Are periodontitis and psoriasis associated? A pre-clinical murine model.

AIM: To investigate the bidirectional influence between periodontitis and psoriasis, using the respective experimental models of ligature- and imiquimod-induced diseases on murine models. MATERIALS AND METHODS: Thirty-two C57/BL6J mice were randomly allocated to four experimental groups: control (P- Pso-), ligature-induced periodontitis (P+ Pso-), imiquimod-induced psoriasis (P- Pso+) and periodontitis and psoriasis (P+ Pso+). Samples (maxilla, dorsal skin and blood) were harvested immediately after death. Measures of periodontitis (distance between the cemento-enamel junction and alveolar bone crest [CEJ-ABC] and the number of osteoclasts) and psoriasis (epidermal thickness and infiltrate cell [/0.03mm2]) severity as well as systemic inflammation (IL-6, IL-17A, TNF-α) were collected. RESULTS: The P+ Pso+ group exhibited the most severe experimental periodontitis and psoriasis, with the highest values of CEJ-ABC, number of osteoclasts, epidermal thickness and infiltrate cells in the dorsal skin, as well as the highest blood cytokine concentration. The P+ Pso- group presented with higher cell infiltrate (/0.03mm2) compared to the control group (p <.05), while the P- Pso+ group showed substantially higher alveolar bone loss (CEJ-ABC) than the control group (p <.05). CONCLUSIONS: Experimental periodontitis may initiate and maintain psoriasiform skin inflammation and, vice versa, experimental psoriasis may contribute to the onset of periodontitis. In a combined model of the diseases, we propose a bidirectional association between periodontitis and psoriasis via systemic inflammation.

Association between apical periodontitis and secondary outcomes of atherosclerotic cardiovascular disease: A case-control study.

AIM: To evaluate the association between apical periodontitis (AP) and atherosclerotic cardiovascular disease (ASCDV). METHODOLOGY: A total of 65 periodontally and systemically healthy patients (age ≥ 40 years) were included in the study. Periapical status was assessed through dental examination and periapical radiographs; 33 subjects had AP (AP+), while 32 acted as control (AP-). Moreover, data regarding their periapical index (PAI) score and the Decayed, Missing, and Filled Teeth (DMFT) index were recorded. All subjects underwent echo-colour Doppler assessment of carotid intima-media thickness (CIMT), carotid plaques, degree of stenosis using the North American Symptomatic Carotid Surgery Trial (NASCET) method, maximum diameter of the abdominal aorta (maximum AA) and common iliac arteries (CIA) diameters. Furthermore, peripheral blood flow was also measured using the ankle-brachial index (ABI). Simple and multiple regression analyses were performed. RESULTS: Among AP+ patients, 57.58% disclosed at least one sign of subclinical carotid atherosclerosis. Multiple regression analysis identified AP as a significant risk indicator for carotid plaques [OR = 4.87 (1.27, 18.98; p = .021)] and marked carotid intima-media thickenings (OR = 14.58 [1.22, 176.15], p = .035). A significant association was established between AP and other cardiovascular (CV) variables (CIMT, NASCET, and maximum AA). On the contrary, a higher PAI score does not correlate to increased odds of carotid alterations, and the presence of AP did not prove any significant change in CIA and ABI. No significant correlation was established between DMFT and other variables. CONCLUSIONS: Results from the current study highlight that the presence of AP may be regarded as a risk indicator for ASCVD, with AP being associated with 5-fold increased odds of having carotid plaques and 15-fold increased odds of having marked carotid intima-media thickenings. Further studies should be conducted in order to verify whether AP treatment could be beneficial for ASCVD signs.

The Limitations of Periapical X-ray Assessment in Endodontic Diagnosis-A Systematic Review.

