Measurement of bristle splaying of toothbrushes using digital imaging and evaluation of plaque removal efficacy over 3 months: A randomized controlled trial (RCT)

Cross-sectional pilot study of relationships between specific oral bacteria and acute respiratory failure requiring intensive care unit admission

OBJECTIVES

Acute respiratory failure (ARF) is a severe condition requiring intensive care unit (ICU) admission. Periodontal disease is a chronic inflammatory disorder caused by periodontal bacteria, though it is unknown whether specific periodontal bacteria are associated with ARF patients admitted to the ICU. The present study was conducted to compare oral environmental factors and numbers of specific oral bacteria between patients with and without ARF related to ICU admission.

METHODS

A cross-sectional investigation was performed with 64 ICU patients, divided into ARF (n = 18) and non-ARF (n = 46) groups based on the causative disease related to admission. Clinical characteristics, oral environment factors, and numbers of 12 oral bacterial species in saliva and tongue samples were examined using a DNA chip.

RESULTS

Dry mouth and coated tongue were more frequently found in the ARF than the non-ARF group. The numbers of Porphyromonas gingivalis in both saliva and tongue samples in the ARF were greater than those in the non-ARF (p = 0.013, p = 0.028, respectively). The numbers of Capnocytophaga gingivalis from the tongues in the ARF group were greater as compared with those in the non-ARF group (p = 0.032).

CONCLUSIONS

The findings obtained in this pilot study indicate the possibility that P. gingivalis and C. gingivalis are associated with ARF requiring ICU admission.

CLINICAL SIGNIFICANCE

The oral microbiota may differ between ARF patients and non-ARF patients.

Anti-fungal effects of slightly acidic electrolyzed water on Candida species

OBJECTIVES

Slightly acidic electrolyzed water (SAEW) is produced by electrolyzing 2-6% diluted hydrochloric acid in a membrane-less chamber, resulting in 5.0-6.5 pH, and can be applied to various foods as a disinfectant. Although SAEW has shown to have bactericidal activity, the details of its anti-fungal effects towards Candida species remain unknown. Therefore, we examined the fungicidal effects of SAEW on Candida spp. and biofilms on acrylic resins.

METHODS

The fungicidal effects of SAEW on Candida spp. at different reaction times and total numbers of colonies in culture plates were examined. Subsequently, SAEW was added to Candida spp. biofilms formed on polystyrene plates, and adenosine triphosphate (ATP) in SAEW was measured to examine its fungicidal effects towards Candida spp. biofilms. The fungicidal effect of SAEW on Candida spp. biofilms was determined by counting the number of colonies on the acrylic resin after adding SAEW.

RESULTS

SAEW completely killing activity within 1 min with the tested Candida spp. C. albicans and C. glabrata ATP were increased 5 min after adding SAEW compared with the controls, suggesting the removal of biofilm. Of the C. albicans on acrylic resin, >99.9%were killed by SAEW compared to their levels in deionized distilled water (DW) (76.2 × 102/mL and 43.3 × 102/mL, respectively). Similarly, 93.1% of C. glabrata were killed by SAEW compared to DW (159.3x102/mL).

CONCLUSIONS

SAEW may be useful in preventing oral candidiasis as part of oral care.

Physicochemical Properties of Curen® Filaments Versus Nylon Filaments in Toothbrush Bristles: An In Vitro Study

