The effect of clinical education on optimizing self-care by dental students in Switzerland.

Students, who may begin their dental education with sub-optimal oral self-care practices, are taught they should motivate patients to clean interdentally and reduce/stop smoking. To better understand their internalization of these concepts, students were surveyed at two distinct time points. Student cohorts from four Swiss universities were asked to complete an interdental cleaning/smoking habit questionnaire at the beginning of their pre-clinical education (n = 110) and again a year later, when beginning treatment of patients (n = 115). A local cohort (n = 28) was observed for comparison. All subjects participated voluntarily and anonymously. Interdental cleaning ≥ 3 times per week was performed by 48% first-year and 43% secondyear students in Basel, 60% and 76% in Bern, 60% and 70% in Geneva, 41% and 49% in Zurich, and 29% in the local cohort. Logistic regression using gender, class year and school as explanatory variables showed gender (p < 0.001) and school (p = 0.018) influenced cleaning frequency, with the odds being 3.16 [95% CI: 1.76, 5.67] times higher for females to perform interdental cleaning ≥ 3 times per week. Smoking was reported both years in numbers too low to analyze. Approximately 29% of the local cohort and 52% of the first-year students displayed an interdental cleaning frequency congruent with oral health recommendations. Adequate cleaning frequency increased for second-year students to 58%, which was not significant. Further study is needed to determine why more dental students do not themselves clean interdentally.

Origin of MMP-8 and Lactoferrin levels from gingival crevicular fluid, salivary glands and whole saliva.

BACKGROUND: Pathologically elevated levels of matrix metalloproteinase-8 (MMP-8) and Lactoferrin in oral fluids have been associated with the presence of gingivitis/periodontitis. This study aimed to assess the origin of MMP-8 and Lactoferrin in periodontitis patients and to identify the degree to which conventional clinical parameters correlate with their presence. METHODS: A total of ten periodontitis and ten healthy patients were included in this study. Whole saliva (stimulated and unstimulated), parotid/sublingual glandular fluid and gingival crevicular fluid from pockets and sulci were tested for MMP-8 and Lactoferrin and protein concentrations were quantified using an ELISA assay. Clinical parameters were checked for potential associations with MMP-8 and Lactoferrin levels. RESULTS: Periodontal patients presented higher concentrations of MMP-8 and Lactoferrin in pockets than other sources (P = 0.03). Lactoferrin measurement was higher in the parotid compared to sublingual glandular fluid in periodontitis patients (P = 0.03). Increased probing pocket depth was positively correlated with high MMP-8 and Lactoferrin levels. CONCLUSIONS: Periodontal pockets appear to be the major source of active matrix metalloproteinase and Lactoferrin, which also may also enter the oral cavity through the salivary glands. Since clinically healthy sites in periodontitis patients also had elevated biomarker levels, gingival crevicular fluid biomarker testing may be more predictive of future tissue breakdown than conventional clinical parameters.

Comparison of the cleaning efficiency between interdental brushes and sticks: a laboratory study. / Vergleich der Reinigungseffizienz zwischen Interdentalbürsten und Sticks. Eine Laborstudie.

Studies on interdental cleaning have shown an advantage of interdental brushes (IDB) over other interdental care products. Sticks (STK) made of rubber are often recommended as an alternative, as they are considered user-friendly, gentle but nevertheless effective. This laboratory study aimed to compare the cleaning efficiency with the same application force between IDB and STK. Brushes with different geometries and diameters were tested. Two conical STK from two manufacturers of the sizes "XS/S" (0.7-2.6 mm) and "L" (0.9-3.4 mm) were tested. For the IDB, one conical (2.7-3.4 mm), two cylindrical (1.9 and 2.5 mm) and one waisted brush (4-2-4 mm) were assessed. A geometric model with parallel-walled metal blocks (black and coated with titanium oxide) was used. The brushes were tested with one and five cleaning cycles each in horizontal direction. The test surfaces were measured planimetrically for cleaning efficiency by calculating the areas freed from titanium oxide in relation to the maximum cleanable total area. The maximum cleaning efficiency of the IDB was 45% at 1 mm distance with one cleaning cycle and 95% with five cycles. For the sticks, the cleaning efficiency with one cleaning cycle was 30% and 67% with five cycles. At a distance of 2 mm, the maximum cleaning efficiency was 50% with one cleaning cycle and 87% with five cycles for the IDBs and only 10% for the STKs. Taking into account the limitations of this study, the IDBs showed an overall better cleaning efficiency with the same application force, compared to STKs, with the waisted IDB achieving better cleaning efficiency than the conical IDB. In conclusion, STKs can be used in narrow interdental spaces where app opriate, but overall IDBs are more preferable in narrow and wider contact point conditions.

