Detection of dental plaque and its potential pathogenicity using quantitative light-induced fluorescence

Analysis of cariogenic biofilms by using a swept-source optical coherence tomography in vitro

OBJECTIVE

The objective was to measure the thickness of Streptococcus mutans (S. mutans) biofilms forming in an oral biofilm reactor (OBR) by using a noninvasive swept-source optical coherence tomography (SS-OCT) system at every 4 h time interval until 20 h and analyze the correlations with the amounts of biofilms.

METHODS

S. mutans biofilms were formed on square-shaped bovine enamel blocks inside an OBR. Biofilms were analyzed at every 4 h stage (4 h, 8 h, 12 h, 16 h and 20 h) using a SS-OCT system and a laser scanning confocal microscope (LSCM). The amounts of biofilms were measured at each stage by separating the water insoluble glucan (WIG) and bacterial cells. Co-relationships between the SS-OCT measured biofilm thickness and the amounts of adhered biofilms were analyzed.

RESULTS

The thickness of biofilms detected on SS-OCT images at 4 h stage was 0.059 ± 0.029 (Av ± SD) mm which increased time-dependently in a linear fashion after 8 h stage and reached to 0.435 ± 0.159 mm at 20 h stage and the correlation coefficient was about 0.89. The amounts of biofilms; bacterial optical density (OD) and WIG concentration increased time-dependently were 0.035 ± 0.008 / mm2 and 10.328 ± 2.492 µg/ mm2 respectively at 20 h stage. Correlation coefficients of 0.66 between 'the amounts of bacteria' and 'biofilm thickness on OCT' and 0.67 between 'the amounts of WIG' and 'biofilm thickness on OCT' were obtained, suggesting that there was a relatively positive correlation between them.

CONCLUSION

The SS-OCT can be a useful tool to measure time-dependent growth of biofilms. Further studies are needed in order to assess biofilms using SS-OCT more accurately.

Influence of Biofilm Maturity on the Antibacterial Efficacy of Cold Atmospheric Plasma in Oral Microcosm Biofilms

As biofilms mature, biomass and extracellular polysaccharide (EPS) content increases, enhancing pathogenicity. Therefore, this study aimed to evaluate the antibacterial efficacy of cold atmospheric plasma (CAP) against oral microcosm biofilms and the influence of biofilm maturity on treatment. Oral microcosm biofilms were cultured on hydroxyapatite disks for 2 and 6 days. Based on the treatment and biofilm maturity, these were subsequently allocated into six groups (N = 19 each): Groups 1 and 2 were incubated with distilled water for 1 min; Groups 3 and 4 were treated with CAP for 2 min, and Groups 5 and 6 were treated with 0.12% chlorhexidine gluconate for 1 min. Groups 1, 3, and 5 represent 2-day biofilms, and Groups 2, 4, and 6 represent 6-day biofilms. Treatments were repeated daily for 5 days. Antibacterial efficacy was analyzed by measuring oral biofilms' red fluorescence intensity (RatioR/G) and quantifying EPS content and bacterial viability. The RatioR/G was 1.089-fold and 1.104-fold higher in Groups 4 and 6 than in Groups 3 and 5 following antibacterial treatment, respectively (p < 0.001). EPS content increased by 1.71-fold in Group 6 than in Group 5 (p < 0.001). Bacterial survival rate was the lowest in Group 3 (p = 0.005). These findings underscore the relevance of CAP treatment in maintaining antibacterial efficacy regardless of the biofilm development stage, highlighting its potential utility in oral care.

A scoping review of new technologies for dental plaque quantitation: Benefits and limitations

OBJECTIVES

To determine the validity and reliability of novel digitalized tools for dental plaque detection and explore the benefits and limitations connected to their use.

DATA

Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. All human clinical studies comparing dental plaque detection using digitalized systems against a standard reference were included.

SOURCES

PubMed and Scopus were screened from 01 January 2013 to 28 September 2023. Bibliographies of primary studies and principal peer-reviewed scientific journals were manually searched.

STUDY SELECTION

The initial search identified 576 articles, with a total of 13 included in the review, published between 2015 and 2023. Most of the studies included (77 %) were cross-sectional with three being prospective. Digital devices captured 2D and 3D images via cameras and intra-oral scanners, respectively. The Turesky's modified plaque index was the most frequent clinical index. Correlation with clinical examination was moderate to strong, with good to excellent intra- and inter-system agreement.

