Thesis title: Evaluating Laser and Photodynamic Therapies for the Management of Peri- implantitis and Consideration of Diagnostic Challenges Associated with Peri-Implant Malignancies
1. Background
This research addressed a critical gap in the evidence-based management of peri-implantitis by systematically evaluating non-surgical adjunctive therapies, specifically laser and photodynamic interventions, and assessed the current diagnostic landscape, with an emphasis on identifying peri-implant malignancies. This research aimed to evaluate and synthesize clinical and biochemical outcomes of non-surgical laser and photodynamic therapies in the management of peri-implantitis and to investigate diagnostic indicators that differentiate peri-implantitis from peri-implant malignancies.
2. Specific study objectives
1. To assess whether laser-assisted therapy yielded more improved treatment outcomes when compared to other therapy in the treatment of periimplantitis?
2. To evaluate the clinical and biomarker outcomes of photodynamic therapy (PDT) as an adjunctive non-surgical treatment for peri-implantitis compared to other modalities, including mechanical debridement (MD) alone and combined therapies.?
3. To investigate the potential associations between peri-implantitis (PI) and peri-implant oral malignancies (PIOM).
3. Methodology
Work package 1: Two structured reviews were conducted focusing on randomized controlled trials and prospective clinical studies comparing adjunctive laser and PDT interventions with mechanical debridement. Data on clinical parameters (PD, BOP, PI, CAL, and CBL) and biochemical markers (e.g., IL-1β, TNF-α, IL-6) were extracted and analyzed following PRISMA guidelines. Risk of bias were assessed using the Cochrane RoB2 framework.
Work package 2: A third separate systematic review examined case reports and retrospective studies reporting peri-implant oral malignancies. Descriptive data (age, sex, lesion characteristics, site, initial diagnosis, final diagnosis, prosthetic design, time since implant placement) were compiled. Proportional meta-analysis and Kaplan–Meier survival estimates were performed to assess diagnostic delay and misclassification rates.
4. Significance and Innovation
This research was positioned at the intersection of therapeutic innovation and diagnostic safety in implant dentistry. It aimed to:
• Clarify the clinical value and limitations of emerging adjunctive therapies.
• Advance the understanding of host inflammatory responses in peri-implant environments.
• Address a critical gap in the recognition of malignancies mimicking peri-implantitis.
By integrating clinical, biochemical, and diagnostic perspectives, this research contributed not only to improving peri-implantitis outcomes but also to safeguarding patient health through timely identification of potentially life-threatening conditions.
5. Publication and Dissemination
The following papers were published for the successful completion of this PhD thesis:
1. Efficacy of non-surgical laser-assisted therapy for the management of peri-implantitis: A systematic review and meta-analysis
2. Non-surgical management of peri-implantitis with photodynamic therapy: A systematic review and meta-analysis of clinical parameters and biomarkers
3. Peri-implantitis and peri-implant oral malignancies: a systematic review and meta-analysis of diagnostic challenges and potential associations
Summary: Paper 1. Efficacy of non-surgical laser-assisted therapy for the management of peri-implantitis: A systematic review and meta-analysis
Objective:
This systematic review and meta-analysis aimed to evaluate the clinical efficacy of non-surgical laser therapies compared to other treatment modalities for the management of peri-implantitis. It specifically sought to address (1) whether laser therapy yields improved treatment outcomes compared to other therapies and (2) what the post-treatment outcome efficacy is of various non-surgical interventions.
Results:
A total of 15 randomized controlled trials (RCTs) including 540 patients and 658 implants were reviewed, with 10 studies included in the meta-analysis. Er:YAG laser therapy significantly reduced bleeding on probing (BOP) by 35.6% (95% CI: 17.3–53.9%) and probing depth (PD) by 0.65 mm (95% CI: 0.33–0.97). The combination of mechanical debridement (MD) with Er,Cr:YSGG laser therapy showed greater reductions: PD by 1.23 mm (95% CI: 0.76–1.70) and BOP by 47.3% (95% CI: 38.4–56.1%). However, none of the laser-based therapies demonstrated a significant advantage in preventing crestal bone loss (CBL). Overall, laser therapies did not significantly outperform traditional mechanical debridement in long-term outcomes. The findings underscore the need for standardized treatment protocols and further high-quality studies.
Summary: Paper 2. Photodynamic Therapy (PDT) as an Adjunct in Peri-Implantitis Management
Objective:
This systematic review and meta-analysis evaluated the efficacy of adjunctive photodynamic therapy (PDT) in non-surgical peri-implantitis treatment, compared to mechanical debridement (MD) alone or other non-surgical modalities. It addressed two questions: (1) Does PDT provide superior clinical and biomarker outcomes? and (2) What are the post-treatment efficacies of MD alone versus MD+PDT?
Results:
Twenty-five studies were included (15 RCTs, 5 quasi-experimental, and 5 cohort studies). The meta-analysis revealed that adjunct PDT yielded significantly better short-term clinical outcomes than MD alone at 3-month follow-up:
• BOP (SMD = 0.90; p = 0.005)
• PD (SMD = 1.15; p < 0.0001)
• PI (SMD = 0.74; p = 0.0004)
• CBL (SMD = 0.38; p = 0.04)
However, additional benefits in clinical attachment level (CAL), mucosal recession, and inflammatory biomarkers (e.g., IL-6, TNF-α) were limited. Over longer follow-up durations, the advantages of PDT diminished. These findings suggest that PDT can enhance short-term treatment efficacy, but long-term effectiveness and biological impacts remain uncertain. The study calls for future research with standardized protocols and extended follow-ups.
Summary: Paper 3. Peri-Implantitis and Peri-Implant Oral Malignancies (PIOM): Diagnostic Overlap and Association
Objective:
This systematic review and meta-analysis aimed to investigate the potential association between peri-implantitis and peri-implant oral malignancies (PIOM). Specifically, it explored (1) whether peri-implant inflammation may be a risk factor for PIOM and (2) the frequency with which PIOM is misdiagnosed as peri-implantitis.
Results:
Fifty-seven studies involving 161 patients (51 case reports/series and 6 retrospective studies) were included. The meta-analysis revealed that 50% of PIOM cases were initially misdiagnosed as peri-implantitis. Squamous cell carcinoma (SCC) was the most frequent final diagnosis, accounting for 81% of case reports and 97% of retrospective study cases. The median time from implant placement to PIOM diagnosis was five years, and notably, traditional risk factors (e.g., smoking, alcohol use, cancer history) were absent in a substantial number of cases. Most lesions presented as exophytic, ulcerative, or multifaceted with bone loss. Misdiagnosis delayed accurate diagnosis and appropriate treatment. While causality could not be established, the findings highlight the importance of early biopsy and histopathological evaluation for non-resolving peri-implant lesions.
6. Conclusion:
The confluence of these findings leads to a broader understanding: peri-implant disease management cannot be siloed into treatment or diagnosis—it must be approached holistically. The thesis demonstrates that while advanced non-surgical therapies may improve short-term clinical markers, they are not panaceas. Their value lies in their judicious application, guided by individualized clinical assessment and embedded within a framework that prioritizes early detection of pathologies beyond inflammation.