Background Toothbrush manufacturers commonly use bristle materials such as nylon, polybutylene terephthalate, polypropylene, polyethylene terephthalate, boar hair, bamboo, carbon fiber, silicone, polylactic acid, or their modifications such as Curen®. Nylon filaments have long been demonstrated to be durable and are widely used, but not much is known regarding the performance of Curen® filaments compared to nylon filaments. This in vitro study compared the stiffness, abrasion potential, abrasion resistance, and bristle surface changes of Curen® and nylon filaments. Methodology Ten specimens (five dry and five wet) each of Curaprox CS5460 toothbrushes featuring Curen® filaments and those with nylon filaments were subjected to tensile strength and force-displacement analyses. Brushing simulation (1,000, 2,000, 3,000, and 5,000 cycles) was conducted using six freshly extracted central incisors (three specimens each for the Curen® and nylon filament groups). Pre- and post-brushing simulation parameters included filament abrasion potential (atomic force microscopy of extracted tooth surface), filament abrasion resistance (field emission scanning electron microscopy), and bristle surface changes (stereomicroscopy and micro- and nano-computed tomography). Results Curen® filaments exhibited lower tensile strengths (41.69 MPa [dry] and 35.18 MPa [wet]) than nylon filaments (321.56 MPa [dry] and 325.44 MPa [wet]), indicating that Curen® filaments have lower abrasion potential (87% [dry] and 89% [wet]) and cause less mechanical wear of enamel, thereby resulting in a gentler cleaning experience compared to nylon filaments. Furthermore, the enamel surface roughness in the crown region decreased by 19.4% with the use of the Curen® filaments, whereas it increased by 92.3% with the use of nylon filaments, indicating that Curen® filaments are 72.84% less abrasive to enamel than nylon filaments. After 5,000 cycles of brushing simulation, Curen® filaments showed 30% less splaying than nylon filaments, highlighting the longevity of Curen® filaments up to six months of tooth brushing, which is twice the longevity of nylon filaments. There was a minimal decrease in height (12.0 mm to 11.95 mm, -0.4% change), an increase in top diameter (2.157 mm to 2.390 mm, 10.8% change), and a rise in base diameter (1.784 mm to 2.035 mm, 14% change) in the Curen® filaments group. Taken together, these results indicate that Curen® filaments are superior to nylon filaments as teeth-cleansing agents. Conclusion The findings of this in vitro analysis demonstrate the lower tensile strength and lesser abrasion potential of Curen® filaments when compared with nylon filaments. Thus, Curen® filaments cause fewer microscratches and abrasion of enamel when compared with nylon filaments, occurring due to day-to-day mechanical wear because of improper brushing technique. Furthermore, the lower tensile strength of Curen® filaments provides greater flexibility, facilitating more effective cleaning of hard-to-reach areas compared to nylon filaments. Additionally, the lesser splaying of Curen® filaments highlights their longevity, demonstrating that Curen® filaments last twice as long as nylon filaments under regular brushing conditions. Based on these advantages, toothbrushes with Curen® filaments should be a preferred choice over nylon filaments.

Manual toothbrushes, self-toothbrushing, and replacement duration to remove dental plaque and improve gingival health: A scoping review from recent research

OBJECTIVE

To investigate characteristics of manual toothbrushes, self-toothbrushing methods, and replacement duration of manual toothbrushes that effectively remove dental plaque, reduce gingivitis, and promote gingival health.

STUDY DATA AND SOURCES

PubMed-MEDLINE, Scopus and Central Register Cochrane of Controlled trials (CENTRAL) were searched for randomized control trials (RCTs) from 01 January 2018 to 12 December 2023. Articles were subjected for including participants aged six years and older with a study duration of at least four weeks to investigate the efficacy of manual toothbrushes used self-toothbrushing. To investigate the appropriate time to replace manual toothbrushes, this study was focused on the physical properties of the bristles and changes in the microorganisms present in the bristles over time.

STUDY SELECTION

Of 1520 retrieved articles, 26 studies were included after screening. The total number of manual toothbrushes was 40 and 5 kinds of self-toothbrushing techniques were selected in the review. 4 studies investigated the changes the physical properties bristles of manual toothbrushes.

