Effect of loading on the microtensile bond strength and microleakage of a self-etching and etch-and-rinse adhesive in direct Class II MOD composite restorations in vitro.

The effect of loading on microleakage and microtensile bond strength of MOD composite restorations bonded with either self-etching or etch-and-rinse adhesive was investigated. MOD cavities were prepared in 28 extracted molar teeth. 14 teeth were bonded with a one-step self-etching adhesive (G-Bond) and 14 with an etch-and-rinse adhesive (Optibond Solo Plus) then restored with resin composite. For each adhesive, 7 teeth were loaded and 7 unloaded (controls). Loading was achieved with an axial force of 80 N at 2.5 cycles/s for 250,000 cycles. All the teeth were stored in 0.25% rhodamine solution for 24 h and sectioned in a bucco-lingual direction at the proximal boxes to examine microleakage then further sliced mesiodistally into beams for the µTBS test. Failure modes were determined using confocal and scanning electron microscopy. ANOVA assessed the effect of loading on microleakage and bond strength. After loading, restorations bonded with G-Bond exhibited significantly greater dye penetration compared to Optibond Solo Plus at both the axial walls and cavity floor. On the other hand, loading significantly reduced the µTBS of Optibond Solo Plus, whereas it had no significant effect on the µTBS of G-Bond.

The effect of smoking on periodontal bone regeneration: a systematic review and meta-analysis.

BACKGROUND: The effect of smoking on soft tissues after periodontal treatment has been extensively studied. However, little focus has been placed on the impact of smoking on bone regeneration after treatment. The aim of this review is to systematically assess the effect of smoking on bone regeneration after periodontal treatment. METHODS: A protocol was established and studies were sourced from five electronic databases. Screening, data abstraction, and quality assessment was conducted by two review authors. Prospective and retrospective clinical studies assessing bone regeneration in smokers and non-smokers after periodontal therapy were selected. In addition, arms of clinical trials comparing different interventions that reported results separately for smokers and non-smokers were also included. Primary outcome measures were based on clinical and/or radiographic indicators of bone regeneration after periodontal therapy. The review and meta-analysis followed many of the recommendations outlined in the preferred reporting items for systematic reviews and meta-analyses statement. RESULTS: Six of 10 studies included in this review concluded that smoking negatively influenced bone regeneration. A meta-analysis of a subgroup of three studies demonstrated that smoking resulted in significantly less bone gain (P = 0.03) as measured by a change in the probing bone level after the treatment of intrabony defects with guided tissue regeneration. The meta-analysis showed a standardized mean difference of -2.05 (95% confidence interval: -2.64 to -1.47) using the random-effects model. CONCLUSIONS: Smoking has a negative effect on bone regeneration after periodontal treatment. Patients should be advised that their smoking habit may result in poorer bone regeneration after periodontal treatment.

Effect of rinsing with ethanol-containing mouthrinses on the production of salivary acetaldehyde.

It has been suggested that the use of alcohol-containing mouthrinses could lead to the presence of acetaldehyde in saliva. In this cross-over study, salivary acetaldehyde levels and microbial profiles were determined before and after rinsing with ethanol-containing mouthrinses with essential oils (EO) and cetyl pyridinium chloride (CPC) as the active ingredients, and with 21.6% ethanol and water controls. After rinsing with all ethanol-containing rinses, acetaldehyde was detected in saliva after 30 s but declined to low levels after 5 min. The highest peak levels were seen with the ethanol control (median = 82.9 µM at 2 min) and were significantly higher than those seen at the same time after rinsing with the EO rinse (43.1 µM). There was no correlation between microbial counts or plaque scores and acetaldehyde levels, although dividing the subjects on the basis of a peak acetaldehyde salivary concentration of > 90.8 µM after the ethanol rinse revealed that the high responders were highly significantly more likely to harbour salivary yeasts than were the low responders. Rinsing with ethanol-containing mouthrinses causes a rapid, but transient, increase in salivary acetaldehyde levels.

Effect of resin coating and occlusal loading on microleakage of Class II computer-aided design/computer-aided manufacturing fabricated ceramic restorations: a confocal microscopic study.

