One-Year Clinical, Microbiological and Immunological Results of Local Doxycycline or Antimicrobial Photodynamic Therapy for Recurrent/Persisting Periodontal Pockets: A Randomized Clinical Trial

Exploring the Impact of Biological Agents on Protecting Against Experimental Periodontitis: A Systematic Review of Animal-Based Studies

Aim: This systematic review was aimed at addressing the focused question: What is the protective potential of biological agents against alveolar bone resorption during the progression of experimental periodontitis (EP)? Material and Methods: The study protocol was registered in the Open Science Framework database (doi:10.17605/OSF.IO/3P2HY). A comprehensive literature search was conducted across PubMed, Web of Science, Cochrane Library, Scopus, and Embase databases up to December 2023. Inclusion criteria consisted of preclinical studies in animal models of EP that examined the effects of biological agents on preventing periodontal bone loss and reducing tissue inflammation. Studies were excluded if they (i) used non-EP animal models; (ii) focused on antimicrobial agents; (iii) centered on prebiotics or probiotics; (iv) evaluated compounds not classified as biologicals; or (v) included randomized clinical trials, clinical studies, or reviews. Eligibility was determined based on the PI/ECOs framework, and study quality was assessed using the SYRCLE risk-of-bias tool. Results: After screening an initial pool of 5236 records from databases, registries, and hand searches, 39 studies met the inclusion criteria. A total of 23 biological agents were evaluated across these studies. The majority of studies employed the ligature-induced model of EP to test the effectiveness of biologicals as preventive or therapeutic interventions. The dosage of biological agents and the duration of disease induction varied depending on the EP model. In all studies, the main outcome-alveolar bone loss, a hallmark of EP-was significantly inhibited by biological agents, which also reduced proinflammatory mediators when compared to untreated controls. A key strength of this review is the high number of studies included, most of which were classified as having low risk of bias. However, a notable limitation is the absence of a meta-analysis, the short follow-up periods in the included studies, and the heterogeneity among the compound dosages and route of administration. Conclusion: This systematic review demonstrates that biological agents are effective in reducing bone loss and mitigating inflammation during EP progression. Randomized clinical trials are needed to confirm these findings in human populations.

Adjunctive antimicrobial photodynamic therapy for treating periodontal and peri-implant diseases

BACKGROUND

Periodontitis and peri-implant diseases are chronic inflammatory conditions occurring in the mouth. Left untreated, periodontitis progressively destroys the tooth-supporting apparatus. Peri-implant diseases occur in tissues around dental implants and are characterised by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Treatment aims to clean the pockets around teeth or dental implants and prevent damage to surrounding soft tissue and bone, including improvement of oral hygiene, risk factor control (e.g. encouraging cessation of smoking) and surgical interventions. The key aspect of standard non-surgical treatment is the removal of the subgingival biofilm using subgingival instrumentation (SI) (also called scaling and root planing). Antimicrobial photodynamic therapy (aPDT) can be used an adjunctive treatment to SI. It uses light energy to kill micro-organisms that have been treated with a light-absorbing photosensitising agent immediately prior to aPDT.

OBJECTIVES

To assess the effects of SI with adjunctive aPDT versus SI alone or with placebo aPDT for periodontitis and peri-implant diseases in adults.

SEARCH METHODS

We searched the Cochrane Oral Health Trials Register, CENTRAL, MEDLINE, Embase, two other databases and two trials registers up to 14 February 2024.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) (both parallel-group and split-mouth design) in participants with a clinical diagnosis of periodontitis, peri-implantitis or peri-implant disease. We compared the adjunctive use of antimicrobial photodynamic therapy (aPDT), in which aPDT was given after subgingival or submucosal instrumentation (SI), versus SI alone or a combination of SI and a placebo aPDT given during the active or supportive phase of therapy.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures, and we used GRADE to assess the certainty of the evidence. We prioritised six outcomes and the measure of change from baseline to six months after treatment: probing pocket depth (PPD), bleeding on probing (BOP), clinical attachment level (CAL), gingival recession (REC), pocket closure and adverse effects related to aPDT. We were also interested in change in bone level (for participants with peri-implantitis), and participant satisfaction and quality of life.

