Center of Dental Medicine, Faculty of Medicine, University of Zurich

We are pleased to introduce the collection Frontiers in Dental Medicine: Highlights in Periodontics 2021/22. This collection will welcome and showcase a selection of high impact articles authored by leaders in the field. The work presented here highlights the broad diversity of research performed across the Periodontics section, and aims to put a spotlight on the main areas of interest. This collection aims to further support Frontiers’ strong community by shining a spotlight on our authors' highly impactful research.

Malmö University

Frontiers in Dental Medicine

Periodontics

Frontiers in Dental Medicine: Highlights in Periodontics 2021/22

In this study, we prepared cellulose acetate membranes, by means of casting mold, incorporated with two additives, sodium carboxymethyl lignin and calcium glycerophosphate, in order to improve properties for periodontal applications. The membranes were characterized from the morphological, structural, thermal and mechanical point of view, as well as by physiological pH tests. The results showed that membranes with additives improve the physical-chemical and mechanical properties, especially when the two additives are present in the same membrane, which can be attributed to the important synergy between them. The most significant effects occur in increasing the thickness and decreasing the density, which reflects in the porosity of the membranes, although the added amounts do not exceed 1.4%. A 1% increase in lignin concentration does not change the thickness and density of the membrane, but that amount of lignin plus 0.4% calcium glycerophosphate increases the thickness of the membrane by 42% and decreases the density by about 6%. Although there is a decrease in mechanical properties, as observed in Young's modulus and crystallinity, the significant and intermittent increase in sample weight loss with both additives in physiological solution indicates that, in the long run, it can be used as a degradable barrier.

In this study, we prepared cellulose acetate membranes, by means of casting mold, incorporated with two additives, sodium carboxymethyl lignin and calcium glycerophosphate, in order to improve properties for periodontal applications. The membranes were characterized from the morphological, structural, thermal and mechanical point of view, as well as by physiological pH tests. The results showed that membranes with additives improve the physical-chemical and mechanical properties, especially when the two additives are present in the same membrane, which can be attributed to the important synergy between them. The most significant effects occur in increasing the thickness and decreasing the density, which reflects in the porosity of the membranes, although the added amounts do not exceed 1.4%. A 1% increase in lignin concentration does not change the thickness and density of the membrane, but that amount of lignin plus 0.4% calcium glycerophosphate increases the thickness of the membrane by 42% and decreases the density by about 6%. Although there is a decrease in mechanical properties, as observed in Young&apos;s modulus and crystallinity, the significant and intermittent increase in sample weight loss with both additives in physiological solution indicates that, in the long run, it can be used as a degradable barrier.

Additives Incorporated in Cellulose Acetate Membranes to Improve Its Performance as a Barrier in Periodontal Treatment

Objectives: Peri-implant tissue maintenance and treatment is becoming a serious challenge in implantology. With increasing numbers of implants being placed, more cases of peri-implant mucositis and peri-implantitis is seen. A digital survey on peri-implant disease management was issued to experts in periodontology and implantology to identify the tools and procedures most commonly used today to treat peri-implant diseases and successfully manage peri-implant health. The primary aim was to assess whether there is consensus in the choice of treatment to manage peri-implant diseases and to prevent their recurrence once treated. The secondary aim was to obtain insight into future protocols and /or devices, and the research and development needed.Materials and Methods: Participants in this digital survey were professionals specialising in periodontology, oral surgery, and implant dentistry. The questionnaire included both a series of closed- and open-ended questions. A total of 16 countries participated. The survey was sent by e-mail to 70 individuals, 66 received the survey and 37 of receivers responded, two of the participants were excluded due to insufficient filling of the survey. In the end 35 respondents completed the survey.Results: Respondents agree that the efficacy of mechanical and chemical decontamination of implant surfaces needs to be improved and better documented. It is a common opinion that the current remedies, mostly adapted from periodontal practises, do not provide effective and reliable clinical outcomes when treating peri-implant ailments. There is a general agreement amongst experts that regularly scheduled (3–6-month intervals) maintenance treatments are essential for maintaining peri-implant health in patients experiencing implant complications. Respondents are also concerned about unnecessary use of systemic antibiotics for managing peri-implant health.Conclusion: Regardless of agreements in parts, there was no observed consensus on the most effective treatment options for treating peri-implantitis. The experts all agree it is an urgent need for well-designed, long-term follow-up randomised and controlled clinical trials comparing interventions to provide an evidence-based strategy for peri-implant health management.

