Cross-angled versus flat-trim bristle tuft configurations in manual toothbrushes: A systematic review.

AIM: This systematic review synthesizes and evaluates the literature regarding the effect of manual toothbrushes (MTBs) with cross-angled bristle tufts (CA-TB) compared to flat-trim (FT-TB) configurations on plaque scores and parameters of gingival health in adult patients. MATERIALS AND METHODS: PubMed-MEDLINE and Cochrane-CENTRAL databases were searched, from their insertion up to August 1st, 2023, to detect appropriate papers. Clinical trials involving adult patients without periodontitis who performed self-brushing were eligible for inclusion. Primary outcome parameters included plaque, bleeding, and gingival scores. Secondary outcomes encompassed signs of soft and hard tissue abnormalities. A descriptive analysis was conducted. When feasible, a meta-analysis was performed using either the 'fixed' or 'random effects' model, as appropriate. RESULTS: Nine eligible papers were retrieved, presenting 20 comparisons. There was considerable heterogeneity in the clinical and methodological design aspects of the included studies. In the descriptive analysis, eight out of 12 comparisons demonstrated a difference in plaque removal performance in favour of the CA-TB. However, data regarding bleeding and gingival index scores were inconclusive. A meta-analysis was performed on plaque, bleeding, and gingival index scores, including different indices used for scoring. The meta-analysis of short-term studies showed a medium effect statistically significant difference in the reduction of plaque scores in favour of the CA-TB (SMD = 0.75; 95% CI (0.51; 0.99)), but this was not substantiated in longer-term studies (SMD = -0.06; 95% CI(-0.44; 0.31)). No adverse events were described in any group. CONCLUSION: Within the limitations of the present study design, short-term evaluations, as assessed with various plaque indices, show a weak certainty in favour of the cross-angled toothbrush over the flat-trim toothbrush. However, based on longer-term evaluations, there is insufficient support due to the inconsistent outcomes of the analysis.

Contemporary practices for mechanical oral hygiene to prevent periodontal disease.

It is well established that dental plaque on teeth leads to gingivitis and periodontitis, and that several mechanical and chemical methods of plaque control can prevent gingivitis. The aim of the current review is to summarize and synthesize the available scientific evidence supporting practices for mechanical oral hygiene to prevent periodontal diseases. Evidence for contemporary practices of mechanical oral hygiene to prevent periodontal disease relies on studies of gingivitis patients. General recommendations concerning the ideal oral hygiene devices and procedures are still inconclusive. However, toothbrushing and interdental cleaning remain the mainstays of prevention of periodontal diseases. The primary approach requires individually tailored instruction for implementation of a systematic oral hygiene regimen.

Plaque control and reduction of gingivitis: The evidence for dentifrices.

This paper focuses on plaque control and the management of gingivitis in adults and summarizes the evidence of commercially available dentifrices as gathered from existing systematic reviews. Three internet sources were used to search for appropriate papers (up to and including February 2017). The search strategy was designed to include any systematic review published on dentifrices that also included an evaluation of plaque and gingivitis scores. Characteristics of the individual reviews, such as methodological aspects, quantitative data and conclusions, were extracted. The potential risk of bias was estimated and the acquired evidence was graded. Independent screening of 205 unique reviews resulted in 10 published and eligible systematic reviews. One publication evaluated the mechanical contribution of dentifrice to plaque removal. Eight papers were identified that evaluated the efficacy of a proposed single active ingredients, of which two reviewed more than one potentially active ingredient. One study compared two active ingredients. This meta-review appraised the current state of evidence and found that toothbrushing with a standard fluoride dentifrice does not provide an added effect for the mechanical removal of dental plaque. Evidence suggests that compared with a standard dentifrice, those containing triclosan or stannous fluoride have benefits with respect to gingival health and control of dental plaque.

Toothbrush wear in relation to toothbrushing effectiveness.