The Strange Case of a Broken Periodontal Instrument Tip.

This case report describes a rare case of a broken periodontal probe tip and its removal. A male patient presented himself in June 2019 due to a painful tooth in the upper left quadrant. The patient elected treatment in the dental school's student course. In October 2019, in preparation for full-mouth rehabilitation, a complete diagnostic status was performed, including radiographs. In this context, a metal-dense fragment was identified in the apical region of the (missing) tooth 45. It was diagnosed as the broken tip of a periodontal probe (type AE P OWB). Since a PCP-12 probe is generally used in-house, iatrogenic damage during the initial examination or student course could be excluded a priori. The patient was not able to remember any treatment that could be associated with the instrument's breaking. Since the probe fragment was palpable and a translocation could not be precluded, the patient agreed to its removal under local anesthesia, after a cone-beam CT. This article describes and discusses this particular case, with special emphasis on iatrogenic instrument fractures and their removal.

In vitro cleaning potential of waist-shaped interdental brushes

There are many interdental cleaning aids available for patient use, including toothpicks, dental floss and interdental brushes (IDBs). Most are available in various shapes and sizes. The aim of this laboratory study was to evaluate and compare the cleaning efficacy of waist-shaped interdental brushes to those of cylindrical shape. Four groups of IDBs, ranging in diameter from 2 mm to 9 mm, were tested. To reduce production and material bias, all brushes tested were from the same manufacturer. Cleaning efficacy was tested on two different devices: 1) a geometrical model, using opposing rectangular blocks at separation distances of 1 mm to 4 mm and 2) an anatomical model, displaying a standardized maxillary segment from canine to 3rd molar. The surfaces in both devices were coated with a titanium oxide slurry, then cleaned under standardized conditions and planimetrically evaluated. The measurements took place after 1, 5 and 10 cleaning strokes, respectively. Both models showed significant superiority in the cleaning efficacy of the waistshaped brush (p < 0.001), at 1, 5 and 10 strokes. Based on the present results, it can be concluded that interdental brushes with a waistshaped form showed cleaning potential superior to their cylindrical-shaped counterparts, under standardized laboratory conditions.

Preclinical competency in scaling/root planing: comparing dental and dental hygiene student's outcomes

Dental students in Zurich receive 8.5 hours of preclinical training in scaling/root planing. Dental hygiene students receive a multiple of this amount. This study was undertaken to assess the students' acquired preclinical competencies and to what degree they may differ. 34 undergraduate dental students and 20 dental hygiene (DH) students from two different schools in Zurich were tasked with scaling/root planing a maxillary left canine, coated with black lacquer from the apex to ca. 5 mm above the cemento-enamel junction, after completing their preclinical periodontal instrumentation course. The students were allowed to use any instrument in their set (Gracey or universal curettes) for a 5-minute period. Positive (experienced DHs) and negative (laypeople) control groups performed the same task. After instrumentation, teeth were scanned and planimetrically assessed. The percentage of cleaned tooth surface was calculated and statistically analysed (Kruskal-Wallis rank sum test, Conover's test for pairwise comparisons). The dental students achieved the highest median cleaning efficacy (80.6%), followed by the experienced DHs (65.3%), the DH students (62.0%) and the laypeople (26.7%). When split by schools, a significant difference in instrumentation efficacy by the student DHs was seen (p <0.001). Despite their limited instruction time, the dental students acquired preclinical scaling/root planing skills comparable to, or better than, DH students with more training time.

Oral status and aesthetics after nonsurgical periodontal treatment: Do patient's perception and dentist's evaluation agree?

