Role of dental plaque,saliva and periodontal disease in Helicobacter pylori infection

Helicobacter pylori(H.pylori)infection is one of the most common bacterial infections in humans.Although H.pylori may be detected in the stomach of approximately half of the world’s population,the mechanisms of transmission of the microorganism from individual to individual are not yet clear.Transmission of H.pylori could occur through iatrogenic,fecal-oral,and oral-oral routes,and through food and water.The microorganism may be transmitted orally and has been detected in dental plaque and saliva.However,the role of the oral cavity in the transmission and recurrence of H.pylori infection has been the subject of debate.A large number of studies investigating the role of oral hygiene and periodontal disease in H.pylori infection have varied significantly in terms of their methodology and sample population,resulting in a wide variation in the reported results.Nevertheless,recent studies have not only shown that the microorganism can be detected fairly consistently from the oral cavity but also demonstrated that the chances of recurrence of H.pylori infection is more likely among patients who harbor the organism in the oral cavity.Furthermore,initial results from clinical trials have shown that H.pylori-positive dyspeptic patients may benefit from periodontal therapy.This paper attempts to review the current body of evidence regarding the role of dental plaque,saliva,and periodontal disease in H.pylori infection.

Effect of acid etching on marginal adaptation of mineral trioxide aggregate to apical dentin:microcomputed tomography and scanning electron microscopy analysis

The present investigation assessed the effect of acid etching on marginal adaptation of white- and gray-colored mineral trioxide aggregate （MTA） to apical dentin using microcomputed tomography （micro-CT） and scanning electron microscopy （SEM）. Sixty-four extracted single-rooted human maxillary teeth were used. Following root-end resection and apical preparation, the teeth were equally divided into four groups according to the following root end filling materials： （i） white-colored MTA （WMTA）, （ii） etched WMTA （EWMTA）, （iii） gray-colored MTA （GMTA） and （iv） etched GMTA （EGMTA）. After 48 h, the interface between root-end filling materials and the dentinal walls was assessed using micro-CT and SEM. Data were statistically analyzed using the KruskaI-Wallis and Dunn tests. Micro-CT analysis revealed gap volumes between the apical cavity dentin walls and EGMTA, GMTA, EWMTA and WMTA of （0.007 1±0.004） mm3, （0.053±0.002） mm3, （0.003 6±0.001） mm3 and （0.005 9±0.002） mm3 respectively. SEM analysis revealed gap sizes for EGMTA, WMTA, EWMTA and GMTA to be （492.3±13.8） μm, （594.5±17.12）μm, （543.1±15.33） μm and （910.7±26.2）μm respectively. A significant difference in gap size between root end preparations filled with GMTA and EGMTA was found （P〈O.05）. No significance difference in gap size between WMTA and EWMTA were found in either SEM or micro-CT analysis. In conclusion, pre-etching of apical dentin can provide a better seal for GMTA but not for WMTA.

Real-time-guided bone regeneration around standardized critical size calvarial defects using bone marrow-derived mesenchymal stem cells and collagen membrane with and without using tricalcium phosphate: an in vivo microcomputed tomographic and histologic e

The aim of the present real time in vivo micro-computed tomography （pCT） and histologic experiment was to assess the efficacy of guided bone regeneration （GBR） around standardized calvarial critical size defects （CSD） using bone marrow-derived mesenchymal stem cells （BMSCs）, and collagen membrane （CM） with and without tricalcium phosphate （TCP） graft material. In the calvaria of nine female Sprague-Dawley rats, full-thickness CSD （diameter 4.6 mm） were created under general anesthesia. Treatment-wise, rats were divided into three groups. In group 1, CSD was covered with a resorbable CM; in group 2, BMSCs were filled in CSD and covered with CM; and in group 3, TCP soaked in BMSCs was placed in CSD and covered with CM. All defects were closed using resorbable sutures. Bone volume and bone mineral density of newly formed bone （NFB） and remaining TCP particles and rate of new bone formation was determined at baseline, 2, 4, 6, and 10 weeks using in vivo pCT. At the lOth week, the rats were killed and calvarial segments were assessed histologically. The results showed that the hardness of NFB was similar to that of the native bone in groups I and 2 as compared to the NFB in group 3. Likewise, values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2. This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical ＂lock＂ between the natural bone and NFB. The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adiunct BMSC therapy.

