Long-term bonding to eroded dentin requires superficial bur preparation

Objectives

This study aims to evaluate the influence of different surface preparation techniques on long-term bonding effectiveness to eroded dentin.

Materials and methods

Dentin specimens were eroded by pH cycling or were left untreated as control, respectively. Five different “preparation” techniques were applied: (1) cleaning with pumice, (2) air abrasion, (3) silicon polisher, (4) proxo-shape, and (5) diamond bur. The three-step etch-and-rinse adhesive OptiBond FL (O-FL; Kerr) and the mild two-step self-etch adhesive Clearfil SE Bond (C-SE; Kuraray) were evaluated. Micro-tensile bond strength was measured after water storage for 24?h and 1?year. Fracture analysis was performed by stereomicroscopy and SEM. Interfaces were characterized by TEM. Differences were statistically analyzed with a linear mixed effects model (α?=?0.05).

Results

Erosion reduced bond strength in all groups, but this effect was less prominent when eroded dentin was prepared by diamond bur. Storage lowered bond strength in almost all groups significantly, but this ageing effect was more prominent for the eroded surfaces than for non-eroded controls. Whereas after 1-year control specimens revealed superior bond strength with the three-step etch-and-rinse adhesive (O-FL), the mild two-step self-etch adhesive (C-SE) revealed a better 1-year bond strength to eroded dentin. The interface at eroded dentin appeared very prone to degradation as was shown by the increased amount of adhesive failures and by the silver infiltration detected by TEM.

Conclusions and clinical relevance

Although a minimally invasive approach should clinically always be strived for, superficial preparation (or minimal roughening) with a diamond bur is recommendable for long-term bonding to eroded dentin.     

A 13-year clinical evaluation of two three-step etch-and-rinse adhesives in non-carious class-V lesions

This 13-year randomized clinical trial compared the clinical effectiveness of two three-step etch-and-rinse adhesives in combination with a hybrid, stiffer composite versus a micro-filled, more flexible composite. The influence of composite stiffness on the clinical performance of one of the adhesives was assessed as well. One hundred and forty-two non-carious cervical lesions were restored with composites with contrasting stiffness. Seventy-one patients randomly received two cervical restorations placed following two out of three adhesive procedures: (1) the three-step etch-and-rinse adhesive Permaquick applied with the stiff micro-hybrid composite Amelogen Hybrid (PMQ-H, Ultradent), (2) Permaquick applied with the more flexible micro-filled Amelogen Microfill (PMQ-M, Ultradent), or (3) the “gold-standard” three-step etch-and-rinse adhesive Optibond FL applied with the micro-hybrid composite Prodigy (OFL-P, Kerr). The restorations were evaluated after 6 months, 1, 2, 3, 5, 7, and 13 years of clinical service regarding their retention, marginal integrity and discoloration, caries occurrence, preservation of tooth vitality, and post-operative sensitivity. Retention loss, severe marginal defects, and/or discoloration that needed intervention (repair or replacement) and the occurrence of caries were considered as clinical failures. The recall rate at 13 years was 77%. Bond degradation after 13 years was mainly characterized by a further increase in the presence of small but clinically acceptable marginal defects and superficial marginal discoloration. Twelve percent of the OFL-P restorations were clinically unacceptable. In the PMQ group, 22% of the PMQ-M restorations and 26% of the PMQ-H restorations needed repair or replacement. Regarding the clinical failure rate, Optibond FL scored significantly better than Permaquick (McNemar; p = 0.015). No statistically significant differences were found between the micro-filled and the hybrid composite for each of the parameters evaluated (McNemar, p > 0.05). After 13 years of clinical functioning, the clinical effectiveness of the three adhesive/composite combinations remained highly acceptable.     

Systematic review of medical therapy to prevent recurrent diverticulitis

Aim and background

One of today’s controversies remains the prevention of recurrent diverticulitis. Current guidelines advise a conservative approach, based on studies showing low recurrence rates and a high operative morbidity and mortality. Conservative measures in prevention recurrence are dietary advises and medical therapies, including probiotics and 5-aminosalicylic acid.

