Time- and Species-Dependent Bacterial Adhesion to Titanium over Short Exposure Periods: An In Vitro Study

A considerable percentage of dental implant patients experience biofilm-mediated peri-implant disease following transmucosal abutment application. Bacterial adhesion is an early step in biofilm development. Our purpose was to assess adhesion of specific bacterial species to titanium over short exposure periods. Eight bacterial species were selected for this analysis: Streptococcus oralis, Streptococcus mitis, Gemella haemolysans, Streptococcus gordonii, Streptococcus sanguinis, Neisseria flavescens, Streptococcus salivarius, and Pseudomonas aeruginosa. We cultured each species with appropriate media and exposed titanium foil discs to the bacteria for 60, 15, 5, 1, or 0.25 minutes. Optical density at 600-nm wavelength (OD600) was assessed for the baseline inoculum and each species/exposure combination. The proportion of bacteria adherent to titanium was determined for each experimental condition. Striking titanium adhesion was noted for all evaluated species even when exposure time was limited to 15 seconds. Strategies to limit bacterial adhesion at dental implant surfaces may offer potential for improved treatment outcomes and preservation of peri-implant health.

Focus on Epithelialized Palatal Grafts. Part 2: Implant Site Development

INTRODUCTION

The epithelialized palatal graft (EPG), introduced in 1963, has persisted as the gold standard for gingival augmentation, and in the present era, mucosal augmentation around dental implants has become an important concern. A limited body of evidence suggests peri-implant mucosal augmentation may favorably impact bone and mucosal stability and peri-implant health under some circumstances. Although more contemporary procedures for peri-implant mucosal augmentation are often preferred based on convenience and esthetic considerations, EPG augmentation at dental implant sites is distinguishable from methods which do not deepen the vestibule and eliminate unfavorable superficial soft tissue. Implant sites augmented with EPG are qualitatively distinct from sites augmented using other methods.

CASE SERIES

Seven generally healthy patients received EPG augmentation before dental implant placement, at implant placement, before implant uncovering, or after implant uncovering. In each case, the patient exhibited a favorable zone of attached peri-implant mucosa following treatment.

CONCLUSIONS

Reliable mucosal augmentation with EPG is achievable at multiple phases in the course of dental implant therapy. EPG augmentation offers distinct clinical advantages and may be preferable to other mucosal augmentation strategies at some dental implant sites.

Preparing Dental Students and Residents to Overcome Internal and External Barriers to Evidence-Based Practice

In recent years, evidence-based dentistry has become the ideal for research, academia, and clinical practice. However, barriers to implementation are many, including the complexity of interpreting conflicting evidence as well as difficulties in accessing it. Furthermore, many proponents of evidence-based care seem to assume that good evidence consistently exists and that clinicians can and will objectively evaluate data so as to apply the best evidence to individual patients' needs. The authors argue that these shortcomings may mislead many clinicians and that students should be adequately prepared to cope with some of the more complex issues surrounding evidence-based practice. Cognitive biases and heuristics shape every aspect of our lives, including our professional behavior. This article reviews literature from medicine, psychology, and behavioral economics to explore the barriers to implementing evidence-based dentistry. Internal factors include biases that affect clinical decision making: hindsight bias, optimism bias, survivor bias, and blind-spot bias. External factors include publication bias, corporate bias, and lack of transparency that may skew the available evidence in the peer-reviewed literature. Raising awareness of how these biases exert subtle influence on decision making and patient care can lead to a more nuanced discussion of addressing and overcoming barriers to evidence-based practice.

Gingival Recession Treatment With Connective Tissue Grafts in Smokers and Non-Smokers

BACKGROUND

Cigarette smoking can adversely affect the results of many periodontal procedures. The purpose of this study was to determine whether cigarette smoking affects wound healing of subepithelial connective tissue grafts.

METHODS

Seventeen systemically healthy patients with 22 Miller Class I or II mucogingival defects were divided into a non-smoker group or smoker group. Patients were regarded as smokers if they reported smoking 10 to 20 cigarettes per day. The following parameters were documented at the surgery date and 3 and 6 months postoperatively: recession depth (RD), recession width (RW), keratinized gingiva height measured apico-coronally (KG), relative attachment level (RAL), probing depths (PD), bleeding on probing (BOP), and the full-mouth plaque score (FMP). Salivary cotinine samples were taken at the surgery to confirm the smoking history and to quantify cigarette use.

RESULTS

Non-smokers (0- to 10-ng/ml cotinine level) healed with statistically more recession coverage than the smokers (>10-ng/ml cotinine level) (98.3% versus 82.3%, respectively; P=0.001). Six months postoperatively, the non-smokers healed with a 0.2-mm mean recession depth compared to a 1.0-mm mean recession depth for the smokers. This difference in recession depth was statistically significant (P=0.014).

CONCLUSIONS

Root coverage with connective tissue grafts appears to be negatively associated with cigarette smoking. Smokers should consider smoking cessation or reducing the use of cigarettes for optimal results with connective tissue grafts.

Perioral Angioedema Associated With Angiotensin-Converting Enzyme Inhibitor

BACKGROUND

Angioedema is a non-pruritic swelling usually limited to the skin and mucous membranes of the face and perioral soft tissues. It can be life threatening but usually is not, and can be managed with conservative medical treatment unless the airway is endangered. Recent reports suggest that angiotensin-converting enzyme (ACE) inhibitors can predispose and/or precipitate angioedema, with a predilection toward patients of African American ancestry.

METHODS

This case report involved a 65-year-old African American female who was being treated surgically for localized chronic periodontitis. The procedure was performed without incident, and the patient was alert and stable when released. The next day, the patient called and reported that her lips were swollen. She stated that this had happened a number of times over the past several years, sometimes related to eating shellfish and other times without any known precipitating factor. All previous episodes of perioral swelling occurred after ACE inhibitor therapy had been initiated.

RESULTS

The patient was in no distress, with no other site involvement. She was prescribed oral hydroxyzine and her appearance returned to normal after 5 days. Although the patient had experienced previous episodes of angioedema, none had been in response to any dental procedure. She was referred to the Allergy and Immunology Clinic for skin testing, the results of which were negative to shellfish with good controls. Other potentiating etiologies were also ruled out by the allergist.

CONCLUSIONS

Angioedema is a recognized possible side effect of ACE inhibitor therapy. The exact mechanism by which ACE inhibitors induce angioedema is not known, although the risk of occurrence is much greater in African Americans. Practitioners should be alert to this potentially fatal condition in patients who take ACE inhibitors or the newer angiotensin II receptor blockers (ARBs).