An interventional study of Multi-unit Abutments Xeal™ with Nobel TiUltra™ implant Parallel CC and Conventional titanium multi-unit abutments with Nobel TiUltra™ implant Parallel CC in Edentulism, Dental Implant and Prosthetic Abutment, sponsored by Kutahya Health Sciences University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-23.
Sponsored by Kutahya Health Sciences University · Not applicable, Interventional, and Treatment
The placement of dental implants has been a routine procedure for the rehabilitation of fully or partially edentulous patients for nearly 40 years. Dental abutments are intermediary components that connect prosthetic teeth to the implants after healing. Depending on the properties of the abutment material, plaque accumulation and bacterial adhesion may lead to inflammation and bone loss in peri-implant tissues. Developed by Nobel Biocare, the Xeal™ abutment surface protects the underlying bone, supports stable soft tissue integration, and has been shown to reduce marginal bone loss and promote healthier mucosa compared to machined abutments. However, previous studies have mostly relied on clinical and radiographic evaluations, without three-dimensional evaluation or microbiological analysis. This study aimed to evaluate peri-implant marginal bone loss (MBL), digital evaluation of peri-implant soft tissue, and differences in the microbial composition of the oral microflora colonizing the soft tissue/abutment interface between Multi-unit Abutments Xeal™ and conventional titanium multi-unit abutments placed in the posterior region.
The study will include 44 patients (88 implants) with tooth loss in the maxillary or mandibular posterior region, for whom implant-supported fixed prostheses (supported by two implants each) are planned. These two-unit, splinted, implant-supported bridges will utilize two different types of abutments. Each implant will be randomly assigned to either the control group or the test group using the sealed-envelope method.
All patients will undergo the same surgical procedure and receive the same type of dental implant, in accordance with the established protocol. For the placement of both provisional and definitive fixed prostheses, multi-unit abutments with a "Xeal™" surface will be used for the test group, while titanium multi-unit abutments will be used for the control group.
Prior to surgery, clinical measurements will be recorded, and the peri-implant soft tissues will be digitally scanned using an intraoral scanner (IOS). For both abutment groups, the thickness and width of the keratinized mucosa, as well as the implant placement site, will be measured digitally with the aid of an intraoral scanner (IOS). Before and during the dental implant procedure, the bone thickness around the implant site-in the mesial, distal, buccal, and lingual/palatal directions-and the height of the supracrestal tissue will be recorded.
The dental implants will be placed, and the multi-unit abutments will be tightened to the appropriate torque values. Primary and secondary stability values for the implants will be measured via the multi-unit abutments.
Subsequently, provisional fixed prostheses will be fabricated. After 3 months, the definitive prostheses will be constructed.
For the purpose of radiographic evaluation; Standard periapical radiographs will be taken postoperatively (Tb), immediately after prosthetic loading (T0), and at 1 month (T1), 3 months (T2), 6 months (T3), and 1 year (T4). Marginal bone loss (MBL) will be assessed using measurements taken from these standard periapical radiographs with the aid of software throughout the one-year follow-up period. Following the surgery-at time points T0, T1, T2, T3, and T4-digital soft tissue assessment will be performed using an intraoral scanner (IOS), clinical parameters will be recorded, and subgingival microbial samples will be collected from the deepest pocket area of each implant.
Kutahya Health Sciences University is the lead sponsor of 216 studies on the registry; 49 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion criteria:
According to the protocol, each patient will receive two Nobel TiUltra™ implant Parallel CCs, with one implant being fitted with a Conventional titanium multi-unit abutment.
Device: Conventional titanium multi-unit abutments with Nobel TiUltra™ implant Parallel CC
According to the protocol, each patient will receive two Nobel TiUltra™ implant Parallel CCs, with one implant being fitted with a Multi-unit Abutments Xeal™.
Device: Multi-unit Abutments Xeal™ with Nobel TiUltra™ implant Parallel CC
All implant surgeries will be performed under local anesthesia. A midcrestal incision will be made with a 15C blade, followed by careful elevation of a full-thickness flap. Implant insertion will be carried out according to the manufacturer's instructions, and a Nobel TiUltra™ implant will be placed 0.5-1 mm subcrestally. Following implant placement, primary implant stability will be measured using the Osstell device. Non-engaging temporary abutment will be placed for fabrication of the temporary fixed prosthesis, which will be constructed approximately 1 mm infraocclusally. The flap will be closed primarily. After 12 weeks, the temporary prosthesis will be removed and secondary implant stability will be assessed with an Osstell device. Impressions will be taken at the abutment level, and a permanent metal-supported porcelain fixed prosthesis will be fabricated and screwed onto the Multi-unit Abutments Xeal™ with a torque of 15 Ncm.
All implant surgeries will be performed under local anesthesia. A midcrestal incision will be made with a 15C blade, followed by careful elevation of a full-thickness flap. Implant insertion will be carried out according to the manufacturer's instructions, and a Nobel TiUltra™ implant will be placed 0.5-1 mm subcrestally. Following implant placement, primary implant stability will be measured using the Osstell device. Non-engaging temporary abutment will be placed for fabrication of the temporary fixed prosthesis, which will be constructed approximately 1 mm infraocclusally. The flap will be closed primarily. After 12 weeks, the temporary prosthesis will be removed and secondary implant stability will be assessed with an Osstell device. Impressions will be taken at the abutment level, and a permanent metal-supported porcelain fixed prosthesis will be fabricated and screwed onto the Conventional titanium multi-unit abutments with a torque of 15 Ncm.
qPCR analysis outcomes of microbiological samples
Microbiological composition will be the primary outcome measure, assessed at the T1-T4 time points up to 12 months after prosthesis loading
Time frame: 12 month follow-up
Marginal bone level changes (ΔMBL) (mm)
Peri-implant ΔMBL (change in marginal bone loss) values during the period from T0 to T4 (from the time of prosthetic loading up to 12 months) post-loading on periapical radiographs.
Time frame: 12 month follow-up
Peri-implant keratinized width changes digitally (mm)
Differences in keratinized gingival width measurements between time points T0 and T4 (from the time of prosthetic loading up to 12 months), as assessed via IOS, between the two groups
Time frame: 12 month follow-up
Implant stabilization values (ISQ)
Primary and secondary stabilization values will be measured at intraoperation and follow-up 3rd months (before prosthetic loading)
Time frame: At intraoperatively and before prosthetic loading session
Plan to share: Undecided
Started Sep 2026 (actual). Primary completion is estimated for Jun 2028, 21 months after the start.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Kutahya Health Sciences University →