Skin treatment with non-thermal plasma modulates the immune system through miR-223-3p and its target genes.

Non-thermal plasma, a partially ionized gas, holds significant potential for clinical applications, including wound-healing support, oral therapies, and anti-tumour treatments. While its applications showed promising outcomes, the underlying molecular mechanisms remain incompletely understood. We thus apply non-thermal plasma to mouse auricular skin and conducted non-coding RNA sequencing, as well as single-cell blood sequencing. In a time-series analysis (five timepoints spanning 2 hours), we compare the expression of microRNAs in the plasma-treated left ears to the unexposed right ears of the same mice as well as to the ears of unexposed control mice. Our findings indicate specific effects in the treated ears for a set of five miRNAs: mmu-miR-144-5p, mmu-miR-144-3p, mmu-miR-142a-5p, mmu-miR-223-3p, and mmu-miR-451a. Interestingly, mmu-miR-223-3p also exhibits an increase over time in the right non-treated ear of the exposed mice, suggesting systemic effects. Notably, this miRNA, along with mmu-miR-142a-5p and mmu-miR-144-3p, regulates genes and pathways associated with wound healing and tissue regeneration (namely ErbB, FoxO, Hippo, and PI3K-Akt signalling). This co-regulation is particularly remarkable considering the significant seed dissimilarities among the miRNAs. Finally, single-cell sequencing of PBMCs reveals the downregulation of 12 from 15 target genes in B-cells, Cd4+ and Cd8+ T-cells. Collectively, our data provide evidence for a systemic effect of non-thermal plasma.

Bacterial contamination potential of personal protective equipment itself in dental aerosol-producing treatments.

Personal protective equipment (PPE) has long been a high priority in dental aerosol-producing treatments. Since COVID-19 pandemic, its importance has increased yet again. While importance of PPE in preventing transmission and thus possible infection of pathogens is well known, contamination potential of PPE after treatment itself is less investigated. This review aims to give an overview of the current literature and contamination potential (viral, blood, bacterial) of components of protective equipment itself. The literature search was performed using the Medline database; furthermore, a hand search was conducted. Last search took place on 23 November 2022. Two categories of hygiene-related keywords were formed (category A: mask, face shield, goggles, eyewear, personal protective equipment; category B: contamination, aerosol). Each keyword from one category was combined with all keywords from the other one. In addition, the keyword "dental" was always added. First, a title and abstract screening was performed. Afterward, a full-text analysis was followed for the included studies. A total of 648 search hits were found in the Medline database. 47 were included after title and abstract screening. 22 studies were excluded after full-text analysis, 25 studies were included. The hand search resulted in 4 studies that were included. Bacterial contamination of PPE after treatment has been adequately studied, contamination with blood less. Microorganisms mainly originate from the oral and cutaneous flora; however, a transmission of potential pathogens like Staphylococcus aureus or Escherichia coli was also described. Studies showing transmission pathways starting from PPE and its various components are lacking. No measures have yet been described that fully protect the protective equipment from contamination. There is growing awareness that PPE itself can be a source of pathogen transmission, and thus possible infection. Therefore, not only wearing of protective clothing, but also conscious handling of it is crucial for transmission and possible infection prevention. However, studies showing transmission pathways starting from PPE and its various components are lacking. Several studies have investigated what measures can be taken to protect the protective equipment itself. So far, none of the methods evaluated can prevent contamination of PPE.

Dental aerosol-producing treatments: Comparison of contamination patterns of face shields and surgical masks.

