Early Stability of Short Dental Implants With Shallow Threads in the Posterior Mandible: A Controlled Clinical Pilot Study .
Phase: NA
Conditions: Alveolar Bone Atrophy
Sponsor: University of Science and Technology, Yemen

Research Protocol
Protocol Title: 
Early Stability of Short Implants with Shallow Threads in the 
Posterior Mandible: A Controlled Clinical Pilot Study.
 Date: August - 19- 2025
Principal Investigator 
Mohammad Abdulwahab Abdullah Al-Jonaid 
Thesis Supervisor:
Dr. Ali Hussain Al-Hudaied
 (Associate Professor of Oral and Maxillofacial Surgery) 
University of Science and Technology, 
 Yemen.

1. Background and Rationale 
Patients with severely resorbed posterior mandibles face a significant 
challenge.While short implants (SHI, ≤8mm) offer a less invasive alternative to 
complex bone augmentation, they are associated with a higher risk of early 
failure, often linked to compromised stability during the critical healing phase 
known as the "stability dip." This dip, a period of osteoclast-mediated 
resorption, creates micromotion that can disrupt osseointegration. The role of 
implant macrodesign, specifically shallow threads, and bone density in 
modulating this early stability trajectory remains unclear. This study aims to 
prospectively compare the early stability dynamics of short (7mm) versus 
standard (11mm) shallow-threaded implants to provide evidence for their use 
as a viable graft-less solution.
2. Study Objectives and Hypotheses
· Primary Objective: 
To compare the early stability dynamics (primary stability, stability dip, 
and onset of secondary stability) of 7 mm short implants (SHI) versus 11 mm 
standard implants (SDI), both with an identical shallow-threaded macrodesign, 
in the non-augmented posterior mandible over 4 weeks.

· Secondary Objective: 
To assess the effect of bone density (D2 vs. D3) on these stability 
parameters.
Hypotheses:
· H₀1: No significant difference in primary stability (ITV, ISQ-T0) exists between 
SHI and SDI.
· H₀2: No significant relationship exists between baseline ISQ and the stability 
dip magnitude/duration for either implant type.
· H₀3: Bone density has no differential effect on stability parameters between 
SHI and SDI.

3. Study Design 
A 
prospective, 
controlled, 
non-randomized 
clinical 
pilot 
study 
employing ≥ 80% split-mouth design where anatomically feasible. Implant 
allocation follows clinical necessity principles:
·  Short Implant (SHI; 7 mm): Sites with 8–10 mm bone height above the 
inferior alveolar canal.
· Standard Implant (SDI; 11 mm): Sites with >10 mm bone height. 
Randomization is precluded on ethical grounds, as placing an SHI in a site 
suitable for an SDI violates the standard of care.
4. Participant Selection
· Inclusion Criteria:
  · Aged 18–65 years.
  · Posterior mandibular partial edentulism requiring implant placement.
  · Native bone height of 8–13 mm above the inferior alveolar canal.
  · Bone width ≥5.5 mm.

  · Bone density classified as D2 (850–1250 HU) or D3 (350–850 HU) via 
pre-operative CBCT.
  · Plaque Index ≤1.
  · ASA physical status I or II.
  · Provides written informed consent.
· Exclusion Criteria:
  · Absolute surgical contraindications.
  · Uncontrolled diabetes (HbA1c >7%) or immunosuppression.
  · History of head/neck radiation or bisphosphonate therapy.
  · Active periodontitis (PPD >5 mm) or bone pathology.
  · Smoking >10 cigarettes/day.
  · Parafunctional habits.
  · Previous bone grafting at the intended implant site.

5. Sample Size
 The  sample will consist of Ten participants receiving 20 implants (10 
SHI, 10 SDI). This is a pilot feasibility sample, determined by strict eligibility 
criteria and a post-hoc power analysis indicating 80% power to detect a 
clinically significant difference in ISQ dip (ΔISQ ≥5) with an alpha of 0.05.
6. Materials and Methods
· Implant System: 
A tiologic TWINFIT implants (DENTAURUM GmbH). Both SHI (7mm) and 
SDI (11mm) share an identical design: 
•
4.2mm diameter 
•
5-degree taper 
•
Shallow threads (0.35-0.45mm), 
•
Sandblasted, acid-etched (SLA) surface.

· Key Equipment:
  · CBCT Machine (Vatech EZ-3D) for pre-surgical planning and bone density 
assessment.
  · Surgical motor (W&H Implantmed) with a 20:1 reduction handpiece.
  · Calibrated torque wrench.
 · Resonance Frequency Analysis (RFA) device (Penguin RFA) with type 4 
SmartPegs.
7. Study Procedures
· Pre-Operative Phase:
  1. Screening against inclusion/exclusion criteria.
  2. Clinical examination and plaque index recording.
  3. CBCT scan with Hounsfield Unit (HU) calibration using a hydroxyapatite 
phantom to determine bone density (D2/D3).
  4. Obtaining written informed consent.

