Soft Tissue Response and IL-1β Levels Around CAD/CAM-Milled vs 3D-Printed PMMA Healing Abutments

NCT07287722 | Active Not Recruiting DMC

• 1 other identifier: AlexandriaUali
• Study Type: interventional
• Target: 22
• Locations: 1 country
• Sites: 1

Brief Summary

This study looked at how the gums and tissues around dental implants heal when using two different types of temporary healing caps made of PMMA (a common dental material). These healing caps help shape the gums before placing the final crown. There are two ways to make these caps:

• 22 dental implants in 22 patients were included.
• Each implant received one healing cap-either milled or 3D-printed.
• Patients were checked after 1 week, 2 weeks, and 4 weeks.
• The team measured:
• Gum inflammation
• Bleeding around the implant
• Plaque buildup
• Pocket depth around the implant
• Levels of an inflammatory marker called Interleukin-1β (IL-1β) in the gum fluid (higher levels mean more inflammation).
• Surface smoothness and material quality of each type of healing cap. What the Study Found
• Gum inflammation and bleeding were higher with 3D-printed caps, especially at week 4.
• IL-1β levels were much higher around 3D-printed caps-showing more inflammation.
• Both types had some increase in plaque and probing depth over time, but there was no major difference between groups.
• The milled caps had smoother surfaces and better material quality, which may have helped reduce irritation and inflammation.
• 3D-printed caps were rougher and had lower polymerization (more leftover monomers), which may trigger soft-tissue irritation. What This Means
• CAD/CAM-milled PMMA healing caps appear to be safer and healthier for gum healing around dental implants.
• They may help reduce early inflammation, support better tissue health, and more predictably shape the gums during healing. Why This Matters for Patients
• Using a smoother, better-finished healing cap may lower the risk of early gum inflammation.
• Healthier soft tissue around an implant leads to better long-term implant stability.
• This information can help dentists choose the best healing cap for optimal healing. Study Timeframe
• The follow-up was 4 weeks, so results focus on early healing. More research is needed to know long-term differences.

Conditions

Peri-implant Soft Tissue Healing

Keywords

Dental implants; Healing abutments; PMMA; CAD/CAM milled abutments; 3D-printed abutments; Peri-implant soft tissue; Peri-implant inflammation; Interleukin-1 beta (IL-1β); Peri-implant crevicular fluid; Surface roughness; Degree of conversion; Biocompatibility; Digital dentistry; Soft tissue healing

Outcome Measures

Primary Outcomes (1)

• Interleukin-1β (IL-1β) Level in Peri-Implant Crevicular Fluid

  Concentration of IL-1β in peri-implant crevicular fluid collected using sterile paper points. Samples are stored at -80°C and analyzed using ELISA kits. Higher IL-1β levels indicate greater inflammatory response. Mean IL-1β values are compared between CAD/CAM-milled and 3D-printed PMMA healing abutment groups at each time point.

  up to 4 weeks

Secondary Outcomes (6)

• Modified Gingival Index (MGI)

  up to 4 weeks

• Plaque Index (PI)

  up to 4 weeks

• Bleeding on Probing (BOP)

  up to 4 weeks

• Probing Pocket Depth (PPD)

  up to 4 weeks

• Surface Roughness of PMMA Healing Abutments

  Immediately after fabrication

Study Arms (2)

CAD/CAM-Milled PMMA Healing Abutment

EXPERIMENTAL

Participants receive a customized PMMA healing abutment manufactured using CAD/CAM milling from a pre-polymerized PMMA block. The abutment is attached to the implant at second-stage surgery to guide soft-tissue healing.

Device: CAD/CAM-Milled PMMA Healing Abutment

3D-Printed PMMA Healing Abutment

EXPERIMENTAL

Participants receive a customized PMMA healing abutment manufactured using 3D printing from a light-cured PMMA resin, followed by post-processing and UV curing. The abutment is attached to the implant at second-stage surgery.

Device: 3D-Printed PMMA Healing Abutment

Interventions

3D-Printed PMMA Healing Abutment DEVICE

A customized healing abutment produced by additive manufacturing (3D printing) using a light-cured PMMA resin. The abutment is printed layer-by-layer, washed in isopropyl alcohol, UV-cured, finished, and polished. This manufacturing technique results in a different surface texture and polymerization level compared to milled PMMA. The abutment is attached to a Ti-base and placed at second-stage surgery.

3D-Printed PMMA Healing Abutment

CAD/CAM-Milled PMMA Healing Abutment DEVICE

A customized healing abutment fabricated by subtractive CAD/CAM milling from a pre-polymerized PMMA block. Milling produces a highly polished, low-porosity surface with a high degree of polymerization. The abutment is connected to a Ti-base and placed at second-stage surgery to shape peri-implant soft tissues.

CAD/CAM-Milled PMMA Healing Abutment

Eligibility Criteria

• Age: 25 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 25 to 65 years
• Presence of one osseointegrated dental implant placed at least 8 weeks prior to second-stage surgery
• Adequate zone of attached keratinized gingiva (\> 1 mm) around the implant site
• Good general health and able to provide informed consent
• Willing and able to attend all follow-up visits (1, 2, and 4 weeks)

You may not qualify if:

• Smoking more than 20 cigarettes per day
• Presence of systemic diseases that may affect healing (e.g., autoimmune conditions, uncontrolled diabetes, immunosuppressive disorders)
• Oral inflammatory conditions or active oral infections
• History of head and neck radiation therapy or chemotherapy
• Use of corticosteroids or antibiotics within the last 3 months
• Parafunctional habits (e.g., bruxism)
• Pregnant or breastfeeding individuals
• Implants with insufficient attached gingiva or poor oral hygiene maintenance

Sponsors & Collaborators

• Ali Hassan Eid Toto: lead

Study Sites (1)

Faculty of Dentistry, Alexandria University

Alexandria, 21526, Egypt

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: MSC Candidate in periodontology department Alexandria university

Model Details: Participants are randomly assigned in a 1:1 ratio to one of two parallel groups. Each participant receives only one type of healing abutment either a CAD/CAM-milled PMMA abutment or a 3D-printed PMMA abutment at the time of second-stage implant surgery and remains in that assigned group throughout the 4-week follow-up period. No crossover occurs between groups.

Study Record Dates

• First Submitted: November 23, 2025
• First Posted: December 17, 2025
• Study Start: November 23, 2025
• Primary Completion: December 23, 2025
• Study Completion: December 23, 2025
• Last Updated: December 17, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)