Objectives: Peri-implant tissue maintenance and treatment is becoming a serious challenge in implantology. With increasing numbers of implants being placed, more cases of peri-implant mucositis and peri-implantitis is seen. A digital survey on peri-implant disease management was issued to experts in periodontology and implantology to identify the tools and procedures most commonly used today to treat peri-implant diseases and successfully manage peri-implant health. The primary aim was to assess whether there is consensus in the choice of treatment to manage peri-implant diseases and to prevent their recurrence once treated. The secondary aim was to obtain insight into future protocols and /or devices, and the research and development needed.Materials and Methods: Participants in this digital survey were professionals specialising in periodontology, oral surgery, and implant dentistry. The questionnaire included both a series of closed- and open-ended questions. A total of 16 countries participated. The survey was sent by e-mail to 70 individuals, 66 received the survey and 37 of receivers responded, two of the participants were excluded due to insufficient filling of the survey. In the end 35 respondents completed the survey.Results: Respondents agree that the efficacy of mechanical and chemical decontamination of implant surfaces needs to be improved and better documented. It is a common opinion that the current remedies, mostly adapted from periodontal practises, do not provide effective and reliable clinical outcomes when treating peri-implant ailments. There is a general agreement amongst experts that regularly scheduled (3–6-month intervals) maintenance treatments are essential for maintaining peri-implant health in patients experiencing implant complications. Respondents are also concerned about unnecessary use of systemic antibiotics for managing peri-implant health.Conclusion: Regardless of agreements in parts, there was no observed consensus on the most effective treatment options for treating peri-implantitis. The experts all agree it is an urgent need for well-designed, long-term follow-up randomised and controlled clinical trials comparing interventions to provide an evidence-based strategy for peri-implant health management.

Peri-Implant Health and the Knowing-Doing Gap—A Digital Survey on Procedures and Therapies

The goal of this study was to test if oral health outcomes are associated with the same genetic markers in Black and White individuals who did not have cancer. From a total of 6,100 subjects from the Dental Registry and DNA Repository project, 1,042 individuals who self-identified as White and 266 as Black without a history of cancer were included in this analysis. Genotyping data from IRE1—rs196929, RHEB—rs2374261 and rs1109089, AXIN2—rs2240308 and rs11867417, and RPTOR—rs4396582, present in cell regulatory pathways, were analyzed. We ran separate analyses in self-reported Black and White groups to reduce possible confounding effects of population stratification. Internal diagnostic codes from our dental registry were converted into Phecodes in order to run the analysis using the PheWAS package, installed in R Studio software. Periodontitis was associated with RHEB in both Black and White patients, with the minor allele increasing the likelihood of developing periodontitis in the White group and yielding a protective effect in the Black individuals. The presence of ulcers and gingivitis were associated with RPTOR and AXIN2, respectively, in the White group, but an association was not detected for the Black group. On the other hand, phenotypes such as dental fracture, diseases of the tongue, attrition, erosion, abrasion, fordyce granules, and torus and exostosis were uniquely associated with the Black group. Periodontitis associated with RHEB in both Black and White patients, and associations found in Black individuals may be the result of social disparities that lead to higher levels of stress, and these observed differences require further study.