Diagnosis is a key aspect in endodontic treatment, in a decade where invasive interventions are misapprehended as social tendency instead of medical necessity. All diagnostic facets should be considered before intending the operative phase. Intraoral endodontic radiology-based diagnosis has been shown to be limited. Periapical X-ray is the most used endodontic imaging, yet it does not provide high accuracy. Traditionally, dentists have been trained to diagnose a cyst by certain aspects (size, shape and appearance); hence, an assumption that teeth are affected by "periapical cyst" were subjected to unnecessary extraction or apicoectomy. The aim of this systematic review is to critically appraise the publications that relate the histological diagnosis of a periapical lesion (considered the gold standard) to intraoral X-ray investigation. Ovid Medline, PubMed, ScienceDirect, Mendeley and Scopus were searched for English-language studies comparing periapical diagnosis obtained by using two techniques (histopathology and X-ray). Sixteen articles were included for the final analysis (qualitative and quantitative evaluation) out of which only two supported the statement that periapical diagnosis can be coherently assessed through periapical imaging. Although there is not enough evidence to deliver a definitive conclusion, there are many publications that refute the diagnosis of a cyst via periapical X-ray.

Healthy lifestyles are associated with a better response to periodontal therapy: A prospective cohort study.

AIM: To evaluate the association between lifestyle behaviours and clinical periodontal outcomes following Steps 1/2 of periodontal therapy. METHODS: A total of 120 subjects with untreated Stage II/III periodontitis participated in this study. At baseline, questionnaires were administered to assess the following lifestyle behaviours: adherence to Mediterranean diet (MD), physical activity (PA) and stress levels, sleep quality, smoking and alcohol use. Participants received Steps 1/2 of periodontal therapy and were re-evaluated after 3 months. A composite outcome of the endpoint of therapy (i.e., no sites with probing pocket depth [PPD] ≥4 mm with bleeding on probing, and no sites with PPD ≥ 6 mm) was regarded as the primary outcome. Simple and multiple regression analyses were used to evaluate the association between lifestyle behaviours and clinical periodontal outcomes. Disease severity at baseline, body mass index, diabetes, household disposable income and plaque control were considered as confounders. RESULTS: Multiple regression analyses showed significantly lower odds of achieving the endpoint of therapy in subjects with poor sleep quality (odds ratio [OR] = 0.13; 95% confidence interval [CI]: 0.03-0.47; p < .01), smoking (OR = 0.18; 95% CI: 0.06-0.52; p < .05) and alcohol use above the suggested intake (OR = 0.21; 95% CI: 0.07-0.63; p < .01). Subjects with a combination of 'unhealthy lifestyles' (low adherence to MD and low PA levels and high levels of stress and poor sleep quality) showed higher proportions of residual PPD≥6 mm (MD = 1.51; 95% CI: 0.23-2.80; p < .05) and lower odds of achieving the endpoint of therapy (OR = 0.85; 95% CI: 0.33-0.99; p < .05) at re-evaluation. CONCLUSIONS: Subjects with unhealthy lifestyle behaviours showed worse clinical outcomes 3 months after Steps 1/2 of periodontal therapy.

Leisure-time and occupational physical activity demonstrate divergent associations with periodontitis: A population-based study.

AIM: To evaluate the association between leisure-time/occupational physical activity (LTPA/OPA) and periodontitis in a nationally representative sample of the U.S. MATERIALS AND METHODS: Data from 10,679 adults were retrieved from NHANES 2009-2014 database. Physical activity was assessed through the Global Physical Activity Questionnaire, and accordingly, subjects were classified as performing either high or low LTPA/OPA. Periodontal status was assessed through a full-mouth periodontal examination, and subjects were classified according to the AAP/CDC criteria (no, mild, moderate, or severe periodontitis). Simple and multiple regression analyses were applied to study the association between LTPA/OPA and periodontitis/severe periodontitis. RESULTS: Multiple regression analyses identified high LTPA as a protective indicator for periodontitis (odds ratio [OR] = 0.81; 95% confidence interval [CI]: 0.72-0.92), while high OPA was found to be a significant risk indicator (OR = 1.16; 95% CI: 1.04-1.30). The combination low LTPA/high OPA showed a cumulative independent association with periodontitis (OR = 1.47; 95% CI: 1.26-1.72). Moreover, both high LTPA (OR = 0.72; 95% CI: 0.58-0.90) and high OPA (OR = 1.29; 95% CI: 1.09-1.53) were significantly associated with stronger estimates of severe periodontitis; the same was observed for the combination of low LTPA/high OPA (OR = 1.66; 95% CI: 1.29-2.15). CONCLUSIONS: LTPA and OPA showed divergent associations with periodontitis.

Sealing ability of two root-end filling materials at different retro-preparation lengths.