CONCLUSIONS

Within the limitations of this scoping review, image analysis-based plaque detection systems demonstrated good correlations with clinical plaque indices, using both 2D and 3D imaging systems. Whilst digital plaque detection devices offer advantages in terms of procedural standardization and reproducibility, they also have limitations, therefore currently, their application should be underpinned by a comprehensive clinical examination.

CLINICAL SIGNIFICANCE

Digital plaque detection tools, that provide standardized measurements and store acquired images, facilitate more informed feedback to patients. This objective analysis may enhance clinician confidence in their utility for clinical trials and other applications.

Clinical assessment of various imaging systems for dental plaque scoring after the use of 3 different toothpastes

Purpose

This study was conducted to compare dental plaque scores obtained through clinical examinations and various imaging techniques, as well as to assess the effectiveness of herbal and conventional toothpastes for plaque removal.

Material and Methods

Thirty volunteers were divided into 3 groups. Each group was given a different toothpaste (from 2 herbal toothpastes and a conventional toothpaste) with which to brush their teeth for 21 days. Both initially and after brushing, dental plaque samples were collected, and plaque on the buccal surfaces of anterior teeth was scored using several imaging systems after staining with a disclosing agent. Specifically, digital dental photography, intraoral digital scanning, and FluoreCam imaging were employed to capture intraoral images. The Turesky Modified Quigley-Hein Plaque Index was used for clinical examination and image analysis. Quantitative polymerase chain reaction analyses and correlational assessments between clinical examination and imaging scores were conducted before and after toothpaste use. The Shapiro-Wilk test and Pearson correlations were utilized.

Results

The lowest mean value was observed in the clinical examination without staining, while the highest was obtained using the FluoreCam method. No significant change was found in the level of any microorganism assessed following toothpaste use (P<0.05), with the exception of a decrease in S. mutans levels after using conventional toothpaste (P<0.05).

Conclusion

Herbal toothpaste demonstrated plaque-removal effectiveness comparable to that of conventional toothpaste. The use of imaging methods for measuring plaque index has been suggested as a means to educate patients about plaque control and promote ongoing oral care.

Real-time optical detection of endodontic infection using bacterial autofluorescence

OBJECTIVES

For successful root canal treatment (RCT), it is essential to objectively assess the presence and activity of bacteria in the root canal system. However, current methods rely on subjective observations of root canal exudates. This study aimed to confirm whether real-time optical detection using bacterial autofluorescence can evaluate endodontic infection status by assessing the red fluorescence (RF) detected from root canal exudates.

METHODS

During RCT, endodontic paper points were used to collect root canal exudates scored using conventional organoleptic tests to assess the severity of root canal infections. RF on the paper points was assessed using quantitative light-induced fluorescence (QLF) technology. RF intensity and area from the paper points were quantified, and their correlations with infection severity were assessed using their organoleptic scores. The oral microbiome composition of RF samples was compared with non-red fluorescent (non-RF) samples.

RESULTS

The RF detection rate was nil and >98% in the non-infectious and severe groups. The RF intensity and area significantly increased with infection severity (p<0.001) and showed strong correlations with organoleptic scores (r=0.72, 0.82, respectively). The diagnostic accuracy for detecting root canal infection using RF intensity was good to excellent (AUC = 0.81-0.95) and increased with infection severity. The microbial diversity of the RF samples was significantly lower than that of the non-RF samples. Gram-negative anaerobic bacteria such as Prevotella and Porphyromonas were more predominant in RF samples.

CONCLUSIONS

Optical detection using bacterial autofluorescence can objectively evaluate endodontic infection status in real-time by assessing the RF of endodontic root canal exudates.

CLINICAL SIGNIFICANCE

This real-time optical technology can be utilised to detect endodontic bacterial infection without conventional incubation, allowing clinicians to determine the endpoint of chemomechanical debridement and increase the positive outcomes of RCTs.