During the COVID-19 pandemic, dental face shields were recommended to protect the eyes. This study aimed to examine to what extent face shield and mask contamination differ when a pre-procedural mouth rinsing with Chlorhexidine (CHX) is conducted before treatment. In this prospective, randomized study, three groups of subjects were formed (rinsing with 0.1% CHX, water, or no rinsing (control) before aerosol-producing treatments). After each of the 301 treatments, the practitioner's face shield was swabbed with eSwab and the mask was brought into contact with agar plates. Sampling was done from the exterior surface only. Samples were cultured for 48 h at 35 °C under aerobic and anaerobic conditions. Bacteria were classified by phenotypic characteristics, biochemical test methods, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Colony-forming units were counted and mean values were compared (WSR, H-test, U-test, p < 0.05). Within each subject group, face shields showed significantly more contamination than surgical masks (control group: 350 CFU, 50 CFU; intervention water: 270 CFU, 40 CFU; intervention CHX: 250 CFU, 30 CFU). Comparison of face shields of the different subject groups did not reveal any statistically significant differences. However, CHX resulted in a statistically significant bacterial reduction on surgical masks compared to the water and control group (control: 50 CFU, intervention water: 40 CFU, intervention CHX: 30 CFU). Contamination of face shields and surgical masks was highest in the control group, followed by the water group, and lowest in the intervention group with CHX. Streptococcus spp. and Staphylococcus spp. dominated, representing the oral and cutaneous flora. Contamination of masks worn with or without face shields did not differ. Presumably, face shields intercept first splashes and droplets, while the masks were mainly exposed to bioaerosol mist. Consequently, face shields protect the facial region and surroundings from splashes and droplets, but not the mask itself. A pre-procedural mouth rinse with CHX had no statistically significant reducing effect on contamination of the face shield, but a statistically significant reducing effect was observed on contamination of the mask.

The impact of general medical health status, demographical, and patient-specific variables on need for dental treatment of children and adolescents under general anesthesia.

OBJECTIVES: Aim of this retrospective study was to examine the influence of general medical, demographical, and other patient-specific factors on the need for dental treatment under general anesthesia in children and adolescents at Saarland University Hospital. For assessment of the clinical treatment need, a mixed dt/DT (decayed teeth) was introduced. MATERIALS AND METHODS: A total of 340 patients under 18 years of age who received restorative-surgical dental treatment between 2011 and 2022 were anonymously enrolled. Demographic and other patient-specific data, general medical health, oral health, and treatment related data were recorded. In addition to descriptive analysis, Spearman-Rho-test, Mann-Whitney-U-test, Kruskall-Wallis-test and Chi-square-test were used. RESULTS: More than half of the patients (52,6%) were in general health, but non-cooperative. The majority of the patients (66.8%) was between 1 and 5 years of age (p < 0,001). Mean dmft was 10.95 ± 4.118, mean DMFT was 10.09 ± 7.885, and mean dt/DT was 10.79 ± 4.273. Analysis showed that communication difficulties significantly influenced dmft (p = 0.004), DMFT (p = 0.019), and dt/DT (p < 0.001). Type of insurance significantly affected dmft (p = 0.004) and dt/DT (p = 0.001). There was no significant effect of ASA on caries experience, however on prevalence of severe gingivitis (p < 0.001), number of extractions (p = 0.002), and need for repeated treatment (p < 0.001). CONCLUSIONS: Need for dental treatment in the present collective was high, independent of the considered variables. Non-Cooperativeness along with ECC was the main indication for dental general anesthesia. The mixed dt/DT was the most precise survey to evaluate clinical treatment needs. CLINICAL RELEVANCE: Given the enormous demand for these rehabilitations with strict selection, it is imperative to create more treatment capacities for patients mandatorily requiring general anesthesia by avoiding it in healthy patients.

[Introduction of "professional field exploration" for Saarland University dentistry students]. / Einführung des Fachs "Berufsfelderkundung" für Studierende der Zahnmedizin an der Universität des Saarlandes.

The new dental licensing regulations (ZApprO) have been in effect since the 2021/2022 winter semester and stipulate that a "professional field exploration course" be offered in the dentistry degree program. At Saarland University, the course consists of five parts: (I) introduction, (II) practicum, (III) reflection report, (IV) symposium, and (V) evaluation. The practicum is designed to provide students with earlier exposure to clinical reality, give them more confidence in dealing with patients, motivate them, and teach them about the professional role in the healthcare profession. In addition, the reflection report and symposium will initiate the development of scientific competencies. The evaluation, together with the evaluation of the reflection reports, serves to verify the success of the introduction of the course. The purpose of this paper is to describe the new course and to present the results of the result of the evaluation of the two courses in 2021 and 2022.