OBJECTIVES: Periodontal healing is often accompanied by side effects, which may cause an aesthetic deficit. The present investigation was focussed to compare patient's subjective perception of their posttherapy aesthetics with the objective measures of the results. MATERIALS AND METHODS: Survey results from patients (subjective parameters) on oral status and aesthetics were compared against routine clinical parameters and corresponding survey results from treating dentists (objective parameters), both before and after periodontal treatment. Subjective outcome parameters were then suitably transformed and compared with the objective ones to investigate the agreement between patients' perception and actual outcomes. RESULTS: Objective recordings of periodontal status by the dentist and subjective awareness of the patient are quite contradictory to each other for almost all participants. Further, it was found that their aesthetics in the front were better after treatment, but dentist professionals targeted for future treatment needs. CONCLUSIONS: In this study, it was found that patients improved aesthetically on the upper jaw front after the therapy, which was not shared by the dentists. This discrepancy was due to the clinicians' view on more aesthetic corrective procedures than on patients' need.

Efficacy of chlorhexidine rinses after periodontal or implant surgery: a systematic review.

BACKGROUND: Biofilm management and infection control are essential after periodontal and implant surgery. In this context, chlorhexidine (CHX) mouth-rinses are frequently recommended post-surgically. Despite its common use and many studies in this field, a systematic evaluation of the benefits after periodontal or implant surgery is-surprisingly-still missing. OBJECTIVES: To evaluate the benefits of chlorhexidine rinsing after periodontal or implant surgery in terms of plaque and inflammation reduction potential. Furthermore, to screen whether the concentration changes or additives in CHX solutions reduce side effects associated with its use. MATERIALS AND METHODS: A systematic literature search was performed for clinical trials, which compared CHX rinsing after periodontal or implant surgery with rinsing using placebo, non-staining formulations, or solutions with reduced concentrations of the active compound. Four databases (Medline, PubMed, Embase, Cochrane) were searched up to June 2018. Two reviewers independently identified and screened the literature. RESULTS: From 691 titles identified, only eleven publications met the inclusion criteria and were finally included. Mainly early publications assessed the benefits of CHX over placebo rinsing, whereas more recent publications focused more on the evaluation of new formulations with regard to effectiveness and side effects. The use of CHX after surgery showed in general significant reduction in plaque (means of 29-86% after 1 week) and bleeding (up to 73%) as compared to placebo. No consensus, however, was found regarding the most beneficial CHX formulation avoiding side effects. CONCLUSION: Chlorhexidine rinsing helps to reduce biofilm formation and gingival inflammation after surgery. However, no additional reduction of periodontal probing depth over any given placebo or control solution could be found irrespective of whether CHX was used or not. The use of additives such as antidiscoloration systems (ADS) or herbal extracts may reduce side effects while retaining efficacy. CLINICAL RELEVANCE: Within the limitations of this review, it can be concluded that CHX may represent a valuable chemo-preventive tool immediately after surgery, during the time period in which oral hygiene capacity is compromised. To reduce the side effects of CHX and maintain comparable clinical effects, rinsing with less concentrated formulations (e.g., 0.12%) showed the most promising results so far.

Assessment of treatment field isolation during scaling, root planing and rinsing

Aim: Intensive application of highly concentrated antimicrobials during scaling and root planing may be hazardous if swallowed in quantity. This study evaluates two dental isolation systems for fluid leakage in conjunction with a sham treatment of scaling and root planing. Materials and methods: Eight volunteers were randomly assigned to wear a conventional rubber dam (RD) and a combined suction and isolation device (IsoLite® system [IL]) alternatively on contralateral maxillary and mandibular quadrants. RD was cut between the canine and the first molar and was fixed on the first molar with a rubber dam clamp and with a tissue adhesive (Histoacryl) on the gingiva. IL was applied as recommended by the manufacturer. Ultrasonic instrumentation with corresponding irrigation water was used for 5 min as sham treatment, i.e. no actual therapy. The irrigation liquid was collected and the difference between the amount of liquid applied and that collected during treatment was determined. The volunteers then reported on their comfort during treatment. Results: Neither of the devices offered complete isolation. Mean leakage with both systems was generally low, i.e. approximately 10% (of the applied irrigant). More leakage was recorded in the maxilla than in the mandible, for both systems. Both devices were deemed moderately comfortable to wear. Conclusion: RD and IL isolated the working field to a similar degree. Since RD represents the highest isolation standard currently available, the use of IL must also be considered sufficient to prevent noxious amounts of antiseptic rinses from leaking into the mouth.

