Role of oral yeasts in the etiopathogenesis of peri-implantitis: An evidence-based literature review of clinical studies

Subgingival Yeasts Species Amongst Smokers and Nonsmokers With Peri-implantitis

BACKGROUND

There is a dearth of studies that have assessed yeast species in the subgingival biofilm (SB) samples collected from smokers and nonsmokers with peri-implantitis. This study assesses peri-implant clinical and radiographic profiles and yeasts species in the subgingival SB of cigarette smokers and nonsmokers with peri-implantitis.

METHODS

Participants were divided into 3 groups: group 1, cigarette smokers with peri-implantitis; group 2, nonsmokers with peri-implantitis; and group 3, nonsmokers without peri-implantitis. Information on smoking pack-years and patient demographics was collected. Implant-related parameters were retrieved from health care records. Peri-implant modified plaque and gingival indices (mPI and mGI, respectively), probing depth (PD), and crestal bone loss (CBL) were recorded. The SB samples were collected, subgingival yeasts colonisation was recorded, and yeasts species were identified. P < .05 was considered statistically significant.

RESULTS

Respectively, 22, 22, and 24 individuals were included in groups 1, 2, and 3. In group 1, cigarette smokers had a smoking history of 29.7 ± 7.9 pack-years. The PD, mPI, and mesial and distal CBL were higher in groups 1 (P < .01) and 2 (P < .01) than in group 3. The mGI was higher in group 2 (P < .01) than in groups 1 and 3. The total number of implants in groups 1, 2, and 3 were 22, 22, and 24, respectively. In group 3, implants were in function for a longer duration (12.2 ± 2.3 years; P < .05) than in groups 1 (5.6 ± 1.9 years) and 2 (5.1 ± 0.7 years). Yeasts levels in CFU/mL were higher in group 1 than in groups 2 (P < .05) and 3 (P < .05); they were also higher in group 2 than in group 3 (P < .05). Candida albicans was the most isolated yeasts species, followed by Candida tropicalis, in all groups.

CONCLUSIONS

Cigarette smokers and nonsmokers present similar peri-implant clinicoradiographic profiles, and oral yeasts (predominantly C albicans) seem to play a role in the progression of peri-implant disease in these individuals.

Development of photodynamic therapy in treating oral diseases

The morbidity of oral disorders, including gingivitis, caries, endodontic-periodontal diseases, and oral cancer, is relatively high globally. Pathogenic cells are the root cause of many oral disorders, and oral therapies depend on eradicating them. Photodynamic therapy (PDT) has been established as a potential and non-invasive local adjuvant treatment for oral disorders. PDT consists of three essential components: photosensitizer (PS), a light source with a certain wavelength, and oxygen dissolved in the cells. These three components can interact to cause damage to proteins, lipids, nucleic acids, and other biological components within diseased tissues. Herein, we aimed to provide a detailed understanding of PDT and how it can treat oral diseases. Concerns about PDT and potential remedies are also a factor. PDT has been shown in numerous clinical studies to be an efficient supplementary therapy that can reduce pathogenic cells. The PDT has great potential for dental applications, including treating bacterial and fungal infections during root canal therapy and preventing oral cancer, potentially malignant disorders, periodontitis, dental caries, and peri-implant disorders. Although PDT has been promoted as having significant potential and utility in dentistry, more clinical research must be conducted before being used broadly.

Efficacy of mechanical debridement with adjunct antimicrobial photodynamic therapy against peri-implant subgingival oral yeasts colonization: A systematic review and meta-analysis

BACKGROUND

It is hypothesized that mechanical debridement (MD) with adjunct antimicrobial photodynamic therapy (aPDT) is more efficient in reducing peri-implant subgingival yeasts colonization (SYC) than MD alone. The aim of the present systematic review and meta-analysis was to evaluate randomized controlled trials (RCTs) that assessed the efficacy of MD with and without adjunct aPDT towards the reduction in peri-implant SYC.

