Haemostatic effect and tissue reactions of methods and agents used for haemorrhage control in apical surgery.

AIM: To compare the haemostatic effect and tissue reactions of different agents and methods used for haemorrhage control in apical surgery. METHODOLOGY: Six standardized bone defects were prepared in the calvaria of six Burgundy rabbits. Five haemostatic modalities were tested for their haemostatic effect and tissue reactions, and were compared with untreated control defects: Expasyl + Stasis, Expasyl + Stasi + freshening of the bone defect with a bur, Spongostan, Spongostan+ epinephrine, and electro cauterization. The haemostatic effect was analysed visually and compared using Wilcoxon's signed rank test. Two groups of three animals were evaluated histologically for hard and soft tissue reactions related to the different haemostatic measures, after 3 and 12 weeks of healing respectively. RESULTS: Expasyl + Stasis and electro cauterization proved most effective in reducing bleeding (P < 0.05), but were accompanied by unfavourable tissue reactions, as indicated by the presence of necrotic bone, inflammatory cells and the absence of bone repair. These adverse tissue reactions did not recover substantially over time. However, adverse reactions were not observed when the superficial layer of bone had been removed with a rotary instrument. In contrast, Spongostan + epinephrine showed only a moderate haemostatic effect, but elicited also only mild adverse tissue reactions. CONCLUSIONS: Haemostasis in experimental bone defects is most effectively accomplished by using Expasyl + Stasis or electro cauterization. However, the bone defects should be freshened with a rotary instrument before suturing so as not to compromise healing.

Teaching and assessment of implant dentistry in undergraduate and postgraduate education: a European consensus.

This paper constitutes a summary of the consensus documents agreed at the First European Workshop on Implant Dentistry University Education held in Prague on 19-22 June 2008. Implant dentistry is becoming increasingly important treatment alternative for the restoration of missing teeth, as patients expectations and demands increase. Furthermore, implant related complications such as peri-implantitis are presenting more frequently in the dental surgery. This consensus paper recommends that implant dentistry should be an integral part of the undergraduate curriculum. Whilst few schools will achieve student competence in the surgical placement of implants this should not preclude the inclusion of the fundamental principles of implant dentistry in the undergraduate curriculum such as the evidence base for their use, indications and contraindications and treatment of the complications that may arise. The consensus paper sets out the rationale for the introduction of implant dentistry in the dental curriculum and the knowledge base for an undergraduate programme in the subject. It lists the competencies that might be sought without expectations of surgical placement of implants at this stage and the assessment methods that might be employed. The paper also addresses the competencies and educational pathways for postgraduate education in implant dentistry.

Ligature-induced marginal inflammation around osseointegrated implants and ankylosed teeth: stereologic and histologic observations in cynomolgus monkeys (Macaca fascicularis).

The aim of the investigation was to provide quantitative and qualitative histologic data on marginal inflammation around osseointegrated implants. The significance of the lack of a periodontal ligament in the initial breakdown phase of supporting tissues in implants was examined by comparing stereologic and histologic manifestations of ligature-induced marginal inflammation around osseointegrated implants with those around ankylosed and normal control teeth in 8 cynomolgus monkeys (Macaca fascicularis). Clinical and radiographic findings have been reported elsewhere. The marginal connective tissue around ligated implants was infiltrated by a significantly increased total number of lymphocytes, plasma cells, and neutrophils compared to non-ligated implants and teeth. The total number of lymphocytes around ligated implants was significantly higher than around ligated ankylosed and normal control teeth. There were, however, no significant differences in the total number of plasma cells and neutrophils within the ligated group. Osteoclasts were exclusively observed around ligated implants and ankylosed teeth. Although variations in microbiota and susceptibility of different jaw positions to periodontal break-down may influence the results of the present study, the results seem to substantiate the theory that marginal inflammation around implants and ankylosed teeth may have more serious implications than does marginal inflammation around teeth with a periodontal ligament. Since presence of osteoclasts was not related to the absence of cervical cementum with inserting gingival fibers around ligated ankylosed teeth, the increased susceptibility of bone loss of implants is probably not caused by the absence of these tissue components. In contrast, the histologic observations seem to support that the increased susceptibility for bone loss around implants may be related to the absence of a periodontal ligament.