Oral Bacteriome and Mycobiome across Stages of Oral Carcinogenesis

Oral microbial dysbiosis contributes to the development of oral squamous cell carcinoma (OSCC). Numerous studies have focused on variations in the oral bacterial microbiota of patients with OSCC. However, similar studies on fungal microbiota, another integral component of the oral microbiota, are scarce. Moreover, there is an evidence gap regarding the role that microecosystems play in different niches of the oral cavity at different stages of oral carcinogenesis. Here, we catalogued the microbial communities in the human oral cavity by profiling saliva, gingival plaque, and mucosal samples at different stages of oral carcinogenesis. We analyzed the oral bacteriome and mycobiome along the health-premalignancy-carcinoma sequence. Some species, including Prevotella intermedia, Porphyromonas endodontalis, Acremonium exuviarum, and Aspergillus fumigatus, were enriched, whereas others, such as Streptococcus salivarius subsp. salivarius, Scapharca broughtonii, Mortierella echinula, and Morchella septimelata, were depleted in OSCC. These findings suggest that an array of signature species, including bacteria and fungi, are closely associated with oral carcinogenesis. OSCC-associated diversity differences, species distinction, and functional alterations were most remarkable in mucosal samples, not in gingival plaque or saliva samples, suggesting an urgent need to define oral carcinogenesis-associated microbial dysbiosis based on the spatial microbiome. IMPORTANCE Abundant oral microorganisms constitute a complex microecosystem within the oral environment of the host, which plays a critical role in the adjustment of various physiological and pathological states of the oral cavity. In this study, we demonstrated that variations in the "core microbiome" may be used to predict carcinogenesis. In addition, sample data collected from multiple oral sites along the health-premalignancy-carcinoma sequence increase our understanding of the microecosystems of different oral niches and their specific changes during oral carcinogenesis. This work provides insight into the roles of bacteria and fungi in OSCC and may contribute to the development of early diagnostic assays and novel treatments.

Novel protein-repellent and antibacterial polymethyl methacrylate dental resin in water-aging for 6 months

Background

The present study aimed to develop a novel protein-repellent and antibacterial polymethyl methacrylate (PMMA) dental resin with 2-methacryloyloxyethyl phosphorylcholine (MPC) and quaternary ammonium dimethylaminohexadecyl methacrylate (DMAHDM), and to investigate the effects of water-aging for 6 months on the mechanical properties, protein adsorption, and antibacterial activity of the dental resin.

Methods

Four groups were tested: PMMA control; PMMA + 3% MPC; PMMA + 1.5% DMAHDM; and PMMA + 3% MPC + 1.5% DMADDM in acrylic resin powder. Specimens were water-aged for 1 d, 3 months, and 6 months at 37 ℃. Their mechanical properties were then measured using a three-point flexure test. Protein adsorption was measured using a micro bicinchoninic acid (BCA) method. A human saliva microcosm model was used to inoculate bacteria on water-aged specimens and to investigate the live/dead staining, metabolic activity of biofilms, and colony-forming units (CFUs).

Results

The flexural strength and elastic modulus showed a significant loss after 6 months of water-ageing for the PMMA control (mean ± SD; n = 10); in contrast, the new protein repellent and antibacterial PMMA resin showed no strength loss. The PMMA–MPC–DMAHDM-containing resin imparted a strong antibacterial effect by greatly reducing biofilm viability and metabolic activity. The biofilm CFU count was reduced by about two orders of magnitude (p < 0.05) compared with that of the PMMA resin control. The protein adsorption was 20% that of a commercial composite (p < 0.05). Furthermore, the PMMA–MPC–DMAHDM-containing resin exhibited a long-term antibacterial performance, with no significant difference between 1 d, 3 months and 6 months (p > 0.05).

Conclusions

The flexural strength and elastic modulus of the PMMA–MPC–DMAHDM-containing resin were superior to those of the PMMA control after 6 months of water-ageing. The novel PMMA resin incorporating MPC and DMAHDM exhibited potent and lasting protein-repellent and antibacterial properties.

Intraoral optical coherence tomography and angiography combined with autofluorescence for dental assessment

There remains a clinical need for an accurate and non-invasive imaging tool for intraoral evaluation of dental conditions. Optical coherence tomography (OCT) is a potential candidate to meet this need, but the design of current OCT systems limits their utility in the intraoral examinations. The inclusion of light-induced autofluorescence (LIAF) can expedite the image collection process and provides a large field of view for viewing the condition of oral tissues. This study describes a novel LIAF-OCT system equipped with a handheld probe designed for intraoral examination of microstructural (via OCT) and microvascular information (via OCT angiography, OCTA). The handheld probe is optimized for use in clinical studies, maintaining the ability to detect and image changes in the condition of oral tissue (e.g., hard tissue damage, presence of dental restorations, plaque, and tooth stains). The real-time LIAF provides guidance for OCT imaging to achieve a field of view of approximately 6.9 mm × 7.8 mm, and a penetration depth of 1.5 mm to 3 mm depending on the scattering property of the target oral tissue. We demonstrate that the proposed system is successful in capturing reliable depth-resolved images from occlusal and palatal surfaces and offers added design features that can enhance its usability in clinical settings.