METHODS

The focused question was "Is MD with adjunct aPDT more effective then MD alone in reducing peri-implant SYC?" Indexed databases were searched without time and language restrictions until February 2024. The Population/Patients, Intervention, Control, Outcome (PICO) strategy was adopted. The literature search was performed using the preferred reporting items for systematic reviews and meta-analysis guidelines. The risk of bias (RoB) was assessed using the Cochrane RoB tool.

RESULTS

Three randomized controlled trials with a follow-up duration of 90 days were included and processed for data extraction. In one study, all participants were male and in the remaining two studies, males and females were included. One study showed that peri-implant MD with adjunct aPDT is more effective in reducing SYC than MD alone. In another study, there was no significant difference in SYC following MD with or without adjunct aPDT. In one study, the role of peri-implant MD with adjunct aPDT remained unclear due to missing data. The overall RoB was high and low in one and two studies, respectively.

CONCLUSION

The role of MD with or without adjunct aPDT in reducing peri-implant SYC remains debatable.

Peri-implant clinical profile and subgingival yeasts carriage among cigarette-smokers with peri-implant mucositis

BACKGROUND

The present observational clinical investigation is based on the hypothesis that subgingival yeast carriage (SYC) is higher in cigarette-smokers with peri-implant mucositis (PM) than non-smokers with and without PM.

OBJECTIVE

The aim was to assess peri-implant clinical profile and SYC among cigarette-smokers with PM.

METHODOLOGY

Participants were divided into four groups: Group-1-Cigarette-smokers with PM; Group-2-Cigarette-smokers without PM; Group-3-Non-smokers with PM; and Group-4-Non-smokers without PM. Information on duration and daily frequency of cigarette smoking (pack years), age, gender, familial history of smoking and most recent visit to a dentist and/or dental hygienist was collected. The following information was retrieved from healthcare records: implant dimensions, implant insertion torque, depth of insertion (credidastal or subcrestal), implant abutment connection, jaw location, implant surface characteristic, and mode of implant prosthesis retention. Peri-implant modified plaque and gingival indices (mPI and mGI), probing depth (PD) and crestal bone loss were recorded. Subgingival biofilm samples were collected, and SYC was recorded in colony forming units per milliliter (CFU/ml). P < 0.05 were considered statistically significant.

RESULTS

Eighty male individuals (20, 19, 21 and 20 individuals were included in groups 1, 2, 3 and 4, respectively) were included. The mPI was higher in Group-1 than groups 2 (P < 0.05) and 4 (P < 0.05). The mPI was higher in Group-3 than groups 2 (P < 0.05) and 4 (P < 0.05). The mGI was higher in Group-3 than groups 1 (P < 0.05), 2 (P < 0.05) and 4 (P < 0.05). The PD was higher in Group-1 than groups 2 (P < 0.05) and 4 (P < 0.05). The PD was higher in Group-3 than Groups 2 (P < 0.05) and 4 (P < 0.05). The CFU/ml were higher in Group-1 than groups 2 (P < 0.05) and 4 (P < 0.05). The CFU/ml were higher in Group-3 than groups 2 (P < 0.05) and 4 (P < 0.05).

CONCLUSION

Peri-implant soft-tissue inflammatory parameters are worse and SYC is higher in moderate smokers than light smokers with PM and non-smokers without PM.

Short-term influence of antimicrobial photodynamic therapy as an adjuvant to mechanical debridement in reducing soft-tissue inflammation and subgingival yeasts colonization in patients with peri-implant mucositis

OBJECTIVE

The objective of this short-term follow-up study was to evaluate the influence of antimicrobial photodynamic therapy (aPDT) as an adjuvant to mechanical debridement (MD) in reducing soft-tissue inflammation and subgingival yeasts colonization (SYC) in patients with peri‑implant mucositis (PiM).

