The exact relationship between plaque-induced periodontal diseases and vitamin C deficiency is not known. The aim of this study was to evaluate the possible effect of ascorbic acid (AA) on the severity of periodontal diseases. The periodontal condition of 75 dentulous subjects with a low level of AA in the plasma (< or = 25 mumol/l) was compared with that of 75 control subjects (plasma level > or = 50 mumol/l) matched for age, sex and number of teeth. The subjects were asked to list foods containing AA in their diet, and intake of AA in milligrams per day was calculated. The daily diet of the study subjects contained on average 52 mg +/- 24.9 (SD) of AA, and that of the controls 77 mg +/- 43.2 (SD). For each individual, site-specific recordings for the presence or absence of plaque and supra- and subgingival calculus, filling overhangs, gingival bleeding after probing, probing pocket depth, and gingival recession were made clinically in a double blind examination carried out by one dentist. Five per cent of the subjects in the study group (low plasma level of AA) and 18 per cent of the controls had healthy periodontal tissues. The proportion of sites in which bleeding after probing and a probing pocket depth of 4 mm or over were observed was significantly higher in the study group than in the controls. Sixty per cent of the subjects in the study group and 37 per cent of the controls had pathological pockets of 4 mm or over.(ABSTRACT TRUNCATED AT 250 WORDS)

Examination of the state of affairs of oral biology cannot be endeavoured without considering the mutual interactions and interdependencies of sciences, and without considering the impact human acts will exert on these developments. Oral biology deals with the biochemical, chemical, molecular biologic, general biologic and physical aspects of all processes that take place in the oral cavity, in the masticatory organ, and in tissues and body fluids that are associated with the above processes. Oral biology also reaps the harvest sown by (other) basic sciences. From the methodological point of view, oral biology is indistinguishable from basic sciences; it is the anatomical object that makes it specific. Oral biology cannot be regarded as "big science" (i.e. compared with the human genome project, space research, AIDS research etc.). This fact may preserve the attractiveness of oral biology. Important science--this concerns oral biology as well--still emerges in smaller settings, although there are omens that large research cartels will swallow larger and larger portions of research appropriations. A key to staying competitive is to use new science sources and--in some cases--to join bigger groups. Once upon a time oral biologists--or scientists in general--assumed that a record of solid accomplishments was sufficient to maintain research support. Today, in several countries, politics and public visibility unfortunately determine the funding privileges. Provided that human operations on earth will render future development of sciences possible, the future of oral biology will depend 1) on concomitant development in the above basic fields, and 2) on innovations in the individual psyches. This combination will unravel the structure of genes involved in the development and metabolism of oral processes, clone important salivary and connective tissue proteins, and control most important oral diseases. To achieve these goals, oral biology must attract young talent and funding must be made available. There is no shortcut, however. Individual efforts and persistent labouring at the laboratory bench will still remain prerequisites. Although successful prevention of certain oral diseases, such as dental caries, may be possible in certain regions of the Earth, the prospects are much gloomier globally.

Twenty-two subjects with clinically diagnosed unilateral anterior disk displacement were followed up for two years. Seventeen of the patients were women and five were men, with ages ranging from 17 to 68 years (median 27 years). In 20 cases the duration of locking at the time of the examination was less than 6 months; the other two cases had experienced locking for more than 6 months but less than one year. Case histories were recorded and clinical examinations performed according to accepted principles, followed by calculation of Helkimo's anamnestic dysfunction index Ai and clinical dysfunction index Di. The patients were treated using full coverage splints combined with occlusal adjustment. Follow-up examinations were made after 6 months, one year and two years. At the time of the first visit, 17 patients had severe subjective symptoms such as difficulty in opening the mouth wide and pain on movement of the mandible, while five experienced locking without subjective symptoms. All patients apart from one belonged to Di III and had a maximal mouth opening capacity ranging from 24 to 38 mm. During follow-up, one patient was treated surgically because of continuous severe symptoms; in one case, spontaneous disk reduction was confirmed by MR imaging. At the last examination the rest of the patients (n = 20) had a mouth opening capacity ranging from 31 to 60 mm and belonged to Di II. However, eight patients were completely symptom free and 12 had only mild symptoms. All patients regarded their condition and good as were able to manage well.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognosis in relation to an exarticulated, replanted tooth is poor. Late complications are frequent and often lead to tooth loss. However, the root of a replanted, avulsed tooth may be slowly resorbed preserving alveolar width and postpones replacement of the tooth to a more convenient time. During healing following transplantation or replantation of teeth, various dental and oral structures are involved. Late complications relate to various factors. Tissues and factors involved are reviewed. Knowledge of this subject derives mostly from results of transplantation studies in animals.