The goal of this study was to test if oral health outcomes are associated with the same genetic markers in Black and White individuals who did not have cancer. From a total of 6,100 subjects from the Dental Registry and DNA Repository project, 1,042 individuals who self-identified as White and 266 as Black without a history of cancer were included in this analysis. Genotyping data from IRE1—rs196929, RHEB—rs2374261 and rs1109089, AXIN2—rs2240308 and rs11867417, and RPTOR—rs4396582, present in cell regulatory pathways, were analyzed. We ran separate analyses in self-reported Black and White groups to reduce possible confounding effects of population stratification. Internal diagnostic codes from our dental registry were converted into Phecodes in order to run the analysis using the PheWAS package, installed in R Studio software. Periodontitis was associated with RHEB in both Black and White patients, with the minor allele increasing the likelihood of developing periodontitis in the White group and yielding a protective effect in the Black individuals. The presence of ulcers and gingivitis were associated with RPTOR and AXIN2, respectively, in the White group, but an association was not detected for the Black group. On the other hand, phenotypes such as dental fracture, diseases of the tongue, attrition, erosion, abrasion, fordyce granules, and torus and exostosis were uniquely associated with the Black group. Periodontitis associated with RHEB in both Black and White patients, and associations found in Black individuals may be the result of social disparities that lead to higher levels of stress, and these observed differences require further study.

Phenome-Wide Association Study With Focus on Oral Health Disparities and Individuals Who Did Not Have Cancer

Personal protective equipment is used to prevent healthcare workers from contaminants. With the advent of COVID-19 pandemic, the use of effective PPE becomes more critical to avoiding infection by SARS-CoV-2. This preclinical double-blind study evaluated the performance of surgical gown textiles for penetration resistance against aerosols. The different textiles were divided into seven groups: (1) SMS PP OE Phobic; (2) Laminated Phobic; (3) Medical Barrier; (4) Trilayer Fabric; (5) Impermeable gown; (6) Impermeable with heat sealing tape; and (7) Clean Wear. All groups were exposed to aerosol-generating procedure for 5 min, according to Barboza et al. 2020. All measurements were recorded and exported to a datasheet for analysis using SPSS software. The groups showed significant differences (p < 0.01). Groups 2, 3, 4, 5, and 6 proved to be effective barriers against aerosols and presented a constant behavior. Groups 1 and 7 showed pigmented areas of 13.05 and 48.23%, respectively, suggesting that, in the present test model, these water-repellent and antimicrobial fabrics were not effective barriers against 5-min aerosols generated by a high-speed dental handpiece. Polyethylene or polyurethane laminated fabrics were efficient against 5-min aerosols. The SMS textile, globally used for surgical gowns, and the cotton fabric, impregnated with nanoparticles, were not effective barriers. The breathability and comfort of these textiles should be tested in future studies. Healthcare workers should be aware of the exact specifications of their surgical gown textiles.

Personal protective equipment is used to prevent healthcare workers from contaminants. With the advent of COVID-19 pandemic, the use of effective PPE becomes more critical to avoiding infection by SARS-CoV-2. This preclinical double-blind study evaluated the performance of surgical gown textiles for penetration resistance against aerosols. The different textiles were divided into seven groups: (1) SMS PP OE Phobic; (2) Laminated Phobic; (3) Medical Barrier; (4) Trilayer Fabric; (5) Impermeable gown; (6) Impermeable with heat sealing tape; and (7) Clean Wear. All groups were exposed to aerosol-generating procedure for 5 min, according to Barboza et al. 2020. All measurements were recorded and exported to a datasheet for analysis using SPSS software. The groups showed significant differences (p &lt; 0.01). Groups 2, 3, 4, 5, and 6 proved to be effective barriers against aerosols and presented a constant behavior. Groups 1 and 7 showed pigmented areas of 13.05 and 48.23%, respectively, suggesting that, in the present test model, these water-repellent and antimicrobial fabrics were not effective barriers against 5-min aerosols generated by a high-speed dental handpiece. Polyethylene or polyurethane laminated fabrics were efficient against 5-min aerosols. The SMS textile, globally used for surgical gowns, and the cotton fabric, impregnated with nanoparticles, were not effective barriers. The breathability and comfort of these textiles should be tested in future studies. Healthcare workers should be aware of the exact specifications of their surgical gown textiles.