Apical periodontitis after intense bruxism.

BACKGROUND: Bruxism is known to cause masticatory muscle pain, temporomandibular joint pain, headaches, mechanical tooth wear, prosthodontic complications and cracked teeth. Less known to the practitioner, and described only experimentally in literature, is that bruxism can also damage the pulp. To our knowledge, this is the first known clinical case of a patient developing apical periodontitis due to bruxism. CASE PRESENTATION: This article presents the case and successful treatment of a 28-year-old healthy male patient with apical periodontitis on teeth 36 and 46 requiring root canal treatment after an intense phase of bruxism. Due to an unclear diagnosis, treatment had been delayed. CONCLUSIONS: Incomprehensible tooth pain can be the result of bruxism. Practitioners need to be informed that intense bruxism can possibly lead to apical periodontitis. It is important, therefore, that a thorough anamnesis is collected and taken into account during diagnostics.

The Composite Quality Score (CQS) as a trial appraisal tool: inter-rater reliability and rating time.

OBJECTIVE: To establish the CQS inter-rater reliability and rating time and to compare both against that of the Jadad scale and Cochrane's Risk of Bias Tool (ROBT). MATERIAL AND METHODS: Four independent raters rated 45 trial reports. The inter-rater reliability was established by use of the Brennan-Prediger coefficient (BPC). The coefficients were compared using the two-sample z-test. Secondary analysis included comparison of the inter-rater reliability of the randomization component of all tools, as well as of the allocation concealment component of the CQS to that of the ROBT. The mean rating time with standard deviation (SD) for each tool was determined using one-way repeated measures analysis of variance. Post hoc comparisons were made using the Tukey-Kramer adjustment for three pair-wise multiple comparisons. RESULTS: The inter-rater reliability was significantly higher for the CQS (BPC, 95% CI: 0.95, 0.87-1.00) compared to Jadad (0.70, 0.58-0.82) (adjusted p = 0.0005) and most components of ROBT. The mean (SD) time to complete the CQS (4.0 (1.0) min) did not differ significantly from that of the Jadad scale 4.8 (1.1) min (adjusted p = 0.11), but was significantly shorter compared to that of the ROBT 15.3 (5.9) min (adjusted p < 0.0001). CONCLUSIONS: The results suggest the CQS to be a very reliable and fast trial appraisal tool. Clinical relevance The higher the inter-rater reliability, the higher the probability that trial results reflect therapeutic truth. The CQS will need to take further bias sources into consideration, in order to increase its utility.

Contamination of surgical mask during aerosol-producing dental treatments.

OBJECTIVES: Surgical masks are usually contaminated during dental treatment. So far it has not been investigated whether a surgical mask itself can be a source of microbial transmission. The aim of this study was therefore to investigate the microbiological contamination of surgical masks during dental treatment and the transfer of microorganisms from the mask to the hands. MATERIALS AND METHODS: Five dental treatment modalities were studied: carious cavity preparation (P-caries, n = 10), tooth substance preparation (P-tooth, n = 10), trepanation and root canal treatment (P-endo, n = 10), supragingival ultrasonic application (US-supra, n = 10), and subgingival periodontal ultrasonic instrumentation (US-sub, n = 10). Bacterial contamination of mask and gloves worn during treatment was tested by imprinting on agar plates. Additionally, before masks were tested, their outer surface was touched with a new sterile glove. This glove was also imprinted on agar. Bacteria were identified by MALDI TOF mass spectrometry. Colony-forming units (CFU) were scored: score 0: 0 CFU, score 1: < 102 CFU, score 2: > 102 CFU, score 3: dense microbial growth. RESULTS: All masks and all gloves used during treatment displayed bacterial contamination (sample scores 0/1/2/3: masks 0/46/3/1 and gloves 0/31/10/9). After touching the masks with new sterile gloves, microorganisms were recovered with the following contamination scores: P-caries: 4/6/0/0, P-tooth: 2/8/0/0: P-endo: 7/3/0/0, US-supra: 0/9/1/0, US-sub: 2/8/0/0. No statistically significant differences were detected between the treatment modalities. Streptococci spp. and Staphylococci spp. representing the oral and cutaneous flora dominated. CONCLUSIONS: Surgical masks are contaminated after aerosol-producing dental treatment procedures. Used masks have a potential to be a source of bacterial contamination of the hands. CLINICAL RELEVANCE: Dental staff should avoid touching the outer surface of masks with their hands to prevent transmission of pathogens. It is recommendable to change the mask after each treated patient followed by hand disinfection.