OBJECTIVE: To investigate to what extent the degree of toothbrush wear of 3-month-old manual toothbrushes influence plaque scores. MATERIAL AND METHODS: During a recently published study with a follow-up of 1 year, all participants performed a similar basic home-based oral hygiene regimen. Hence, they were instructed to brush for 2 minutes twice daily according to the Bass method technique and using a standard dentifrice containing sodium fluoride. Toothbrushes were turned in every 3-month, and the degree of wear was scored. The mean plaque score data were additionally analysed and correlated with wear scores of the toothbrushes. RESULTS: For analysis, for each of 172 individual participants, a set of three identical, 3-month-old used toothbrushes were available. Toothbrush wear varied widely between participants. However, per patient, the 3-month wear status of the three evaluated toothbrushes was strongly correlated (rho = 0.8, P < 0.0001). Participants who returned toothbrushes with extreme wear had significantly higher plaque scores than those who returned toothbrushes with no visible or light wear (P = 0.01). CONCLUSION: Toothbrush wear per individual patient is fairly consistent. Toothbrushes with extreme wear were less effective than those with no or light wear. Therefore, bristle splaying appears to be a more appropriate measure of brush replacement time then the commonly used toothbrush age. Splaying of the outer tufts beyond the base of the toothbrush is a condition that indicates it is time to change the brush.

Prevalence of diabetes mellitus in people clinically diagnosed with periodontitis: A systematic review and meta-analysis of epidemiologic studies.

OBJECTIVES: Diabetes mellitus and periodontitis are complex chronic diseases with an established bidirectional relationship. This systematic review evaluated in subjects with professionally diagnosed periodontitis the prevalence and odds of having diabetes. METHODS: The MEDLINE-PubMed, CENTRAL and EMBASE databases were searched. Prevalence of diabetes mellitus among subjects with periodontitis was extracted or if possible calculated. RESULTS: From the 803 titles and abstracts that came out of the search, 27 papers met the initial criteria. Prevalence of diabetes was 13.1% among subjects with periodontitis and 9.6% among subjects without periodontitis. Based on subanalysis, for subjects with periodontitis, the prevalence of diabetes was 6.2% when diabetes was self-reported, compared to 17.3% when diabetes was clinically assessed. The highest prevalence of diabetes among subjects with periodontitis was observed in studies originating from Asian countries (17.2%, n = 18,002) and the lowest in studies describing populations from Europe (4.3%, n = 7,858). The overall odds ratio for patients with diabetes to be among subjects with periodontitis as compared to those without periodontitis was 2.27 (95% CI [1.90;2.72]). A substantial variability in the definitions of periodontitis, combination of self-reported and clinically assessed diabetes, lack of confounding for diabetes control in included studies introduces estimation bias. CONCLUSIONS: The overall prevalence and odds of having diabetes are higher within periodontitis populations compared to people without periodontitis. Self-reported diabetes underestimates the prevalence when compared to this condition assessed clinically. Geographical differences were observed: the highest diabetes prevalence among subjects with periodontitis was observed in studies conducted in Asia and the lowest in studies originating from Europe.

Does dentifrice use help to remove plaque? A systematic review.

AIMS: The aim of this systematic review was to establish the efficacy of brushing with and without a dentifrice for dental plaque removal. MATERIALS AND METHODS: MEDLINE-PubMed, Cochrane-CENTRAL, EMBASE and other electronic databases were searched. The inclusion criteria were randomized controlled trials and controlled clinical trials and subjects ≥18 years of age with good general health. Studies that evaluated the effect of toothbrushing with a dentifrice compared to brushing without a dentifrice were included. Data were extracted from the eligible studies, and a meta-analysis was performed where feasible. RESULT: The search was conducted until June 2016 and retrieved 10 eligible publications that included 20 comparisons. On average, 49.2% of plaque was removed when brushing was performed with a dentifrice, and 50.3% of plaque was removed when toothbrushing was performed without a dentifrice. The descriptive analysis indicated that the majority of the comparisons did not show an additional effect of dentifrice use. Regarding the meta-analysis of post-brushing scores, no significant difference was observed between toothbrushing with and without a dentifrice (DiffM 0.00, 95%CI [-0.05: 0.05], p = 0.91). The meta-analysis of incremental data (as means or percentages) supported and strengthened these findings. CONCLUSION: The cumulative evidence for this systematic review demonstrates that there is moderate certainty that toothbrushing with a dentifrice does not provide an added effect for the mechanical removal of dental plaque.