Pre-treatment anxiety in a dental hygiene recall population: a cross-sectional pilot study.

BACKGROUND: Increased levels of anxiety may affect a patient's receptiveness to treatment, health care information and behaviour modification. This study was undertaken to assess pre-treatment anxiety in a dental hygiene recall population maintaining a schedule of regular preventive care appointments. METHODS: The sample population consisted of 46 consecutive adult recall patients waiting for their regularly scheduled dental hygiene appointment. Pre-treatment state (current) anxiety was assessed using the State-Trait-Anxiety Inventory (STAI), State form; dental anxiety with the Hierarchical Anxiety Questionnaire (HAQ); subjective stress using a visual analogue scale (VAS); and mood/alertness/calmness using the Multidimensional Mood Questionnaire (MDMQ). RESULTS: Two distinct groups, based on state anxiety scores, were formed; one displaying increased levels of pre-treatment anxiety (n = 14), the other low anxiety (n = 32). The HA group was characterized by significantly higher dental anxiety and subjective stress levels prior to treatment; as well as worse mood, lower alertness, and less calmness in the dental office setting. There was no correlation between anxiety level and years in dental hygiene recall. CONCLUSIONS: A high level of pre-treatment anxiety was present in about one third of the sample population. The prevalence of this anxiety demonstrates the need for both early recognition and patient management strategies (psychological and pain management) to positively influence their treatment experience.

In vitro cleaning potential of three different implant debridement methods.

OBJECTIVES: To assess the cleaning potential of three different instrumentation methods commonly used for implant surface decontamination in vitro, using a bone defect-simulating model. MATERIALS AND METHODS: Dental implants were stained with indelible ink and mounted in resin models, which represented standardized peri-implantitis defects with different bone defect angulations (30, 60 and 90°). Cleaning procedures were performed by either an experienced dental hygienist or a 2nd-year postgraduate student. The treatment was repeated 20 times for each instrumentation, that is, with a Gracey curette, an ultrasonic device and an air powder abrasive device (PAD) with glycine powder. After each run, implants were removed and images were taken to detect color remnants in order to measure planimetrically the cumulative uncleaned surface area. SEM images were taken to assess micromorphologic surface changes (magnification 10,000 ×). Results were tested for statistical differences using two-way ANOVA and Bonferroni correction. RESULTS: The areas of uncleaned surfaces (%, mean ± standard deviations) for curettes, ultrasonic tips, and airflow accounted for 24.1 ± 4.8%, 18.5 ± 3.8%, and 11.3 ± 5.4%, respectively. These results were statistically significantly different (P < 0.0001). The cleaning potential of the airflow device increased with wider defects. SEM evaluation displayed distinct surface alterations after instrumentation with steel tips, whereas glycine powder instrumentation had only a minute effect on the surface topography. CONCLUSION: Within the limitations of the present in vitro model, airflow devices using glycine powders seem to constitute an efficient therapeutic option for the debridement of implants in peri-implantitis defects. Still, some uncleaned areas remained. In wide defects, differences between instruments are more accentuated.

Mechanical and hydrodynamic homecare devices to clean rough implant surfaces - an in vitro polyspecies biofilm study.