[Design and quality control of the oral health status examination in the German National Cohort (GNC)]. / Design und Qualitätskontrolle der zahnmedizinischen Untersuchung in der NAKO Gesundheitsstudie.

BACKGROUND: Caries and periodontitis are highly prevalent worldwide. Because detailed data on these oral diseases were collected within the framework of the German National Cohort (GNC), associations between oral and systemic diseases and conditions can be investigated. OBJECTIVES: The study protocol for the oral examination was designed to ensure a comprehensive collection of dental findings by trained non-dental staff within a limited examination time. At the mid-term of the GNC baseline examination, a first quality evaluation was performed to check the plausibility of results and to propose measures to improve the data quality. MATERIALS AND METHODS: A dental interview, saliva sampling and oral diagnostics were conducted. As part of the level­1 examination, the number of teeth and prostheses were recorded. As part of the level­2 examination, detailed periodontal, cariological and functional aspects were examined. All examinations were conducted by trained non-dental personnel. Parameters were checked for plausibility and variable distributions were descriptively analysed. RESULTS: Analyses included data of 57,967 interview participants, 56,913 level­1 participants and 6295 level­2 participants. Percentages of missing values for individual clinical parameters assessed in level 1 and level 2 ranged between 0.02 and 3.9%. Results showed a plausible distribution of the data; rarely, implausible values were observed, e.g. for measurements of horizontal and vertical overbite (overjet and overbite). Intra-class correlation coefficients indicated differences in individual parameters between regional clusters, study centres and across different examiners. CONCLUSIONS: The results confirm the feasibility of the study protocol by non-dental personnel and its successful integration into the GNC's overall assessment program. However, rigorous dental support of the study centres is required for quality management.

Modifying Adhesive Materials to Improve the Longevity of Resinous Restorations.

Dental caries is a common disease on a global scale. Resin composites are the most popular materials to restore caries by bonding to tooth tissues via adhesives. However, multiple factors, such as microleakage and recurrent caries, impair the durability of resinous restorations. Various innovative methods have been applied to develop adhesives with particular functions to tackle these problems, such as incorporating matrix metalloproteinase inhibitors, antibacterial or remineralizing agents into bonding systems, as well as improving the mechanical/chemical properties of adhesives, even combining these methods. This review will sum up the latest achievements in this field.

Enzymology and Ultrastructure of the in situ Pellicle in Caries-Active and Caries-Inactive Patients.