PURPOSE: The aim of the present study was to evaluate the sealing performance, expressed as microleakage (ML), of two root-end filling materials when used at different retro-preparation lengths. METHODS: Fifty single-rooted human teeth were collected for the study. The teeth were cut at the cement-enamel junction and endodontic treatment was performed. Each root was cut at 3 mm from the apex and then stored in wet condition. The teeth were divided into three groups according to the retro-preparation length: control group (no retro-preparation); group 1 (retro-preparation of 3 mm); group 2 (retro-preparation of 9 mm). The teeth were equally allocated to either Biodentine or Super EBA treatment group. The teeth were immersed in 3% methylene blue dye solution for 24 h. The samples were split longitudinally and the depth of dye penetration was examined through light microscopy. RESULTS: No significant statistical differences were found at different retro-preparation lengths (P > 0.05). Differences were found between materials (P > 0.05). CONCLUSION: Biodentine showed significantly lower ML when compared to Super-EBA and no statistical significative differences were observed when samples were retro-prepared at 3 mm or 9 mm.

A rare mandibular neoplasm: case report of a Central Giant Cell Granuloma.

Mandible can be affected by a great variety of neoformations, like aneurysmal bone cyst, odontogenic myxoma, CGCG (Central Giant Cell Granuloma), GCT (giant cell tumor), sarcoma, ameloblastoma, lymphoma, ossifyng fibroma, odontogenic mixoma, granuloma, arteriovenous malformations and Schwannoma. Occasionally is not possible to find clinical or radiological distinctive findings so is usefull to perform additional exams, think about rare disease and perform an explorative surgical treatment which can be adapted to the intraoperatory findings. This attitude may help to reduce overtreatment but also to be radical especially in case of rare condition like the case presented: a Central Giant Cell Granuloma of the jaws. In this case report the authors present a 19-year-old female with a slowly enlarging, painfull swelling on the left side of the lower jaw. Ortopantomography exam revealed an osteolytic bone formation confirmed by Tomographic Dental Scan, MRI and Eco-Doppler exam. No one of these procedures, however, allowed to characterize the neoformation. For that reason was planned immediately an explorative surgical treatment, instead of an agosbiopsy. Macroscopic free margins resection provided radicality on one side and saved much bone tissue as possible on the other; morever it would have permitted to be more demolitive with a further procedure if the histopathological examination of specimen didn't show complete neoformation removal. KEY WORDS: Central Giant Cell Granuloma, Rare Mandibular Neoplasm, Explorative Surgical Treatment.

Crossover Clinical Trial of Tablets Containing Sodium Tripolyphosphate on Dental Stain Formation.

OBJECTIVES: The purpose of this clinical investigation was to evaluate the effectiveness of sugar-free tablets containing sodium tripolyphosphate 2% or sodium tripolyphosphate 0.65%, compared to a no-tablet control in preventing the formation of extrinsic stains over a 12- week period of regular unsupervised use preserving daily oral hygiene with dentifrice and usual tooth brushing. METHODS: This was a single-center, examiner-blind, randomized, 12-week crossover clinical trial. Sixty-six adult participants were enrolled in the study and were submitted to a professional cleaning to have a stain-free baseline. They either consumed two sugar-free tablets four times per day or not for 12 weeks. At the crossover, all procedures were repeated and subjects were assigned to another group. Extrinsic stain was measured at each 12-week period by the Modified Lobene Stain Index (MLSI). RESULTS: After the three legs of 12 weeks, 60 subjects completed the trial, their MLSI stain scores showed a significant 35.5% reduction (p < 0.001) in new stain formation for those using the sodium tripolyphosphate 2% tablets, and a significant 23.3% reduction (p < 0.001) in new stain formation for those using the sodium tripolyphosphate 0.65% tablets versus the control group. CONCLUSIONS: This clinical study showed that regular use of sugar-free tablets added with sodium tripolyphosphate 2% or 0.65% can reduce stain formation on the anterior teeth respectively by 35.5% (p < 0.001) or 23.3% (p < 0.001), both on facial and lingual/palatal surfaces.

Evolution of Nickel-titanium Alloys in Endodontics.