OBJECTIVE: To evaluate the effect of resin coating and occlusal loading on microleakage of class II computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic restorations. MATERIAL AND METHODS: Molars were prepared for an mesio-occlusal-distal (MOD) inlay and were divided into two groups: non-coated (controls); and resin-coated, in which the cavity was coated with a combination of a dentin bonding system (Clearfil Protect Bond) and a flowable resin composite (Clearfil Majesty Flow). Ceramic inlays were fabricated using the CAD/CAM technique (CEREC 3) and cemented with resin cement (Clearfil Esthetic Cement). After 24 h of water storage, the restored teeth in each group were divided into two subgroups: unloaded or loaded with an axial force of 80 N at a rate of 2.5 cycles/s for 250,000 cycles while stored in water. After immersion in 0.25% Rhodamine B solution, the teeth were sectioned bucco-lingually at the mesial and distal boxes. Tandem scanning confocal microscopy (TSM) was used for evaluation of microleakage. The locations of the measurements were assigned to the cavity walls and floor. RESULTS: Loading did not have a significant effect on microleakage in either the resin-coated or non-coated group. Resin coating significantly reduced microleakage regardless of loading. The cavity floor exhibited greater microleakage compared to the cavity wall. TSM observation also revealed that microleakage at the enamel surface was minimal regardless of resin coating. In contrast, non-coated dentin showed extensive leakage, whereas resin-coated dentin showed decreased leakage. CONCLUSIONS: Resin coating with a combination of a dentin-bonding system and a flowable resin composite may be indicated prior to impression-taking when restoring teeth with CAD/CAM ceramic inlays in order to reduce microleakage at the tooth-resin interface.

Risk of implant failure and marginal bone loss in subjects with a history of periodontitis: a systematic review and meta-analysis.

BACKGROUND: A number of studies have suggested that implant failure and associated bone loss is greater in subjects with a history of periodontitis. PURPOSE: To evaluate the risk for marginal bone loss around implants and implant failure in subjects with a history of periodontitis compared with periodontally healthy subjects in studies with a minimum 3-year follow-up. DATA SOURCES: The MEDLINE, EMBASE, and PubMed databases and relevant journals were searched up to July 1, 2008, with restriction to English language. REVIEW METHODS: Prospective and retrospective longitudinal observational clinical studies comparing periodontal/peri-implant variables among subjects with periodontitis and subjects who were periodontally healthy were included. Screening of studies, quality assessment, and data extraction were conducted independently and in duplicate. Clarification of missing and unclear information was not sought. Outcome measures were: implant survival/failure, peri-implant parameters, changes in radiographic marginal bone level, probing pocket depth, and gingival index. RESULTS: Seventeen potential studies were identified and six studies were accepted comparing patients with periodontitis and periodontally healthy patients treated with implants. Five studies were eligible for meta-analysis of implant survival and four studies were eligible for meta-analysis of bone loss around implants. The odds ratio for implant survival was significantly in favor of periodontally healthy patients (3.02, 95% confidence intervals 1.12-8.15). A random effects model showed more marginal bone loss in periodontitis subjects compared with periodontally healthy subjects (standard mean difference 0.61, 95% confidence interval 0.14-1.09). CONCLUSIONS: Within the limitations of the heterogenous studies available, a moderate level of evidence indicates that periodontitis subjects were at significantly higher risk for implant failure and greater marginal bone loss as compared with periodontally healthy subjects. Prospective observational studies with subject-based designs are recommended.

Effect of resin coating on adhesion and microleakage of computer-aided design/computer-aided manufacturing fabricated all-ceramic crowns after occlusal loading: a laboratory study.

This study investigated the effect of resin coating and occlusal loading on adhesion and microleakage of all-ceramic crowns. Molars were prepared for an all-ceramic crown and were divided into two groups: non-coated (control) and resin-coated with Clearfil Tri-S Bond. Crowns were fabricated using CEREC 3 and cemented using Clearfil Esthetic Cement. After 24 h of storage in water, the restored teeth in each group were divided into two subgroups: unloaded, or loaded while stored in water. Mechanical loading was achieved with an axial force of 80 N at 2.5 cycles s(-1) for 250,000 cycles. After immersion in Rhodamine B, the specimens were sectioned and processed for microleakage evaluation by confocal microscopy, which was followed by further sectioning for microtensile bond testing. Loading had no significant effect on microleakage in either the resin-coated or non-resin-coated groups. Resin coating did not reduce the microleakage at the dentine interface but increased the microleakage at the enamel interface. All the beams fractured during slicing when non-coated and loaded. The bond strengths of non-coated and unloaded, resin-coated and unloaded, and resin-coated and loaded groups were 15.82 +/- 4.22, 15.17 +/- 5.24, and 12.97 +/- 5.82 MPa, respectively. Resin coating with Clearfil Tri-S Bond improved the bonding of resin cement to dentine for loaded specimens. However, it was not effective in reducing the microleakage, regardless of whether it was loaded or unloaded.

Smoking behaviour and attitudes to periodontal health and quit smoking in patients with periodontal disease.