MAIN RESULTS

We included 50 RCTs with 1407 participants. Most studies used a split-mouth study design; only 18 studies used a parallel-group design. Studies were small, ranging from 10 participants to 88. Adjunctive aPDT was given in a single session in 39 studies, in multiple sessions (between two and four sessions) in 11 studies, and one study included both single and multiple sessions. SI was given using hand or power-driven instrumentation (or both), and was carried out prior to adjunctive aPDT. Five studies used placebo aPDT in the control group and we combined these in meta-analyses with studies in which SI alone was used. All studies included high or unclear risks of bias, such as selection bias or performance bias of personnel (when SI was carried out by an operator aware of group allocation). We downgraded the certainty of all the evidence owing to these risks of bias, as well as for unexplained statistical inconsistency in the pooled effect estimates or for imprecision when evidence was derived from very few participants and confidence intervals (CI) indicated possible benefit to both intervention and control groups. Adjunctive aPDT versus SI alone during active treatment of periodontitis (44 studies) We are very uncertain whether adjunctive aPDT during active treatment of periodontitis leads to improvement in any clinical outcomes at six months when compared to SI alone: PPD (mean difference (MD) 0.52 mm, 95% CI 0.31 to 0.74; 15 studies, 452 participants), BOP (MD 5.72%, 95% CI 1.62 to 9.81; 5 studies, 171 studies), CAL (MD 0.44 mm, 95% CI 0.24 to 0.64; 13 studies, 414 participants) and REC (MD 0.00, 95% CI -0.16 to 0.16; 4 studies, 95 participants); very low-certainty evidence. Any apparent differences between adjunctive aPDT and SI alone were not judged to be clinically important. Twenty-four studies (639 participants) observed no adverse effects related to aPDT (moderate-certainty evidence). No studies reported pocket closure at six months, participant satisfaction or quality of life. Adjunctive aPDT versus SI alone during supportive treatment of periodontitis (six studies) We were very uncertain whether adjunctive aPDT during supportive treatment of periodontitis leads to improvement in any clinical outcomes at six months when compared to SI alone: PPD (MD -0.04 mm, 95% CI -0.19 to 0.10; 3 studies, 125 participants), BOP (MD 4.98%, 95% CI -2.51 to 12.46; 3 studies, 127 participants), CAL (MD 0.07 mm, 95% CI -0.26 to 0.40; 2 studies, 85 participants) and REC (MD -0.20 mm, 95% CI -0.48 to 0.08; 1 study, 24 participants); very low-certainty evidence. These findings were all imprecise and included no clinically important benefits for aPDT. Three studies (134 participants) reported adverse effects: a single participant developed an abscess, though it is not evident whether this was related to aPDT, and two studies observed no adverse effects related to aPDT (moderate-certainty evidence). No studies reported pocket closure at six months, participant satisfaction or quality of life.

AUTHORS' CONCLUSIONS

Because the certainty of the evidence is very low, we cannot be sure if adjunctive aPDT leads to improved clinical outcomes during the active or supportive treatment of periodontitis; moreover, results suggest that any improvements may be too small to be clinically important. The certainty of this evidence can only be increased by the inclusion of large, well-conducted RCTs that are appropriately analysed to account for change in outcome over time or within-participant split-mouth study designs (or both). We found no studies including people with peri-implantitis, and only one study including people with peri-implant mucositis, but this very small study reported no data at six months, warranting more evidence for adjunctive aPDT in this population group.

Efficacy of photodynamic therapy as an adjunct to scaling and root planing on clinical parameters and microbial composition in subgingival plaque of periodontitis patients: A split-mouth randomized clinical trial

BACKGROUND

The aim of this study was to assess the efficacy of photodynamic therapy (PDT) as an adjunct to scaling and root planing (SRP) on clinical parameters and microbial composition in subgingival plaque of periodontitis patients.

METHODS

Seventeen patients were included in this split-mouth randomized clinical trial. Sites with probing pocket depth (PPD) ≥5 mm in combination with bleeding on probing in different quadrants were randomized into the control group, the group with a single PDT application right after SRP, and the group with three repeated PDT applications 1 week after SRP. The subgingival plaque was collected for 16S rRNA gene sequencing at baseline, Week 2, and Week 8.

RESULTS

Seventeen patients with 60 sites completed this 8-week follow-up, and 157 subgingival plaques were successfully analyzed by sequencing. Significant improvements were observed in two primary outcomes: PPD at Week 8 and subgingival microbial composition. Compared to the control group, the repeated-PDT group showed a notable improvement in PPD, substantial alterations in the microbial profile, including a reduction in α-diversity and anaerobic bacteria, and an increase in aerobic bacteria at Week 2. Secondary outcomes, such as clinical attachment level and sulcus bleeding index, also showed improvement at Week 8. Furthermore, both the single- and repeated-PDT groups exhibited a decrease in periodontopathogens and an increase in beneficial bacteria compared with baseline.