To improve clinical use of nickel-titanium (NiTi) endodontic rotary instruments by better understanding the alloys that compose them. A large number of engine-driven NiTi shaping instruments already exists on the market and newer generations are being introduced regularly. While emphasis is being put on design and technique, manufacturers are more discreet about alloy characteristics that dictate instrument behavior. Along with design and technique, alloy characteristics of endodontic instruments is one of the main variables affecting clinical performance. Modification in NiTi alloys is numerous and may yield improvements, but also drawbacks. Martensitic instruments seem to display better cyclic fatigue properties at the expense of surface hardness, prompting the need for surface treatments. On the contrary, such surface treatments may improve cutting efficiency but are detrimental to the gain in cyclic fatigue resistance. Although the design of the instrument is vital, it should in no way cloud the importance of the properties of the alloy and how they influence the clinical behavior of NiTi instruments. CLINICAL SIGNIFICANCE: Dentists are mostly clinicians rather than engineers. With the advances in instrumentation design and alloys, they have an obligation to deal more intimately with engineering consideration to not only take advantage of their possibilities but also acknowledge their limitations.

Influence of Continuous or Reciprocating Optimum Torque Reverse Motion on Cyclic Fatigue Resistance of Two Single-File Nickel-Titanium Rotary Instruments.

OBJECTIVE: Different single-file instruments and kinematics have been introduced on the market. It is important to know the cyclic fatigue performance of these instruments in these new kinematics such as reciprocation of Optimum Torque Reverse (OTR) motion. The aim of this study was to evaluate the resistance to cyclic fatigue of F6 SkyTaper and OneShape used in continuous rotation (proper rotation) or in reciprocating OTR motion. METHODS: A total of forty-eight nickel-titanium files were tested. Twenty-four instruments of both brands were divided into two groups (n=12) on the basis of the motion tested: continuous rotation (group 1) or reciprocating OTR motion (group 2). Resistance to cyclic fatigue was determined by recording time to fracture (TtF) in a stainless steel artificial canal with a 60° angle of curvature and 5 mm radius of curvature. Data were analysed by two-way analysis of variance and post-hoc Bonferroni tests for multiple comparisons with P<0.05 as the level of significance. RESULTS: F6 SkyTaper showed higher TtF compared with OneShape, both in continuous and in OTR motion (P<0.0001). The two tested instruments showed higher cyclic fatigue resistance in reciprocating OTR motion than continuous rotation (P<0.0001). CONCLUSION: OTR motion significantly improves cyclic fatigue resistance of the tested instruments. In addition, F6 SkyTaper showed higher cyclic fatigue resistance than OneShape in both motions.

Effect of Green Tea-Added Tablets on Volatile Sulfur-Containing Compounds in the Oral Cavity.

OBJECTIVES: A controlled, clinical, double-blind, cross-over study was conducted to assess the efficacy of sugar-free tablets containing green tea extract on oral volatile sulfur-containing compounds (VSC) versus placebo tablets for 30 minutes. METHODS: To join the study, subjects had to have at least 24 teeth, no report of oral and systemic diseases, and no removable dentures. All eligible participants had to avoid professional oral hygiene and drugs for two weeks, to not be menstruating, to avoid brushing their teeth and tongue, to not smoke, to not consume alcohol, coffee or tea, nor onion, garlic, or licorice for six hours before the test. Moreover, they had to score a level of VSC ≥ 75 ppb at the basal measurement. Subjects were entered into their respective groups after a minimum 48-hour wash-out period. The test tablet (0.7 g) contained 0.05% green tea extract (equivalent of 1 mg polyphenols for three tablets); the control tablet was identical but without the active agent. The OralChroma2™ device was utilized to evaluate VSC in the oral air. The levels were recorded at baseline, after sucking three tablets in succession, and after 30 minutes. Data were analyzed with SPSS software and significance was set at α = 0.05. RESULTS: 54 subjects completed the trial (23 men, 31 women). None reported problems linked to green tea. The mean reductions in VSC level from baseline at the end of tablet sucking were 34% (p < 0.001) in the control and 55% (p < 0.001) in the test group; after 30 minutes, reductions were 7% in the control (p = NS) and 26% (p < 0.005) in the test group. The comparisons between the two groups after baseline adjustment showed a statistically significant difference in reductions both at the end of the sucking period (p < 0.01) and after 30 minutes (p < 0.01). CONCLUSIONS: Tablets containing green tea extract can statistically significantly reduce the oral VSC levels immediately, and after 30 minutes. Moreover, the test tablets reduced oral VSC significantly more than the control tablets.