AIM: The present study aimed to evaluate the impact of caries activity on the key enzymes and the ultrastructure of the in situ pellicle. METHODS: Pellicle formation was performed on bovine enamel slabs. Intraoral exposure (3, 30, and 120 min) was accomplished by 14 caries-active (DMFS: 22.7 ± 12.1) and 13 caries-inactive (DMFS: 1.5 ± 1.8) individuals. The enzyme activities (lysozyme, peroxidase, α-amylase, glycosyltransferase [GTF]) in the in situ pellicle and resting saliva of all participants were analyzed directly after oral exposure. In addition, a simultaneous visualization of these enzymes, extracellular glucans, and adherent bacteria was carried out. Fluorescent patterns were analyzed with fluorescence labeling and 4',6-diamidino-2-phenylindole/concanavalin A staining. In addition, the distribution of GTF B, C, and D and the ultrastructure of the pellicle were examined by gold immunolabeling and transmission electron microscopy with selected samples. RESULTS: Enzyme activities of amylase, peroxidase, lysozyme, and GTF were detected on all enamel slabs in an active conformation. Neither exposure time nor caries activity had an impact on the enzyme activities. Gold immunolabeling indicated that the pellicle of caries-active subjects tends to more GTF D molecules. The pellicles of caries-inactive and -active individuals revealed a similar ultrastructural pattern. CONCLUSION: The enzyme activities as well as the pellicle's ultrastructure are of high similarity in caries-active and -inactive subjects. Thereby, oral exposure time has no significant influence. This reflects a high uniformity during the initial phase of bioadhesion (3-120 min) concerning enzymatic functions. However, there is a tendency towards more GTF D in caries-active individuals.

Initial microbial colonization of enamel in children with different levels of caries activity: An in situ study.

PURPOSE: To investigate patterns of overnight in situ microbial colonization of enamel in children. METHODS: Overall, 29 children (aged 5-9 years) participated in the study. Nine were caries-free with no decayed, missing, or filled teeth (DMFT), 11 were caries-rehabilitated (DMFT ≥ 2, no active carious lesions), and nine were caries-active (DMFT ≥ 2, at least two carious lesions). Bovine enamel samples were fixed on individual upper jaw splints stored overnight in situ. 4',6-diamidino-2-phenylindole (DAPI) combined with Concanavalin A staining was applied for fluorescence microscopic visualization of total adherent bacteria and glucans. Fluorescence in situ hybridization (FISH) was used for distinction of eubacteria, streptococci, and Candida albicans. Salivary samples were investigated for Streptococcus mutans (S. mutans) by using CRT bacteria test and yeasts with Calcofluor white (CFW) staining. RESULTS: With all fluorescence methods, bacteria but not Candida albicans were detected on enamel samples. No statistically significant differences were observed in distribution patterns of the adherent bacteria between the groups. CFW staining indicated fungal structures in saliva samples of all participants. Based on CRT test results, the lowest amount of S. mutans were observed in caries-free children. Thus, initial microbial colonization patterns of enamel in children are not influenced by caries activity. CLINICAL SIGNIFICANCE: Caries activity in children may influence the process of initial bioadhesion and thus distribution patterns of bacterial attachment to the enamel surface. Investigation of in situ biofilm formation might provide valuable insights regarding the varying caries susceptibility in children.

Exposure of patient and dental staff to fine and ultrafine particles from scanning spray.

OBJECTIVES: Sprays containing fine and ultrafine particles are commonly used for optical scanning. The aim of this study was to measure the particle exposure of patient and dentist during application of scanning spray and to evaluate measures for its reduction. MATERIALS AND METHODS: A lower molar in a dental simulator was powdered with scanning spray. Patient's particle exposure was measured by a condensation particle counter in the nasal region of the simulator without (P) and with rubber dam (PC). Dentist's exposure (D) was measured behind a surgical mask. Particle concentrations were determined 5-fold without suction (NS), using conventional dental suction (CDS), or high volume evacuation (HVE). RESULTS: Mean background air particle concentrations for the patient were 3.3 × 10(3) and 1.3 × 10(3) pt/cm(3) for the dentist. Particle concentrations increased after spraying; mean cumulated additional particle exposures for the patient were the following: P-NS 7.2 × 10(6), P-CDS 4.6 × 10(6), P-HVE 2.4 × 10(4); using rubber dam: PC-NS 3.6 × 10(6), PC-CDS 3.3 × 10(5), PC-HVE 2.2 × 10(5). The particle exposures of the dentist were the following: D-NS 9.7 × 10(5), D-CDS 1.8 × 10(5), D-HVE 1.6 × 10(4). CONCLUSIONS: The use of HVE is recommended to reduce exposure of patients and dental staff to fine and ultrafine particles when using scanning sprays. CLINICAL RELEVANCE: Effective protection is available for staff and patient by means of high volume evacuation. In patients suffering from obstructive lung diseases, the use of scanning sprays should be avoided altogether.