The multidimensional nature of chronic pain often requires a variety of therapies, ranging from reassurance and relaxation training to invasive treatment. The high spontaneous rate of recovery in temporomandibular dysfunction can lead to overtreatment of a benign disorder. However, a tendency to undertreat chronic facial pain and malignant pain conditions also exists. In therapy-resistant chronic pain cases, alternative therapies merit consideration, even though they may generally be rejected by Western medicine as unscientific and no better than placebo. Working with chronic pain patients is demanding and fulfilling but can be wearing. Doctors, nurses and other staff involved in pain treatment should take part in supervision of therapeutic work, to prevent burn-out. This article offers guidelines for treatments rarely considered as routine therapy, and describes an extreme case of therapy-resistant chronic facial pain.

The purpose of this survey was to determine whether children in northern Finland had different dental arch dimensions from children in southern Finland. Dental casts of 9-year-old healthy children from Helsinki (southern Finland) and from Oulu and Sodankylä (northern Finland) were measured. Each group contained 41 subjects who had received no orthodontic treatment. The children from Sodankylä and Oulu had narrower dental arches and greater palatal heights than those from Helsinki. The lengths and perimeters of dental arches were significantly shorter in the children from Sodankylä than in those from Helsinki. We suggest these differences could have resulted from adaptation to different climatic conditions, affecting modes of breathing.

Radiocephalometric analysis, based mainly on the foramina of the trigeminal nerve branches, was applied to three samples of adults, two representing fairly extreme profile types, the third representing "normal" dentofacial build. The aim of the study was to find out whether the analytical method could be used to differentiate between facial types. It appeared that some elements of the method had diagnostic powers, and could substitute for traditional methods. Many dimensions inspected, however, were fairly similar in all facial types, thus suggesting a general basic role of the trigeminal nerve in relation to craniofacial structure. Generally speaking, the foraminal pattern was relatively stable in "normal" faces, but more variable in deviant faces.

The aim of this study was to describe edentulousness, numbers of remaining teeth, dental caries, caries experience, periodontal pockets, and background factors in a Finnish village. It was particularly aimed at determining the incidence of simultaneous occurrence of untreated caries lesions and periodontal pockets. It was carried out in 1988 in Viekijärvi, a village in North Karelia. Half of the population was invited to participate in the investigation. Seventy-two percent of those invited participated (n = 179). The subjects were examined clinically using standard WHO methods and criteria. The subjects were interviewed to establish socioeconomical factors and health habits. Thirty-five per cent of subjects were edentulous. Numbers of remaining teeth decreased with age, except in the age group 55-59 years. Numbers of teeth and edentulousness were strongly associated with use of dental services but not with health habits. More than half of the dentate population had untreated caries. Of habits affecting health, only smoking was associated with caries. Twenty-nine per cent of the dentate population had shallow pockets and 7% deep pockets. The occurrence of pockets was negatively associated with frequency of handwashing. Only 20% of the dentate population were orally healthy. The age group 55-59 years was healthier than the younger and older groups.

