Gingival inflammation assessment: Image analysis

Functional characterization of Vibrio alginolyticus T3SS regulator ExsA and evaluation of its mutant as a live attenuated vaccine candidate in zebrafish (Danio rerio) model

Vibrio alginolyticus, a Gram-negative bacterium, is an opportunistic pathogen of both marine animals and humans, resulting in significant losses in the aquaculture industry. Type III secretion system (T3SS) is a crucial virulence mechanism of V. alginolyticus. In this study, the T3SS regulatory gene exsA, which was cloned from V. alginolyticus wild-type strain HY9901, is 861 bp encoding a protein of 286 amino acids. The ΔexsA was constructed by homologous recombination and Overlap-PCR. Although there was no difference in growth between HY9901 and ΔexsA, the ΔexsA exhibited significantly decreased extracellular protease activity and biofilm formation. Besides, the ΔexsA showed a weakened swarming phenotype and an ~100-fold decrease in virulence to zebrafish. Antibiotic susceptibility testing showed the HY9901ΔexsA was more sensitive to kanamycin, minocycline, tetracycline, gentamicin, doxycycline and neomycin. Compared to HY9901 there were 541 up-regulated genes and 663 down-regulated genes in ΔexsA, screened by transcriptome sequencing. qRT-PCR and β-galactosidase reporter assays were used to analyze the transcription levels of hop gene revealing that exsA gene could facilitate the expression of hop gene. Finally, Danio rerio, vaccinated with ΔexsA through intramuscular injection, induced a relative percent survival (RPS) value of 66.7% after challenging with HY9901 wild type strain. qRT-PCR assays showed that vaccination with ΔexsA increased the expression of immune-related genes, including GATA-1, IL6, IgM, and TNF-α in zebrafish. In summary, these results demonstrate the importance of exsA in V. alginolyticus and provide a basis for further investigations into the virulence and infection mechanism.

A pilot study to evaluate the impact of digital imaging on the delivery of oral hygiene instruction

AIMS

To determine whether personalised Oral Hygiene Advice (OHA) using an intra-oral-camera (IOC) combined with standard OHA as provided in general dental practice reduces plaque levels after 4 weeks more than the provision of standard OHA.

MATERIALS AND METHODS

22 healthy adult participants diagnosed with gingivitis took part in this pilot parallel-designed, randomised, examiner-blind, 2xtreatment, study regarding their home-care oral hygiene habits and attitudes to oral health. An IOC-image was taken and plaque, gingival and bleeding scores were recorded. Test group participants received standard OHA with IOC-images to indicate areas for improvement, control group participants received standard OHA. Questionnaires and plaque, gingival and bleeding scores were repeated after 4 weeks. Plaque was scored from the IOC-images and scores compared to clinical plaque scores.

RESULTS

Lifestyle habits, attitudes to oral health, plaque (0.63vs0.61, control vs test) and bleeding scores (1.17vs0.96, control vs test) were similar at baseline. After 4-weeks, plaque scores improved more in test as compared to control group (39.4vs20.6%, p<0.05, while gingival and bleeding scores approached significance. There was no difference in lifestyle habits between groups, but the test group reported significantly greater confidence in adhering to their bespoke oral health plan. Agreement between the clinical and IOC plaque scores was good.

CONCLUSIONS

Use of IOC further personalises the prevailing standard of oral hygiene advice and generates great patient engagement with pictorial reports to facilitate a more in-depth patient explanation of their gingival health, resulting in significant plaque reduction and improved gingival health compared to the standard OHA alone.

CLINICAL SIGNIFICANCE

Clinically significant improved plaque control can be achieved by individuals with mild-moderate gingivitis following one episode of personalised tailored IOC OHA combined with the standard of OHA provided in the general dental services compared to only the latter. IOC better engages patients and facilitates remote index scoring.

Using Health Concept Surveying to Elicit Usable Evidence: Case Studies of a Novel Evaluation Methodology

BACKGROUND

Developers, designers, and researchers use rapid prototyping methods to project the adoption and acceptability of their health intervention technology (HIT) before the technology becomes mature enough to be deployed. Although these methods are useful for gathering feedback that advances the development of HITs, they rarely provide usable evidence that can contribute to our broader understanding of HITs.

OBJECTIVE

In this research, we aim to develop and demonstrate a variation of vignette testing that supports developers and designers in evaluating early-stage HIT designs while generating usable evidence for the broader research community.

METHODS

We proposed a method called health concept surveying for untangling the causal relationships that people develop around conceptual HITs. In health concept surveying, investigators gather reactions to design concepts through a scenario-based survey instrument. As the investigator manipulates characteristics related to their HIT, the survey instrument also measures proximal cognitive factors according to a health behavior change model to project how HIT design decisions may affect the adoption and acceptability of an HIT. Responses to the survey instrument were analyzed using path analysis to untangle the causal effects of these factors on the outcome variables.