Application of the Composite Quality Score (CQS-2B) versus Cochrane's Risk of Bias tool (Version 2) in systematic reviews of clinical trials - an exploratory study.

Objectives: To explore whether systematic review conclusions generated from Cochrane's second version of its Risk of Bias tool (RoB 2) for trial appraisal differ when the Composite Quality Score, Version 2.B (CQS-2B) is used instead and to develop a testable hypothesis based on these findings. Methods: PubMed was searched for one single systematic review. From the review's accepted trials, data concerning effect estimates and overall bias risk according to the RoB 2 tool were extracted. All trial reports were appraised again using the CQS-2B. Datasets were stratified according to overall bias risk (RoB 2) or corroboration (C-) level (CQS-2B). The effect estimates from trials with 'low bias risk' (RoB 2) and with highest C-level (CQS-2B) were pooled separately. These pooled effect estimates were statistically and all clinical conclusions qualitatively compared. Results: The pooled effect estimates for trials with 'low bias risk' (RoB 2) were -0.07, 95% CI: -0.10 to -0.04 (I2 = 0.0%) and for the highest C-levels (CQS-2B) 0.08, 95% CI: -0.12 to -0.04 (I2 = 57.0%). The difference was statistically not significant (p = 0.70). Contrary to the RoB 2 tool, no clinical conclusions in line with the CQS-2B were made, because the effect estimates were judged to be erroneously overestimated, due to high risk of bias. Conclusion: A testable hypothesis was generated suggesting that trial appraisal using the CQS-2B may provide more conservative conclusions based on similar data than with the RoB 2 tool.

Detection of viable oral bacteria of the patient on the surgical mask of dentists.

INTRODUCTION AND AIM: Bioaerosols contaminate the personal protective equipment (PPE), especially masks. The PPE harbors microorganisms from various sources. However, no previous studies have investigated the specific sources of bacteria found on used masks and their correlation with those from the treated patient. SETTING, DESIGN, MATERIAL AND METHODS: Intraoral samples from the patient were collected prior to dental aerosol-producing treatments using a nylon flock fiber swab. After treatment, the practitioner's mask was imprinted onto agar plates. MAIN OUTCOME METHODS: Following cultivation, colony forming units were counted and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). After the samples were analyzed, the intraoral samples as well as the mask samples were assessed for the presence of identical species, which were subsequently quantified. RESULTS: 126 treatments were included. One species match occurred most frequently (26.2%), followed by two (11.9%%) and three or more (3.97%). In the intraoral samples, Neisseria subflava occurred most often, within mask samples Staphylococcus epidermidis were detected most. Staphylococcus aureus could be cultivated three times more often in intraoral samples than on the mask. DISCUSSION AND CONCLUSION: Oral microorganisms originating from the patient's oral cavity can be found on the outside of masks. When using PPE during treatments, it should therefore always be in mind that potentially pathogenic microorganisms may land on the mask becoming a source of for itself.

L. reuteri in Supportive Periodontal Therapy-Are There Already Clinical Effects after 3 Months with One Lozenge a Day? A Double-Blind Randomized Placebo-Controlled Study.

AIM: The purpose of this study was to investigate whether a clinical effect of Lactobacillus reuteri in supportive periodontal therapy can already be detected with a minimum dose of one tablet a day and a minimum observation and intake period of 3 months. MATERIALS AND METHODS: 28 patients with stage III and IV periodontitis undergoing periodontal follow-up were randomly divided into two groups receiving a lozenge containing L. reuteri or a placebo preparation daily for 90 days. After 0, 4, 8, and 12 weeks, the parameters bleeding on probing (BoP), plaque control record (PCR), periodontal probing depth (PPD), and clinical attachment level (CAL) were recorded in the test and control groups. RESULTS: The results sed a different effect of L. reuteri on the respective patients. In certain patients, clinical parameters worsened or remained largely unchanged. However, in other patients, there were positive effects on the clinical parameters. In the overall analysis, BoP was the only clinical parameter that was statistically significantly reduced. CONCLUSIONS: The oral administration of one lozenge per day for 3 months with L. reuteri in supportive periodontal therapy might have a positive influence on clinical parameters in supportive periodontal therapy, depending on the individual.

