Cemental tear related to rapid periodontal breakdown: a case report

Cemental tears have been described both in exposed and unexposed cementum. The phenomenon is believed to be elicited by overloading or acute trauma from occlusion. In this case report a patient, with a history of periodontal health, presented with an acute periodontal lesion on the distal aspect of a bridge abutment tooth. Periapical radiographs demonstrated an extensive vertical intrabony defect adjacent to the vital abutment tooth containing a radiopaque "foreign body." Histological examination of the surgically removed "foreign body" revealed a piece of dental cementum with some attached soft tissue. The lesion responded well to a surgical approach. Healing was uneventful and periodontal health was restored. This case illustrates that cemental tear should be considered as a differential diagnostic entity in isolated sites with rapid periodontal breakdown.

The effect of hygiene instruments on dentin surfaces: scanning electron microscopic observations

The present study consists of two separate parts. The first section is an in vitro evaluation of the relative abrasiveness of some hygiene instrumentations commonly used during maintenance therapy. In the second section, one of the instruments, a recently developed plastic tip for use on a sonic scaler, was examined for its ability to remove dental plaque from root surface specimens instead for 5 weeks in the oral cavities of dogs. The in vitro study was performed on recently obtained dentin specimens where a ridge had been machined parallel to the long axis of the tooth. The sonic scaler fitted with the plastic tip gave considerably less removal of dentin and a smoother dentin surface than the curet, the rubber cup with polishing paste, or the sonic scaler with an ordinary metal tip. These findings further demonstrated that the plastic tip was able to efficiently remove 5-week old dental plaque from experimental root surface areas within a time frame of 5 seconds. The new plastic tip may be valuable in maintenance therapy giving less risks for iatrogenic effects on the root surfaces than other debridement methods.

Influence of polishing procedures on sonic scaling root surface roughness

The present in vitro study aimed to evaluate the efficacy of various polishing procedures in reducing root roughness caused by sonic scaling. Proximal root surface areas of extracted, formalin-stored teeth were scaled in a bucco-lingual direction by a sonic scaler. The resulting roughness was measured along the direction of scaling and perpendicular to that direction by a profilometer. The specimens were then split into two groups. Group 1 was polished by an air-powder polishing instrument followed by a rotating rubber cup and chalk; Group 2 was polished by pumice followed by chalk. Root roughness (Ra) was recorded for each step in the procedures. The measurements revealed lower Ra values when the stylus of the profilometer was running perpendicular to the scaling direction, and a weak negative correlation was found when scaling time and Ra values were compared. In both groups Ra values were significantly reduced at each step of the polishing procedures and the terminal result was similar for the groups. Pumice and air-powder polishing gave a similar reduction of the sonic scaling roughness.

Periodontal awareness, health, and treatment need in dental school patients. III. Treatment need

The need for periodontal treatment in a group of dental school patients was estimated by means of the periodontal treatment need system (PTNS). The findings were related to information about the regularity of dental visits, awareness of own disease, and periodontal treatment experience. All the patients required motivation and oral hygiene instruction (treatment need, class A). All their quadrants needed scaling or adjustment of subgingival restorations (treatment need, class B). As many as 71% of the patients and about 49% of the quadrants needed periodontal surgery (treatment need, class C). The mean periodontal treatment time per patient was 279 min (4 h 39 min). The middle age group (30-59 years) required more treatment time than the oldest group (greater than or equal to 60 years). This was probably due to more missing teeth in the oldest age group. There were no significant differences in treatment need between males and females. The regular dental visitors had a greater periodontal treatment need than the individuals visiting their dentist less frequently. This finding emphasizes the responsibility of the general practitioner in diagnosing and treating periodontal disease.

The prevalence of hepatitis A and B in Norwegian merchant seamen--a serological study

The prevalence of viral hepatitis in Norwegian merchant seamen in overseas trade was studied in 523 volunteers during compulsory health control before embarkation from the port of Oslo. The prevalence of hepatitis B markers was 9.4%, which is significantly higher than in the general Norwegian population. The prevalence increased with the number of years of occupation. It was associated with frequent casual sexual contacts in foreign countries, but not significantly increased in participants who had been exposed to tattooing or different types of medical treatment under poor hygienic conditions in foreign areas. The prevalence of antibodies against hepatitis A (HAV) was 36% in seamen born in 1945 or earlier and 5% in younger individuals, an age-dependent pattern which is essentially similar in the general Norwegian population. However, the prevalence of hepatitis A antibodies seemed to increase with years in foreign trade. The incidence of viral hepatitis infections in the occupation was noticeably high, suggesting that vaccination of seamen in certain areas of trade should be considered.