Cyclic fatigue resistance of nickel-titanium instruments after immersion in irrigant solutions with or without surfactants.

INTRODUCTION: The aim of the study was to assess cyclic fatigue resistance of reciprocating (Reciproc and WaveOne) and continuous rotating (ProTaper) nickel-titanium files after immersion in different irrigation solutions with or without surfactants during several short time periods. METHODS: A total of 270 new Reciproc R25, WaveOne Primary, and ProTaper F2 files were tested. Instruments of each brand were divided into 1 control group (n = 10) formed by new files and 4 test groups (n = 20) formed by instruments dynamically immersed at 37°C for 16 mm in 5.25% sodium hypochlorite (NaOCl), Hypoclean (5.25% NaOCl with surfactant), 17% EDTA, or EDTA Plus (17% EDTA with surfactant). Each test group was subdivided into 2 subgroups (n = 10) on the basis of the time of dynamic immersion in the endodontic irrigant solution (45 seconds or 3 minutes). Resistance to cyclic fatigue was determined by recording time to fracture in a stainless steel artificial canal with a 60° angle of curvature and 5-mm radius of curvature. The fracture surface was examined by using scanning electron microscopy. RESULTS: Immersion in NaOCl did not reduce the cyclic fatigue of reciprocating or continuous nickel-titanium files. The 17% EDTA reduced the fatigue resistance of all instruments after 3 minutes. The immersion in irrigants with surfactants did not influence the cyclic fatigue of instruments except for Reciproc immersed in Hypoclean solution. CONCLUSIONS: EDTA immersion reduced the cyclic fatigue resistance of all instruments after 3 minutes. Addition of surfactants did not influence the cyclic fatigue of files except when added to NaOCl when it contacts Reciproc instruments.

Comparison of two techniques for assessing the shaping efficacy of repeatedly used nickel-titanium rotary instruments.

INTRODUCTION: The shaping capacity of nickel-titanium (NiTi) rotary instruments is often assessed by photographic or micro-computed tomography (micro-CT) measurements, and these instruments are often used more than once clinically. This study was conducted to compare photographic and micro-CT measurements and to assess if the repeated use of NiTi instruments affected the shape of canal preparation. METHODS: Ten new sets of ProTaper Universal instruments (Dentsply-Maillefer, Ballaigues, Switzerland) were used in 60 resin blocks simulating curved root canals. Groups 1 to 6 (n=10) represented the first to sixth use of the instrument, respectively. Digitized images of the prepared blocks were taken in both mesiodistal (MD) and buccolingual (BL) directions and area measurements (mm(2)) were calculated using AutoCAD (Autodesk Inc, San Rafael, CA). The volumes of the same prepared canals were measured using micro-CT (mm(3)). Statistical analysis was performed to detect differences between photographic and volumetric measurements and differences between uses. RESULTS: Two-way repeated-measures analysis of variance revealed significant differences between groups (P < .001). Regarding measurement type, there were no significant differences between BL and MD measurements, but there were significant differences between micro-CT and BL measurements (P < .001) and micro-CT and MD measurements (P=.001). Significant differences were also noted between uses. CONCLUSIONS: Within the limitations of the present study, micro-CT scanning is more discriminative of the changes in canal space associated with repeated instrument use than photographic measurements. Canal preparations are significantly smaller after the third use of the same instrument.

Effect on dental stain occurrence by chewing gum containing sodium tripolyphosphate--a double-blind six-week trial.