Red fluorescence for assessing longitudinal tooth fractures

BACKGROUND

This study was designed to determine whether autofluorescence emitted from longitudinal tooth fractures (LTFs) differs between fracture types, with the aim of determining which clinical factors are related to red fluorescence at the fracture line.

METHODS

Thirty-three extracted teeth were classified into cracked teeth, split teeth, and root fractures using LTF types according to the American Association of Endodontists classification. The types of LTFs were identified using an operating microscope. LTF autofluorescence was captured using a fluorescence technique. Clinical examinations were performed using the preoperative factors from clinical and radiographic findings.

RESULTS

Red fluorescence was identified in 82% and 83% of cracked and split teeth, respectively. None of the vertical root fractures exhibited red fluorescence (p<0.001). When red fluorescence was identified on the outer tooth surface, it penetrated into the crack line, but fluorescence that was not red at the tooth surface did not penetrate the fracture line. Among the examined preoperative clinical factors, differences between the presence and absence of red fluorescence were identified for sinus tract formation (p=0.021), and radiographic features (p=0.027). Regression analysis revealed a significant factor related to the red fluorescence, with sinus tract formation having a negative effect on red fluorescence (odds ratio [OR]=0.09). The presence of comprehensive periradicular lesions in radiography had a positive effect on red fluorescence (OR=5.04).

CONCLUSIONS

Cracks originating from tooth crowns in certain types of LTFs were associated with red fluorescence, and cracks with red fluorescence were associated with extensive periodontal bone resorption around the teeth roots.

Gingivitis resolution followed by optical coherence tomography and fluorescence imaging: A case study

Gingivitis is highly prevalent in adults, and if left untreated, can progress to periodontitis. In this article, we present an interesting case study where the resolution of gingivitis was followed over a period of 10 days using optical coherence tomography (OCT) and light-induced autofluorescence (LIAF). We demonstrate that OCT and its functional angiography can distinctively capture the changes during the resolution of gingivitis; while LIAF can detect red-fluorescent signals associated with mature plaque present at the inflamed site. The acute inflammatory region showed evidence of angiogenesis based on the quantification of vessel density and number; while no angiogenesis was detected within the less inflamed region. Gingival thickness showed a reduction of 140 ± 26 μm on average, measured between the peak gingivitis event and the period wherein the inflammation was resolved. Vessels in the angiogenesis site was found to reduce exponentially. The mildly inflamed site showed a decreasing trend in the vessel size, which however was within the error of the measurement.

Evaluation of Periodontal Risk Factors with Quantitative Light-Induced Fluorescence Based Fluorescent Plaque Index, in Comparison to Radiographic and Oral Health Habit Scoring: A Retrospective Case Study

The aim of this study was to evaluate periodontal risk factors with oral health habits and fluorescent plaque index (FPI) using quantitative light-induced fluorescence (QLF) images, and to evaluate their effect on the degree of radiographic bone loss (RBL). Selected were 276 patients over 19 years of age to complete the questionnaire for oral health habit and take QLF images, periapical and panoramic radiographs. Oral health habit score, age, and sex showed a statistically significant correlation with FPI. FPI showed a lower value as the oral health habit score increased and the age decreased. Moreover, females showed lower FPI values than did males. RBL showed a statistically significant positive correlation with age but did not show any correlation with oral health habit scores and sex. There was no correlation between FPI and RBL. The results of this study suggest that the clinical use of QLF allows plaque detection by non-invasive procedures and can aid in a more objective estimation for oral hygiene status.

Evaluation of wound dehiscence after vertical bone graft by using quantitative light-induced fluorescence

Wound dehiscence is a common complication following vertical bone augmentation of implant dentistry. If the implanted titanium mesh becomes exposed, the exposed titanium mesh should be removed with the contaminated grafts before a clinical graft infection develops. However, no generally accepted evaluation methods have been suggested to determine the removal timing or the extent of contaminated bone grafts to be removed. Quantitative light-induced fluorescence (QLF) technology has been used for various oral bacterial condition such as dental caries, plaque, peri-implantitis, and osteomyelitis. This paper reports two patients with wound dehiscence within the third week after vertical bone augmentation with autogenous particulate bone on the posterior maxilla. With conservative treatment, a QLF technology was applied to determine whether to remove the mesh. The exposed mesh of the first patient was removed when red-fluorescence was observed the red fluorescence by QLF. However, the other case did not show red fluorescence during the fifth week after dehiscence, and secondary healing was achieved without complications. The remaining bone grafts were well integrated into the sound cortico-cancellous complex sufficient to support the dental implant. Based on these clinical, radiological, and histological results, we discussed the rationale of QLF application on wound dehiscence after the bone graft in implant dentistry.