The views of fathers of young families on health education were obtained using questionnaires issued through Maternity Health Care Clinics and Well-Baby Clinics. The present study is part of the Finnish Family Competence Study. The first phase of the study included 1,414 fathers whose wives were expecting their first baby. Of them, 1,279 returned a questionnaire. In the second phase, at week 28 of the wife's pregnancy, 1,123 fathers returned a questionnaire. A third questionnaire issued when the baby was born was completed by 1,134 fathers. A further questionnaire issued three months after the baby's birth was completed by 1,089 fathers. When the child was three years old, 753 fathers returned a questionnaire. Basic educational level, age and occupation were used as demographic variables. Backgrounds of respondents were studied using questions on the socioeconomic status of the fathers, as well as that of their wives and parents, and the locations of respondents' childhood and present homes. Subjects were asked comment on health education intended for their children. The socioeconomic status and age of the father affected preferences for the content and form of the child's health education. In memorizing their childhood experience of dental visits, most fathers stated that they had been frightened. Attention was not paid in the study to the extent to which the fathers had transferred this fear to their children.

Thirty-two subjects were interviewed about their pre- and post-treatment symptoms of craniomandibular disorders (CMD) and examined for signs of CMD at follow up 2-5 years after surgical-orthodontic treatment for maxillomandibular discrepancies. Symptoms of CMD were among the main reasons for seeking treatment in 31% of the patients. Patients with retrognathic mandibles had significantly more severe symptoms than patients with mandibular prognathism before treatment. After treatment, the severity of subjective symptoms had decreased for the patients as a whole, and significantly in the subjects with originally severe symptoms. Ten subjects out of 12 reported a decrease in the occurrence of headache. The clinical findings of CMD after surgery were usually mild. The importance of occlusal adjustment and rehabilitation as final steps after surgical-orthodontic treatment is stressed.

The use of procedures adapted from a routinely successful method of culturing bovine bone has led to the first system for the study of dentinogenesis in vitro. Two types of cells have been grown from pulp obtained from the growing root tips of impacted third molars extracted from 14- to 19-years olds: (1) epithelial-like cells that are probably derived from fragments of the epithelial root sheath and (2) odontoblast-like cells. The cultured epithelial-like cells grow out in distinctive rounded plaques while the odontoblast-like cells are tethered to and/or grow on top of the epithelial-like cells. The odontoblast-like cells produce mineralized matrix by 10 days when cultured on a defined mineralization formula containing conditioned medium obtained from fetal bovine bone cell cultures. Growth factors in this conditioned medium are important to cell proliferation and growth and to the synthesis of mineralized matrix. Sequential enzyme digestion in dispase and dispase/collagenase in serum-free Dulbecco's Modified Eagle's Medium is essential to obtaining adequate cell yields from the apical 3-5 mm of the developing root. Reduction of the number of fibroblasts by treating cultures with dispase in Tyrode's solution midway through the initial growth period enhances the purity of these cell cultures.

Numerous studies using various animal and human models have reported changes in the morphology and metabolic activity of primary odontoblasts in the mature tooth pulp after perturbations of the tooth including cavity preparation and restoration, pulpal exposures and pulp capping with various capping agents. The first part of this study investigated changes in primary and replacement odontoblast activity after cavity preparation or pulpal exposure. Two groups of rats were used in this investigation. One group of rats had Class V cavities prepared to the DEJ of the first maxillary molars. These rats were immediately injected with 3H-proline and killed 15, 30 or 60 minutes later. Rats killed at day 1, 3, 5, 7, 10 or 14 were injected one hour prior to sacrifice. The second group of rats each had a pulp exposure that was capped with a calcium hydroxide containing material and restored with a composite resin. Rats were sacrificed as previously described. Tissue was processed routinely for ultrastructural analysis and E.M. autoradiography. The second part of this study consisted of an injection of 125I-fibrinogen one hour prior to a class V cavity preparation 1/2 the distance through dentin thickness. Rats were sacrificed at 5, 10, 15 and 30 minutes postsurgery. Differences in the location and distribution of the reduced silver halide grains were recorded as well as differences in the amount and distribution of the various organelles measured between primary and replacement odontoblasts. The results of this study suggests that primary and replacement odontoblasts were morphologically and physiologically dissimilar at the time periods tested in this study. 125I-fibrinogen was demonstrated within the dentinal tubules and in the floor of the cavity preparation as early as 5 minutes after completion of the cavity preparation. The preliminary results of the 125I-fibrinogen suggest that operative trauma can effect very rapid changes to the dental pulp leading to leakage of plasma proteins from the circulation, between odontoblasts, out of the tubules to the cut dentin surface.