CONCLUSIONS

Among manual toothbrushes, the cross-angle and indicator bristles were found to significantly improve dental plaque index and gingival condition. Most toothbrushes with soft bristles had a trend of superior dental plaque removal and gingivitis improvement efficacy. Toothbrush with end-round shape bristles tip has tended to reduce the dental plaque and gingival index scores. Studies reported that brushing twice a day for at least two minutes using the Bass method had a positive effect on the dental plaque and gingival index. Further research is required to investigate the relationships between property physical bristle and clinical intraoral indices to clarify the replacement duration of manual toothbrushes.

CLINICAL SIGNIFICANCE

The findings of this study could guide people's daily self-brushing habits, thereby aiding the prevention of periodontal disease. Moreover, our findings suggest the need for strategic clinical trial designs to verify the ideal timing to replace manual toothbrushes.

Prevalence of oral Capnocytophaga species and their association with dental plaque accumulation and periodontal inflammation in middle‑aged and older people

Capnocytophaga species are commonly found in human oral microbiome. The aim of the present study was to understand the association of the prevalence of oral Capnocytophaga species with oral hygiene and periodontal inflammation. A total of 136 patients (median age 72 years) who visited the Hiroshima University Hospital (Hiroshima, Japan) between April 2021 and June 2023 were enrolled. Swab samples were obtained from the tongue surface. DNA from Capnocytophaga species (C. ochracea and C. sputigena) was detected by real-time PCR analysis. Dental plaque accumulation was observed to assess the oral hygiene condition of participants. Additionally, clinical periodontal inflammation was assessed with periodontal inflamed surface area (PISA) scores. Clinical confounding factors such as age, sex, lifestyle-related disease, remaining teeth and denture wearing between Capnocytophaga species-positive and -negative groups were adjusted with a propensity score matching method. Mann-Whitney U and χ2 or Fisher's exact test were employed for statistical analysis. The prevalence rate was 67.6% for oral C. ochracea and 83.1% for C. sputigena. C. ochracea-positive participants showed significantly higher plaque control record scores (an indicator of dental plaque accumulation) than C. ochracea-negative participants (P=0.03). Additionally, C. ochracea/C. sputigena dual-positive participants exhibited significantly higher plaque control record and PISA scores than non-dual-positive participants (P=0.01 and P=0.04, respectively). Propensity score matching was conducted in the C. ochracea/C. sputigena dual-positive group and the non-dual-positive group for adjustment of clinical factors, resulting in 51 matched patient pairs. C. ochracea/C. sputigena dual-positive participants had significantly higher plaque control record scores than non-dual-positive participants (P=0.02). The present results suggest that the prevalence of both oral C. ochracea and C. sputigena is associated with poor oral hygiene in middle-aged and older people.

Relationship of oral bacterial number with medical hospitalization costs in analysis of Diagnosis Procedure Combination database from single institution in Japan

Oral bacteria are known to be associated with perioperative complications during hospitalization. However, no presented reports have clarified the relationship of oral bacterial number with medical costs for inpatients. The Diagnosis Procedure Combination (DPC) database system used in Japan provides clinical information regarding acute hospital patients. The present study was conducted to determine the association of oral bacterial numbers in individual patients treated at a single institution with length of hospital stay and medical costs using DPC data. A total of 2369 patients referred by the medical department to the dental department at Hiroshima University Hospital were divided into the low (n = 2060) and high (n = 309) oral bacterial number groups. Length of hospital stay and medical costs were compared between the groups, as well as the associations of number of oral bacteria with Charlson comorbidity index (CCI)-related diseases in regard to mortality and disease severity. There was no significant difference in hospital stay length between the low (24.3 ± 24.2 days) and high (22.8 ± 20.1 days) oral bacterial number groups. On the other hand, the daily hospital medical cost in the high group was significantly greater (US$1456.2 ± 1505.7 vs. US$1185.7 ± 1128.6, P < 0.001). Additionally, there was no significant difference in CCI score between the groups, whereas the daily hospital medical costs for patients in the high group treated for cardiovascular disease or malignant tumors were greater than in the low number group (P < 0.05). Multivariate regression analysis was also performed, which showed that oral bacterial number, age, gender, BMI, cardiovascular disease, diabetes, malignant tumor, and hospital stay length were independently associated with daily hospitalization costs. Monitoring and oral care treatment to lower the number of oral bacteria in patients affected by cardiovascular disease or cancer may contribute to reduce hospitalization costs.

