Zygomatic Versus Conventional Dental Implants in Augmented Maxillae

Zygomatic Versus Conventional Dental Implants in Augmented Maxillae: a Pragmatic Multicentre Randomised Clinical Trial.

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 Overview

• Status: Withdrawn
• Conditions: Edentulous Maxilla; Resorbed Maxilla; Implant Therapy
• Intervention / Treatment: Device: Zygomatic implant placement; Device: conventional implants and augmentation of maxilla

• Study Type: Interventional
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Glasgow, United Kingdom
    • Glasgow Dental Hospital and School
  • Livingston, United Kingdom
    • St John's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• fully edentulous patients
• atrophic maxilla
• insufficient bone volume for placement of dental implants
• patients with no more than 4mm of bone height sub-antrally

Exclusion Criteria:

• general contraindications to implant surgery
• history of radiation therapy
• immunosuppressed/immunocompromised patients
• patients taking bisphosphonates
• poor oral hygiene
• patients with untreated periodontitis
• uncontrolled diabetes
• pregnancy
• alcohol/drug addiction
• lack of opposite occluding dentition/prosthesis
• restricted mouth opening.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: Zygomatic Implants; 2-4 zygomatic implants inserted into edentulous maxilla with no augmentation/grafting prior to providing patient with dental prosthesis	Device: Zygomatic implant placement
ACTIVE_COMPARATOR: Bone Graft and Conventional implants; Edentulous maxilla which is deficient in bone is first grafted using bone grafting material derived from cows and then ordinary implants are placed into the augmented jaw bone approximately 6 monhts after grafting. Patients will be provided with a dental prosthesis following osseointegration.	Device: conventional implants and augmentation of maxilla

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Implant success	Implant failure is defined by implant mobility +/- infection dictating implant removal.	1 year following implant loading
Implant success	Implant failure is defined by implant mobility +/- infection dictating implant removal	3 years following implant loading
Implant success	Implant failure is defined by implant mobility +/- infection dictating implant removal.	5 years after implant loading
Implant Success	Implant failure is defined by implant mobility +/- infection dictating implant removal	7 years after implant loading
Implant Success	Implant failure is defined by implant mobility +/- infection dictating implant removal	10 years after implant loading
Implant success	Implant failure is defined by implant mobility +/- infection dictating implant removal	15 years after implant loading

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Complications	Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis,abscess, fistula, gingival dehiscence. Prosthetic complication: abutment fracture	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.	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.	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.	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	3 years
Complications	Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis, abscess, fistula, gingival dehiscence Prosthetic complication: abutment fracture	5 years
Complications	Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis, abscess, fistula, gingival dehiscence Prosthetic complication: abutment fracture	7 years
Complications	Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis, abscess, fistula, gingival dehiscence Prosthetic complication: abutment fracture	10 years
Complications	Biologic and prosthetic complications will be assessed. Biologic complications include perimplantitis, maxillary sinusitis, abscess, fistula, gingival dehiscence Prosthetic complication: abutment fracture	15 years

Collaborators and Investigators

• Sponsor: NHS Lothian
• Collaborators: NHS Greater Glasgow and Clyde
• Investigators: Study Chair: Victor Lopes, PhD, NHS Lothian

Study record dates

Study Major Dates

• Study Start: October 1, 2013
• Primary Completion (ACTUAL): August 1, 2017
• Study Completion (ACTUAL): August 1, 2017

Study Registration Dates

• First Submitted: September 4, 2013
• First Submitted That Met QC Criteria: October 10, 2013
• First Posted (ESTIMATE): October 11, 2013

Study Record Updates

• Last Update Posted (ACTUAL): September 25, 2017
• Last Update Submitted That Met QC Criteria: September 20, 2017
• Last Verified: September 1, 2017

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Stomatognathic Diseases; Mouth Diseases; Tooth Diseases; Mouth, Edentulous
• Other Study ID Numbers: 13/SS/0106