Bone Loss, Gingival Recession, Implant Complication
Conditions
Keywords
One abutment one time, Disconnection and reconnection, Definitive abutment
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.
Interventions
DEVICEDefinitive abutment
With two height options available, On1 Base are selected depending on the thickness of the soft tissue. It remains in position from implant placement to finalization, which leaves the soft tissue undisturbed for optimized healing, moved the restorative platform of Nobel Biocare conical connection implants from bone level to tissue level, thereby simplifying the restorative procedures
Sponsors
Nobel Biocare
Loma Linda University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Single center, prospective, randomized modified split mouth clinical trial
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Countries
United States
Participant flow
Recruitment details
1. Read, sign, and receive a copy of the consent form. 2. Male or female, at least 18 years old, with good oral and general health. 3. Healed edentulous site with two or more missing teeth in the posterior maxilla or mandible (excluding third molars). 4. Adequate bone width and height for a 4.3 mm diameter, 8 mm length implant. 5. Have at least 8 mm restorative space. 6. Willing to participate and attend a 1-year follow-up before implant restoration procedures.
Pre-assignment details
19 participants were initially enrolled. 2 participants withdrew: one moved away during the COVID-19 pandemic, and another agreed to participate and signed the consent form but later withdrew due to being unable to attend the scheduled surgery.
Participants by arm
| Arm | Count |
|---|---|
| Split Mouth Subject Control group: Healing abutments are connected on the implants on the day of surgery, which will be subjected to multiple disconnection and reconnection during the prosthetic phase
Test group: Definitive abutments connected to the implants on the day of surgery. No disconnection or reconnection during the prosthetic phase
Definitive abutment: With two height options available, On1 Base are selected depending on the thickness of the soft tissue. It remains in position from implant placement to finalization, which leaves the soft tissue undisturbed for optimized healing, moved the restorative platform of Nobel Biocare conical connection implants from bone level to tissue level, thereby simplifying the restorative procedures | 17 |
| Split Mouth Subject Control group: Healing abutments are connected on the implants on the day of surgery, which will be subjected to multiple disconnection and reconnection during the prosthetic phase
Test group: Definitive abutments connected to the implants on the day of surgery. No disconnection or reconnection during the prosthetic phase
Definitive abutment: With two height options available, On1 Base are selected depending on the thickness of the soft tissue. It remains in position from implant placement to finalization, which leaves the soft tissue undisturbed for optimized healing, moved the restorative platform of Nobel Biocare conical connection implants from bone level to tissue level, thereby simplifying the restorative procedures | 38 |
| Total | 55 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Withdrawal by Subject | 2 | 2 |
Baseline characteristics
| Characteristic | Split Mouth Subject |
|---|---|
| Age, Continuous | 64 years STANDARD_DEVIATION 12 |
| Region of Enrollment United States | 17 participants |
| Sex: Female, Male Female | 9 Participants |
| Sex: Female, Male Male | 8 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 17 | 0 / 17 |
| other Total, other adverse events | 0 / 17 | 0 / 17 |
| serious Total, serious adverse events | 0 / 17 | 0 / 17 |
Outcome results
Primary
Changes in Peri-implant Marginal Bone Level Between 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.
Time frame: At baseline (implant placement) and 1 year follow up
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control Group | Changes in Peri-implant Marginal Bone Level Between Baseline (Implant Placement) and 1 Year Follow up | 0.80 millimeters | Standard Deviation 0.92 |
| Test Group | Changes in Peri-implant Marginal Bone Level Between Baseline (Implant Placement) and 1 Year Follow up | 0.32 millimeters | Standard Deviation 0.47 |
Comparison: The null hypothesis was that there would be no significant difference in peri-implant bone levels between implants with definitive abutments delivered at the time of surgery, and those subjected to multiple abutment disconnections and reconnections. Power analysis was performed and showed that a sample size of 38 implants was needed to achieve 80% power to detect a difference between the null proportion of 0.500 at a significance level of 0.05.p-value: 0.00995% CI: [0.1, 0.85]Wilcoxon (Mann-Whitney)
Secondary
Changes in Keratinized Mucosa Width
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.
Time frame: At baseline (implant placement) and 1 year follow up
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control Group | Changes in Keratinized Mucosa Width | 0.90 millimeters | Standard Deviation 0.77 |
| Test Group | Changes in Keratinized Mucosa Width | 0.42 millimeters | Standard Deviation 0.42 |
Comparison: The null hypothesis was that there would be no significant difference in peri-implant bone levels between implants with definitive abutments delivered at the time of surgery, and those subjected to multiple abutment disconnections and reconnections. Power analysis was performed and showed that a sample size of 38 implants was needed to achieve 80% power to detect a difference between the null proportion of 0.500 at a significance level of 0.05.~Type of Statistical Testp-value: 0.04995% CI: [-0.0000168, 1.25]Wilcoxon (Mann-Whitney)
Secondary
Changes in Lingual Mucosa Thickness
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.
Time frame: At baseline (implant placement) and 1 year follow up
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control Group | Changes in Lingual Mucosa Thickness | 0.71 millimeters | Standard Deviation 0.59 |
| Test Group | Changes in Lingual Mucosa Thickness | 0.38 millimeters | Standard Deviation 0.26 |
Comparison: The null hypothesis was that there would be no significant difference in peri-implant bone levels between implants with definitive abutments delivered at the time of surgery, and those subjected to multiple abutment disconnections and reconnections. Power analysis was performed and showed that a sample size of 38 implants was needed to achieve 80% power to detect a difference between the null proportion of 0.500 at a significance level of 0.05.~Type of Statistical Testp-value: 0.05395% CI: [-0.0000522, 0.75]Wilcoxon (Mann-Whitney)
Secondary
Implant Success Rate According to the 2017 Classification Criteria Set by the American Academy of Periodontology (AAP)
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.
Time frame: 12 months after surgical implantation
| Arm | Measure | Value (COUNT_OF_UNITS) |
|---|---|---|
| Control Group | Implant Success Rate According to the 2017 Classification Criteria Set by the American Academy of Periodontology (AAP) | 0 Implants |
| Test Group | Implant Success Rate According to the 2017 Classification Criteria Set by the American Academy of Periodontology (AAP) | 0 Implants |