METHODS

Individuals diagnosed with PiM were included. Demographic data was collected using a questionnaire. Peri-implant plaque index (PI), bleeding index (BI), probing depth (PD), crestal bone levels and SYC were measured at baseline. Therapeutically, these individuals were divided into test and control groups. In the control-group patients underwent MD and in the test-group patients underwent MD with adjunct single session of aPDT. Clinical peri‑implant parameters and SYC were reassessed after 12-weeks. Correlation between age, gender and duration of implants with SYC and clinical peri‑implant status was assessed using logistic regression models. P < 0.05 was selected as an indicator of statistical significance.

RESULTS

The test and control-groups comprised of 24 and 23 individuals, respectively. In the test and control groups, toothbrushing twice daily was reported by 7 (29.2%) and 5 (21.7%) individuals, respectively. None of the individuals had ever used a dental floss. At baseline, there was no difference in peri‑implant PI, BI, PD and CBL in the test and control groups. At follow-up, peri‑implant PI (P < 0.01), BI (P < 0.01) and PD (P < 0.01) were significantly higher in the control compared with the test-group. At baseline, SYC in the test and control groups were 1865.3 ± 403.4 CFU/ml and 1963.7 ± 512.4 CFU/ml, respectively. At 90 days' follow-up, SYC in the test and control groups were 1472 ± 202.7 and 1538.4 ± 331.7 CFU/ml, respectively. There was no significant difference in SYC in both groups when baseline values were compared with 90 days' follow-up.

CONCLUSION

One session of aPDT after MC with adjunct aPDT is effective in reducing soft tissue inflammation but not SYC in patients with PiM.

Cross-kingdom microbial interactions in dental implant-related infections: is Candida albicans a new villain?

Candida albicans, an oral fungal opportunistic pathogen, has shown the ability to colonize implant surfaces and has been frequently isolated from biofilms associated with dental implant-related infections, possibly due to its synergistic interactions with certain oral bacteria. Moreover, evidence suggests that this cross-kingdom interaction on implant can encourage bacterial growth, leading to increased fungal virulence and mucosal damage. However, the role of Candida in implant-related infections has been overlooked and not widely explored or even considered by most microbiological analyses and therapeutic approaches. Thus, we summarized the scientific evidence regarding the ability of C. albicans to colonize implant surfaces, interact in implant-related polymicrobial biofilms, and its possible role in peri-implant infections as far as biologic plausibility. Next, a systematic review of preclinical and clinical studies was conducted to identify the relevance and the gap in the existing literature regarding the role of C. albicans in the pathogenesis of peri-implant infections.

Disinfection of implant abutment connection using antimicrobial photodynamic therapy and 0.2% chlorhexidine gel applications immediately before prosthesis delivery: Clinical and radiographic status at 1-year of follow-up

OBJECTIVE

The aim of this 1-year follow-up randomized control trial was to compare the clinicoradiographic status of implants that were disinfected with antimicrobial photodynamic therapy (aPDT) and 0.2% chlorhexidine gel immediately before prosthesis delivery.

METHODS

Forty-five partially edentulous patients with implants placed in the region of missing mandibular first molars and a history of periodontal diseases were included. Immediately before prosthesis delivery, patients were divided into three groups. In groups 1 and 2, implant abutment disinfection (IAD) was performed using aPDT and 0.2% chlorhexidine immediately before prosthesis delivery. In Group-3, IAD was performed using a steaming protocol. Peri-implant modified plaque index (mPI), modified gingival index (mGI), probing depth (PD) and crestal bone loss (CBL) were assessed at 1 year of follow-up. Power analysis was done and group comparisons were done. Logistic regression analysis was done to corelate clinical parameters with demographic variables. P<0.01 was considered statistically significant.