Histologic response after implantation of porous hydroxylapatite ceramic in humans.

After periods of observation from 3 to 36 months, biopsies were obtained from 22 patients in whom porous block and particulate hydroxylapatite ceramic (Interpore 200) had been used for augmentation procedures and in two patients in whom nonporous particulate hydroxylapatite (Calcitite) had been used. Histologic examination of serial sections of decalcified specimens revealed vital bone formation in relation to the blocks, whereas the particulate was encapsulated in fibrous tissue. The differences in biological behavior are discussed.

ITI implants with overdentures: a prevention of bone loss in edentulous mandibles?

Changes in the bone mineral content (BMC) of edentulous mandibles with osseointegrated ITI implants supporting overdentures were measured in vivo by dual-photon absorptiometry. The BMC measurements were performed 3 weeks postoperatively and at the 2-year follow-up visit. Measurements were made in the ITI site (anteriorly), the premolar region just behind the fixtures, and the standard site of the mandible for obtaining reference values of the age-related MBC loss. The increased function of the mandible after this treatment seems to cause a load-related bone formation that minimizes, or in some cases may counteract, the physiologic age-related BMC loss leading to osteoporosis.

Tissue reaction and material characteristics of four bone substitutes.

The aim of the present study was to qualitatively and quantitatively compare the tissue reactions around four different bone substitutes used in orthopedic and craniofacial surgery. Cylinders of two bovine bone substitutes (Endobon and Bio-Oss) and two coral-derived bone substitutes (Pro Osteon 500 and Interpore 500 HA/CC) were implanted into 5-mm bur holes in rabbit tibiae. There was no difference in the amount of newly formed bone around the four biomaterials. Interpore 500 HA/CC resorbed completely, whereas the other three biomaterials did not undergo any detectable biodegradation. Bio-Oss was osseointegrated to a higher degree than the other biomaterials. Material characteristics obtained by diffuse reflectance infrared Fourier transform spectrometry analysis and energy-dispersive spectrometry did not explain the differences in biologic behavior.

Bone resorption after advancement genioplasty. Pedicled and non-pedicled grafts.

The influence of soft tissue attachment in augmentation genioplasty on the amount of postoperative bone remodelling was studied in 29 patients. The soft tissue was completely detached from the advanced genial segment in 15 patients and the lingual soft tissue was maintained in 14 patients. The advancement of the chin and postoperative bone remodelling was analysed by measuring linear distances and areas on lateral cephalograms. The genial segments with a soft tissue pedicle underwent significantly less resorption than the free grafts (p less than 0.01). The difference in postoperative infection between the two groups (p less than 0.05) indicates that the likelihood of postoperative infection is significantly reduced by maintaining the soft tissue pedicle. Considerably less variation in amount of bone resorption was also observed in the patients with a pedicled graft.

Influence of skin graft pathology on residual ridge reduction after mandibular vestibuloplasty. A 5-year clinical and radiological follow-up study.

The present study is a 5-year clinical and radiographic follow-up of 51 patients who had undergone a combined vestibuloplasty with a split skin graft and lowering of the floor of the mouth. Our purpose was to examine the effect of clinically evident graft pathology on the residual ridge reduction. The clinical records of the graft condition were classified into: healthy graft, partial loss of keratinization, and total loss of keratinization. The residual ridge reduction was monitored by ridge height measurements at different locations, and by the symphyseal and mandibular body areas. Patients with clinical signs of graft pathology (reddening, loss of keratinization) suffered a significantly more severe residual ridge reduction than those with a healthy skin graft (p less than 0.01). Subsequent findings including smear tests showing Candida albicans hyphae, and improvement of graft condition after antimycotic therapy, indicated that the graft pathology observed is a candidiasis.

Surgical treatment of premalignant lesions of the oral mucosa.