A current Med-line search from 1966 to present cited over 344 juried publications employing the term microleakage. Dentistry recognizes microleakage as a multifaceted biological phenomenon. Brännström et al. (1967), Trowbridge (1982), Närhi (1983), and others have reported the sensory component of microleakage as a consequence of hydrodynamic fluid movement within the dentinal tubule complex. This movement of dentinal fluid has been demonstrated to displace nociceptive receptors which stimulate the nerves of the Group A fibers which run and terminate within the odontoblastic layer (see Matthews 1992). Penetration of oral fluids, bacteria and their toxic products within the preparation-material interface following material insertion accounts for the pathological component of microleakage (Browne and Tobias 1986). Continued microleakage of bacterial infiltrates eventually present as an inflammatory process which may initially signal the dentin complex to respond by deposition of a hypermineralized or sclerotic dentin. The pulp-dentin interface will repair with a specialized zone of reparative dentin. An overwhelming carious lesion often results in pulp infection and eventual necrosis. Vital dentin is an extension of the pulp, presenting the first line of defense to the consequences of microleakage. Recent publications have demonstrated that microleakage of dental materials in non-exposed and exposed pulps is a function of controlling bacterial infection. In an exposed mature dental pulp, the mesenchymal tissue permits the reorganization of pulp tissue and regeneration of a new dentin bridge in the presence of a biological seal. New odontoblastoid cells appear to regenerate from deeper pulpoblasts in the presence of various dental materials, apparently without an epithelial stimulating factor (Yamamura 1985). This inherent healing of the dental pulp and regeneration of a new dentin bridge is expressed in the presence of various dental materials, but only in the absence of bacterial infection. Data which evaluates the biological deposition of reparative and dentin bridges as either repair or regeneration are presented as a basis for considering the clinical selections of dental materials. Recent data demonstrate that dentin and pulp healing are ensured when a proper biological seal is provided to control and prevent microleakage.

The reactions of sensory nerves to restorative procedures can be classified as immediate, early and late. For each of these, the neural response depends upon the severity of pulpal injury and the stages of inflammation and healing. Immediate responses in the first few minutes include destruction of nerve fibers in the injured dentin and pulp, hypersensitivity of surviving fibers, release of neuropeptides into the pulp and neurogenic inflammation. Early responses occur during the first few days after cavity preparation, with nerve fibers sprouting in the surviving pulp and gaining increased axonal transport and neuropeptide contents. Sensory fibers containing calcitonin gene related peptide (CGRP) greatly outnumber those with substance P (SP); but both types grow toward the surviving odontoblasts and associated pulp tissue surrounding the lesion. Later during subsequent weeks the nerve fibers accompany granulation tissue as it replaces acute inflammation; and nerve sprouting subsides when inflammation is reduced and when reparative dentin covers the injury site. An important response to tooth injury that may regulate nerve sprouting reactions is the increased production of nerve growth factor (NGF) by pulpal fibroblasts near the lesion. The timing of the nerve sprouting reactions suggests that they may contribute to tooth hypersensitivity after restorative procedures.

Hypersensitive dentin appears to be mainly the result of an activation of the dentinal pain fibres, the A-fibres, at the pulpal wall. The stimuli which activate these nerves are primarily those which remove fluid from the dentinal tubules and mobilize capillary forces, causing a rapid outward flow. Application of a cold stimulus causes the fluid to contract, resulting in a similar rapid outward flow in the pulpal region of the tubules. Hypersensitivity to cold is also marked when there is a fluid-filled gap containing bacteria in the tooth. Experiments have shown that a freshly exposed dentin surface with patent tubules is more sensitive than a surface contaminated by a smear layer. Inflammation in the adjacent pulpal region can also increase sensitivity. The development of hypersensitive cervical and occlusal surfaces is due to mechanical and acidic effects from the oral environment, toothbrush abrasion, erosive components in the diet, plaque and bacterial invasion of dentin. Sometimes dentin is exposed by restorative therapy and occasionally eccentric occlusal loads can contribute to hypersensitivity. The sensitivity may persist unless the open tubular apertures are sealed.