OBJECTIVES: To investigate the cleaning efficacy of a mechanical and a hydrodynamic homecare device on biofilm-coated titanium surfaces with and without chlorhexidine. MATERIAL AND METHODS: Six-species biofilms were grown on 108 SLA-titanium discs, which were cleaned as follows: sonic toothbrush alone (i) or in combination with either a 0.2% chlorhexidine (ii) or a placebo gel (iii) and oral irrigator (hydrodynamic action) with water (iv) or combined with 0.2% chlorhexidine solution (v). Untreated samples served as control (vi). Biofilms were then harvested either immediately after treatment (study part A) or after a regrowth phase of 24 h (study part B) and colony-forming units (CFU) were assessed. Results were analysed using Whitney U-tests between the treatment groups. After the Bonferroni correction, the significance level was set at α = 0.0033. RESULTS: The median CFU counts directly after instrumentation accounted - in ascending order (P-values in comparison with the control group A6 were <0.001 for all groups except for A3: P = 0.014) - 2.0E1 (A5), 1.1E5 (A4), 3.6E5 (A2), 3.3E5 (A1) and 6.8E6 (A3), respectively. The untreated control group showed the highest CFU counts: 1.8E7 (A6). After regrowth, the following CFU counts were measured in ascending order (all P-values <0.001 when compared to the control group B6 = 2.0E8): 1.6E2 (B5), 1.9E5 (B2), 1.4E7 (B4), 3.1E7 (B1) and 3.9E7 (B3). CONCLUSIONS: An oral irrigator combined with 0.2% chlorhexidine is effective in reducing biofilms attached to rough titanium surfaces immediately after cleaning. Following a regrowth phase of 24 h, micro-organisms could be equally effective removed with a sonic toothbrush combined with 0.2% chlorhexidine and an oral irrigator with 0.2% chlorhexidine.

Effects of Music Listening on Pre-treatment Anxiety and Stress Levels in a Dental Hygiene Recall Population.

BACKGROUND: Waiting for a medical procedure can exert significant feelings of state anxiety in patients. Music listening has been shown to be effective in decreasing anxiety levels. No study so far examined the potential anxiety and stress-reducing effect of a music intervention on pre-treatment anxiety and stress in patients waiting for dental hygiene treatment. Knowing whether the anxiety-reducing effect of music would also be detectible in the context of preventive routine medical procedures in healthy individuals would widen the area of application of music from the hospital or clinical environment to medical offices in general. PURPOSE: Waiting for a medical treatment can induce anxiety and may lead to the experience of stress. We set out to examine the effect of music on pre-treatment anxiety in a healthy patient sample waiting for a dental treatment. METHODS: In a randomized controlled clinical trial, 92 consecutive volunteer patients (mean age, 57 years) waiting for their scheduled dental hygiene treatment were randomly allocated to either an experimental (n = 46, listening to music for 10 min) or a control group (n = 46, waiting in silence). State and habitual anxiety, subjective stress, and mood measures were assessed before and after music listening or silence, respectively. RESULTS: State anxiety levels in the music group decreased significantly after intervention as compared to the control group (F(1/90) = 8.06; p = 0.006). Participants' trait anxiety and dental anxiety were not found to moderate this effect. CONCLUSIONS: Listening to music prior to dental hygiene treatment decreases anxiety levels to a greater extent than waiting in silence.

Polyspecies biofilm formation on implant surfaces with different surface characteristics.

OBJECTIVE: To investigate the microbial adherence and colonization of a polyspecies biofilm on 7 differently processed titanium surfaces. MATERIAL AND METHODS: Six-species biofilms were formed anaerobically on 5-mm-diameter sterilized, saliva-preconditioned titanium discs. Material surfaces used were either machined, stained, acid-etched or sandblasted/acid-etched (SLA). Samples of the latter two materials were also provided in a chemically modified form, with increased wettability characteristics. Surface roughness and contact angles of all materials were determined. The discs were then incubated anaerobically for up to 16.5 h. Initial microbial adherence was evaluated after 20 min incubation and further colonization after 2, 4, 8, and 16.5 h using non-selective and selective culture techniques. Results at different time points were compared using ANOVA and Scheffé post hoc analysis. RESULTS: The mean differences in microorganisms colonizing after the first 20 min were in a very narrow range (4.5 to 4.8 log CFU). At up to 16.5 h, the modified SLA surface exhibited the highest values for colonization (6.9±0.2 log CFU, p<0.05) but increasing growth was observed on all test surfaces over time. Discrepancies among bacterial strains on the differently crafted titanium surfaces were very similar to those described for total log CFU. F. nucleatum was below the detection limit on all surfaces after 4 h. CONCLUSION: Within the limitations of this in vitro study, surface roughness had a moderate influence on biofilm formation, while wettability did not seem to influence biofilm formation under the experimental conditions described. The modified SLA surface showed the highest trend for bacterial colonization.