Evaluation of Surgical Gown Textiles for Resistance Against Aerosols: A Preclinical Double-Blind Study

Periodontitis, a destructive periodontal inflammatory disease, negatively impacts oral-health related quality of life. It's characterized by the generation of inflammatory mediators and the excess-production of collagenolytic tissue-destructive enzymes (especially matrix metalloproteinases, MMPs). Many biomarkers can be used to define/diagnose disease progression. However, there is still a critical lack of specific, fast, and reliable biomarkers that correlate well with early response to treatment, which can be used to predict/monitor disease. Here, we report that an early marker, MMP-9, was found to be sensitive in response to a 1-month systemic therapy of CMC2.24, a novel chemically-modified curcumin, in beagle dogs with naturally-occurring periodontitis. In brief, eight adult female dogs with generalized periodontitis were distributed into placebo and treatment groups (n = 4/group). After a 1-h full-mouth scaling and root planing at time 0, placebo or CMC2.24 (10 mg/kg) capsules were orally-administered once/day for 1-month. Clinical periodontal parameters were measured at time 0 and 1-month; in addition, peripheral blood samples from these dogs were collected and analyzed for the pro-, activated-, and total-forms of MMP-9 by gelatin zymography. Interestingly, we found that the 1-month systemic therapy of CMC2.24 did appear to significantly reduce both pro- and activated-MMP-9 in peripheral blood at this early stage compared to placebo, prior to apparent clinical improvements seen at a later stage in a previous study (3-months). Thus, MMP-9 may serve as an early/sensitive biomarker that can precede/predict future clinical changes in disease severity and response to treatment which we observed in the long-term study in this dog model of natural periodontitis.

Periodontitis, a destructive periodontal inflammatory disease, negatively impacts oral-health related quality of life. It's characterized by the generation of inflammatory mediators and the excess-production of collagenolytic tissue-destructive enzymes (especially matrix metalloproteinases, MMPs). Many biomarkers can be used to define/diagnose disease progression. However, there is still a critical lack of specific, fast, and reliable biomarkers that correlate well with early response to treatment, which can be used to predict/monitor disease. Here, we report that an early marker, MMP-9, was found to be sensitive in response to a 1-month systemic therapy of CMC2.24, a novel chemically-modified curcumin, in beagle dogs with naturally-occurring periodontitis. In brief, eight adult female dogs with generalized periodontitis were distributed into placebo and treatment groups (n = 4/group). After a 1-h full-mouth scaling and root planing at time 0, placebo or CMC2.24 (10 mg/kg) capsules were orally-administered once/day for 1-month. Clinical periodontal parameters were measured at time 0 and 1-month; in addition, peripheral blood samples from these dogs were collected and analyzed for the pro-, activated-, and total-forms of MMP-9 by gelatin zymography. Interestingly, we found that the 1-month systemic therapy of CMC2.24 did appear to significantly reduce both pro- and activated-MMP-9 in peripheral blood at this early stage compared to placebo, prior to apparent clinical improvements seen at a later stage in a previous study (3-months). Thus, MMP-9 may serve as an early/sensitive biomarker that can precede/predict future clinical changes in disease severity and response to treatment which we observed in the long-term study in this dog model of natural periodontitis.

A Novel Chemically-Modified Curcumin 2.24: Short-Term Systemic Therapy for Natural Periodontitis in Dogs

Periodontitis is a common chronic inflammatory disease driven by the interaction between a dysbiotic oral microbiome and the dysregulated host immune-inflammatory response. Naturally derived nutraceuticals, such as resveratrol and its analogs, are potential adjunctive therapies in periodontal treatment due to their antimicrobial and anti-inflammatory properties. Furthermore, different analogs of resveratrol and the choice of solvents used may lead to varying effects on therapeutic properties. This review presents the current findings and gaps in our understanding on the potential utility of resveratrol and its analogs in periodontal treatment.

Periodontitis is a common chronic inflammatory disease driven by the interaction between a dysbiotic oral microbiome and the dysregulated host immune-inflammatory response. Naturally derived nutraceuticals, such as resveratrol and its analogs, are potential adjunctive therapies in periodontal treatment due to their antimicrobial and anti-inflammatory properties. Furthermore, different analogs of resveratrol and the choice of solvents used may lead to varying effects on therapeutic properties. This review presents the current findings and gaps in our understanding on the potential utility of resveratrol and its analogs in periodontal treatment.