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The Role of a New Prosthodontics Device in Hard and Soft Tissue Changes After Subcrestal Implant Placement

The Role of a New Prosthodontics Device in Hard and Soft Tissue Changes After Subcrestal Implant Placement: 12-months, Parallel, Randomized Clinical Trial

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06182670
Acronym
NABUT
Enrollment
40
Registered
2023-12-27
Start date
2021-06-06
Completion date
2023-06-07
Last updated
2023-12-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Edentulous Alveolar Ridge

Keywords

Oral Implants, Abutment, Subcrestal

Brief summary

The present randomized controlled trial aims to assess the influence of a new prosthodontics device (Gingival Former Abutment -GFA) on peri-implant bone loss and soft tissue changes and health after subcrestal oral implant placement. The participants will be divided in two groups and receive either crestal implant placement and traditional healing abutment or subcrestal implant placement and GFA. Clinical and radiographic examination will be performed at implant placement surgery, prosthetic load, 6 and 12 months follow-up.

Detailed description

According to current literature, physiological bone loss around oral implants is expected after placement and load (1 mm during the first year and 0.2 mm each subsequent year). Different implant designs and surgical protocols have been tested to minimize bone resorption, and subcrestal implant placement partially seems to overcome this issue. However, if this procedure increases the length of the transmucosal tunnel, increasing the risk of peri-implant soft tissue infection. The GFA was created to limit both the loss of peri-implant crestal bone and the extension of the transmucosal tunnel. The GFA follows the one abutment one time concept, which is believed to limit disturbances of the peri-implant hard and soft tissues healing due to the removal of the traditional healing abutments during prosthetic load procedures. Our objective is to validate or deny this claim. The study is a monocentric, pragmatic, single-blinded, randomized clinical trial (RCT) of parallel design. The trial will have a one-year duration, with data collection at the surgical phase, at implant load and 6 and 12 months after load. The primary outcome will be radiographical MBL (marginal bone level) changes around the implant. Secondary outcomes will be the assessment of the peri-implant soft tissues.

Interventions

DEVICEGingival Former Abutment

GFA is positioned on the sub-crestal implant during the surgery and it is no longer removed. This follows the one abutment one time concept and should prevent bone loss and transmucosal tunnel.

PROCEDURESubcrestal Implant

Placement of the endosseous sub-crestal dental implant through dedicated drills with 35 Newton insertion torque. It is positioned 2 mm under the crestal bone.

A healing abutment is positioned on crestal implant during surgery. It is removed at prosthetic finalization.

A zirconia prosthetic crown finalizes the implant rehabilitation.

PROCEDURECrestal Implant

Placement of the endosseous crestal implant through dedicated drills with 35 Newton insertion torque at level of the alveolar bone.

Sponsors

Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)

Masking description

Single

Intervention model description

Monocentric, single blinded, randomized clinical trial, parallel design.

Eligibility

Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
Yes

Inclusion criteria

* Ability to comprehend and sign informed consent. * Male and female subjects, aged 18-75 years, inclusive. * Good general health (free of systemic diseases such as diabetes, HIV infection or genetic disorder, ongoing malignant disease of any type that could influence the outcome of the treatment and might interfere with the evaluation of the study objectives). * Good oral health (no decay, periapical or periodontal lesions, PI and BOP \<25%). * Patient with posterior single missing tooth: * for at least 5 months, * mandibular or maxillary, * intercalated (distance between teeth more than 7.5 mm), * at least 11 mm of height residual bone (from bone crest to maxillary sinus or inferior alveolar nerve), * at least 5 mm of bone width (buccal - palatal/lingual). * Availability for the 12-month duration of the study.

Exclusion criteria

* Not willing to follow the agreed protocol. * Presence of orthodontic appliances. * Smokers more than 10 cigarettes per day. * Chronic obstructive pulmonary disease and asthma. * Tumors or significant pathology of the soft or hard tissues of the oral cavity. * Current radiotherapy or chemotherapy. * Pregnant or lactating women. * Parafunctions like bruxism. * Previous interventions to increase bone thickness in the implant area. * Current or past assumption of medications that may influence surgical therapy and/or interfere with healing following surgical treatment. * Systemic diseases that constitute a contraindication to surgical therapy and/or interfere with healing following surgical treatment.

Design outcomes

Primary

MeasureTime frameDescription
Change in Marginal Bone Level (MBL)Surgery, 3, 9 and 15 monthsThe reabsorption of the bone measured through radiographically change on standardised radiographs. Baseline values will be compared to the values recorded in the follow-up visits.

Secondary

MeasureTime frameDescription
Change in PD (periodontal depth) (implant site)3, 9 and 15 monthsChange in periodontal depth value (from the gingival margin to the bottom of the pocket). Baseline values will be compared to the values recorded in the follow-up visits.
Change in REC (Clinical Gingival Recession) (implant site)3, 9 and 15 monthsChange in recession value should be calculated. Baseline values will be compared to the values recorded in the follow-up visits.
Change in BOP (Bleeding on Probing) (implant site)3, 9 and 15 monthsChange in percentage of sites positive to bleeding on probing (4 point each situ). Baseline values will be compared to the values recorded in the follow-up visits.
Change in PI (Plaque Index) (implant site)3, 9 and 15 monthsChange in percentage of site with plaque (4 point each situ). Baseline values will be compared to the values recorded in the follow-up visits.

Countries

Italy

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026