CONCLUSION

PDT promotes changes in the microbial composition of periodontitis patients' subgingival plaque in a direction favorable to periodontal health, and repeated PDT is a promising adjunctive therapy for periodontal treatment.

Evaluating the potency of laser-activated antimicrobial photodynamic therapy utilizing methylene blue as a treatment approach for chronic periodontitis

Chronic periodontitis is a ubiquitous inflammatory disease in dental healthcare that is challenging to treat due to its impact on bone and tooth loss. Conventional mechanical debridement has been challenging in eliminating complex subgingival biofilms. Hence, adjunctive approaches like low-level laser antimicrobial photodynamic therapy (A-PDT) utilising methylene blue (MB) have been emerging approaches in recent times. This review evaluates the latest research on the use of MB-mediated A-PDT to decrease microbial count and enhance clinical results in chronic periodontitis. Studies have shown the interaction between laser light and MB generates a phototoxic effect thereby, eliminating pathogenic bacteria within periodontal pockets. Moreover, numerous clinical trials have shown that A-PDT using MB can reduce probing depths, improve clinical attachment levels, and decrease bleeding during probing in comparison to traditional treatment approaches. Notably, A-PDT shows superior antibiotic resistance compared to conventional antibiotic treatments. In conclusion, the A-PDT using MB shows promise as an adjunctive treatment for chronic periodontitis. Additional research is required to standardize treatment protocols and assess long-term outcomes of A-PDT with MB in the treatment of periodontitis.

Factorial design of in situ gelling two-compartment systems containing chlorhexidine for the treatment of periodontitis

Periodontitis is one of the most widespread bacterial infectious oral diseases that affects a significant percentage of the population worldwide. Different bacterial strains are responsible for the chronic inflammation and subgingival plaque that could be effectively treated with prolonged exposure to therapeutic levels of antibiotics and antiseptics in the periodontal pockets. Medicated in situ gels of chlorhexidine (CHX), for extended drug release and long-lasting antiseptic effect in the targeted cavities, were prepared in a two-compartment system. One compartment was loaded with sodium alginate solution while other was filled with CHX and calcium solution. The mixing of the solutions during the application resulted in gelation. Two 33 full factorial designs were applied in this study in order to optimize the gel formulation. Initially, the effects of concentration of gelling agent, crosslinker, and pH of the system on the dependent variables such as gel formation and structure characteristics were investigated. Then, the concentration of the crosslinker was optimized. Afterwards, the effect of gelling agent, loading of the drug, and pH of the gel system were correlated with the gel characteristics through another factorial design. Optimized formulations were tested for mucoadhesion, in vitro drug release, and microbiological investigation. Based on the results of the factorial design, mucoadhesiveness, antimicrobial investigation, and drug release, a 4 % alginate composition can be considered optimal. Overall, the optimized in situ periodontal gel was found to be effective with prolonged retention time and desirable outcomes.

Photoinactivation and Photoablation of Porphyromonas gingivalis

Several types of phototherapy target human pathogens and Porphyromonas gingivitis (Pg) in particular. The various approaches can be organized into five different treatment modes sorted by different power densities, interaction times, effective wavelengths and mechanisms of action. Mode 1: antimicrobial ultraviolet (aUV); mode 2: antimicrobial blue light (aBL); mode 3: antimicrobial selective photothermolysis (aSP); mode 4: antimicrobial vaporization; mode 5: antimicrobial photodynamic therapy (aPDT). This report reviews the literature to identify for each mode (a) the putative molecular mechanism of action; (b) the effective wavelength range and penetration depth; (c) selectivity; (d) in vitro outcomes; and (e) clinical trial/study outcomes as these elements apply to Porphyromonas gingivalis (Pg). The characteristics of each mode influence how each is translated into the clinic.