· Surgical Protocol:
  1. Premedication: Ibuprofen 400 mg.
  2. Asepsis with povidone-iodine (perioral) and chlorhexidine (intraoral).
  3. Local anesthesia (2% lidocaine with 1:80,000 epinephrine).
  4. Crestal incision and full-thickness flap elevation.
  5. Osteotomy performed with an under-preparation protocol.
  6. Implant placement with slow manual seating. Insertion Torque Value (ITV) 
is recorded during the final 90° rotation.
 7. SmartPeg attachment and baseline Implant Stability Quotient (ISQ) 
measurement using RFA (T0).
  8. Closure with sutures.
· Post-Operative Care:
  · Analgesics (Diclofenac) and antibiotics (Amoxicillin/Clavulanate).
  · Instructions for soft diet and chlorhexidine mouth rinses.

· Follow-up and Stability Monitoring:
  · Participants will return for ISQ measurements at the end of weeks 1, 2, 3, 
and 4 (T1, T2, T3, T4).
  · At each visit, quadruple RFA measurements (buccal, lingual, mesial, distal) 
will be taken, and the mean ISQ value calculated.
8. Outcome Measures
· Primary Stability:
  · Insertion Torque Value (ITV) in Ncm.
  · Baseline ISQ value (T0).
· Stability Dip Characteristics:
  · Dip Magnitude (ΔISQ-min): Difference between ISQ at T0 and the lowest ISQ 
value (ISQ-min) recorded between T1-T4.
  · Time of Dip (T-min): The week (T1-T4) at which the lowest ISQ value 
occurred.

· Secondary Stability Onset: The first timepoint where ISQ values consistently 
increase by ≥2 units from the ISQ-min.
· Effect Modifier: Bone density (D2 vs. D3) as a primary covariate.
9. Data Management and Statistical Analysis
· Data Collection: 
De-identified data will be recorded on standardized Case Report Forms (CRFs) 
and stored in a password-protected electronic database (Excel).
· Statistical Analysis: 
Will be performed using SPSS Statistics (v28). Analysis will include:
  · Descriptive statistics for all variables.
  · Paired t-tests (for bilateral cases) and independent samples t-tests (for full 
dataset) to compare primary stability (H₀1).
  · Pearson/Spearman correlation to assess the relationship between baseline 
ISQ and dip magnitude (H₀2).
  · Linear Mixed Models (LMM) to analyze longitudinal ISQ trajectories.

  · Two-Way ANOVA to test the interaction effect of Implant Type and Bone 
Density on dip magnitude (H₀3).
  · A p-value of <0.05 will be considered statistically significant, with Bonferroni 
correction for multiple comparisons.
10. Ethical Considerations
· Approval: 
This study has been approved by the University of Science and 
Technology 
Institutional 
Review 
Board. 
(IRB 
Approval 
No: 
1447/0062/UREC/UST).
· Informed Consent: 
Written informed consent will be obtained from all participants after a 
detailed explanation of the study procedures, potential risks, and benefits.

· Confidentiality: 
All participant data will be de-identified and stored securely. Access will 
be limited to the research team.
· Risk Management:
 The study follows the ALARA principle for radiation. All surgical 
procedures will adhere to standard clinical protocols to minimize risks. An 
adverse event reporting plan is in place.
11. Dissemination Plan 
The results of this study will be presented in the candidate's Master's 
thesis and submitted for publication in a peer-reviewed international journal 
in the field of oral implantology.Findings may also be presented at relevant 
scientific conferences.

INFORMED CONSENT FORM
”Early Stability of Shallow-Threaded Short vs. Standard Implants in Posterior
Mandible: A Controlled Pilot Trial”
Principal Investigator: Mohammad Abdulwahab Al-Jonaid
University of Science and Technology, Sana’a, Yemen
Supervisor: Dr. Ali Al-Hudaied
1. Study Purpose
You are invited to participate in a research study comparing two dental implant 
designs. The goal is to evaluate early stability patterns of short (7mm) versus 
standard (11mm) implants with shallow threads in the lower jaw.  
2. Procedures
If you agree, you will:  
- Undergo a dental exam and 3D scan (CBCT).  
- Receive implant (length determined by your bone anatomy).  
- Attend 5 visits over 4 weeks for stability measurements (painless RFA tests).  
- Follow post-operative care instructions.  
3. Risks and Discomforts
Potential risks include:  
- Mild pain/swelling after surgery (managed with medication).  
- Rare: Infection, nerve injury, or implant failure (<5% based on literature).  
4. Benefits
- Free implant/implants placement and follow-up care.  
- Contribution to scientific knowledge about minimally invasive implant options.  
5. Confidentiality
Your data will be:  
- Stored under a code (no names).  
- Accessible only to the research team.  

- Published only in aggregated form.  
6. Voluntary Participation
You may:  
- Withdraw anytime without penalty.  
- Ask questions before/during the study.  
- Receive alternative treatments if you decline.  
7. Costs & Compensation
- No cost for study procedures.  
- Compensation for travel expenses (if applicable).  
8. Contact Information
For questions, contact:  
- Researcher: Mohammad Abdulwahab Al-Jonaid [711726732/
mohjon6@gmail.com]
- Supervisor: Dr. Ali Al-Hudaied
(@gmail.com)
- Ethics Committee: [UST]
Participant’s Declaration
I confirm that:
- I have read this form (or it was read to me).  
- I understand the purpose, procedures, and risks.  
- I voluntarily agree to participate.  
- I will receive a copy of this form.  
Participant’s Name: _________________________  
Signature: _________________________ Date: ___/___/___  
Investigator’s Name: _________________________  
Signature: _________________________ Date: ___/___/___