Comparison of red autofluorescing plaque and disclosed plaque-a cross-sectional study.

OBJECTIVES: The aim of this cross-sectional study was to assess the correlation between dental plaque scores determined by the measurement of red autofluorescence or by visualization with a two-tone solution. Clinical photographs were used for this study. MATERIALS AND METHODS: Overnight plaque from the anterior teeth of 48 participants was assessed for red fluorescence on photographs (taken with a QLF-camera) using a modified Quigley & Hein (mQH) index. A two-tone disclosing solution was applied. Total disclosed plaque was clinically assessed using the mQH index. In addition, total and blue disclosed plaque was scored on clinical photographs using the mQH index. RESULTS: A strong correlation was observed between the total disclosed plaque scored on photographs and the clinical scores (r = 0.70 at site level; r = 0.88 at subject level). The correlation between red fluorescent plaque and total plaque, as assessed on the photographs, was moderate to strong and significant (r = 0.50 at the site level; r = 0.70 at the subject level), with the total plaque scores consistently higher than the red fluorescent plaque scores. The correlation between red fluorescent plaque and blue disclosed plaque was weak to moderate and significant (r = 0.30 at the site level; r = 0.50 at the subject level). CONCLUSIONS: Plaque, as scored on white-light photographs, corresponds well with clinically assessed plaque. A weak to moderate correlation between red fluorescing plaque and total disclosed plaque or blue disclosed plaque was found. CLINICAL RELEVANCE: What at present is considered to be matured dental plaque, which appears blue following the application of a two-tone disclosing solution, is not in agreement with red fluorescent dental plaque assessment.

The concomitant administration of systemic amoxicillin and metronidazole compared to scaling and root planing alone in treating periodontitis: =a systematic review=.

BACKGROUND: The treatment of periodontitis begins with a non-surgical phase that includes scaling and root planing(SRP) and on occasion the use of systemic antibiotics. The goal was to systematically evaluate in systemic healthy adults the effect of the concomitant administration of amoxicillin (amx) and metronidazole (met) adjunctive to SRP compared to SRP alone. METHODS: The PubMed-MEDLINE, Cochrane-CENTRAL and EMBASE databases were searched up to November 2014 to identify appropriate studies. Probing Pocket Depth (PD), Clinical Attachment Level (CAL), Bleeding on Pocket Probing(BOP) and Plaque Indices(PI) were selected as outcome variables. Based on the extracted data a meta-analysis was conducted. RESULTS: A total of 526 unique articles were found, 20 studies met the eligibility criteria. A meta-analysis showed that SRP + amx + met provided significantly better effects overall and more pronounced PD reduction in periodontal pockets initially measuring ≥6 mm (DiffM:-0.86 mm, p < 0.00001) and gain in CAL(DiffM:+0.75 mm, p = 0.0001). The meta-analysis for the secondary inflammatory parameter BOP showed that SRP + amx + met provided full mouth significantly greater reduction in BOP than SRP alone (DiffM:-6.98 %, p = 0.0001). CONCLUSION: Adjunctive systemic amoxicillin and metronidazole medication to SRP significantly improved the clinical outcomes with respect to mean PD, CAL and BOP compared to SRP alone. There is moderate to strong evidence in support of the recommendation that adjunctive amx + met therapy to SRP significantly improves the clinical outcomes, with respect to mean PD and CAL compared to SRP alone especially in initially deep (≥6 mm) pockets. No major side effects associated with the intake of amx + met were reported. This treatment regimen is an efficacious, minimally invasive, practical and inexpensive approach for periodontitis therapy. The key components are mechanical tooth and pocket debridement, supportive treatment of the disease with systemic antibiotics and attention to proper self-care.