OBJECTIVE: The aim of this study was to assess oral health-related beliefs and attitudes, health behaviour of smokers in relation to the Transtheoretical Model (TTM) of behaviour change, willingness to have smoking cessation provided together with periodontal treatment. MATERIAL AND METHODS: Postal questionnaire was sent to 500 referred patients. Part 1 looked at attitudes and beliefs about periodontal disease, Part 2 aimed at current smokers focused on the TTM and smoking cessation. RESULTS: Response rate was 56% (n=277); 67% females, 33% males. Mean age was 44.9 years (SD 12.45); 24.5% current smokers, 30.3% past smokers, 45.5% never smokers. Fewer smokers reported "bleeding gums" (p=0.027), but more smokers reported "having loose teeth" (p=0.016). The TTM stages of change indicated that 31% of current smokers were in pre-contemplation of quitting smoking, 46% were in contemplation and 23% were in preparation. Twenty-three percent of the past smokers were in action and 77% in maintenance. Smokers showed differences in the "self-re-evaluation" (p=0.001) and "self-liberation" (p=0.015) processes of change depending on their stage of change (pre-contemplation or preparation). Nearly half (49%) of the current smokers who wanted to quit requested smoking cessation to be provided alongside their periodontal treatment. CONCLUSION: A large proportion of periodontal patient smokers may be considering quitting, and nearly half requested provision of smoking cessation intervention in conjunction with the periodontal treatment.

Effect of ultrasonic debridement using a chlorhexidine irrigant on circulating levels of lipopolysaccharides and interleukin-6.

AIM: Transient bacteraemia and endotoxaemia, and elevated levels of systemic cytokines have been reported following subgingival debridement. This study aimed to investigate the effect of chlorhexidine (CHX) solution on circulating levels of lipopolysaccharide (LPS) and interleukin-6 (IL-6) when used as an irrigant during ultrasonic debridement in patients with periodontitis. MATERIAL AND METHODS: Eighteen patients with moderate to advanced chronic periodontitis were treated in a split-mouth, crossover, single-masked study. Irrigation with 0.02% CHX solution or water was used during treatment of two ipsilateral quadrants on two separate occasions 7 days apart, randomized as to order. Peripheral blood samples were collected for circulating levels of LPS and IL-6 at baseline, 5 and 120 min. after instrumentation commenced. RESULTS: Median concentrations of LPS were elevated from baseline to 5 min. into treatment with both CHX and control irrigant (p<0.05). Median levels of IL-6 increased with both treatments from baseline to 120 min. (p<0.001): CHX, 0.81-1.85 pg/ml; control, 0.78-1.78 EU/ml. CONCLUSIONS: Ultrasonic instrumentation in patients with moderate to advanced periodontitis increases circulating levels of LPS after 5 min. and IL-6 120 min. after commencement of treatment, and is not affected by using 0.02% CHX as an irrigant instead of water.

Investigation of periodontal destruction patterns in smokers and non-smokers.

BACKGROUND: Previous work has suggested that tobacco smoking has a local as well as a systemic effect on the severity of periodontal disease. OBJECTIVE: To test the hypothesis that smokers have more disease in the upper anterior region. METHODS: A retrospective stratified random sample of 49 non-smokers and 39 heavy smokers (>or=20 cigarettes/day) was obtained from a total of 3678 referred patients with adult periodontitis. Probing depth data were collected from clinical records and radiographic measurements were carried out on existing dental panoramic tomographs to assess the inter-proximal bone levels. RESULTS: The proportion of sites with "bone loss" 4.5 mm or greater was higher in smokers, the greatest difference being observed in upper anterior sites (smokers: 73.3+/-25.5%, non-smokers: 48.3+/-31.2%, p<0.001). A difference was also observed when the number of palatal sites probing 4 mm or greater in the upper anterior region was expressed as a proportion of all such sites in the mouth (smokers: 12.3+/-6.8%, non-smokers: 9.8+/-8.8%; p=0.050). CONCLUSION: The overall pattern of tissue destruction was consistent with a systemic effect of smoking. The suggestion of a marginal local effect of the smoking habit in maxillary anterior palatal sites requires further investigation.

Mechanisms of action of environmental factors--tobacco smoking.

