Titanium allergy: could it affect dental implant integration?

Purpose: Degradation products of metallic biomaterials including titanium may result in metal hypersensitivity reaction. Hypersensitivity to biomaterials is often described in terms of vague pain, skin rashes, fatigue and malaise and in some cases implant loss. Recently, titanium hypersensitivity has been suggested as one of the factors responsible for implant failure. Although titanium hypersensitivity is a growing concern, epidemiological data on incidence of titanium‐related allergic reactions are still lacking. Materials and methods: A computer search of electronic databases primarily MEDLINE and PUBMED was performed with the following key words: ‘titanium hypersensitivity’, ‘titanium allergy’, ‘titanium release’ without any language restriction. Manual searches of the bibliographies of all the retrieved articles were also performed. In addition, a complementary hand search was also conducted to identify recent articles and case reports. Results: Most of the literature comprised case reports and prospective in vivo/in vitro trials. One hundred and twenty‐seven publications were selected for full text reading. The bulk of the literature originated from the orthopaedic discipline, reporting wear debris following knee/hip arthroplasties. The rest comprised osteosynthesis (plates/screws), oral implant/dental materials, dermatology/cardiac‐pacemaker, pathology/cancer, biomaterials and general reports. Conclusion: This review of the literature indicates that titanium can induce hypersensitivity in susceptible patients and could play a critical role in implant failure. Furthermore, this review supports the need for long‐term clinical and radiographic follow‐up of all implant patients who are sensitive to metals. At present, we know little about titanium hypersensitivity, but it cannot be excluded as a reason for implant failure. To cite this article:
Siddiqi A, Payne AGT, De Silva RK, Duncan WJ. Titanium allergy: could it affect dental implant integration?
Clin. Oral Impl. Res. 22 , 2011; 673–680
doi: 10.1111/j.1600‐0501.2010.02081.x     

High labial incisions for genioplasty

Clinical experience in genioplasty has shown that high labial incisions heal with fewer scar bands than conventional deep labial incisions. In a prospective randomized trial, we compared 18 high labial curvilinear incisions with 27 high labial W-shaped (‘royal’) incisions for access and visibility during chin osteotomy. Both incisions were 3 cm wide. Maximal incision lengthening between two skin hooks was recorded with a ruler before closure, and there was no significant difference between the two. The maximum wound area between three skin hooks was photographed and computed, and showed a mean difference of 188.75 mm² (t-test, P < 0.001), which corroborated the clinical findings that access and visibility were superior in the W-shaped incision group. Complications were few in both groups. We now use the high labial royal incision about 3.5 cm wide, with 90° limb angle for complicated chin osteotomies and ostectomies. A smaller curvilinear high labial incision is used for simple advancement osteotomies.     

In vivo forces on oral implants supporting a mandibular overdenture: the influence of attachment system

This study was designed to gain insight into the influence of the attachment system on the loading conditions of oral implants supporting a mandibular overdenture on two implants. Five patients were selected and were provided with two implants in the canine area of the mandible (Brånemark System). All patients received a new mandibular overdenture that could be mounted on an ovoid-shaped bar (Dolder, C&;M): (a) with and (b) without bilateral extensions and (c) on ball-attachments (Nobel Biocare). Using three strain gauges attached to the outer surface of the 5.5-mm standard abutments, the axial forces and bending moments on both supporting implants could be quantified. Load registrations were made during application of 50 N on seven predetermined positions along the occlusal surface of the prosthesis and during maximal biting in maximal occlusion (clenching). The results revealed no differences in induced axial force for the various anchorage devices, unlike the differences in bending moment. Although there is a tendency for better axial load sharing with bars and better sharing of bending moments with ball attachments, these differences were not significant.     

Periodontal infections contribute to elevated systemic C-reactive protein level

BACKGROUND: Periodontitis is a local inflammatory process mediating destruction of periodontal tissues triggered by bacterial insult. However, this disease is also characterized by systemic inflammatory host responses that may contribute, in part, to the recently reported higher risk for cardiovascular disease (CVD) among patients with periodontitis. Moderate elevation of C-reactive protein (CRP) has been found to be a predictor of increased risk for CVD. Elevated CRP levels in periodontal patients have been reported by several groups. In this study, we examined whether CRP plasma levels are increased in periodontitis and if there is a relation to severity of periodontal disease and to the periodontal microflora. METHODS: CRP serum levels were assessed using radial immunodiffusion assay in 174 subjects, 59 with moderate mean clinical attachment loss (AL) (2.39+/-0.29 mm) and 50 with high AL (3.79+/-0.86 mm) as compared to 65 periodontally healthy controls (AL, 1.74+/-0.18 mm). Clinical attachment loss, probing depths, and percentage of periodontal pocket sites > or =5 mm were measured. The presence of periodontal pathogens Porphyromonas gingivalis (P.g.), Prevotella intermedia (P.i.), Campylobacter recta (C.r.), and Bacteroides forsythus (B.f.) in subgingival plaque samples was measured by immunofluorescence microscopy. RESULTS: Statistically significant increases in CRP levels were observed in subjects with periodontal disease when compared to healthy controls (P= 0.036). Subjects with high levels of mean clinical attachment loss had significantly higher mean CRP levels (4.06+/-5.55 mg/l) than controls (1.70+/-1.91 mg/l), P= 0.011. The CRP levels were adjusted for factors known to be associated with elevated CRP, including age, smoking, body mass index (BMI), triglycerides, and cholesterol. Age and BMI were found to be significant covariates. The reported range for CRP as a risk factor for CVD, peripheral vascular diseases, or stroke is 1.34 mg/l to 6.45 mg/l and the mean of this range is 3 mg/l. The percentage of subjects with elevated levels of CRP > or = 3 mm was significantly higher in the high clinical AL group (38%; 95% Cl: 26.7%, 49.3%) when compared to the control group (16.9%; 95% CI: 9.25%, 24.5%), P= 0.011. The presence of periodontal pathogens P.g., P.i., C.r., and B.f. in subgingival samples was positively associated with elevated CRP levels (P= 0.029). CONCLUSIONS: The extent of increase in CRP levels in periodontitis patients depends on the severity of the disease after adjusting for age, smoking, body mass index, triglycerides, and cholesterol. Also, there are elevated levels of CRP associated with infection with subgingival organisms often associated with periodontal disease, including P.g., P.i., C.r., and B.f. Recent investigations emphasized the role of moderate elevated CRP plasma levels as a risk factor for CVD. The positive correlation between CRP and periodontal disease might be a possible underlying pathway in the association between periodontal disease and the observed higher risk for CVD in these patients.     