Polyspecies biofilm formation on implant surfaces with different surface characteristics

Objective: To investigate the microbial adherence and colonization of a polyspecies biofilm on 7 differently processed titanium surfaces. Material and Methods: Six-species biofilms were formed anaerobically on 5-mm-diameter sterilized, saliva-preconditioned titanium discs. Material surfaces used were either machined, stained, acid-etched or sandblasted/acid-etched (SLA). Samples of the latter two materials were also provided in a chemically modified form, with increased wettability characteristics. Surface roughness and contact angles of all materials were determined. The discs were then incubated anaerobically for up to 16.5 h. Initial microbial adherence was evaluated after 20 min incubation and further colonization after 2, 4, 8, and 16.5 h using non-selective and selective culture techniques. Results at different time points were compared using ANOVA and Scheffé post hoc analysis. Results: The mean differences in microorganisms colonizing after the first 20 min were in a very narrow range (4.5 to 4.8 log CFU). At up to 16.5 h, the modified SLA surface exhibited the highest values for colonization (6.9±0.2 log CFU, p<0.05) but increasing growth was observed on all test surfaces over time. Discrepancies among bacterial strains on the differently crafted titanium surfaces were very similar to those described for total log CFU. F. nucleatum was below the detection limit on all surfaces after 4 h. Conclusion: Within the limitations of this in vitro study, surface roughness had a moderate influence on biofilm formation, while wettability did not seem to influence biofilm formation under the experimental conditions described. The modified SLA surface showed the highest trend for bacterial colonization.

A double role of sperm in scorpions: the mating plug of Euscorpius italicus (Scorpiones: Euscorpiidae) consists of sperm.

Mating plugs occluding the female gonopore after mating are a widespread phenomenon. In scorpions, two main types of mating plugs are found: sclerotized mating plugs being parts of the spermatophore that break off during mating, and gel-like mating plugs being gelatinous fluids that harden in the female genital tract. In this study, the gel-like mating plug of Euscorpius italicus was investigated with respect to its composition, fine structure, and changes over time. Sperm forms the major component of the mating plug, a phenomenon previously unknown in arachnids. Three parts of the mating plug can be distinguished. The part facing the outside of the female (outer part) contains sperm packages containing inactive spermatozoa. In this state, sperm is transferred. In the median part, the sperm packages get uncoiled to single spermatozoa. In the inner part, free sperm is embedded in a large amount of secretions. Fresh mating plugs are soft gelatinous, later they harden from outside toward inside. This process is completed after 3-5 days. Sperm from artificially triggered spermatophores could be activated by immersion in insect Ringer's solution indicating that the fluid condition in the females' genital tract or females' secretions causes sperm activation. Because of the male origin of the mating plug, it has likely evolved under sperm competition or sexual conflict. As females refused to remate irrespective of the presence or absence of a mating plug, females may have changed their mating behavior in the course of evolution from polyandry to monandry.

In vitro evaluation of three curettes with edge retention technology after extended use.

This study assessed the edge cutting efficiency of three new curettes with different edge retention technologies after simulated wear in vitro. Three test curettes (two with a titanium nitride coating and one without coating, but made of a cryogenically treated stainless steel alloy) were used to root plane prepared bovine dentin specimens. Nine curettes of each type were used to instrument one dentin sample each. Dentin removal was determined after the first ten strokes and again cumulatively for the strokes 500-510 and 1,000-1,010 by means of atomic absorption spectrophotometry (AAS). The effects of chemical and thermal stress were analysed after repeated disinfection and sterilization of the instruments then followed by a final 10-stroke sequence of dentin removal to determine cutting efficacy. A standard, untreated stainless steel curette was used as a control. Test and control instruments showed no statistical evidence of diminished dentin removal over 1010 strokes. Dentin surface roughness also displayed insignificant differences for all instruments. However, sterilization negatively affected the test and control instruments to an equal degree. Sterilization procedures appear to be an important factor in the dulling of curettes, which affected dentin removal efficacy but not surface roughness.