Cold Atmospheric Plasma Improves the Colonization of Titanium with Primary Human Osteoblasts: An In Vitro Study.

Several studies have shown that cold atmospheric plasma (CAP) treatment can favourably modify titanium surfaces to promote osteoblast colonization. The aim of this study was to investigate the initial attachment of primary human osteoblasts to plasma-treated titanium. Micro-structured titanium discs were treated with cold atmospheric plasma followed by the application of primary human osteoblasts. The microwave plasma source used in this study uses helium as a carrier gas and was developed at the Leibniz Institute for Surface Modification in Leipzig, Germany. Primary human osteoblasts were analyzed by fluorescence and cell biological tests (alkaline phosphatase activity and cell proliferation using WST-1 assay). The tests were performed after 4, 12, and 24 h and showed statistically significant increased levels of cell activity after plasma treatment. The results of this study indicate that plasma treatment improves the initial attachment of primary human osteoblasts to titanium. For the first time, the positive effect of cold atmospheric plasma treatment of micro-structured titanium on the initial colonization with primary human osteoblasts has been demonstrated. Overall, this study demonstrates the excellent biocompatibility of micro-structured titanium. The results of this study support efforts to use cold atmospheric plasmas in implantology, both for preimplantation conditioning and for regeneration of lost attachment due to peri-implantitis.

Destruction of oral biofilms formed in situ on machined titanium (Ti) surfaces by cold atmospheric plasma.

The decontamination of implant surfaces represents the basic procedure in the management of peri-implant diseases, but it is still a challenge. The study aimed to evaluate the degradation of oral biofilms grown in situ on machined titanium (Ti) discs by cold atmospheric plasma (CAP). ~200 Ti discs were exposed to the oral cavities of five healthy human volunteers for 72 h. The resulting biofilms were divided randomly between the following treatments: CAP (which varied in mean power, treatment duration, and/or the gas mixture), and untreated and treated controls (diode laser, air-abrasion, chlorhexidine). The viability, quantity, and morphology of the biofilms were determined by live/dead staining, inoculation onto blood agar, quantification of the total protein content, and scanning electron microscopy. Exposure to CAP significantly reduced the viability and quantity of biofilms compared with the positive control treatments. The efficacy of treatment with CAP correlated with the treatment duration and plasma power. No single method achieved complete biofilm removal; however, CAP may provide an effective support to established decontamination techniques for treatment of peri-implant diseases.

Experimental and clinical evaluation of a self-etching and an etch-and-rinse adhesive system.

PURPOSE: To assess the one-step self-etching adhesive iBond Gluma inside (1-SE) and the two-step etch-and rinse adhesive Gluma Comfort Bond (2-ER), both used in combination with the fine particle hybrid composite Venus, in a laboratory and in a prospective clinical study. MATERIALS AND METHODS: In the in vitro study, tooth-composite interaction, microleakage, and adhesive failure of 8 Class V restorations per system were evaluated by light and scanning electron microscopy. In the in vivo study, 90 paired Class III/IV restorations were scored over 48 months (modified USPHS criteria). Cumulative failure rates (CFR) were calculated. RESULTS: In vitro, microleakage and adhesive failure at enamel margins were significantly increased with 1-SE in comparison with 2-ER. With 1-SE, micromechanical interlocking at enamel was reduced and pores within the adhesive layer arose. In vivo, after 48 months with 1-SE, decreased marginal integrity and an increased number of dark marginal color lines were observed. CONCLUSION: Because the results of the 4-year clinical study showed lower esthetics and marginal integrity for the 1-SE adhesive, its use should be viewed critically, which is in line with the reduced enamel-adhesive-composite interaction found in vitro.