Short-term anti-plaque effect of two chlorhexidine varnishes

BACKGROUND: Chlorhexidine (CHX) varnishes have been mainly used for the prevention of caries in high-risk populations. Reports regarding their anti-plaque effect on a clinical level are limited to non-existing as opposed to their microbiological impact on plaque formation. AIM: The aim of this preliminary investigation was to evaluate the anti-plaque effect of two CHX varnishes applied on sound enamel in relation to a positive control, a negative control and to one another. METHODS: Sixteen healthy subjects volunteered for this randomized-controlled, single-blind, four-treatment-four-period crossover-designed clinical trial. A 3-day plaque re-growth model was used to determine de novo plaque accumulation following CHX rinsing, Cervitec application, EC40 application and no therapy. The amount of plaque was measured using the Quigley and Hein plaque index and "automatic image analysis" (AIA). RESULTS AND CONCLUSIONS: Varnish treatment resulted in significantly higher plaque levels than CHX rinsing irrespective of the varnish that was used (p< or =0.002), implying that the latter is likely to remain the gold standard as an anti-plaque agent. However, highly significant differences were also found in favour of both varnish systems when compared with no therapy (p<0.001), which indicates that varnish treatment is an effective means of inhibiting plaque formation in a short time span. Cervitec exhibited slightly, yet significantly, higher plaque levels in comparison with EC40 as determined by AIA (p=0.006). Large-scale trials with a longer observation period are necessary to substantiate these results.     

Attitudes toward patient safety standards in U.S. dental schools: a pilot study

The objective of this study was to assess the patient safety culture among students, staff, and faculty in seven U.S. dental school clinics when compared to those from a similar study in twenty U.S. hospitals. A survey on patient safety culture developed by the Agency for Healthcare Research and Quality (AHRQ) was used to measure attitudes towards patient safety by anonymous faculty, students, and support staff members who work in the clinics of seven U.S. dental schools. This survey instrument was also administered to staff at twenty U.S. hospitals. In three of the twelve sections of the survey (Overall Perceptions of Safety, Management Support for Patient Safety, and Teamwork Across Units), dental school personnel responses rated above the hospital benchmark results. In Section 2 (Frequency of Adverse Events Reported) and Section 4 (Organizational Learning/ Continuous Improvement), average dental school responses were below those recorded for hospital personnel. The overall score from the twelve sections of the survey indicated that patient safety attitudes of dental school participants were higher than those of their hospital counterparts.     

Recurrent melanotic neuroectodermal tumor of infancy: a proposal for treatment protocol with surgery and adjuvant chemotherapy

The case of a 4-month-old male infant treated with combined surgery and chemotherapy for an aggressive recurrent melanotic neuroectodermal tumor of infancy (MNTI) on the top of the alveolar process of the mandible with a long-term follow-up is presented. Initial treatment comprised conservative local excision and curettage of the mandible. After several local recurrences and because radical surgical excision would give gross functional and aesthetic mutilation, finally complete, long-lasting remission was achieved with adjuvant chemotherapy, according to a neuroblastoma protocol (10-year follow-up). The reason for this protocol was because molecular genetic studies of this tumor showed loss of heterozygosity of chromosome 1p and gain of chromosome 7q analogue to neuroblastomas. A combination of surgery and chemotherapy should be the preferred treatment in case of a recurrence MNTI because optimal functional and aesthetic outcome.     

Investigation of platelet-rich plasma in rabbit cranial defects: A pilot study.

PURPOSE: The purpose was to evaluate the effect of platelet-rich plasma (PRP) on bone healing. MATERIALS AND METHODS: Fifteen rabbits were included in this randomized, blinded, prospective pilot study. Four equal 8 mm diameter cranial bone defects were created and immediately grafted with autogenous bone, PRP alone, autogenous bone and PRP, and no treatment as a control. The defects were evaluated by digital subtraction radiography with step-wedge calibration, histology, and histomorphometric analysis performed at 1, 2, and 4 months. RESULTS: The results showed a significant increase in histomorphometric bone area and radiographic bone density in both bone and bone and PRP samples as compared with the control and PRP alone. No significant increase in bone formation was seen with the addition of PRP to autogenous bone. No significant difference in bone formation was seen between defects treated with PRP alone and control sites. CONCLUSIONS: No significant improvement, radiographically or histomorphometrically, was seen with the addition of PRP in bone formation in noncritical sized defects in the rabbit cranial model. However, bone and bone and PRP showed a histomorphometric tendency toward increased bone formation at 1, 2, and 4 months.     

