Dental implants are used for replacing missing teeth. Placing dental implants is limited by the presence of adequate bone volume permitting their anchorage. In order to solve this problem several bone augmentation procedures have been developed. In principle the missing bone is taken from a donor site (for example the hip), transplanted where needed and then implants are placed. Sometimes, major bone grafting operations have to be undertaken under general anaesthesia requiring patients to be hospitalised for a few days. Some degree of morbidity related to the donor site must be expected, though more recently bone substitutes are used to minimize morbidity, and 2 to 3 surgical interventions may be needed before the implants can be functionally used. Sometimes patients have to wait more than 1 year before a prosthesis can be fixed to the implants and the total cost of the treatment is high. At the beginning of the 1990s a long screwshaped implant was developed by Professor PI Brånemark as an alternative to bone augmentation procedures: the zygomatic implant. Zygomatic implants are generally inserted through the palate to engage the body of the cheek bone. One to three zygomatic implants can be inserted through the posterior palate to engage the body of each cheek bone. The potential main advantages of zygomatic implants could be that bone grafting may not be needed and a fixed prosthesis could be fitted the same day of their placement. Despite that zygomatic implants have been used for more than 20 years, their effectiveness has never been compared with conventional dental implants in augmented maxillae. The aim of the project is to compare the longtermclinical outcome of fullarch upper jaw bridges supported by zygomatic implants versus conventional implants placed in augmented bone in the palate.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Glasgow Dental Hospital and School
Glasgow, United Kingdom
St John's Hospital
Livingston, United Kingdom
Implant success
Implant failure is defined by implant mobility +/- infection dictating implant removal.
Time frame: 1 year following implant loading
Implant success
Implant failure is defined by implant mobility +/- infection dictating implant removal
Time frame: 3 years following implant loading
Implant success
Implant failure is defined by implant mobility +/- infection dictating implant removal.
Time frame: 5 years after implant loading
Implant Success
Implant failure is defined by implant mobility +/- infection dictating implant removal
Time frame: 7 years after implant loading
Implant Success
Implant failure is defined by implant mobility +/- infection dictating implant removal
Time frame: 10 years after implant loading
Implant success
Implant failure is defined by implant mobility +/- infection dictating implant removal
Time frame: 15 years after implant loading
Complications
Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis,abscess, fistula, gingival dehiscence. Prosthetic complication: abutment fracture
Time frame: 1 year
Change in marginal bone levels on intra oral radiographs
To be evaluated on intraoral radiographs taken with the paralleling technique at implant placement, at delivery of the provisional prostheses, 1, 3, 5, 7, 10 and 15 years after loading.
Time frame: 1,3,5,7,10,15 years
Failure of augmentation procedure
The augmentation procedure will be considered a failure if, after it has been performed, it will not be possible to place the planned implants in the augmented site.
Time frame: 6 months after augmentation procedure
Change in Oral Health impact profile OHIP-14
To be filled in i)at patient enrolment prior to delivering any interventions, ii)12 weeks after delivery of the definitive prostheses and iii) 1, 3, 5, 7, 10 and 15 years after loading. Patients' number of days with total or partial impaired activity assessed at delivery of the provisional prosthesis A days of total impaired activity is one where patient is unable to perform his/her ordinary life activity including work. A days of partial impaired activity is one where the patient is only partially able to perform his/her ordinary life activity including work.
Time frame: 1,3,5,7,10,15
Complications
Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis, abscess, fistula, gingival dehiscence Prosthetic complication: abutment fracture
Time frame: 3 years
Complications
Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis, abscess, fistula, gingival dehiscence Prosthetic complication: abutment fracture
Time frame: 5 years
Complications
Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis, abscess, fistula, gingival dehiscence Prosthetic complication: abutment fracture
Time frame: 7 years
Complications
Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis, abscess, fistula, gingival dehiscence Prosthetic complication: abutment fracture
Time frame: 10 years
Complications
Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis, abscess, fistula, gingival dehiscence Prosthetic complication: abutment fracture
Time frame: 15 years
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