OBJECTIVE: A six-week controlled double-blind clinical study was conducted to assess and to measure the efficacy of a sugar-free chewing gum containing sodium tripolyphosphate (1%) on dental stain occurrence versus a placebo sugar-free chewing gum. METHODS: One-hundred and eleven subjects who had a Lobene Modified Index for stain extent score between 0.33 and 1.5 in their frontal teeth joined this study. Each subject entered in the test or the control group using a random table which allowed for an equal distribution of smokers and habitual tea users. Participants agreed to chew two gums (two grams each) three times per day, after meals, for ten minutes over six weeks. All received the same dentifrice containing only fluoride as the active agent. After six weeks, participants were scored for dental stain with the Lobene Modified Index. Data were scored by the same blinded operator for all measurements. Comparisons between the groups with respect to baseline scores were performed using an unpaired t-test, and inside the groups with a paired t-test (alpha = 0.05). RESULTS: One-hundred and eight subjects completed the trial; three left, but none reported problems linked to sodium tripolyphosphate. The mean difference for stain extent index after the six-week trial was 0.04 (+/- 0.08) in the control group, and -0.05 (+/- 0.08) in the test group (p < 0.001). A statistically significant reduction was also reported for intensity and composite indexes. The initial mean for stain extent index in the test group was 0.8 (+/- 0.34), and at six weeks was 0.74 (+/- 0.33; p < 0.001). The initial mean for extent index in the control group was 0.78 (+/- 0.3), and at six weeks was 0.81 (+/- 0.32; p < 0.005). CONCLUSION: This trial showed a reduction in dental stain by a chewing gum containing sodium tripolyphosphate after six weeks.

Quantitative and qualitative elemental analysis of different nickel-titanium rotary instruments by using scanning electron microscopy and energy dispersive spectroscopy.

This study was designed to determine if the alloy composition shares an influence with the geometric design on the physical behavior of nickel-titanium rotary endodontic instruments. ProTaper, HERO, and K3 files were selected. After sterilized and cleaning with alcohol, surface analysis was performed using energy dispersive spectroscopy. Measurements were performed on the active part and on the shank. SEM images of fractured instruments were also obtained and assessed. All three types of instruments were composed mainly of Nickel (54.3%, SD +/- 0.8) and Titanium (45.2%, SD +/- 0.9). SEM images revealed similar aspect with the presence of Kirkendall voids regularly distributed in the alloy. The results indicate that the difference in properties and behavior of these three endodontic rotary shaping instruments is solely related to the respective geometric characteristics of the instrument design.

Post space cleaning using a new nickel titanium endodontic drill combined with different cleaning regimens.

This study compared the effect of two drills and five cleaning regimens on post space debridement. One hundred extracted premolars were instrumented and obturated with warm vertical compaction of gutta percha. The teeth were divided into two groups according to the drill used to remove gutta percha/sealer and for post space preparation: a Largo drill (Largo; Dentsply, St Quentin en Yvelines, France) or a MTwo-PF drill (Sweden&Martina, Due Carrare, Padova, Italy). The following cleaning regimens were used: EDTA, ultrasonics, ultrasonics + EDTA, phosphoric acid, and distilled water. Scanning electron microscopic images of the post spaces were taken, and the presence of debris and of open dentin tubules were evaluated. The ultrasonics + EDTA, phosphoric acid, and EDTA groups were comparable in open tubules scores for both drills and in debris scores after the use of MTwo-PF (p > 0.05). The ultrasonics and control groups performed significantly worse (p < 0.05). The MTwo-PF drill resulted as effective as the Largo drill in obtaining a good post space cleaning, especially when followed by ultrasonics + EDTA irrigant regimen.

Effect of clinical use on the cyclic fatigue resistance of ProTaper nickel-titanium rotary instruments.

The resistance of ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) nickel-titanium rotary instruments to cyclic fatigue was examined after their initial use in straight or curved canals in vivo. These instruments were rotated freely inside a steel phantom until separation. The number of rotations before failure and the lengths of the separated fragments were compared with data derived from new instruments under the same experimental setup (n = 20). With the exception of F1 and F3, instruments previously used in curved canals were more susceptible to cyclic fatigue than those previously used in straight canals (p < 0.05). Separation occurred predominantly at the D10 to D12 level. For the F series, a negative correlation (p < 0.05) was observed between the number of rotations before failure and the file diameters at their separation levels. ProTaper F3 instruments are highly susceptible to cyclic fatigue failure and should be reused with caution irrespective of whether they are initially used for shaping straight or curved canals.

Whitening effect by stain inhibition from a chewing gum with sodium hexametaphosphate in a controlled twelve-week single-blind trial.