Wisdom Tooth Autotransplantation for the Missing Maxillary Central Incisors Using a 3D-Printed Replica: A Case Report

In this case report, we describe a 19-year-old man who underwent an autotransplantation of a lower third molar into the extracted region of his upper central incisors. Due to trauma, the patient's upper right and left central incisors had been extracted. He visited our clinic and requested to perform autotransplantation of his own teeth into the upper central incisor part because he wanted to use his natural teeth. So, we decided to extract his lower right third molar and autotransplant it into the extraction part of the upper central incisors. Immediately after extraction of the lower right third molar, the tooth was autotransplanted into the upper anterior region using a 3D-printed resin replica of the donor tooth and artificial sockets of the recipient site. Then, the root canal treatment was performed, and a temporary crown was set. Next, orthodontic treatment was done to flatten the curve of Spee. After completing the orthodontic treatment, a final prosthodontic restoration was set on the autotransplanted tooth. Four years later, the autotransplanted tooth remained stable with a healthy periodontium. This case demonstrates that if a patient has a request to use their natural teeth, autotransplantation of a wisdom tooth into the anterior region can be a useful method to replace the missing teeth.

Development and evaluation of the "Toothbrushing Timer with Information on Toothbrushes" application: A prospective cohort pilot study

OBJECTIVES

For people, it is challenging to be conscious of the appropriate toothbrushing time to maintain good oral health in daily life. The aim of this study was to preliminarily examine the utility of an application (app) that combines a toothbrushing timer and information on toothbrushes.

MATERIALS AND METHODS

We developed the "Toothbrushing Timer with Information on Toothbrushes" app to help users ensure appropriate toothbrushing time and learn about the beneficial characteristics of toothbrushes. A total of 18 participants were registered for the study. At baseline (T0) and after 1 month (T1) of app usage, study participants answered a digital questionnaire that comprised three questions on oral health practice, self-efficacy in oral hygiene, and quality of life related to oral health (Oral Health Impact Profile-14 [OHIP-14]).

RESULTS

Five participants were excluded from the analysis as they did not answer the digital questionnaire. Finally, 13 participants completed the survey with a follow-up of 1 month. The 13 participants were grouped into health professionals (n = 8) and non-health professionals (n = 5). The total scores for oral health practice and self-efficacy related to oral hygiene increased after a month of app usage in health professional and non-health professional groups. However, there were no significant differences between T0 and T1 in either group. The total score of OHIP-14 was lower at T1 than at T0 in both groups. Therefore, participants showed better oral health practice, self-efficacy in oral hygiene, and quality of life related to oral health at T1 compared with that at T0.

CONCLUSIONS

Our app showed positive results for the users and is useful in maintaining and promoting oral health awareness and practice. However, our pilot study lacks sufficient power and did not yield significant differences. Therefore, high-quality clinical trials with larger sample sizes are warranted for further improvement and evaluation.

Analysis of the Deflection, Bristle Splaying, and Abrasion of a Single Tuft of a Polybutylene Terephthalate Toothbrush after Use: A Randomized Controlled Trial

The aim of this study is to clarify the deflection, splaying, and abrasion of single tufts of polybutylene terephthalate (PBT) toothbrushes after use. A single-center randomized controlled trial is performed. The changes in deflection, bristle splaying, and abrasion are investigated for the middle single tuft of the top line (top–middle tuft) and the middle single tuft of the bottom line (bottom–middle tuft) of PBT toothbrushes with medium stiffness after 1 month, 2 months, and 3 months of use by 34 participants. A soft-material bending-resistance tester is used to assess the deflection of the single tufts. The deflection value of the top–middle tuft significantly increased after 1 month of use compared with the baseline. In contrast, the deflection of the bottom–middle tuft significantly increased after 3 months of use compared with the baseline and after 1 month and 2 months of use. Importantly, the change in deflection was distinctly different between the top– and bottom–middle tufts. The bristle splaying of both tufts significantly increased after use, but a significant change in bristle abrasion was not found. The bending stiffness of the top tuft of a PBT toothbrush may decrease more rapidly than that of the bottom tuft with use.