Photodynamic Therapy with Tolonium Chloride and a Diode Laser (635 nm) in the Non-Surgical Management of Periodontitis: A Clinical Study

This study aimed to evaluate the efficacy of photodynamic therapy (PDT) using tolonium chloride and a 635 nm diode laser as an adjunct to non-surgical periodontitis treatment, specifically scaling and root planing (SRP) alone. A total of 32 patients with a pocket probing depth > 5 mm were included in the study. Among them, 16 patients underwent SRP alone (control group), and the remaining 16 patients received SRP along with PDT (study group). The PDT procedure utilized a 635 nm diode laser (Smart M, Lasotronix, Poland) and tolonium chloride. Clinical periodontal parameters, such as the plaque index (PI), bleeding on probing (BOP), gingival recession (GR), probing pocket depth (PPD), and clinical attachment loss (CAL), were assessed before treatment (T0) and at 3 months after treatment (T3). At T3, both groups demonstrated a significant reduction in the PI, BOP, PD, and CAL compared to T0. The SRP + PDT group displayed a significant reduction in PPD (3.79 mm ± 0.35) compared to the SRP alone group (4.85 mm ± 0.42) at T3. Furthermore, the SRP + PDT group exhibited a significant reduction in CAL (5.01 ± 0.81) compared to the SRP group (5.99 ± 1.08) at T3. Within the study's limitations, it was concluded that PDT, with tolonium chloride and a 635 nm diode laser, significantly contributed to the non-surgical treatment of periodontitis.

Clinical applications of antimicrobial photodynamic therapy in dentistry

Given the emergence of resistant bacterial strains and novel microorganisms that globally threaten human life, moving toward new treatment modalities for microbial infections has become a priority more than ever. Antimicrobial photodynamic therapy (aPDT) has been introduced as a promising and non-invasive local and adjuvant treatment in several oral infectious diseases. Its efficacy for elimination of bacterial, fungal, and viral infections and key pathogens such as Streptococcus mutans, Porphyromonas gingivalis, Candida albicans, and Enterococcus faecalis have been investigated by many invitro and clinical studies. Researchers have also investigated methods of increasing the efficacy of such treatment modalities by amazing developments in the production of natural, nano based, and targeted photosensitizers. As clinical studies have an important role in paving the way towards evidence-based applications in oral infection treatment by this method, the current review aimed to provide an overall view of potential clinical applications in this field and summarize the data of available randomized controlled clinical studies conducted on the applications of aPDT in dentistry and investigate its future horizons in the dental practice. Four databases including PubMed (Medline), Web of Science, Scopus and Embase were searched up to September 2022 to retrieve related clinical studies. There are several clinical studies reporting aPDT as an effective adjunctive treatment modality capable of reducing pathogenic bacterial loads in periodontal and peri-implant, and persistent endodontic infections. Clinical evidence also reveals a therapeutic potential for aPDT in prevention and reduction of cariogenic organisms and treatment of infections with fungal or viral origins, however, the number of randomized clinical studies in these groups are much less. Altogether, various photosensitizers have been used and it is still not possible to recommend specific irradiation parameters due to heterogenicity among studies. Reaching effective clinical protocols and parameters of this treatment is difficult and requires further high quality randomized controlled trials focusing on specific PS and irradiation parameters that have shown to have clinical efficacy and are able to reduce pathogenic bacterial loads with sufficient follow-up periods.

In Vitro Antimicrobial Effect of Novel Electrospun Polylactic Acid/Hydroxyapatite Nanofibres Loaded with Doxycycline

The present study aimed to assess the in vitro antimicrobial effects of a novel biomaterial containing polylactic acid (PLA), nano-hydroxyapatite (nano-HAP) and Doxycycline (Doxy) obtained by electrospinning and designed for the non-surgical periodontal treatment. The antimicrobial activity of two samples (test sample, PLA-HAP-Doxy7: 5% PLA, nano-HAP, 7% Doxy and control sample, PLA-HAP: 5% PLA, nano-HAP) against two periodontal pathogens—Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis—was assessed using the Kirby−Bauer Disk Diffusion Susceptibility Test and compared with the effect of four antibiotics used as adjuvants in periodontal therapy: Amoxicillin, Ampicillin, Doxy and Metronidazole. The test sample (embedded with Doxy) showed higher inhibitory effects than commonly used antibiotics used in the treatment of periodontitis, while the control sample showed no inhibitory effects. Moreover, significant differences were observed between the inhibition zones of the two samples (p < 0.05). The Doxy-loaded PLA nanofibres had an antimicrobial effect against the periodontal pathogens. Based on these results, the novel biomaterial could be a promising candidate as adjuvant for the non-surgical local treatment in periodontitis.