One-year rotational relapse frequency following conventional circumferential supracrestal fiberotomy

BACKGROUND Relapse following orthodontic treatment has been a common problem that can occur due to several factors. It was suggested that surgical circumferential supracrestal fiberotomy(CSF) is an effective measure to reduce this relapse.However, very few studies have reported the amount of relapse that occurs afterward.AIM To assess the frequency of rotational relapse on anterior teeth 1 year following CSF.METHODS Eleven adults(six male and five female) with a mean age of 23 years(standard deviation = 5.2), who had a total of 90 rotated anterior teeth, were included in this study. CSF was performed after comprehensive orthodontic treatment involving the use of full-fixed preadjusted edgewise appliances(Victory Series APC, 3 M,United States) with a 0.022-inch slot and Roth prescription brackets(Ovation;DENTSPLY GAC, Bohemia, New York, United States) and placement of a fixed lingual retainer from canine to canine in both arches using a 0.016 Australian wire(AJ Wilcock, Australia). Degrees of rotational correction and relapse were measured on three sets of casts [pretreatment, post-treatment(at the debond visit), and 1-year post-treatment]. Rotational relapse was categorized as follows:Unnoticeable relapse(0°), barely noticeable relapse(1°-3°), noticeable relapse(4°-9°), and clearly noticeable relapse(≥ 10°). The percent relapse that had occurred 1 year after teeth were aligned to their ideal position was calculated. Data were analyzed by dental arch type and tooth types.RESULTS Mean rotational correction was 14.05° during posttreatment. Mean relapse at 1-year follow-up was 1.1°(10.8%). More than half(n = 52, 57.8%) of teeth were categorized as having unnoticeable relapse(0°). Of the remaining teeth, 31(34.5%) had barely noticeable relapse(1°-3°), 6(6.6%) had noticeable relapse(4°-9°), and only one(1.1%) had clearly noticeable relapse(> 10°). When analyzed by arch, 54.5%(n = 6) of the relapsed maxillary teeth had barely noticeable relapse(1°-3°). While most of the mandibular teeth(3, 37.5%) fell into noticeable relapse category(4°-9°), only 1(12.5%) tooth had clearly noticeable relapse(≥ 10°).CONCLUSION When relapse was measured following CSF, it was found to be more pronounced in maxillary than in mandibular arch. Most frequent relapse was found in maxillary lateral incisors and mandibular canines.

Role of salivary matrix metalloproteinase-8 （MMP-8） in chronic periodontitis diagnosis

Periodontitis is an inflammatory disease of the periodontium. Any imbalance between the matrix metalloproteinases （MMPs） secreted by neutrophils and tissue inhibitors initiates the destruction of collagen in gum tissue, leading to chronic periodontitis. This study aimed to correlate salivary levels of MMP-8 and periodontal parameters of chronic periodontitis to establish MMP-8 as a noninvasive marker for the early diagnosis of chronic periodontitis. The study involved 40 subjects visiting the periodontic OPD of Dr. Ziauddin Ahmad Dental College and Hospital, located in Aligarh, U.P., India, from 2011 to 2012. The subjects were divided into two groups： group I consisted of 20 periodontally healthy subjects （controls） while group II consisted of 20 patients with chronic periodontitis. Chronic periodontitis was assessed on the basis of several periodontal parameters, including pocket probing depth （PPD）, clinical attachment level （CAL）, gingival index （GI）, and plaque index （PI）. Around 3 ml of unstimulated and whole expectorated saliva was collected for MMP-8 estimation by ELISA using Quantikine human total MMP-8 immunoassay kits. Data were analyzed using STATISTICA （Windows version 6） software. Salivary MMP-8 levels of groups I and II were 190.91 ± 143.89 ng/ml and 348.26± 202.1 ng/ml, respectively. The MMP-8 levels and periodontal status （PPD, CAL, GI, and PI） of groups I and II showed positive and significant correlations （for PPD, r = 0.63, P 〈 0.001; for CAL, r = 0.54, P 〈 0.001; for GI, r = 0.49, P 〈 0.001; and for PI, r = 0.63, P 〈 0.001）. The results of this study demonstrate elevated concentrations of MMP-8 in individuals with chronic periodontitis.