RESULTS

We demonstrated health concept surveying in 3 case studies of sensor-based health-screening apps. Our first study (N=54) showed that a wait time incentive could influence more people to go see a dermatologist after a positive test for skin cancer. Our second study (N=54), evaluating a similar application design, showed that although visual explanations of algorithmic decisions could increase participant trust in negative test results, the trust would not have been enough to affect people's decision-making. Our third study (N=263) showed that people might prioritize test specificity or sensitivity depending on the nature of the medical condition.

CONCLUSIONS

Beyond the findings from our 3 case studies, our research uses the framing of the Health Belief Model to elicit and understand the intrinsic and extrinsic factors that may affect the adoption and acceptability of an HIT without having to build a working prototype. We have made our survey instrument publicly available so that others can leverage it for their own investigations.

Quantitative Assessment of Gingival Inflammation in Patients Undergoing Nonsurgical Periodontal Therapy Using Photometric CIELab Analysis

Visual inspection and gingival indices have been traditionally used for diagnosis of gingival inflammation. These methods are prone for subjective variability. Thus, the study is aimed at evaluating gingival inflammation quantitatively by using CIELab colour space value obtained from digital photographs. An experimental study was conducted with 27 patients each in group A (gingivitis) and group B (chronic periodontitis, CP). Preoperative and postoperative (1 month) photographs of maxillary anterior sextant were recorded to evaluate CIELab coordinate values. Simultaneously, clinical parameters such as bleeding on probing (BOP) and periodontal probing depth (PPD) along with indices such as plaque index (PI), gingival index (GI), and sulcus bleeding index (SBI) were evaluated before and after the nonsurgical periodontal therapy. Data was presented as the $\text{mean}\pm \text{SD}$ , and a paired $t$ -test was used for the testing hypothesis with $p<0.05$ considered as significant. Data analysis was carried out with Statistical Package for the Social Sciences (SPSS) version 21. A significant reduction ( $p<0.001$ ) is seen in all the clinical parameters and indices before and after the intervention in chronic periodontitis patients. Similar results were seen in gingivitis patients ( $p<0.001$ ) except for PPD. A significant ( $p<0.001$ ) reduction in postoperative values of the $a\ast$ and $b\ast$ coordinates was seen in CP patients; whereas, only the $a\ast$ coordinate value reported a significant ( $p<0.001$ ) reduction in the gingivitis group of patients. The $\Delta E$ of the gingivitis and chronic periodontitis groups was 2.25 and 2.96, respectively. Within the confinements of the study, estimating the gingival colour with the help of CIELab values taken via digital photographs can be an excellent valuable tool to assess the gingival colour as a sign of gingival inflammation.

A proof of concept study to confirm the suitability of an intra oral scanner to record oral images for the non-invasive assessment of gingival inflammation

OBJECTIVES

To compare gingival inflammation scores obtained chairside using the non-invasive modified gingival index (MGI) with MGI scores from an intraoral scan (IOS) captured at the clinical visit but viewed 10 days later.

METHODS

Single visit, anterior teeth, observational, proof of concept study in healthy adult participants with a spectrum of gingival inflammation. One investigator performed both clinical and intraoral scan MGI assessments, a second repeated the MGI evaluation from the IOS.

RESULTS

23 participants aged 18-72 yielded data for 552 gingival sites. There was agreement at 90 % of sites comparing clinical with IOS MGI scores. The commonest disagreements were MGI grade 0 read as 1 and 2 read as 3, the highest single probability of error occurring where a clinical score of 0 was scored 1 from the IOS: 0.118 and 0.129 for examiners 1 and 2 respectively. The second most common probability of error occurred where an IOS score of 3 was scored clinically as 2: 0.089 and 0.097 for examiners 1 and 2 respectively. MGI scores from the scans were similar for both examiners (91 % agreement), with no discrepancies of greater than 1 scale point. There was very close agreement between clinical MGI and IOS colour/texture scores.

CONCLUSION

This study conclusively demonstrated that the MGI score from the scanned image was very similar to the MGI scored clinically. This study confirms that a digital IOS accurately captures gingival contour images allowing a clinician to determine health or degree of gingival inflammation from it using MGI scores.

CLINICAL SIGNIFICANCE STATEMENT

This study confirms that IOS images of teeth and soft tissues are sufficiently accurate to allow the clinical evaluation of health or inflammatory gingival status using non-invasive indices. IOS has great potential for efficient and accurate data capture, for general practice and research facilitating remote evaluation and data verification.

Semi-automated registration and segmentation for gingival tissue volume measurement on 3D OCT images

The change in gingival tissue volume may be used to indicate changes in gingival inflammation, which may be useful for the clinical assessment of gingival health. Properly quantifying gingival tissue volume requires a robust technique for accurate registration and segmentation of longitudinally captured 3-dimensional (3D) images. In this paper, a semi-automated registration and segmentation method for micrometer resolution measurement of gingival-tissue volume is proposed for 3D optical coherence tomography (OCT) imaging. For quantification, relative changes in gingiva tissue volume are measured based on changes in the gingiva surface height using the tooth surface as a reference. This report conducted repeatability tests on this method drawn from repeated scans in one patient, indicating an error of the point cloud registration method for oral OCT imaging is 63.08 ± 4.52µm (1σ), and the measurement error of the gingival tissue average thickness is -3.40 ± 21.85µm (1σ).