Periodontal awareness, health, and treatment need in dental school patients. II. Periodontal conditions

The present study aimed to evaluate the periodontal conditions in a group of randomly selected patients scheduled for periodontal treatment in a dental school. The patients' age, sex, and responses to interview questions were used as predictors. About 64% of the lateral tooth surfaces had visible plaque after disclosure with erythrosine, and males had significantly more plaque-covered surfaces than females. All subjects had some areas showing 'bleeding on probing', and a total of 58% of the gingival units bled. About 99% of the subjects, 61% of the teeth, and 33% of the gingival sites had probing depths greater than or equal to 4 mm, whereas 70% of the subjects, 19% of the teeth, and 8% of the gingival sites had probing depths greater than or equal to 6 mm. Mean individual bone score for the 'Ramfjord teeth' was 5.60. Yearly dental visitors tended to keep their teeth to a greater extent than patients with a less regular treatment pattern. This is probably because irregular and emergency patients more often ask for extraction instead of restorative treatment. Since periodontal treatment usually is not offered, the periodontal conditions in the three regularity groups were not considerably different.

Periodontal health in a group of industrial employees

The aim of this study was to evaluate the dental health conditions of male employees in a large aluminum factory. The present report deals only with the periodontal findings. Five percent of the 181 examined subjects between 25 and 60 yr were edentulous, and all dentate individuals had some degree of periodontal disease. Surfaces harboring stainable plaque were high in all age groups, varying between 65 and 85%. Surfaces without retention factors were 31% and decreased with increasing age. The percentage of sites with bleeding increased from about 40% in the lowest to about 60% in the highest age group. Teeth with probing depths greater than or equal to 4 mm increased from about 30% in the age group 25-29 yr to about 45% in the age group 30-34 yr, after which it increased gradually with increasing age. The difference in bone scores (marginal bone loss) was the most extensive between the ages of 25 and 34 yr, but with a significant increase throughout the age groups. The administrators had a somewhat better oral hygiene, fewer retention factors, less bleeding, fewer pockets and some more marginal bone support than the workers. Still, the administrators had more missing teeth than the workers.

Periodontal awareness, health, and treatment need in dental school patients. I. Patient interviews

The present study aimed to evaluate the periodontal awareness and the amount of information and periodontal treatment received previously in a group of randomly selected patients scheduled for periodontal treatment in a dental school. A group of 124 patients were interviewed by a dental hygienist before the treatment started. Age, sex, and regularity of dental visits were used as predictors. Around 68% of the patients were not aware of the existing periodontal disease, and 74% had never received any information about the treatment possibilities. Ninety per cent claimed that they had never received any periodontal treatment at all. The modality of periodontal treatment and the extent to which the patients had been instructed in toothbrushing were almost equal in patients who visited the dentist yearly and in emergency patients.

Abrasivity of toothpastes. An in vitro study of toothpastes marketed in Norway

The purpose of this study was to measure the abrasivity of 23 toothpastes available on the Norwegian market. Additionally, the pH was registered. The testing was based on The British Standards Institution's specification for toothpastes, using a profilometer technique to evaluate the abrasion. The results showed that the abrasivity ranged from 0.049 to 1.367 relative to a standard reference paste. The products were classified as having 'none/slight', 'medium', or 'high' abrasivity. The pH varied between 3.7 and 10.1. Products with low pH showed evidence of a combined erosive/abrasive effect. For some brands there were statistically significant differences between the fluoride and the nonfluoride version.

Computerized evaluation of the effectiveness of subgingival scaling in jaw models. An introduction to the program developed at the School of Dentistry, University of Bergen

The purpose of the present study was to improve the quality and the effectiveness of subgingival scaling managed by dental students. A training program was developed and the scaling was performed in jaw models. The teeth of these models were modified in order to ensure a quick inspection of the scaled root surfaces. Artificial "calculus", consisting of a mixture of shellac, umbra, pumice and plaster dissolved in ethanol, was painted on the root surfaces. Following the completion of the scaling test, remaining "calculus" was evaluated by adoption of a grading system. This system had scores from 0 to 3 and was defined by illustrated and described criteria. A menu-directed computer program was developed in order to ensure a rapid transformation of surface scores into clinically-related variables. The output from this program gave valuable information about the proficiency of individual students, as well as about the whole class of students as one body. Other advantages and potentials of this system are described.

Effects of chlorhexidine gel in a group of maintenance-care patients with poor oral hygiene

An intraindividual double-blind crossover study was designed in order to see if a 1% chlorhexidine gel used twice a day could substitute for ordinary toothpaste in group of maintenance-care patients with poor oral hygiene. Twenty patients from a student clinic participated, each with a long history of maintenance-care problems. A 4-week test period with chlorhexidine gel or placebo gel was followed by an intermediate period with ordinary toothpaste, and then by another 4-week test period. Plaque-covered surfaces (%), bleeding sites (%) and extraneous staining (color slides) were recorded at each sitting. The results demonstrated that brushing with chlorhexidine gel significantly influenced both the oral hygiene level and the gingival inflammation. The only adverse effect observed was a marked increase in the amount of brown staining, especially on the facial surfaces of the nonsmokers. In this short-term study, the staining was not considered cosmetically unacceptable by the patients. The total amount of staining was always greater in smokers than in nonsmokers.

