Immediate/Early loading of zygomatic implants: clinical experiences after 2 to 5 years of follow-up.

BACKGROUND: Conventional prosthetic treatment of the edentulous and resorbed maxilla with zygomatic implants is a lengthy procedure. Today, immediate/early loading is a clinical reality and it is possible that such protocols could be used also for zygomatic implants. PURPOSE: The aim of the present study is to report on the clinical outcomes of immediate/early loading of zygomatic implants for prosthetic rehabilitation of edentulous and severely resorbed maxillary cases. MATERIALS AND METHODS: A total of 47 zygomatic and 129 regular implants were placed in 25 consecutive patients with total (N = 23) or partial (N = 2) edentulism in the maxilla. The patients had less than 4 mm of available bone height and width distal to the canine pillars. Straight and angulated abutments and impression copings were attached to the implants during surgery. Impressions and bite registrations were made and 19 patients received a bridge within 24 hours and six patients were rehabilitated within 5 days. Screw-retained full arch restorations were used in 23 patients and cemented in 2 patients. The patients were instructed for a soft diet during 4 months. Follow-up controls were performed at 1, 4, and 12 months and thereafter annually. All patients were followed for at least 2 years and up to 5 years in function. RESULTS: All zygomatic implants were stable during the follow-up (cumulative survival rate 100%). One regular implant placed in the pterygoid plate failed after 52 months of loading (cumulative survival rate 99.2%). Apart from fracture of one abutment screw and of anterior teeth in five patients, no other complications were noted. CONCLUSIONS: Within the limitations of the present study, it is concluded that immediate/early loading is a viable treatment modality for prosthetic rehabilitation of the severely resorbed maxilla using zygomatic and conventional implants.

Extrasinus zygomatic implants: three year experience from a new surgical approach for patients with pronounced buccal concavities in the edentulous maxilla.

BACKGROUND: The surgical protocol for zygomatic fixtures prescribes an intrasinus approach ideally maintaining the sinus membrane intact and the implant body inside the sinus while gaining access to the zygomatic bone. In the presence of a pronounced buccal concavity, the implant head has to be placed far from the alveolar crest in a palatal direction, which results in a bulky bridge construction. PURPOSE: The aim of this study was to report on the preliminary experiences with zygomatic implants placed with an extrasinus approach in order to have the implant head emerging at or near the top of the alveolar crest. MATERIALS AND METHODS: Twenty consecutive patients with pronounced buccal concavities in the edentulous posterior maxilla were treated with 104 regular and 36 zygomatic implants as support of fixed dental bridges. Sixteen patients were treated bilaterally and four patients were treated unilaterally. The zygomatic implants were inserted by using an extrasinus surgical approach with the implant body passing from the alveolar crest through the buccal concavity into the zygomatic bone. This enabled placement of the implant head at or close to the alveolar crest. The patients were followed from 36 to 48 months after occlusal loading with a mean follow-up of 41 months. The relation of the zygomatic implants to the crest was measured and compared with a control group of 20 patients treated with conventional placement of zygomatic implants. RESULTS: No implants were lost during the study period. No pain, discomfort, or complications related to the extrasinus path of the zygomatic implants were recorded after the initial healing period and up to the 36th-month checkup. The zygomatic implants emerged, on average, 3.8 mm (SD 2.6) palatal to the top of the crest compared with 11.2 mm (SD 5.3) to the conventional technique. CONCLUSION: The present 3-year clinical study shows that an extrasinus approach can be utilized when placing zygomatic implants in patients with pronounced buccal concavities in the posterior maxilla. Moreover, the technique results in an emergence of the zygomatic fixture close to the top of the crest, which is beneficial from a cleaning and patient-comfort point of view.

A prospective clinical study on titanium implants in the zygomatic arch for prosthetic rehabilitation of the atrophic edentulous maxilla with a follow-up of 6 months to 5 years.

BACKGROUND: Prosthetic rehabilitation with implant-supported prostheses in the atrophic edentulous maxilla often requires a bone augmentation procedure to enable implant placement and integration. However, a rigid anchorage can also be achieved by using so-called zygomatic implants placed in the zygomatic arch in combination with regular implants placed in residual bone. PURPOSE: The aim of the present study was to report on the clinical outcome of using zygomatic and regular implants for prosthetic rehabilitation of the severely atrophic edentulous maxilla. MATERIALS AND METHODS: Sixty-nine consecutive patients with severe maxillary atrophy were, during a 5-year period, treated with a total of 69 fixed full-arch prostheses anchored on 435 implants. Of these, 131 were zygomatic implants and 304 were regular implants. Fifty-seven bridges were screw-retained and 12 were cemented. The screw-retained bridges were removed at the examination appointments and each implant was tested for mobility. In addition, the zygomatic implants were subjected to Periotest (Siemens AG, Bensheim, Germany) measurements. The patients had at the time of this report been followed for at least 6 months up to 5 years in loading. RESULTS: Two regular implants failed during the study period giving a cumulative survival rate of 99.0%. None of the zygomatic implants was removed. All patients received and maintained a fixed full-arch bridge during the study. Periotest measurements of zygomatic implants showed a decreased Periotest values value with time, indicating an increased stability. Three patients presented with sinusitis 14-27 months postoperatively, which could be resolved with antibiotics. Loosening of the zygomatic implant gold screws was recorded in nine patients. Fracture of one gold screw as well as the prosthesis occurred twice in one patient. Fracture of anterior prosthetic teeth was experienced in four patients. CONCLUSIONS: The results from the present study show that the use of zygomatic and regular implants represents a predictable alternative to bone grafting in the rehabilitation of the atrophic edentulous maxilla.