Efficacy of homecare regimens for mechanical plaque removal in managing gingivitis a meta review.

FOCUSED QUESTION: Based on evidence as presented in systematic reviews what is the efficacy and safety of available homecare toothbrush regimens for mechanical plaque removal on plaque and gingivitis in adults? MATERIAL & METHODS: Three Internet sources were used (up to and including August 2014) to search for appropriate papers that satisfied the study purpose. Plaque scores and gingivitis scores were considered to be the primary parameter of interest. Safety was considered an important facet in relation to efficacy. Data and conclusions as presented in the selected papers were extracted. The potential risk of bias was estimated and the emerging evidence was graded. RESULTS: Independent screening of 176 unique reviews resulted in 10 published and eligible systematic reviews. They were categorized into one review evaluating the effect of an oral hygiene instruction with a toothbrush on plaque and gingivitis scores, five evaluating the efficacy of manual and power toothbrushes and three reviews evaluating toothbrush safety and one evaluating toothbrush contamination. CONCLUSION: Tooth brushing is effective in reducing levels of dental plaque. With respect to gingivitis power toothbrushes have a benefit over manual toothbrushes. The greatest body of evidence was available for oscillating-rotating brushes. Tooth brushing generally can be considered safe for the teeth and their investing tissues.

Treatment of oral malodour. Medium-term efficacy of mechanical and/or chemical agents: a systematic review.

FOCUSED QUESTION: What is the effect of a dentifrice (DF), a mouthwash (MW), tongue cleaning (TC), or any combination of these as adjunct to toothbrushing on intra-oral malodour and tongue coating as compared to toothbrushing alone in systemically healthy patients, when used for a minimum follow-up period of 2 weeks? MATERIAL AND METHODS: The MEDLINE-PubMed, Cochrane-CENTRAL and EMBASE databases were searched up to August 2014. Measurements of Volatile Sulphur Compounds and organoleptic scores of oral malodour were selected as outcome variables. Data were extracted and a descriptive analysis was performed. RESULTS: Independent screening of 1054 unique papers resulted in 12 eligible clinical trials with a medium-term (≥2 weeks) duration. The majority of studies provided a significant reduction in oral malodour when evaluating products with an active ingredient (incorporated into a DF or a MW) used adjunctively to toothbrushing. The added value of tongue cleaning over a MW was evaluated in one study. CONCLUSION: Due to very limited evidence, the potential effect of a specifically formulated dentifrice, a mouthwash or a tongue scraper for treating oral malodour is, in general, unclear. For mouthwashes containing the active ingredients chlorhexidine + cetylpyridinium chloride + zinc (CHX + CPC + Zn) and zinc chloride + cetylpyridinium chloride (ZnCl + CPC) most evidence was available. The strength of a recommendation to use these products was graded to be 'weak'.

Efficacy of inter-dental mechanical plaque control in managing gingivitis--a meta-review.

FOCUSED QUESTION: What is the effect of mechanical inter-dental plaque removal in addition to toothbrushing, on managing gingivitis using various formats of inter-dental self-care in adults based on evidence gathered from existing systematic reviews? MATERIAL & METHODS: Three Internet sources were searched by a strategy designed to include systematic reviews on inter-dental cleaning devices. Plaque and gingivitis scores were the primary parameters of interest. Characteristics of selected papers were extracted. The potential risk of bias was estimated and the acquired evidence was graded. RESULTS: Screening of 395 papers resulted in six systematic reviews. Two papers evaluated the efficacy of dental floss, two of inter-dental brushes (IDB), one of woodsticks and one of the oral irrigator. Weak evidence of unclear or small magnitude was retrieved that supported dental floss, woodsticks and the oral irrigator to reduce gingivitis in addition to toothbrushing. No concomitant evidence for an effect on plaque emerged. There is moderate evidence that IDBs in combination with toothbrushing reduce both plaque and gingivitis. CONCLUSION: Evidence suggests that inter-dental cleaning with IDBs is the most effective method for inter-dental plaque removal. The majority of available studies fail to demonstrate that flossing is generally effective in plaque removal. All investigated devices for inter-dental self-care seem to support the management of gingivitis, however, to a varying extend.