Oral premalignant lesions were treated by surgical excision in 61 patients. Criteria for inclusion in the study were epithelial dysplasia varying from slight to carcinoma in situ, or a non-dysplastic lesion located sublingually or on the tongue. The clinical diagnosis of the treated lesions were: erythroplakia 10, erythroleukoplakia 15, nodular leukoplakia 9, verrucous leukoplakia 9, homogeneous leukoplakia 13, and lichen planus 5. The surgically created defects were closed by direct approximation of the wound edges in 25 patients, transposition by a local mucosal flap in 9, covered with a free mucosal graft in 3, and by a free split skin transplant in 24 patients. The patients have been followed for an average period of 3.9 years after the operation. A recurrence rate of 20% was found, and 3 carcinomas developed in the follow-up period. The importance of using a surgical technique permitting histological examination of the entire lesion was documented by the finding of 4 superficial carcinomas in the excision specimen, undiagnosed in the preoperative biopsy.

Oral health care: more than caries and periodontal disease. A survey of epidemiological studies on oral disease.

A review is presented of the epidemiology of the common oral diseases other than dental caries and periodontal disease. It appears that conditions, such as masticatory dysfunction, traumatic dental and maxillofacial injuries, impactions and oral mucosal disease each normally affect one-quarter to one-half of populations examined. To plan and achieve total oral health care, it is, therefore, necessary to take these conditions into account. As no study to date appears to have registered the total oral health care needs for a given population in either developing or industrialized countries it is suggested that such investigations should be undertaken now by WHO and/or FDI. Only when this total information is at hand can a rational oral health policy be developed.

Healing of experimentally created defects: a review.

Within cranio-maxillofacial surgery and orthopedic surgery a bone graft or a bone substitute is required to recontour or assist bony healing in repair of osseous congenital deformities, or in repair of deformity due to trauma or to surgical excision after elimination of osseous disease processes exceeding a certain size. An autogenous bone graft is the optimal material of choice, however its use is problematic due to donor site morbidity, sparse amounts and uncontrolled resorption. Immunological responses and risk of viral contamination of allogenous and xenogenous bone materials make the use of these materials questionable. Healing and degradation of alloplastic materials are inconsistent with subsequent restricted use. The principle of guided tissue regeneration excluding soft tissue cells from a certain area is not alone sufficient to insure complete bony healing. Recombinant bone morphogenetic proteins have with success been added as adjuncts to already known biomaterials. In the future, inductive materials together with a suitable carrier and a biodegradable membrane may be the choice of bone substitute used within cranio-maxillofacial and orthopaedic surgery.

[Surgical treatment of temporomandibular joint ankylosis]. / Kirurgisk behandling af kaebeledsankylose.

Surgical treatment of temporo-mandibular joint (TMJ) ankylosis may be a particularly difficult procedure due to unfavourable anatomic configurations and the proximity of vital structures. Postoperatively, it is followed by an often long and painful period of physiotherapy. The results of treatment of eight patients with TMJ ankylosis are reported. Different methods were used according to age of the patient and the extent of the ankylotic changes. The importance of early treatment is emphasized. This results in less extensive surgery and reduces secondary growth anomalies of the jaws.

Benign tumors of the jaws.

There are a variety of types of benign tumors of the jaws, ranging from tumors developed from the odontogenic tissues to regular osseous tumors and dysplasias. During the last 20 years, the World Health Organization classification on odontogenic tumors, neoplasms, and lesions related to bone has been used. This year, a revised edition will appear, and this review has been based on the revised edition. A number of good articles have been published during the period of review (late 1988 to early 1991). An attempt has been made to extract the essence of these papers.

Aneurysmal bone cyst--simple bone cyst, two aspects of the same pathologic entity?

An unusual case of aneurysmal bone cyst recurring after operation as a simple bone cyst is reported. Different theories on etiology and pathogenesis of aneurysmal bone cyst, simple bone cyst, and central giant cell granuloma of the jaws are resumed and similarities demonstrated. It is suggested that these three lesions have a common dysvascular etiology and that local environmental factors within the bone may differentiate the pathogenesis.