OBJECTIVE: A twelve-week clinical study was conducted to assess the effect of a chewing gum containing sodium hexametaphosphate (4%) on the inhibition of stain formation. METHODOLOGY: Fifty-four subjects were entered and completed all aspects of the study. Twenty-seven of the subjects were smokers, and the other half did not smoke. Subjects were randomly assigned to the test gum or no-gum group. Each participant received a full oral prophylaxis at the beginning of each period of observation. Those chewing the test gum agreed to chew four times a day, for five minutes each time, over twelve weeks. Those assigned to the no-gum group agreed not to chew any gum. After twelve weeks, participants were scored for stain deposits (Lobene Index), received a second oral prophylaxis, and joined the alternate group in this cross-over format. At the end of the twenty-fourth week, all subjects were again scored for stain deposits and the study was completed. In order to enhance stain formation during the entire 24-week study period, all participants received a supply of a chlorhexidine (0.12%) dentifrice without anionic agents to use three times a day. Stain levels were scored by the same examiner for all measurements and recorded on computer. The examiner was blinded to all treatment assignments. RESULTS: There were no reported problems associated with the chewing gum. The Lobene Index mean score for stain extent was 0.54 +/- 0.36) in the test-gum group and 0.81 +/- 0.47) for the no-gum group. The difference between the mean scores was highly significant with paired sample t-test (p < 0.001). Mean stain intensity was 0.57 +/- 0.38) in the test group and 0.95 (+/- 0.72) in the control group, with a statistically significant difference at p < 0.01. CONCLUSION: The results indicated that chewing gum containing sodium hexametaphosphate reduced induced stain formation by 33% compared to a no-gum treatment.

Anticalculus efficacy of a chewing gum with polyphosphates in a twelve-week single-blind trial.

OBJECTIVE: A twelve-week clinical study was conducted to evaluate the effect of a chewing gum containing pyrophosphate (1%) and tripolyphosphate (1%) on controlling supragingival calculus deposits. METHODOLOGY: One-hundred and seventeen subjects enrolled in the study were randomly assigned to either a test gum or no gum group. Each participant received a full oral prophylaxis. Those chewing the test gum agreed to chew four times a day for five minutes each time over twelve weeks. Those assigned to the no gum group agreed not to chew any gum. After twelve weeks, participants were scored for calculus deposits using the modified Volpe-Manhold Calculus Index (VMI), received a second oral prophylaxis and entered the alternate group in this cross-over format. At the end of the twenty-fourth week, all subjects were again scored for calculus deposits and the study was completed. All participants received a supply of a sodium fluoride (0.32%) dentifrice for the study period. Calculus levels were scored by the same examiner for all measurements and recorded on computer. He was blinded to all treatment assignments. RESULTS: One-hundred and eleven participants completed the study. Six participants left the study but none reported problems linked to the pyrophosphates in the chewing gum. The VMI mean score for the test gum group was 2.55 (+/- 2.50) and the mean score for the no gum group was 4.09 (+/- 3.18). The difference between the mean scores was highly significant with paired sample t-test (p < 0.0001). CONCLUSION: The results indicated that a chewing gum containing tripolyphosphate and pyrophosphate reduced calculus formation by 37.6% compared to a no gum treatment.

A six-week study to evaluate the anti-calculus efficacy of a chewing gum containing pyrophosphate and tripolyphosphate.

OBJECTIVE: A six-week, double-blind, cross-over clinical study was conducted to compare the effect of a new chewing gum containing pyrophosphate (1%) and tripolyphosphate (1%), versus a control chewing gum on supragingival calculus deposits. METHODOLOGY: Twenty-eight adult subjects (mean age 34 +/- 8 years) who entered the study were given a full oral prophylaxis and were assigned to chew two pieces of gum, four times a day for five minutes. The gum, either a test chewing gum or placebo chewing gum, was randomly assigned and the subjects were directed to chew their assigned gum for six weeks. All participants also received a 12-week supply of a sodium fluoride (0.32%) dentifrice (Colgate). They were then scored for calculus deposits using the modified Volpe-Manhold Calculus Index (VMI) by the same two examiners. At the end of the first six weeks, the subjects received a second oral prophylaxis and used the alternate chewing gum for a second six-week period of time. The subjects were again scored for calculus deposits and the study was completed. RESULTS: The results demonstrated a mean VMI of 3.65 +/- 2.82 for the test group, and a mean of 4.24 +/- 3.25 for the placebo group. This difference was significant with paired sample t-test (p < 0.001). CONCLUSION: These results indicated that chewing gum containing pyrophosphate and tripolyphosphate reduced supragingival calculus formation by 13.9%, compared to the placebo chewing gum.