Correlations between two different methods to score bleeding and the relationship with plaque in systemically healthy young adults.

AIM: To evaluate the correlation between bleeding on marginal probing (BOMP) and bleeding on pocket probing (BOPP), and the correlation of both bleeding indices with plaque. MATERIALS AND METHODS: This cross-sectional study screened 336 participants, from which 268 were eligible for examination and analysis. Bleeding and plaque indices were assessed by single examiners, at six sites per tooth. RESULTS: The mean percentage of sites per individual with bleeding on marginal probing, bleeding on pocket probing and dental plaque were 19.9%, 51.2% and 32.2% respectively. In the quadrants where the margin was probed before the pocket, a 4.6 percentage points higher bleeding tendency with BOPP was observed (p < 0.05). At a site level, the correlation coefficients of plaque and bleeding on marginal probing and bleeding on pocket probing were 0.19 and 0.20 respectively. Both bleeding indices were also shown to be correlated (r = 0.89, fixed effect model). CONCLUSION: The prevalence of bleeding upon probing is influenced by the scoring method that is used for the diagnosis. Probing the bottom of the pocket results in significantly more bleeding than running a probe along the margin.

Java project on periodontal diseases: causes of tooth loss in a cohort of untreated individuals.

OBJECTIVE: To assess the relative contribution of caries and periodontal disease to tooth loss over 24 years in a cohort deprived of regular dental care. MATERIAL & METHODS: The study population consisted of 98 subjects from a tea estate on West Java, Indonesia, that had been part of a prospective longitudinal study and provided full datasets of clinical assessments between 1987, 1994 and 2002. In 2011, complete sets of dental radiographs were made which was combined with the survey forms and clinical slides from the previous assessments in order to estimate reasons for tooth loss. RESULTS: Thirty-seven subjects lost no teeth, whereas 61 subjects lost 185 teeth. In this group, 45.9% lost ≤2 teeth, 32.8% lost 3 to 4 teeth and 19.7% lost ≥5 teeth. The majority of teeth were lost due to caries. In five subjects, tooth loss could be attributed solely to periodontitis, whereas in four subjects teeth were lost due to both caries and periodontits. Analyses of the predictor variables age, gender, smoking, education, presence of caries and severe periodontitis showed that male gender and caries were significantly associated with tooth loss. CONCLUSION: The majority of teeth in this population were lost due to caries.

The effect of the thermal diode laser (wavelength 808-980 nm) in non-surgical periodontal therapy: a systematic review and meta-analysis.

FOCUSED QUESTION: What is the adjunctive effect of a diode laser (DL) following non-surgical periodontal debridement (SRP) during the initial phase of periodontal therapy on the clinical parameters of periodontal inflammation. MATERIAL AND METHODS: The MEDLINE-PubMed, Cochrane-Central Register of Controlled Trials and EMBASE databases were searched up to September 2013. Probing pocket depth (PPD) and clinical attachment loss (CAL) were selected as outcome variables. Also plaque scores (PS), bleeding scores (BS) and the Gingival Index (GI) were considered outcome measures. Data were extracted and a meta-analysis (MA) was performed where appropriate. RESULTS: Independent screening of 416 unique papers resulted in nine eligible publications. The MA evaluating PPD, CAL and PS showed no significant effect. The only significance favouring adjunctive use of the DL was observed for the outcome parameters GI and BS. CONCLUSION: The collective evidence regarding adjunctive use of the DL with SRP indicates that the combined treatment provides an effect comparable to that of SRP alone. That is for PPD and CAL. The body of evidence considering the adjunctive use of the DL is judged to be "moderate" for changes in PPD and CAL. With respect to BS, the results showed a small but significant effect favouring the DL, however, the clinical relevance of this difference remains a question. This systematic review questions the adjunctive use of DL with traditional mechanical modalities of periodontal therapy in patients with periodontitis.