The Influence of Diet on Oxidative Stress and Inflammation Induced by Bacterial Biofilms in the Human Oral Cavity

The article is a concise compendium of knowledge on the etiology of pathogenic microorganisms of all complexes causing oral diseases. The influence of particular components of the diet and the role of oxidative stress in periodontal diseases were described. The study investigated the bacteriostatic effect of the diet of adults in in vivo and in vitro tests on the formation of bacterial biofilms living in the subgingival plaque, causing diseases called periodontitis. If left untreated, periodontitis can damage the gums and alveolar bones. Anaerobic bacteria, called periopathogens or periodontopathogens, play a key role in the etiopathogenesis of periodontitis. The most important periopathogens of the oral microbiota are bacteria of all complexes, including the red complex. The obtained results suggest the possibility of using a specific diet in the prevention and treatment of periodontal diseases-already treated as a disease of civilization. The quoted article is an innovative compilation of knowledge on this subject and it can be a valuable source of knowledge for professional hygienists, dentists, peridontologists, dentistry students and anyone who cares about proper oral hygiene. The obtained results suggest the possibility of using this type of diet in the prophylaxis of the oral cavity in order to avoid periodontitis.

Histologic analysis of osteonecrosis of the jaw according to the different aspects on quantitative light-induced fluorescence images

BACKGROUND

Recurrence of osteonecrosis of the jaw has been reported after surgery. It is therefore necessary to develop a real-time diagnostic method, which can clearly distinguish the surgical margin from unaffected bone.

METHODS

We analyzed a sequestrum from a patient with medication-related osteonecrosis of the jaw (MRONJ). Quantitative light induced fluorescence (QLF) was applied to the sequestrum.

RESULTS

In this study, QLF demonstrated three types of fluorescence phenomena (Non-red-fluorescence, hyper-red-fluorescence, and hypo-red-fluorescence) on the sequestrum. Histology revealed geographical, microbiological, and immunological differences based on the fluorescence types on QLF. Non-red-fluorescence showed sclerotic and lamellar bone tissue, hyper-red-fluorescence showed an infectious state due to bacterial invasion and osteolysis, and hypo-red-fluorescence indicated predominantly granular tissue with inflammation, and the absence of bone matrix and bacterial colonies. Based on histologic analysis, we speculated that QLF may be a useful real-time diagnostic tool during surgery for MRONJ.

CONCLUSIONS

In conclusion, QLF can be useful in distinguishing between lamellar and infected bone, which are visually similar; QLF-guided ONJ surgery, preserving the Non-red-fluorescent areas and removing the hyper- and hypo-red-fluorescent areas of bone may be useful.

Photodynamic therapry with curcumin in the reduction of enterococcus faecalis biofilm in bone cavity: rMicrobiological and spectral fluorescense analysis

BACKGROUND

Antimicrobial photodynamic therapy (PDT) has emerged as a therapeutic strategy to conventional procedures using antibiotics.

OBJECTIVE

To evaluate the antimicrobial effectiveness of PDT using blue light emitting diode (LED) associated with curcumin on biofilms of Enterococcus faecalis in bovine bone cavities and also to analyze the presence of these biofilms through spectral fluorescence.

MATERIALS AND METHODS

Standardized suspensions of E. faecalis (ATCC 29212) were incubated in artificial bone cavities for 14 days at 36 °C ± 1 °C for biofilm formation. The test specimens were distributed among the four experimental groups (n = 10): L-C- (control), L + C- (LED for 5 min), L-C+ (curcumin for 5 min) and L + C+ (PDT). Aliquots were collected from the bone cavities after treatments and seeded on BHI agar for 24 h at 36 °C ± 1 °C for CFU count. Before and after each treatment the specimens were submitted to spectral fluorescence, whose images were compared in the Image J program. The log10 CFU/mL results were submitted to the Kruskal-Wallis test (5%) and the biofilm fluorescence spectroscopy results were submitted to the Wilcoxon test (5%).