AIM: To review the potential biological mechanisms underlying the effects of tobacco smoking on periodontitis. MAIN FINDINGS: Smoking has major effects on the host response, but there are also a number of studies that show some microbiological differences between smokers and non-smokers. Smoking has a long-term chronic effect on many important aspects of the inflammatory and immune responses. Histological studies have shown alterations in the vasculature of the periodontal tissues in smokers. Smoking induces a significant systemic neutrophilia, but neutrophil transmigration across the periodontal microvasculature is impeded. The suppression of neutrophil cell spreading, chemokinesis, chemotaxis and phagocytosis have been described. Protease release from neutrophils may be an important mechanism in tissue destruction. Tobacco smoke has been found to affect both cell-mediated immunity and humoral immunity. Research on gingival crevicular fluid has demonstrated that there are lower levels of cytokines, enzymes and possibly polymorphonuclear cells in smokers. In vitro studies have shown detrimental effects of nicotine and some other tobacco compounds on fibroblast function, including fibroblast proliferation, adhesion to root surfaces and cytotoxicity. CONCLUSION: Tobacco smoking has widespread systemic effects, many of which may provide mechanisms for the increased susceptibility to periodontitis and the poorer response to treatment.

The short-term effects of treatment of chronic periodontitis on circulating levels of endotoxin, C-reactive protein, tumor necrosis factor-alpha, and interleukin-6.

BACKGROUND: The acute-phase response involves molecules including tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and C-reactive protein (CRP). This study aimed to determine whether subgingival scaling resulted in rapid changes in plasma concentrations of these molecules. METHODS: Twenty-three non-smoking adults with chronic periodontitis received subgingival scaling for 60 minutes. Venous blood samples were taken at 0, 15, 30, 60, and 120 minutes. TNF-alpha and IL-6 were assayed from all samples and CRP from the baseline and final samples. Lipopolysaccharide (LPS) was assayed at 0, 15, and 30 minutes using limulus lysate assay (LAL) and EndoCAb Ig assays. RESULTS: LPS assays were suggestive of a transient low-grade bacteremia, but changes in LPS approaching significance (P=0.061) were seen with LAL only. There was a significant increase in circulating TNF-alpha (P=0.0387) and IL-6 (P<0.0001), and the degree of change in TNF-alpha was correlated with the severity of periodontal breakdown (P=0.001). There was also a significant correlation between levels of IL-6 and TNF-alpha (P<0.001). CONCLUSIONS: Chronic periodontitis patients undergoing an episode of subgingival scaling show a significant elevation in circulating TNF-alpha and IL-6. This may account for anecdotal reports of pyrexia following treatment and may be significant in terms of the relationship between periodontal disease, bacteremia, and cardiovascular disease.

Balloon dilatation of salivary duct strictures: report on 36 treated glands.

PURPOSE: This paper describes the technique for balloon dilatation of salivary duct strictures and evaluates the clinical and radiographic findings in a consecutive series of 36 affected glands. METHODS: Thirty-four patients (36 glands) had balloon dilatation of their salivary duct strictures performed under fluoroscopic control. They were evaluated immediately afterwards and at review by sialography. RESULTS: In 36 cases attempted, 33 (92%) strictures were dilated. The immediate post-treatment sialogram was available in 28 cases, of which 23 (82%) demonstrated complete and four (14%) partial elimination of stricture. In one case the appearance was unchanged (4%). Review data (mean 6.8 months) were available on 25 glands: 12 were asymptomatic (48%), 12 (48%) had reduced symptoms and one (4%) failed to improve. Sialographic data were available on 21 glands: in 10 (48%) the duct remained patent, in one (5%) the stricture was partially eliminated, in seven (33%) the strictures had returned and in the remaining three (14%) cases there was complete obstruction. CONCLUSIONS: Balloon dilatation is an effective treatment of salivary duct stenosis. In half the cases the stricture recurred but symptomatic improvement was achieved and maintained in the majority of cases.

Minimally invasive radiologically guided intervention for the treatment of salivary calculi.

PURPOSE: To describe the technique and examine the value of salivary stone extraction using a minimally invasive, radiologically guided approach as an alternative to salivary gland surgery for the treatment of benign salivary gland obstruction. METHODS: Eighty-six cases of sialolithiasis (83 patients) were treated by stone removal using a Dormia basket under local anesthesia and fluoroscopic guidance. Postoperative assessment was made clinically at review, by sialogram and by questionnaire. RESULTS: Of 86 cases of sialolithiasis treated, in 55 (64%) it was possible to remove all stones. In 12 cases (14%) part of a stone or some of a number of calculi were removed and in 19 cases (22%) the procedure failed. The commonest reason for failure was fixation of the stone within the duct. Symptoms at review (range 1-49 months, mean 17 months) were relieved in 55 of 67 (82%) of cases where a stone or portion of stone was removed. CONCLUSIONS: Stone removal from the salivary duct system by radiologically guided, minimally invasive approach is a simple procedure with low morbidity and high patient acceptance when appropriate selection criteria are applied. These criteria are considered and recommendations made.