Adjunctive clinical effect of a water-cooled Nd:YAG laser in a periodontal maintenance care programme: a randomized controlled trial.

BACKGROUND: Various laser systems are currently available for intra-oral use. Neodymium:Yttrium-Aluminium Garnet lasers(Nd:YAG) have been approved by the US Food and Drug Administration for soft tissue treatment in the oral cavity. OBJECTIVES: The aim of this study was to test whether the use of a water-cooled Nd:YAG laser during a maintenance care programme as an adjunct to supragingival and subgingival debridement (scaling and root planing, SRP) with hand and ultrasonic instruments results in clinical improvement compared with SRP alone. MATERIAL AND METHODS: This study was an examiner-blind, randomized and controlled clinical trial using a split-mouth design. Thirty subjects were selected, originally diagnosed with moderate to severe generalized periodontitis, following a periodontal maintenance care programme (PMC). Immediately after SRP in two randomly assigned contra-lateral quadrants, all pockets ≥5 mm were additionally treated with a Nd:YAG laser (1064 nm, 4W, 250-µsec pulse). Clinical assessments [probing pocket depth PPD, bleeding on pocket probing (BOPP)] were performed pre-treatment and at 6 months. Based on these assessments, the periodontal inflamed surface area (PISA) was calculated. RESULTS: At 6 months, the clinical parameters had significantly improved for both regimens. No statistically significant differences between treatment modalities were observed for PPD and BOPP scores at any time. PISA scores supported these findings. CONCLUSIONS: In residual pockets ≥5 mm, treated in a PMC, the adjunctive use of an Nd:YAG laser does not provide a clinically significant additional advantage.

Titanium surface alterations following the use of different mechanical instruments: a systematic review.

OBJECTIVE: To systematically collect and evaluate existing evidence on the effects of different mechanical instruments on the surface characteristics of smooth and rough titanium surfaces. MATERIALS AND METHODS: PubMed-MEDLINE, Cochrane-CENTRAL and EMBASE databases were searched up to December 2010 to identify appropriate studies. The eligible studies were controlled studies investigating titanium surface alterations following treatment with different mechanical instruments. RESULTS: In total, 3275 unique papers were identified. A screening of the titles and abstracts resulted in 34 publications that met all of the eligibility criteria. Surface roughness was evaluated using scanning electron microscopy in most studies and using a profilometer in only 10 studies. The rough surfaces evaluated were titanium plasma sprayed and sandblasted and acid-etched surfaces only. Non-metal instruments were found to cause minimal or no damage to both smooth and rough titanium surfaces. Metal instruments were found to cause major damage to smooth surfaces. Burs seemed to be the instruments of choice, if smoothening of a rough surface was required. CONCLUSION: Non-metal instruments and rubber cups seem to be the instruments of choice for the treatment of smooth surfaces. Similarly, for rough implant surfaces, non-metal instruments and air abrasives are the instruments of choice, if surface integrity needs to be maintained. Metal instruments and burs are recommended only in cases requiring the smoothening of the surface roughness. The clinical impact of these findings requires clarification.

Adjunctive effect of a water-cooled Nd:YAG laser in the treatment of chronic periodontitis.

OBJECTIVES: To test whether use of a water-cooled Nd:YAG laser adjunctive to supra- and subgingival debridement (SRP) with hand and ultrasonic instruments results in greater clinical improvement than SRP alone. Another objective was to investigate the reduction in the number of microorganisms. METHODS: This study was an examiner-blind, randomized and controlled clinical trial using a split-mouth design. Nineteen subjects with moderate-to-severe generalized periodontitis were selected. Immediately following SRP in two randomly chosen contra-lateral quadrants, all pockets 4 mm were additionally treated with the Nd:YAG laser (1064 nm, 6 W, 400 mJ). Clinical assessments (Plaque index, bleeding on pocket probing, probing pocket depth) were performed pre-treatment and at 3 months post-treatment. In each quadrant, one site was sampled for microbiological evaluation at pre-treatment, immediately post-instrumentation and 3 months post-treatment. RESULTS: At the 3-month visit, the clinical parameters had significantly improved for both regimens. No significant differences between treatment modalities were observed for any of the clinical parameters at any time. Immediately following instrumentation, the total colony forming units for both groups were significantly reduced as compared with pre-instrumentation. No significant differences between treatment modalities were observed. CONCLUSIONS: Three months after SRP, no additional advantage was achieved with the additional use of the Nd:YAG laser. Microbiological findings reflect these clinical results.