Objectives

The aim of this systematic review is to assess whether medical or dietary therapies can prevent recurrent diverticulitis after a primary episode of acute diverticulitis.

Method and search strategy

We searched different databases for papers published between January 1966 and January 2011.

Study selection

Clinical studies were eligible for inclusion if they assessed the prevention of recurrent diverticulitis with a medical or dietary therapy. Exclusion criteria were studies without a control group.

Results

Three randomized controlled trials (RCT), all with a Jadad quality score of 2 out of 5, were included in this systematic review. Mesalazine results in significantly less disease recurrence and fewer symptoms after an acute episode. The use of probiotics decreases symptoms but does not reduce recurrence. No difference in effect is seen when Balsalazide is added to probiotics compared to probiotics only. No relevant studies on dietary therapy/advices or antibiotics for prevention of recurrent diverticulitis were found.

Conclusion

The evidence that supports medical therapy to prevent recurrent diverticulitis is of poor quality. Treatment with 5-aminosalicylic acid seems promising. Based on current data, no recommendation of any non-operative relapse prevention therapy for diverticular disease can be made.     

Limb motor nerve dysfunction in Miller Fisher syndrome

Typical Miller Fisher syndrome (MFS) lacks limb muscle weakness, but some patients may unpredictably progress to severe Guillain‐Barré syndrome. The compound muscle action potential (CMAP) scan is a recently developed non‐invasive, painless, and reproducible method for detecting early changes in motor nerve excitability. This technique was used to monitor subclinical limb motor nerve dysfunction during disease course in typical MFS. Three Miller Fisher patients with preserved limb muscle strength and normal routine nerve conduction studies were included. Frequent serial CMAP scanning of the median nerve was performed during acute phase and follow‐up and was related to clinical course and outcome. All patients showed an abnormal increase in the range of stimulus intensities at the day of hospital admission, indicating reduced motor nerve excitability already at the earliest stage of disease. Median nerve dysfunction progressed in parallel or even before clinical deterioration, and improved with clinical recovery. Our study shows that typical MFS is a more general neuropathy, affecting peripheral motor nerves even in patients with preserved limb strength and conduction velocity. CMAP scanning is a sensitive technique for early detection of subclinical motor nerve dysfunction and for monitoring disease activity in immune‐mediated neuropathies.     

Falsely Elevated Sodium Levels During Thiopental Treatment in the ICU: Technical Interference on a Laboratory Device with Important Clinical Relevance

Introduction

Thiopental is a cornerstone in the treatment of refractory status epilepticus and intractable intracranial hypertension. In our center we observed that thiopental might cause falsely elevated serum sodium levels.

Methods

Triggered by a recent case experience of extremely elevated serum sodium levels during thiopental treatment, we retrospectively identified 53 patients treated with thiopental in our intensive care unit between 2007 and 2011 and evaluated electrolyte changes. We differentiated the analysis before and after introduction of a new device for sodium assays (Dimension Vista, Siemens) in the central laboratory in April 2010. Standardized in vitro laboratory tests were performed to study the effect of thiopental on sodium analysis.

Results

Before April 2010, serum sodium levels determined in the central laboratory showed a good agreement with the bedside point-of-care (POC) device during thiopental therapy with [sodium]_laboratory ? [sodium]_POC of only 1.08 mmol/L (P = .0517). After April 2010, a strong discrepancy between laboratory values and POC values was observed with [sodium]_laboratory ? [sodium]_POC = 11.57 mmol/L (P < .0001). Standardized in vitro testing confirmed that thiopental induced a dose-dependent false hypernatremia (P = .002).

Conclusions

Thiopental treatment can result in falsely elevated serum sodium. This is a critical finding since high sodium levels preclude administrating mannitol or hypertonic saline for the treatment of elevated intracranial pressure. Moreover, a false high sodium level might lead to the inappropriate administration of hypotonic fluids potentially resulting in increased brain edema and even higher intracranial pressure. To our knowledge, this is the first paper describing this clinically relevant phenomenon.