RESULTS

All treatments presented statistical difference when compared to the control, and PDT was responsible for the largest reduction (1.92 log10 CFU/mL). There was a reduction in the fluorescence emitted after the treatments, with greater statistical difference in the PDT group.

CONCLUSION

PDT was efficient in the reduction of E. faecalis biofilms. In all groups post treatment there was a significant reduction of biofilms in the fluorescence spectroscopy images with greater reduction in the PDT group.

Detection of dentin-exposed occlusal/incisal tooth wear using quantitative light-induced fluorescence technology

OBJECTIVES

To prolong tooth life expectancy, tooth wear resulting in dentin exposure should be detected early. However, the most objective methods are clinically limited. We validated fluorescence parameters for distinguishing enamel from dentin-exposed wear in clinical images.

METHODS

Quantitative light-induced fluorescence (QLF) images of 73 adults (age range: 22-48 years, mean: 33.81 ± 7.71 years), including 1949 teeth with varying tooth wear degrees, without restorations, caries, or cusp area fractures, were used to calculate the ΔF_wear values. Areas-of-interest (AOIs) were selected from QLF images; the ΔF_wear values and the tooth wear index (TWI) were calculated for each tooth. The ΔF_wear values were compared according to the TWI scores. The optimum ΔF_wear values for distinguishing enamel and dentin-exposed wear were determined using the receiver operating characteristic (ROC) curve analysis.

RESULTS

Overall, 1949 AOIs were evaluated. The median ΔF_wear values for teeth with TWI scores 0, 1, and 2 (5.7 %, 10.3 %, and 17.0 %) differed significantly (P < 0.001). The optimum cutoff ΔF_wear values were 12.1 and 14.7 in the anterior and posterior teeth, respectively; the corresponding areas under the ROC values (AUROCs) were 0.86 and 0.93 (sensitivity: 0.79 and 0.85; specificity: 0.79 and 0.85, respectively). The ΔF_wear cutoff values for different age groups were within a range (12.7-13.7) and showed high validity (sensitivity, specificity, and AUROC: 0.78, 0.77-0.78, and 0.87-0.88, respectively).

CONCLUSIONS

At the optimum threshold, the ΔF_wear values showed high validity for distinguishing dentin exposure in worn teeth (AUROC: 0.87‒0.93) and could determine pathological tooth wear, particularly in posterior teeth.

CLINICAL SIGNIFICANCE

We demonstrated the feasibility of using QLF to detect dentin-exposed tooth wear and present optimal thresholds according to age. In addition, we confirmed the possibility using such image data for objective and cost-effective epidemiological investigation and application in tele-dentistry.

Clinical assessment of an automated fluorescent plaque index scoring with quantitative light-induced fluorescence

OBJECTIVE

The aims of this study were to evaluate the clinical applicability of a new fluorescent plaque index scoring (FPI) with the Turesky modified Quigley-Hein plaque index (mQH) and to evaluate its relationship with plaque maturity.

METHODS

In total 69 subjects participated in this study. White-light and fluorescent images of anterior teeth were acquired using a Qraycam (AIOBIO, Seoul, Korea). FPI was obtained from fluorescent images using the proprietary software (Q-Ray v.1.39, Inspektor Research System BV, Amsterdam, The Netherlands). Teeth were stained with a two-tone disclosing agent. mQH was used to manually score the combined red and blue disclosed plaque (Combi-mQH) and blue disclosed plaque (Blue-mQH) with the white-light images. Linear relationships between FPI and Combi-mQH (or Blue-mQH) were evaluated by using simple linear regression analysis. Differences of Combi-mQH (or Blue-mQH) with respect to FPI scores were statistically evaluated by using ANOVA with Duncan post hoc correction.

RESULTS

FPI showed a moderate positive correlation with Combi-mQH (r = 0.66, P < 0.001) and a high positive correlation with Blue-mQH (r = 0.78, P < 0.001). The model explanatory power (R²) between FPI and Blue-mQH was 60.8 %, which is 16.8 % higher than the explanatory power observed with Combi-mQH (44.0 %). Both Combi-mQH and Blue-mQH increased significantly with increasing FPI score (P < 0.001).

CONCLUSION

In this study we found that the FPI scoring system can be used to detect plaque and quantitatively distinguish plaque levels. In addition, FPI was determined to be useful in clinic because of its ability to detect and distinguish old and mature plaque.