The Effects of Dis/Reconnection of Implant Abutments on Peri-implant Bone Levels

Not Applicable

Completed

Brief Summary: The aim of this study was to evaluate the effects of definitive abutment connection at the time of implant placement on peri-implant bone levels and soft tissue changes in posterior maxilla and mandible regions.

Detailed Description: A total of 38 implants were placed in 17 patients with at least 2 missing posterior teeth in the maxilla or the mandible for this study. Each patient received 2 or 4 implants. A definitive prefabricated abutment (test group) was randomly connected to one implant at implant placement (T0) and left undisturbed throughout the duration of the study. On the other implant, a healing abutment (control group) was connected and subjected to go through three disconnections and reconnections at 3 months (T3), 6 months (T6), and 12 months (T12) after the implant placement. Throughout the study period (1 year), all implants remained unrestored. Marginal bone level changes (MBLC) were assessed using standardized periapical radiographs taken at T0 and T12. Peri-implant soft tissue parameters including the keratinized mucosa width and lingual mucosa thickness were also recorded and evaluated.

Recruitment & Eligibility

Inclusion Criteria

Minimum age 18
Good oral hygiene
Healed site that possess two or more missing teeth in the maxillary or mandibular posterior region (excluding third molars)
Adequate bone to accommodate at least a 4.3 mm diameter and 8mm length implant at each site
Have at least 8mm interocclusal restorative space
Willing to participate and attend the planned follow-up visits.

Exclusion Criteria

History of alcohol/drug dependency, or any medical, physical, or psychological factor that might affect the surgical or prosthodontic procedures and follow-up examinations
History of radiation therapy to the head and neck region
History or current habit of smoking
History or current habit of bruxism
No opposing occluding dentition or prostheses
Need for bone augmentation during implant placement
Implant insertion torque value <35 Ncm

Arm && Interventions

Group	Intervention	Description
Test group	Definitive abutment	Definitive abutments connected to the implants on the day of surgery. No disconnection or reconnection during the prosthetic phase

Primary Outcome Measures

Name	Time	Method
Changes in Peri-implant Marginal Bone Level Between Baseline (Implant Placement) and 1 Year Follow up	At baseline (implant placement) and 1 year follow up	Standardized digital periapical radiographs were taken at baseline (implant placement) and at the 1-year follow-up using the long-cone paralleling technique with a custom jig. Peri-implant marginal bone levels were measured on both the mesial and distal aspects to assess bone loss. Changes in peri-implant marginal bone levels were calculated by comparing the measurements at the 1-year follow-up to the baseline values.

Secondary Outcome Measures

Name	Time	Method
Changes in Keratinized Mucosa Width	At baseline (implant placement) and 1 year follow up	The width of the keratinized mucosa was measured at the mid-buccal aspect of the abutments using a periodontal probe with 1.0 mm markings. Measurements were repeated at the 1-year follow-up at the same location and compared to the baseline values.
Changes in Lingual Mucosa Thickness	At baseline (implant placement) and 1 year follow up	The thickness of the lingual mucosa at each implant site was measured at the center of the implant site from the bone crest using a periodontal probe with 1.0 mm markings. Measurements were repeated at the 1-year follow-up at the same location and compared to the baseline values taken on the day of implant surgery.
Implant Success Rate According to the 2017 Classification Criteria Set by the American Academy of Periodontology (AAP)	12 months after surgical implantation	Success was determined by the implant's ability to meet these clinical factors, such as the absence of pain, infection, mobility, and radiographic bone loss beyond the acceptable threshold of the follow-up period, as assessed at 12 months post-surgical implantation.