Plaque-induced gingivitis: Case definition and diagnostic considerations

OBJECTIVE

Clinical gingival inflammation is a well-defined site-specific condition for which several measurement systems have been proposed and validated, and epidemiological studies consistently indicate its high prevalence globally. However, it is clear that defining and grading a gingival inflammatory condition at a site level (i.e. a "gingivitis site") is completely different from defining and grading a "gingivitis case" (GC) (i.e. a patient affected by gingivitis), and that a "gingivitis site" does not necessarily mean a "GC". The purpose of the present review is to summarize the evidence on clinical, biochemical, microbiologic, genetic markers as well as symptoms associated with plaque-induced gingivitis and to propose a set of criteria to define GC.

IMPORTANCE

A universally accepted case definition for gingivitis would provide the necessary information to enable oral health professionals to assess the effectiveness of their prevention strategies and treatment regimens; help set priorities for therapeutic actions/programs by health care providers; and undertake surveillance.

FINDINGS

Based on available methods to assess gingival inflammation, GC could be simply, objectively and accurately identified and graded using bleeding on probing score (BOP%) CONCLUSIONS: A patient with intact periodontium would be diagnosed as a GC according to a BOP score ≥ 10%, further classified as localized (BOP score ≥ 10% and ≤30%) or generalized (BOP score > 30%). The proposed classification may also apply to patients with a reduced periodontium, where a GC would characterize a patient with attachment loss and BOP score ≥ 10%, but without BOP in any site probing ≥4 mm in depth.

Relative Translucency of a Multilayered Ultratranslucent Zirconia Material

AIM

The aim of this study was to compare the translucency parameter (TP) of ultratranslucent multilayered (UTML) zirconia according to thickness and layer level.

MATERIALS AND METHODS

Rectangles of UTML zirconia with four layers [dentin layer (DEL), first transitional layer (FTL), second transitional layer (STL), and enamel layer (ENL)] and four different thicknesses (0.4, 0.6, 0.8, and 1 mm) were milled from blanks. Digital images were taken in a dark studio against white and black backgrounds under simulated daylight illumination and international commission on illumination (CIE) Lab* color values recorded using Photoshop Creative Cloud software. The TP was computed and compared according to thickness and layer level using analysis of variance (ANOVA) followed by Bonferroni post hoc analysis for multiple comparisons. Significance was set at p < 0.05.

RESULTS

In each thickness, TP values were similar between any two layers. The significant effect of thickness on the TP was observed only in the first two layers. In the DEL, translucency was significantly greater at 0.4 mm than all other thicknesses. In the FTL, differences were significant between 0.4 and 0.8 mm and between 0.4 and 1 mm.

CONCLUSION

The investigated zirconia does not seem to show gradational changes in relative translucency from dentin to enamel levels regardless of the thickness used. Thickness affected the TP only in the first two layers with better translu-cency at 0.4 mm.

CLINICAL SIGNIFICANCE

Since relative translucency does not seem to be significantly different between layers, clinicians can modify the apicocoronal positioning of the UTML layers within the restoration according to the desired Chroma without any implications on the clinically perceived translucency. While the thickness of 0.4 mm may be suggested for anterior esthetic veneers because of its higher translucency, the other thicknesses of 0.6 to 1 mm can be used to mask colored abutments in full contour restorations.

Performance of a light fluorescence device for the detection of microbial plaque and gingival inflammation

OBJECTIVES

The hypothesis to be tested was that using the SOPROCARE system in fluorescence perio-mode allows scoring of microbial plaque that is comparable to the Turesky modification of the Quigley Hein plaque index (T-QH) and scoring of gingival inflammation comparable to the Silness and Löe gingival inflammation index (GI).

MATERIALS AND METHODS

Fifty-five subjects with various amounts of microbial plaque were recruited. The T-QH and GI index were recorded. SOPROCARE pictures were recorded in fluorescence perio-mode and in daylight mode. Finally, conventional digital photographs were taken. All pictures were assessed using the same criteria as described for the clinical indices.

RESULTS

The average T-QH was 1.1 ± 1.2 (mean ± SD). Scoring with SOPROCARE perio-mode led to a slightly higher average than the T-QH scores. SOPROCARE daylight mode and digital photography showed the highest plaque scores. The average GI index was 0.7 ± 0.9. SOPROCARE in perio-mode scored slightly lower. Linear regression fits between the different clinical indices and SOPROCARE scores were significantly different from zero demonstrating high goodness of fit.

CONCLUSIONS

The study demonstrated that the SOPROCARE fluorescence assessment tool in perio-mode allows reliable judgment of microbial plaque and gingival inflammation levels similar to the established Turesky-modified Quigley Hein index and the Silness and Löe gingival inflammation index. Training on plaque-free teeth will actually reduce scoring errors.

CLINICAL RELEVANCE

The SOPROCARE fluorescence tool in perio-mode provides reliable evaluation of microbial plaque and gingival inflammation for the dental clinician.