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Biomedical subjects

B U Zachrisson

Publications and source records attributed to B U Zachrisson.

At least 55 records · Page 3Linked to original sources
PubMed1977

Clinical experience with direct-bonded orthodontic retainers.

The experience obtained in clinical evaluation of forty-three direct-bonded mandibular canine-to-canine retainers after a minimum observation period of 1 year (range, 1 to 2.5 years) is summarized. Results indicate that the bonded retainer has all the advantages of a fixed soldered retainer, in addition to being invisible. Patient acceptance was excellent, and the failure rate in terms of loose retainers was low. Also, for a number of other retention problems, direct bonding with different types of lingual wire seems to open up a range of promising new possibilities.

Adolescent↗
PubMed1976

Cause and prevention of injuries to teeth and supporting structures during orthodontic treatment.

The present investigations have shown that, although there are definite risks in undertaking orthodontic treatment with fixed appliances, such treatment need not cause any appreciable damage when accepted orthodontic principles are followed in cooperative patients with good oral hygiene and regular fluoride treatment. On the other hand, when these principles are neglected, the damage may be considerable and the benefits from orthodontic treatment questionable. Progressively increasing evidence from preventive dentistry that the bacterial plaque is the single most important causative factor in periodontal breakdown, and is important also in causing dental caries, opens unique possibilities for the orthodontist and his auxiliary personnel with simple means to increase their patient's oral hygiene awareness. This would not only reduce the prevalence and severity of iatrogenic damage, but would increase the long-term benefits of the orthodontic therapy. Orthodontists may thus provide young adults with an improved esthetic facial appearance, a perfectly functioning occlusion, and the desire, interest, and possibilities of maintaining the dentition in this condition for all or most of their lives (Figs. 3 to 5, 12, and 13).

Dental Bonding↗
PubMed1975

Remodeling of teeth by grinding.

Pulp and dentin reactions to extensive grinding of human teeth were studied clinically and histologically. The facial portions of forty-eight premolars to be extracted for orthodontic reasons were reshaped to "lateral incisors" using diamond instruments and abundant water cooling. Following grinding and polishing with sandpaper discs and pumice, topical fluoride was administered. The patients were asked to report any increased sensitivity reactions. The teeth were extracted at 0, 1, or 3 weeks or 3 to 5 months and examined histologically. No significant discomfort was reported by the patients except for an initial period of a few days during which there was increased sensitivity to temperature changes. The histologic findings indicated that extensive remodeling of young permanent teeth is possible with no or only minor pulp and dentin reactions. Some initial localized effects in terms of aspiration of odontoblast nuclei, hyperemia, absence of a cell-free zone, and slight cellular infiltration were sometimes observed, but the long-term observations indicated that these reactions were transient. Secondary dentin formation was not registered. It is important that gentle grinding techniques with abundant water spray be used and that smooth and self-cleansing surfaces which allow hypermineralization of the ground enamel and dentin be prepared. In a few teeth in which proximal retention areas were unintentionally prepared, caries developed and marked pulp reactions occurred. Therefore, great care must be taken not to introduce proximal steps when mesiodistal tooth width adjustments are performed. The present study has provided histological and clinical evidence to indicate that even extensive recontouring by grinding may not be harmful to the teeth. This should encourage orthodontists to remodel teeth by grinding to improve the final occlusal and esthetic results in a number of different cases.

Bicuspid↗
PubMed1975

Fluoride application procedures in orthodontic practice, current concepts.

A survey is given of present knowledge of different methods of fluoride administration with emphasis on practical measures of proved value for orthodontic patients. The review covers different F administration procedures by dental personnel and self-application and includes the use of prophylaxis pastes, topical solutions, gels, mouth rinses, dentifrices, tablets, cements, coatings, varnishes, etc. Some recommendations are given as to optimal programs in orthodontic practice based upon evaluations of clinical effectiveness, safety and ease of application. Some caries reduction has been obtained from professional application of F prophylaxis pastes, but F pastes cannot replace topical F application. Treatment with F gels or solutions preceded by thorough cleaning and drying of the teeth is advocated before the placement of appliances and at recementations. Because F solutions are tedious to apply, and not more effective than F gels, the latter are preferable. APF gel application is suited in conjunction with impression taking. Daily self-application of SnF2 gels undoubtedly is effective in reducing caries in orthodontic patients. However, daily NaF or APF mouth rinses may have the dual effect of caries inhibition and stimulating hygiene interest and are more thoroughly tested. In addition to the other forms of F administration, a F dentifrice should be used regularly. Daily F application is appropriate also for orthodontic patients in fluoridated areas. In vitro studies with F cements indicate a great F uptake by the enamel, but controlled, long-term clinical studies are lacking. Also the final judgment of a number of new coating techniques and F varnishes must await further clinical testing, although a beneficial effect of F sealing in orthodontic patients is substantiated. In conclusion, APF gel application before insertion of appliances and at regular recementations plus daily rinsing with dilute NaF or APF solutions throughout the periods of treatment and retention plus the regular use of a F dentifrice is recommended as a routine procedure for all orthodontic patients.

Child↗
PubMed1975

Repair characteristics of root fractures in permanent anterior teeth.

A follow-up study was made of repaired root fractures in 51 permanent anterior teeth, with a mean observation period of 6 years. The material was subdivided into three repair types (Figs. 1-3): Type 1 - invisible or hardly discernible fracture line (15 teeth), Type 2 - fragments separated by a narrow radiolucent line and peripheral rounding of the fracture edges (33 teeth), and Type 3 - fragments separated by a distinct bony bridge (3 teeth). The majority of repaired teeth gave a normal or slightly decreased response to electric pulp tests and the mobility was physiologic or slightly increased. Reduced transparency or slight yellowish discoloration was observed in 14 teeth. The most conspicuous radiographic finding was pulp obliteration which occurred in 86%. Two different patterns were observed: (1) partial obliteration located in the apical fragments and the fracture area, and extending 0.5-4 mm into the coronal fragment, and (2) progressive obliteration of the entire pulp cavity ending with almost total obliteration. Pulp necrosis did not develop as a sequel to progressive obliteration in any case. Several different characteristics of the fracture influenced the repair pattern, the most important being the degree of fragment dislocation and mobility, stage of root development and localization of the fracture. Correlation between type of repair and various treatment procedures was observed only with regard to reduction.

Adolescent↗
PubMed1975

Long-term prognosis of 66 permanent anterior teeth with root fracture.

A longitudinal clinical and radiographic follow-up study was made of all permanent teeth with root fractures referred to the Oslo University Department of Pedodontics between 1953 and 1972 (n = 66). The material included 51 patients aged 6-21 years. The mean observation period was 5.2 years, ranging from 1 to 19 years. The present report documents background data and the long-term results. Two teeth with exarticulation of the coronal fragments (3%) were immediately extracted. Repair of the fracture area occurred in 51 teeth (77%). Pulp necrosis was found in 13 teeth (20%), nine of which were successfully treated endodontically; only four teeth had to be extracted. Several factors were found to influence the prognosis, most notably the degree of dislocation of the coronal fragment. The localization of the fracture influenced repair only slightly. Despite somewhat increased mobility in some cases, the longevity of teeth with fractures even in the coronal third of the root was not significantly shortened. It is concluded that when optimally treated by repositioning, fixation and relief of occlusion, anterior teeth with root fracture have a favorable prognosis. Even when pulp necrosis occurs, the long-term prognosis is good.

Adolescent↗