Validation of FreeSurfer-Estimated Brain Cortical Thickness: Comparison with Histologic Measurements

FreeSurfer software package automatically estimates the cerebral cortical thickness. Its use is widely accepted, albeit this tool was validated against histologic measurements in only two post-mortem isolated brain MR scans. Indeed, a comparison between histologic measurements and FreeSurfer estimation from in vivo data was never performed. At the “Claudio Munari” Center for Epilepsy and Parkinson Surgery we have included FreeSurfer in our presurgical workflow since 2008, mainly because the automatic reconstruction of the brain surface is useful for carefully planning the surgical resection. We therefore compared cortical thickness values obtained by the automatic software pipeline with manual histologic measurements performed on 27 histologic specimens resected from the corresponding brain regions of the same epileptic subjects. This method-comparison study, including Passing–Bablok regression and Bland-Altman plot analysis, showed a good agreement between FreeSurfer estimation and histologic measurements of cortical thickness. The mean cortical thickness values (±Standard Deviation) obtained with FreeSurfer and histologic measurements were 3.65 mm?±?0.44 and 3.72 mm?±?0.36, respectively (P value?=?0.32). Our findings strengthen previous reports on cortical thickness changes as biomarkers of different neurological conditions.     

Multimodality Monitoring: Informatics,Integration Data Display and Analysis

The goal of multimodality neuromonitoring is to provide continuous, real-time assessment of brain physiology to prevent, detect, and attenuate secondary brain injury. Clinical informatics deals with biomedical data, information, and knowledge including their acquisition, storage, retrieval, and optimal use for clinical decision-making. An electronic literature search was conducted for English language articles describing the use of informatics in the intensive care unit setting from January 1990 to August 2013. A total of 64 studies were included in this review. Clinical informatics infrastructure should be adopted that enables a wide range of linear and nonlinear analytical methods be applied to patient data. Specific time epochs of clinical interest should be reviewable. Analysis strategies of monitor alarms may help address alarm fatigue. Ergonomic data display that present results from analyses with clinical information in a sensible uncomplicated manner improve clinical decision-making. Collecting and archiving the highest resolution physiologic and phenotypic data in a comprehensive open format data warehouse is a crucial first step toward information management and two-way translational research for multimodality monitoring. The infrastructure required is largely the same as that needed for telemedicine intensive care applications, which under the right circumstances improves care quality while reducing cost.     

Consensus Paper: Language and the Cerebellum: an Ongoing Enigma

In less than three decades, the concept “cerebellar neurocognition” has evolved from a mere afterthought to an entirely new and multifaceted area of neuroscientific research. A close interplay between three main strands of contemporary neuroscience induced a substantial modification of the traditional view of the cerebellum as a mere coordinator of autonomic and somatic motor functions. Indeed, the wealth of current evidence derived from detailed neuroanatomical investigations, functional neuroimaging studies with healthy subjects and patients and in-depth neuropsychological assessment of patients with cerebellar disorders shows that the cerebellum has a cardinal role to play in affective regulation, cognitive processing, and linguistic function. Although considerable progress has been made in models of cerebellar function, controversy remains regarding the exact role of the “linguistic cerebellum” in a broad variety of nonmotor language processes. This consensus paper brings together a range of different viewpoints and opinions regarding the contribution of the cerebellum to language function. Recent developments and insights in the nonmotor modulatory role of the cerebellum in language and some related disorders will be discussed. The role of the cerebellum in speech and language perception, in motor speech planning including apraxia of speech, in verbal working memory, in phonological and semantic verbal fluency, in syntax processing, in the dynamics of language production, in reading and in writing will be addressed. In addition, the functional topography of the linguistic cerebellum and the contribution of the deep nuclei to linguistic function will be briefly discussed. As such, a framework for debate and discussion will be offered in this consensus paper.