prognosis of the tooth, thus increasing its longevity. The purpose of this study was to evaluate, in vivo, the healing response to a newly introduced titanium endodontic implant. Eight implants were placed in the maxillary incisors and mandibular premolars of two adult beagle dogs after completion of root canal and osseous preparation. Peri-implant tissues were examined radiographically and histologically at 6 months postinsertion. Radiographically, the periapical area and tissue surrounding the implants seemed normal. Histologically, fibrous connective tissue and healthy bone intimately surrounded the implant. Epithelium or chronic inflammatory cells were not observed along the length of the implant. These findings suggest that titanium is a biocompatible metal when used as an endodontic endosseous implant.

Resection of a sapphire endodontic stabilizer due to perforation of the maxillary sinus: report of a case

A case is presented which involved resection of a sapphire endodontic stabilizer in a maxillary cuspid. This was necessary due to its perforation of the maxillary sinus. The implant was not readily identifiable upon viewing the preoperative radiograph and could only be resected using a diamond bur. Because of its limited degree of radiopacity, the use of sapphire as a material for endodontic stabilizers may be questioned from a diagnostic standpoint.

Threaded versus porous-surfaced designs for implant stabilization in bone-endodontic implant model

An endodontic implant model system was used to compare the effect of implant design on stabilization in bone. Specifically a porous-surfaced design was compared to conventional threaded and smooth-tapered endodontic implant designs. All implants were placed in immediate function thereby assessing the effect of early limited movement on the fixation achieved. A total of eighty-three endodontic implants were inserted in the mandibles of six adult mongrel dogs. Animals were sacrificed immediately after implantation and after 3, 6, and 12 months. Implants were evaluated by clinical and radiographic examination and after animal sacrifice by pull-out tests of the implant from the tissues, SEM examination of the pulled-out implants and, finally, histology. The pull-out test results indicated increasing shear strength with implantation time for the porous-surfaced implants in contrast to the gradual loss of fixation for the threaded implants and the continuous low shear strength for the smooth implants. Histological studies and SEM examination indicated the reason for these changes. Smooth implants became encapsulated by fibrous connective tissue from early post-implantation time periods. Threaded implants, although initially mechanically interlocked with bone, developed a fibrous connective tissue capsule that gradually thickened with time until, by 6 months, little mechanical interlock of bone and implant was present. It was assumed that this fibrous capsule thickening was caused by implant movement. The porous-surfaced implants, however, became stabilized by bone ingrowth and showed more extensive bone formation within the surface pores with time. It is concluded that for implants that are made functional immediately after implantation, as in this study, porous-surfaced implants can become strongly fixed by bone ingrowth, in contrast to conventional threaded or smooth-surfaced designs, thus presenting a more favourable long term prognosis.

Evaluation of the apical seal obtained with endodontic implant stabilizers and different cementing materials

Preliminary research was conducted to evaluate in vitro the apical seal obtained with endodontic implant stabilizers in conjunction with four different cement sealers. Standard laterally condensed gutta-percha cones and sealer were used as a control. Apical leakage was measured with the use of methylene blue dye solution. Gross leakage patterns resulted from endodontic implants cemented with both zinc phosphate and polycarboxylate. However, leakage appeared notably reduced when the implants were cemented with cyanoacrylate and Kerr Tubli-Seal. Statistical analysis showed that the lateral condensation of gutta-percha cones and sealer yielded the largest proportion of favorable results. Even so, none of the techniques employed was totally effective for obtaining a hermetic sealing of the root canal.

Experimental apical scars in rats

In order to study the etiology of apical scars, vitallium implants were placed in four intra-maxillary and mandibular cavities of Sprague-Dawley rats. After one month the implants were removed. In half of the cavities, which were selected as experimental cavities, bleeding was avoided. In the others, the walls of the cavities were perforated in several places to induce formation of a good-quality clot. These specimens were identified as control cavities. Animals were killed on day 0 and on the second, fourth, eighth, sixteenth, twenty-eighth, and fifty-sixth days after implant extraction. The jaws were isolated and, after fixation, decalcification, and routine procedure for paraffin sections, studied under the light microscope. In the experimental cavities, the bone healing was delayed. Apical scars occurred, even when one of the two cortical bone plates remained intact. Delayed healing has been associated with the absence of a good-quality clot and with the presence of a sequestrum or suture threads in the wound. The proximity of the central nervous system or of a nerve where the cavity was prepared often leads to a delayed bone healing. The interposition of muscle fibers and the proliferation of collagen from the gingival chorion or from the periodontal ligament lead also to collagenous scars.

A new implant philosophy

This form of tooth implant appears to exhibit great potential since it eliminates the disorganized connective tissue layer present at the implant/bone interface of most other devices. Also, as established for other implants, as long as a tight cuff of relatively immovable tissue exists around the polished cervical collar of an implant, an effective seal against the ingress of oral fluid and toxic irritants appears to be maintained, although the nature of this seal has yet to be determined. In addition, the epimobile superstructure serves to dissipate occlusal stress on the "ankylosed" implant. The prognosis of an implant is determined in part by its associated superstructure. There is a need for research into the loading that can be accommodated by an implant. Further study is required to ascertain the full potential of this implant system.

A combined post, core, and endodontic endosseous implant. Case report

A hyperextended chrome-cobalt post and core also used as an endodontic endosseous implant served to stabilize a short mobile root and to provide for placement of a porcelain veneer metal crown. The technique is not complicated and does not require instruments other than those for routine endodontic treatment and for the construction of the post and core.

MP35N: a corrosion resistant, high strength alloy for orthopedic surgical impants: bio-assay results

A cobalt based alloy, MP35N, with excellent mechanical properties has been recently introduced as a material for surgical orthopedic implants. A study was made of local and systemic host response to this material in two different mammal species. The implantation time ranged from one to 12 months. The result of this study indicated: MP35N produces a degree of local tissue response comparable to that of 316L stainless steel. No systemic side effects were observed during the implantation times included in this study.