Lateral alveolar ridge augmentation using a synthetic nano-crystalline hydroxyapatite bone substitution material (Ostim): preliminary clinical and histological results

OBJECTIVES: The purpose of this preliminary two-center clinical prospective study was to evaluate the tissue composition of augmented sites after the use of a nano-crystalline hydroxyapatite (ncHA) bone substitution material by clinical and histological examinations. MATERIAL AND METHODS: A synthetic ncHA augmentation material was used without any additives in 14 patients requiring lateral ridge augmentation 6-7 months before (10 patients) or at implant placement (four patients). The ncHA material was covered by a titanium mesh for space maintenance. Clinical and radiographic parameters were evaluated and bone biopsy cores, obtained 6-7 months following augmentation, were assessed histologically and histomorphometrically. RESULTS: One patient showed gingival swelling, redness and pain at the augmentation site requiring removal of the titanium mesh 6 weeks postoperatively. In seven patients, a premature exposure of the titanium mesh without any inflammatory symptoms was noted. The width of the fixed gingival and the alveolar ridge height did not change significantly at least 6 months following augmentation (P>0.5), whereas a significant gain in alveolar ridge width (P=0.01) was noted. After a median period of prosthetic loading of 24 months, no implant was considered to be a failure. Histology revealed ncHA remnants in peripheral and central parts of biopsy cores obtained from seven patients after at least 6 months without histological symptoms of inflammation, whereas histomorphometry of bone cores revealed no significant differences of the mean percentage area of ncHA in peripheral (23.4%) and central (15.1%) parts of biopsy cores (P=0.262). The mean percentage area of bone colonizing the defect was 52.3%. CONCLUSIONS: Small amounts of ncHA were found after at least 6 months in bone biopsies. The former defect space was filled with bone. The alveolar ridge width gain was found to be significant after lateral augmentation utilizing ncHA, providing a quantitatively and qualitatively sufficient site for primary stable implant placement.     

The Aesthetic Component of the Index of Orthodontic Treatment Need validated against lay opinion

This study aimed to determine the threshold of aesthetic impairment where orthodontic treatment would be sought by a sample of lay people. Using the 10-grade Aesthetic Component (AC) scale of the Index of Orthodontic Treatment Need (IOTN), 215 university students selected the level of aesthetic impairment that represented the point at which they would seek orthodontic treatment. Only nine (4.3 per cent) of the respondents recorded a threshold grade beyond grade 5 in the AC. The AC photograph grade 4 was found to be the most commonly selected threshold photograph. Subjects who visited the dentist every 6 months were more likely to choose a threshold photograph closer to the attractive end of the scale than those who visited their dentist less frequently (P < 0.01). This study, using lay people rather than dental health professionals, suggests that as currently used the AC does not reflect society's aesthetic expectations. The results indicate that when using the AC of the IOTN the 'no need for treatment' category should be grades 1-3 of the AC, rather than grades 1-4.     

The effect of core:dentin thickness ratio on the bi-axial flexure strength and fracture mode and origin of bilayered dental ceramic composites.

OBJECTIVES: The aim of the current study was to assess the effect of core:dentin thickness ratio on the flexure strength, fracture mode and origin of bilayered dental ceramic composite disc specimens. METHODS: Sets of 30 bilayered composite discs with core:dentin thickness ratio of 2:1, 1:1 and 1:2 were tested in bi-axial flexure with both the reinforcing core and veneering dentin loaded in tension. Mean flexure strengths, standard deviations and associated Weibull Moduli (m) were determined. A combination of optical and scanning electron microscopy was employed for identification of the fracture mode and origin. RESULTS: The core:dentin ratio influenced the bi-axial flexure strength and reliability of the flexure strength data when both the reinforcing core and veneering dentin porcelain were tested in tension. The strength and reliability was increased for a core:dentin thickness of 2:1. The number of fracture fragments, the frequency of occurrence of specimen delaminations, Hertzian cone formations and sub-critical radial cracking in the bilayered dental ceramic composite disc shaped specimens was also dependent on the core/dentin ratio and the surface loaded in tension. CONCLUSIONS: Core:dentin thickness ratio influences the bi-axial flexure strength and fracture mode and origin in bilayered dental ceramic composite specimens.     