Evaluation of the effect on root surfaces of air turbine scalers and ultrasonic instrumentation

Three air turbine scalers were compared to each other and to an ultrasonic instrument (CAVITRON) on medium and maximum power setting. The amount of remaining calculus, roughness and loss of tooth substance were estimated by means of well-defined index systems (RCI and RLTSI). The time required to clean the test surfaces--marked on proximal root surfaces of mandibular incisors--was also noted. Standardized scanning electron microscope (SEM) micrographs were independently "blind-scored" by three examiners, and total mean scores were calculated. The results revealed significant differences (P less than 0.001) between the instruments with respect to the amount of remaining calculus. There were also significant differences (P less than 0.05) between roughness and loss of tooth substance produced by CAVITRON at maximum power setting and that produced by the other instruments. No differences were found with regard to the time required to clean the test surface (until visually clean).

Surface coatings on dental cementum incident to periodontal disease. (II). Scanning electron microscopic confirmation of a mineralized cuticle

Root surfaces, exposed by periodontal disease, were studied after treatment with sodium hypochlorite. Observations of the anorganic specimens demonstrated that substantial changes occur in root surfaces incident to periodontal disease. A mineralized surface coating was seen in all areas of the involved root surface, although local regions occurred where the coating was apparently unmineralized. These findings generally confirmed the results of a previous study where the same specimens were studied without hypochlorite treatment. It is concluded that the coating is probably identical to the dental cuticle, and stems from adsorption of components of the gingival inflammatory exudate to the root surface. The coating may also be the carrier matrix for exogenous cytotoxic substances, previously thought to be located in the cementum. The findings may have implications for the way of treating periodontitis-involved root surfaces.

Surface coatings on dental cementum incident to periodontal disease. I. A scanning electron microscopic study

Root surfaces of extracted human teeth with advanced periodontal disease were studied by the apically migrated junctional epithelium, the topography characteristic of uninvolved cementum was frequently masked by a surface coating. The thickness of the coating increased in a coronal direction where it often blended with calculus. The observations indicate that this surface coating may originate from the inflammatory exudate and corresponds to the dental cuticle. The findings also indicate that the coating may be mineralized and may contain exogenous substances. These observations illustrate a need for further study and reexamination of the rationale for removal of tooth substance during scaling and root planing.

Replica study of plaque formation on human tooth surfaces

Plaque formation on buccal tooth surfaces was studied by replica technique, consisting of impressions using low viscosity silicone impression materials and positive models produced in epoxy resins. Bacterial accumulation occurred near the cemento-enamel junction in 6-hr specimens, and subsequently expanded in a coronal direction. This development took place partly by extensions of single layers of bacteria, and partly by a pattern where the colonization was mostly restricted to vertical enamel cracks. Plaque accumulations were also frequently located in abrasion grooves and surface pits in the enamel, and prolific plaque areas were consistently surrounded by a monolayer of bacterial cells. Globular and hemispheric structures which occurred, especially on root surfaces immediately after cleaning, were probably artefacts caused by air bubbles or remaining moisture. In separate series of experiments it was demonstrated that improved reproduction of details from the plaque could be achieved by repeating the replicating procedure. The findings indicate that plaque formation starts by adsorption and proliferation of individual bacteria on tooth surfaces, and not by adsorption of aggregates of cells. Special attention should be directed against the problem of artefacts and moisture in replica studies of dental plaque.

Morphologic studies on dental plaque formation

The present summary and the following papers (I--VII) are submitted in partial fulfillment of the requirements for the degree of Doctor Odontologiae at the University of Bergen. 1: Growth of dental plaque on hydroxyapatite splints. A method of studying early plaque morphology. J. Periodontal Res. 1974, 9, 135--146. II: Pellicle formation on hydroxyapatite splints attached to the human dentition: Morphologic confirmation of the concept of adsorption. Arch. Oral Biol. 1975, 20, 739-742. III: Scanning and transmission electron microscope study of pellicle morphogenesis. Scand. J. Dent. Res. 1977, 85, 217-231. IV: Early dental plaque morphogenesis. A scanning electron microscope study using the hydorxyapatite splint model and a low-sucrose diet. J. Periodontal Res. 1977, 12, 73-89. V: Ultrastructural study of early dental plaque formation. J. Periodontal Res. 1978, 13, 391-409. VI: Dental plaque morphology as revealed by direct observation and by replicating techniques. Acta Odontol. Scand. 1978, 36, 279-288 Co-author: F. Gusberti. VII: Replica study of plaque formation on human tooth surfaces. Acta Odontol. Scand. 1979, 37, 65-72. Co-author: F. Gusberti. These papers are referred to as I-VII in the present summary. Other papers are referred to in conventional manner.