Diabetes Medication Metformin Inhibits Osteoclast Formation and Activity in In Vitro Models for Periodontitis.

Diabetes and periodontitis are comorbidities and may share common pathways. Several reports indicate that diabetes medication metformin may be beneficial for the periodontal status of periodontitis patients. Further research using appropriate cell systems of the periodontium, the tissue that surrounds teeth may reveal the possible mechanism. Periodontal ligament fibroblasts anchor teeth in bone and play a role in the onset of both alveolar bone formation and degradation, the latter by inducing osteoclast formation from adherent precursor cells. Therefore, a cell model including this type of cells is ideal to study the influence of metformin on both processes. We hypothesize that metformin will enhance bone formation, as described for osteoblasts, whereas the effects of metformin on osteoclast formation is yet undetermined. Periodontal ligament fibroblasts were cultured in the presence of osteogenic medium and 0.2 or 1 mM metformin. The influence of metformin on osteoclast formation was first studied in PDLF cultures supplemented with peripheral blood leukocytes, containing osteoclast precursors. Finally, the effect of metformin on osteoclast precursors was studied in cultures of CD14+ monocytes that were stimulated with M-CSF and receptor activator of Nf-κB ligand (RANKL). No effects of metformin were observed on osteogenesis: not on alkaline phosphatase activity, Alizarin red deposition, nor on the expression of osteogenic markers RUNX-2, Collagen I and Osteonectin. Metformin inhibited osteoclast formation and accordingly downregulated the genes involved in osteoclastogenesis: RANKL, macrophage colony stimulating factor (M-CSF) and osteoclast fusion gene DC-STAMP. Osteoclast formation on both plastic and bone as well as bone resorption was inhibited by metformin in M-CSF and RANKL stimulated monocyte cultures, probably by reduction of RANK expression. The present study unraveling the positive effect of metformin in periodontitis patients at the cellular level, indicates that metformin inhibits osteoclast formation and activity, both when orchestrated by periodontal ligament fibroblasts and in cytokine driven osteoclast formation assays. The results indicate that metformin could have a systemic beneficiary effect on bone by inhibiting osteoclast formation and activity.

Water coolant supply in relation to different ultrasonic scaler systems, tips and coolant settings.

OBJECTIVE: This study evaluated "in vitro" the consistency of the water coolant supply for five ultrasonic scaler systems in relation to the tip type and different coolant settings. MATERIAL AND METHODS: The systems were: EMS PM-400, EMS PM-600, Satelec P-max, Dürr Vector and Dentsply Cavitron. For each system, three units were used and on each unit various tips were tested. The tips were run unloaded for 1 min. at full and medium water supply setting. RESULTS: At full water coolant setting, the PM-400, PM-600 and Cavitron supplied on average >45 ml/min. of water coolant (51.5, 46.3 and 46.9 ml/min., respectively). The P-max supplied 25 ml/min. and the Vector supplied 4.9 ml/min. At medium setting, the PM-400 and PM-600 supplied approximately 50% of the volume given at the full coolant setting (25.0 and 26.3 ml/min., respectively). The Cavitron supplied approximately 40% at medium setting (18.2 ml/min.) and the P-max supplied approximately 25% (5.7 ml/min.). CONCLUSION: The coolant control system of the different units did not provide a reliable indication of the water flow. Also, some perio tips gave less water coolant as compared with other tips of the same brand. Consequently, a change of tips during treatment may require adjustment of the water coolant supply.