Bone bioactive liquid enters endodontic microsurgery testing in persistent apical periodontitis
A randomized clinical trial at Ain Shams University will test whether bone bioactive liquid can improve healing after endodontic microsurgery in adults with persistent apical periodontitis in the maxillary anterior region. The study is still not yet recruiting, but its design is clinically focused: investigators want to know whether a surface-conditioning liquid applied to the bony crypt and resected root end can alter the early inflammatory response and translate into better bone repair on cone-beam CT over time.
The target population is narrow and deliberately selected. Eligible participants must have persistent apical periodontitis requiring microsurgery, with lesion diameters between 5 and 8 mm. Adults 21 to 55 years old are eligible, and the protocol excludes smokers, patients with diabetes, pregnancy, root fracture, prior apical surgery, immunocompromise, and cases needing additional procedures such as root amputation, soft tissue grafting, replantation, or perforation repair. By limiting the cohort to relatively uncomplicated surgical cases, the study is trying to isolate the biological effect of the adjunct itself rather than the noise introduced by systemic disease or complex operative anatomy.
Why the surgical adjunct could matter at the root end
Endodontic microsurgery depends on more than retrograde sealing and lesion curettage. Healing is shaped by the local inflammatory burden, the quality of the root-end surface, and the biology of the surrounding bone after the infected tissue has been removed. A bioactive irrigant or conditioning solution may influence mineralized tissues at the surgical interface, potentially encouraging a more favorable environment for cellular attachment and repair. In this trial, the experimental arm receives bone bioactive liquid as a final flush to the bony cavity and as a conditioning step on the root-end surface before closure.
The control arm will undergo conventional endodontic microsurgery without the adjunct. Both groups will follow standardized surgical procedures, which is important because technique variability can distort healing outcomes in periapical surgery. Here, the study is not trying to reinvent surgery. It is testing whether a brief exposure to a bioactive solution, held in passive contact for 60 seconds, can change what happens next.
The protocol uses a parallel assignment design with triple masking of participant, investigator, and outcomes assessor. That level of masking is unusually valuable in a surgical study because postoperative pain scoring and healing ratings are vulnerable to expectation bias. A blinded structure also makes the radiographic endpoint more credible, especially when the main readout is morphologic change rather than a laboratory surrogate.
Inflammatory mediators and early healing are built into the readout
The study does not rely on a single late image. It asks a more mechanistic question. Preoperative gingival crevicular fluid will be collected, then sampled again around day 10 after surgery to measure inflammatory mediator expression by ELISA, including IL-1β and TNF α. Those cytokines sit near the center of the acute inflammatory cascade and are closely tied to tissue breakdown, immune recruitment, and the transition toward repair. If the adjunct reduces their postoperative expression, that would support a biologically plausible anti-inflammatory or pro-resolution effect at the surgical site.
Soft tissue repair will be assessed at 10 days using the Early Healing Score, which incorporates re-epithelialization, hemostasis, and inflammation. Pain will also be tracked using the Visual Analog Scale during the first postoperative week. These are not secondary details. Early postoperative discomfort and mucosal repair often shape whether a surgical intervention feels successful to the patient long before any radiograph shows remodeling.
One clinical detail stands out in the protocol: the investigators plan to use cone-beam CT both before surgery and again at 6 months, with cumulative exposure estimated at about 240 µSv, or 0.24 mSv. In practical terms, that is framed as roughly comparable to 24 days of natural background radiation exposure. The imaging plan reflects a willingness to use three-dimensional assessment when plain radiographs might miss volumetric changes in periapical lesions.
Volumetric CBCT healing is the main test of clinical value
The primary endpoint is periapical bone healing on CBCT, assessed by quantitative three-dimensional analysis of lesion volume reduction. That choice matters because persistent apical lesions do not heal in a purely binary fashion. Bone regeneration is spatial and gradual, and volumetric imaging is better suited than a flat film to capture whether a cavity is truly collapsing over time.
Investigators also plan to calculate the volume of the bioactive liquid according to lesion size using the formula π/6 × D × W × H, applying a method borrowed from implant surgery. The solution will be delivered with a sterile syringe and blunt needle to coat both the bony walls and the resected root surface. Excess material will be gently aspirated without additional irrigation, a step intended to preserve the bioactive layer at the interface rather than wash it away.
The study is modest in size, with an estimated enrollment of 34 participants, and it is scheduled to begin in November 2026. Primary completion is estimated for November 2027, with full study completion expected by December 2027. Those dates mean the field will have to wait for actual outcome data before any claim can be made about efficacy.
A surgical trial that asks a specific question about healing biology
The central question is straightforward: can a bioactive adjunct alter the local wound environment enough to improve radiographic bone repair after endodontic microsurgery? If the answer is yes, the benefit would likely rest on local tissue modulation rather than systemic pharmacology. If the answer is no, the study will still be useful because it narrows the role of surface-conditioning agents in periapical surgery and clarifies whether conventional microsurgery remains sufficient in carefully selected cases.
For now, the protocol offers a careful framework rather than a conclusion. Its strength lies in how tightly it connects a surgical intervention to measurable biology: postoperative pain, soft tissue healing, inflammatory mediators, and CBCT-based bone regeneration. The field rarely gets all four in one randomized design, especially in a study with triple masking and a clearly defined lesion phenotype. The limiting factor is obvious: results are not yet available, and the true value of bone bioactive liquid will depend entirely on whether those planned postoperative differences actually appear.