RESULTS

In total, 15, 15, and 15 implants were present among patients in groups 1, 2 and 3, respectively. There was no statistically significant difference in peri-implant mPI, mBoP, PD and CBL in all groups (Table 2). None of the patients had periodontal disease and there was no statistically significant correlation between peri-implant clinicoradiographic parameters with age, toothbrushing and flossing habits, and duration of implants in function. Eighty percent, 86.7% and 100% individuals in groups 1, 2 and 3, respectively reported that they were brushing teeth twice daily. Flossing of interproximal spaces once daily was reported by 66.7%, 73.3% and 66.7% individuals in groups 1, 2 and 3, respectively.

CONCLUSION

As long as oral hygiene is stringently maintained after implant prosthesis delivery, IAD can be performed using aPDT, 0.2% CHX gel or steam-disinfection.

Role of antimicrobial photodynamic therapy in reducing whole salivary oral yeasts colonization in type-2 diabetic and non-diabetic patients with and without dental implants

OBJECTIVE

The aim was to assess the impact of antimicrobial photodynamic therapy (aPDT) in reducing whole salivary oral yeasts colonization in type-2 diabetic and non-diabetic patients with dental implants.

METHODS

Type-2 diabetic and self-reported non-diabetic patients were included. Participants were divided into the following groups: Group-1: Type-2 diabetic patients with dental implants; Group-2: Non-diabetic patients with dental implants; Group-3: Type-2 diabetic patients without dental prostheses; Group-4: Non-diabetic patients without dental prostheses. In each group, participants were subdivided into 2-sub-groups. In the test-subgroup, participants received routine oral hygiene maintenance instructions (OHMI) and underwent full mouth disinfection using aPDT; and in the control-group, participants received OHMI alone. Unstimulated whole saliva samples were collected, hemoglobin A1c levels were measured and yeast colonization was assessed at baseline and at 3-months' follow-up in all groups. Sample-size estimation was done and group-comparisons were done. P-values <0.01 were considered statistically significant.

RESULTS

At baseline, the mean oral yeasts colonization was significantly higher among patients in Group-1 (P < 0.001) and 3 (P < 0.001) compared with individuals in groups 2 (P < 0.001) and 4 (P < 0.001). At baseline and at 3-months of follow-up, the mean HbA1c levels and oral yeasts colonization were significantly higher among patients in Group-1 (P < 0.001) and 3 (P < 0.001) compared with individuals in groups 2 (P < 0.001) and 4 (P < 0.001).

CONCLUSION

In the short-term, routine OHMI with adjunct aPDT is more effective in reducing whole salivary oral yeasts counts than OHMI alone in patients with and without dental implants.

In vitro Candida albicans biofilm formation on different titanium surface topographies

Objectives

To investigate if differences in titanium implant surface topography influence Candida albicans biofilm formation.

Materials and Methods

Titanium discs were prepared and characterized using a profilometer: Group A (R_a 0.15 µm, smooth), Group B (R_a 0.64 µm, minimally rough) and Group C (R_a 1.3 µm, moderately rough). Contact angle and surface free energy (SFE) were determined for each group. Non-preconditioned titanium discs were incubated with C. albicans for 24 h. In additional experiments, the titanium discs were initially coated with human saliva, bovine serum albumin or phosphate-buffered saline for 2 h before incubation with C. albicans for 24 h. The amount of fungal biofilm formation was quantified using a colorimetric assay.

Results

C. albicans biofilm formation was significantly lower (p < 0.05) on the minimally rough titanium surface compared to smooth and moderately rough surfaces. The titanium surface displaying the lowest SFE (Group B) was associated with significantly lower (p < 0.05) C. albicans biofilm formation than the other two groups. Salivary coating resulted in greater adherence of C. albicans with increased surface roughness.

Conclusions

The minimally rough titanium discs displayed lowest SFE compared to smooth and moderately rough surfaces and showed the least C. albicans biofilm formation. This study demonstrated that C. albicans biofilm formation increased in a SFE-dependent manner. These findings suggest that SFE might be a more explanatory factor for C. albicans biofilm formation on titanium surfaces than roughness. The presence of a pellicle coating may negate the impact of SFE on C. albicans biofilm formation on titanium surfaces.