//第3期：Clinical Application of HA-coated Implants
<President, Mizukami Dentl; Clinical Professor, kyushn University School of Dentustry>
Negative images were popular as to HA-coated implants until recently. This is based on the reflection into peri-implantitis caused by the detachment of the HA coating layer.
Howerver, HA-coated implants have recently been improved, and implant therapy utilizing their high osteoconductivity has been applied frequently during clinical practice. In the paper, we have presented the examples of clinical application of HACEX implant（one of the HA-coated implants）.
Indications of HA-coated implants and essential points in their selection
The greatest advantage of HA-coated implants is their ability to achieve early integration owing to high osteoconductivity. Yamamichi et al. also reported that the survival rate for this type of implant was high in the long-term follow up of implants inserted after maxillary sinus elevation surgery. This type of implants having this feature are suitable for those with type 4 poor bone quality in the vicinity of maxillary sinus floor elevation surgery, socket preservation, and immediate placement after tooth extraction. In addition it is also suitable for the case requiring early recovery after implants loss. Cases for which HA-coated implant is suitable under these unfavorable conditions or requiring early in-regulation are presented below.
A case of sinus elevation while avoiding blood vessels
Outline of the case
The patient by another clinic with a desire to set attachment of fixed prosthetic appliance to 76. He had no noteworthy disease history. After consultation over elevation for this patient and to insert an implant in 76.
Selection of surgical procedure
Preoperative examination revealed that the bone wall off the maxillary sinus floor in the region 76 was inadequately thick (5 mm or less), indicating the necessity of the sinus floor elevation. However,dental X-ray and CT scans revealed the presence of blood vessels within the bone about 10 mm from the alveolar ridge. Of the various approaches available for sinus elevation, we selected an approach from the alveolar ridge for subsequent vertical elevation of the fenestrated bone wall.
Application of surgical procedure
The alveolar wall around 6 7 was walled off with a round bur or fissure bur in an approximately ractangular form to a range not exceeding the buccolingual angle of the alveolar ridge. Cutting off the bone wall was made to a point immediately before the Schneider membrane. After the formation of an approximate form, BOSTOME was driven into induce fracture towards the sinus. Whole freeing the surrounding mucosa, each bone piece was lifted upwards within the sinus. After elevation to an appropriate height, bone transplantation of an appropriate amount of bone, an HA of which top portion was soaked with PPP was inserted as a membrane substitute and the wound was closed. About 6 mounths after sinus lift, bone regeneration was confirmed, and the implant was inserted. 5 mounths after implant insertion, a provisional crown was set, and the final prosthetic appliance (HACEX37-10ST-M) was set about 2 mounths later.
A case undergoing recovery immediately after the loss of the implant
The 2 major factors responsible for the loss of the implant after the initial stage are peri-implantitis and occlusive injury. Inappropriate form of the prosthetic appliance, occlusal trauma, and the presence of malfunction can cause loss of implant integration. If such a situation arises within 5 years after the set of the final prosthetic appliance, or during the application of temporary prosthetic appliance in some cases, the dentist may lose trust from the patient. Unfortunately if such case happened, only immediate rescue action could get recover the trust for the patient. If bone resorption is not sever and poor granulation can be removed easily, one possible option is to insert a new implant immediately after pulling off the failed implant. In such cases, an Ha-coated implant can get early integration and this is its advantage.
Outline of the case
The patient was a female and 55 years at first visit. She consulted our clinic with a desire of receiving total oral management. She had an implant inserted into 6 4. Overall treatment was completed without any problems and she began to receive periodical follow up. During her visit at 5 months after the end of treatment, she complained of discomfort and slight mobility in 4. Dental X-ray revealed inversely under anesthesia, it rotated with slight resistance. Hence, it was retrived.
Curettage was performed after the withdrawal of the fixture. Because pulling was performed at relatively early stage, the amount of granulation tissue was not large. After curettage with a bone curette and removed off soft tissue with laser, we judged re-insertion to be possible. Then, a cavity for insertion was created with a final drill and placed new implant. Initial fixation was good. Accordingly, a custom healing abutment was set to wait for integration. 3 months later, a prosthetic appliance was set . At the periodical check 6 months later, no problem was found.
A patient undergoing socket preservation
Outline of the case
The patient was a female and 45 years at first visit. She desired to receive periodontal treatment. She had no noteworthy disease history. Examination allowed a judgment that the 4 is indicated for extraction because of a broken root. Because the patient did not desire cut out of 3, she wanted to receive insertion of an implant into that region.
Course of treatment
After extraction of 4, soft tissue was removed carefully. After fresh bone surface was exposed, -TCP was inserted by compression. Subsequently, the entrance into the cavity created by compression. Subsequently, the entrance into cavity created by tooth extraction was closed and then set a pontic. Mucosa was treated rapidly. 3 months later, an implant was inserted into that region. Bone regeneration was excellent, and adequate initial fixation was achieved, enabling subsequent insert of the implant (HACEX37-12TP-S). 5 months later, laser punch-out was performed were then taken and the final prosthetic appliance was set 10 months after implant insertion.
A case undergoing implant insertion immediately after tooth extraction
Outline of the case
The patient was a female 44 years at first visit. She desired to receive treatment for dental caries. Basic periodontal treatment of caries of the entire mouth were first provided. Towards the end of treatment, she complained of sudden pain after ingestion of hard food. Examination at that time revealed a breakage line exceeding the tooth root center. Several therapeutic strategies were presented to the patient. The patient desired repair with an implant.
Selection and application of surgical procedure
Preoperative CT scans revealed a fracture line running from the center of the tooth root to the labial side. At the same time, very thin bone wall on the labial side was also revealed. Because breakage had occurred very recently and because bone resorption around the root was small, we selected implant insertion immediately after tooth extraction. Prior to tooth extraction, extrusion was performed. After freeing and reversion of a full-thickness flap, the tooth was extracted, followed by curettage within the cavity created by tooth extraction. The cavity for insertion was formed, with much care paid to the location and direction of insertion. HACEX42-12TP-S was selected as a fixture. The space between the fixture within the tooth cavity and the labial bone wall was filled with -TCP. HA(Osteograft-S) was filled into the lateral side of the labial bone, and a Colla-tape was placed lateral to the HA to ensure stabilization. 3 months after insertion, laser punch-out was performed, and a provisional crown was set. 3 months later, the final prosthetic appliance was set.
In the abovementioned cases where the implant was applied under unfavorable conditions, the selection of HA-coated implant as the first-line product resulted in a good outcome. Among others, high initial success rate, particularly at the stage of acquisition of integration, makes this approach reliable. To date, complications related to peri-implantitis (often observed with conventional HA-coated implants) have been revealed in almost no case during periodical maintenance. Thus, the course after insertion has been favorable. We plan to continue implant therapy making use of anode oxidation and HA.
Long-term evaluation of implant survival in augmented sinuses: a case series.
Yamamichi N, Itose T, Neiva R, Wang HL.
Int J Periodontics Restorative Dent. 2008 Apr;28(2):163-9.