Effects of interactive power toothbrush with or without application assistance on the plaque, gingivitis, and gingival abrasion among dental students: a randomized controlled clinical trial

OBJECTIVE

The purpose of this randomized controlled study is to determine if an interactive power toothbrush (PTB) with application (app) promotes additional benefit on dental plaque, gingivitis, and gingival abrasion to that of a manual toothbrush (MTB).

MATERIALS AND METHODS

Ninety participants (dental students) diagnosed with gingivitis were randomly assigned, into three groups, 1:1:1 ratio, given an app-assisted interactive PTB (PTB-A) (Oral-B Genius® Rechargeable 8000 PTB with CrossAction brush head) or the same PTB without app-assistance (PTB-NA) or a regular MTB for home-use. Plaque was assessed using the Turesky modification of the Quigley and Hein Plaque Index (QHPI-TM), and gingivitis was evaluated using the Bleeding on Marginal Probing Index (BOMP) at baseline (T0), week 2 (T1), and week 8 (T2). Gingival abrasions were recorded at T1 and T2. Exit survey was used to assess brushing time and visual-analogue-scale (VAS) scores.

RESULTS

PTB improved QHPI-TM significantly in terms of time-dependent changes, irrespective of app-assistance. BOMP was observed to be statistically lower in PTB-A than in MTB only at T2. Brushing times were longer in PTB-A than in MTB. Gingival abrasion was less in both PTB than MTB. PTB-A had better results to MTB in cleaning ability according to subject-reported outcomes.

CONCLUSIONS

Both PTBs were more effective to MTB; however, the app-assisted interactive PTB was similar to the non-assisted one in plaque removal efficacy, gingivitis reduction, and incidence of gingival abrasion, yet better than MTB in cleaning ability.

CLINICAL RELEVANCE

Developing an application software to prevent gingival abrasion might be clinically beneficial regardless of the individual factor.

TRIAL REGISTRATION

ClinicalTrial.gov ID: NCT05150132.

Changes in the Bristle Stiffness of Polybutylene Terephthalate Manual Toothbrushes over 3 Months: A Randomized Controlled Trial

We previously reported that polybutylene terephthalate (PBT) toothbrushes become less effective for plaque removal after two months of use. However, it remains unknown how the bristle stiffness of PBT toothbrushes changes after several months of use. We performed a single-center randomized controlled trial to evaluate the bristle stiffness and bristle splaying of soft and medium manual toothbrushes among dental and medical students of Hiroshima University. Subjects were 80 participants who met the criteria. Participants were randomly assigned to the soft toothbrush group (n = 40) or the medium toothbrush group (n = 40). We collected toothbrushes immediately after first use (T0), after one month of use (T1), after two months of use (T2), and after three months of use (T3). Bristle stiffness was measured according to the International Organization for Standardization (ISO) 22254. The mean bristle stiffness (N/cm²) of soft and medium toothbrushes was significantly lower at T2 and T3 than at T0 (T2 vs. T0, soft; 3.63 vs. 3.89, P < 0.01 and medium; 4.33 vs. 4.52, P < 0.05, respectively, and T3 vs. T0, 3.62 vs. 3.89, p < 0.01 and 4.18 vs. 4.52, p < 0.001, respectively). Bristle stiffness was significantly reduced in soft and medium PBT toothbrushes after two months of use.