Factors influencing defects of rotary nickel-titanium endodontic instruments after clinical use

This study examined used, discarded rotary nickel-titanium instruments obtained from 14 endodontists in four countries, and identified factors that may influence defects produced during clinical use. A total of 7,159 instruments were examined for the presence of defects. Unwinding occurred in 12% of instruments and fractures in 5% (1.5% torsional, 3.5% flexural). The defect rates varied significantly among endodontists. Instrument design factors also influenced defect rate, but to a lesser extent. The mean number of uses of instruments with and without defects was 3.3 +/- 1.8 (range: 1-10), and 4.5 +/- 2.0 (range: 1-16), respectively. The most important influence on defect rates was the operator, which may be related to clinical skill or a conscious decision to use instruments a specified number of times or until defects were evident.     

Severe proliferative congenital temporomandibular joint ankylosis: a proposed treatment protocol utilizing distraction osteogenesis

The classical treatment for temporomandibular joint (TMJ) ankylosis in children: 1) joint release; 2) arthroplasty; 3) reconstruction; and 4) postoperative physical therapy (PT), is often unsuccessful. Postoperative physical therapy is difficult in the young patient due to poor cooperation. Moreover, there is a subgroup of patients who have a refractory congenital proliferative bony process that is the cause of their disease. In these patients, a role for distraction osteogenesis (DO) has been defined. We present a series of young patients with congenital proliferative TMJ ankylosis. Some have failed classic treatment. In such cases, DO is used to expand the mandibular size and soft tissue matrix. This creates a static open bite, facilitates mid-facial growth, and avoids compromise of the airway, speech, nutrition, and oral hygiene. To maintain these objectives, mandibular DO may be repeated as the child matures. Once skeletal maturity is reached, DO is used to normalize occlusion and further expand the soft tissue envelope prior to definitive reconstruction and aggressive post-op PT. In seven patients, this protocol has been used. Five patients are currently in the active phase of growth and undergoing interim treatment with mandibular DO. Two patients have reached skeletal maturity and have completed the protocol of DO with definitive arthroplasty and reconstruction. DO is a valuable aid in the treatment of the problematic child with congenital proliferative TMJ ankylosis. Interim DO, prior to definitive arthroplasty and reconstruction, can provide a static open bite that prevents progressive deformity and its associated functional disturbances.     

Screening for cardiovascular risk factors in a dental setting

BACKGROUND: The authors assessed the utilization of oral health care professionals (OHCPs) as a resource for identifying patients who were unaware of their increased risk of developing cardiovascular disease (CVD). METHODS: OHCPs administered a CVD risk-screening questionnaire, measured blood pressure and tested cholesterol levels, high-density lipoprotein levels and hemoglobin A1c (HgA1c) levels using "finger-stick" blood testing in 100 patients treated in a dental school clinic who were unaware of their CVD risk status. The authors determined the prevalence of specific risk factors (that is, smoking and abnormal levels of systolic blood pressure, lipids, body mass index and HgA1c) and calculated Framingham 10-year coronary heart disease (CHD) risk scores. RESULTS: Seventeen percent of the 100 patients (35 percent of men, 5 percent of women) had an increased global risk of experiencing a CHD event within 10 years (Framingham risk score>10 percent). Seventy-three percent of participants had one or more risk factors and 31 percent had two or more risk factors present. More men than women had low levels of high-density lipoprotein (45 percent [18/40] of men versus 3.3 percent [2/60] of women; P<.0001). The mean Framingham CHD risk score increased with increasing risk factor burden. CONCLUSIONS: OHCPs identified patients with an increased CHD risk who could benefit from primary prevention activities. A substantial proportion of study patients who were unaware of their risk status were at an increased risk of experiencing a CHD event within 10 years. OHCPs could contribute to public health CHD control efforts.