M.F. Timmerman

Effect of surface topography of screw‐shaped titanium implants in humans on clinical and radiographic parameters: a 12‐year prospective study

OBJECTIVES Although implants with a roughened surface are widely used today, little is known about the long-term effect of a roughened surface compared with the conventional machined surface on clinical and radiographic parameters. The purpose of this study is to investigate the long-term differences between moderately rough (tioblasted) titanium implants and minimally rough machined/turned surfaces with respect to marginal bone resorption and the peri-implant soft tissues in the same patient. MATERIAL AND METHODS In 20 fully edentulous patients, with severely resorbed mandibles, a total of 80 Astra Tech dental implants were placed in the mandible to support a bar construction with a full overdenture. In each patient two minimally rough-surfaced (turned) and two moderately rough-surfaced (tioblast) implants were placed alternately. Clinical evaluation was carried out at base line (prosthetic installation), 6 months, 1, 2, 3, 4, 5 and 12 years. Radiographic evaluation using standardized individual filmholders was carried out at base line (prosthetic installation), 6 months, 1, 5 and 12 years. RESULTS In two patients, during the abutment surgery, one turned implant showed insufficient osseointegration and was replaced. One implant showed an abutment fracture after 9 years and was kept as a sleeper. From base line up to 12 years, no implant was lost. No significant differences were found between both implant surfaces concerning the clinical parameters such as plaque, calculus, bleeding and probing pocket depth. The mean (SD) marginal bone changes up to 12 years varied between -0.11 and +0.01 mm for the turned and -0.2 and +0.01 mm for the tioblast implants. No significant difference in marginal bone loss was found between both implant surfaces. CONCLUSION We conclude that after 12 years of follow-up, no differences could be found between the turned and the tioblasted implants, both for soft and for hard tissue parameters.

An oscillating/pulsating electric toothbrush versus a high-frequency electric toothbrush in the treatment of gingivitis

OBJECTIVES The objective of this study was to compare the effect of an oscillating/pulsating power toothbrush (Oral-B ProfessionalCare 7000; PC 7000) and a high-frequency power toothbrush (Philips Sonicare Elite; SE) on the reversal of experimental gingivitis. METHODS The study had a randomised, examiner-blind, split-mouth design. After dental prophylaxis, subjects refrained from brushing mandibular teeth for 21 days to allow development of gingivitis. During a 4-week treatment phase, the right or left side of the mouth was brushed with either the PC 7000 or the SE toothbrush as randomly allocated. Plaque and gingivitis were assessed at baseline (Day 0), after 21 days of no oral hygiene, and after 1, 2 and 4 weeks of brushing twice daily. Gingival abrasion was assessed at Day 0 and after 1, 2 and 4 weeks of product use. RESULTS Of 38 enrolled subjects, 35 provided evaluable data. The experimentally induced gingivitis (EIG) phase resulted in higher bleeding and plaque scores as compared to Day 0. During the treatment phase, plaque and bleeding scores were significantly lower with the PC 7000 than the SE toothbrush. After 4 weeks of use, the mean plaque scores changed from 2.78 (Day 21 of EIG phase) to 0.70 for the PC 7000 and from 2.67 (Day 21) to 0.88 for the SE. The mean bleeding scores changed from 1.86 (Day 21) to 1.24 for the PC 7000 and from 1.88 (Day 21) to 1.42 for the SE. No major differences were found between brushes with regard to gingival abrasion. CONCLUSIONS The oscillating/pulsating power toothbrush (Oral-B ProfessionalCare 7000) was more effective than the high-frequency power toothbrush (Philips Sonicare Elite) at plaque removal and improvement of gingival condition, with no greater potential for causing gingival abrasion.

Increased Salivary Fluoride Concentrations after Post-Brush Fluoride Rinsing Not Reflected in Dental Plaque

The aim of the present study was to assess fluoride concentrations in unstimulated saliva and buccal dental plaque 6 h after an oral hygiene procedure that consisted of brushing with an AmF/SnF2 dentifrice and different post-brush rinsing protocols: expectorating the excess of dentifrice foam and rinsing with tap water, expectorating only, or rinsing with 10 ml AmF/SnF2 mouthwash. The fluoride concentrations in plaque and saliva were increased after all three experimental protocols compared to F-free periods. The increase of the fluoride concentration in saliva was more pronounced after AmF/SnF2 mouthrinse as compared to rinsing with water and expectorating the excess of dentifrice foam. Such an effect was not seen in dental plaque. It is concluded that the potentially beneficial effect of not rinsing or fluoride rinsing after tooth brushing is not reflected in an increased fluoride concentration in newly formed dental plaque 6 h after brushing.

Clinical efficacy of a chlorhexidine-delivering toothbrush

OBJECTIVES Evaluate the efficacy and safety of an experimental toothbrush with a slow-release system of chlorhexidine (CHX) and determine its ability to inhibit plaque, bleeding, staining and oral tissue abnormalities during 6 weeks of use. MATERIAL AND METHODS One hundred and fifty healthy volunteers were randomly assigned to one of three groups: the Test Brush group with a template slow-delivery system of CHX (Ttb), the Control Brush group without CHX (Ctb) and the Control Brush group without CHX but rinsing post-brushing with a 0.2% CHX mouthrinse (Ctb+R). At baseline as well as at 3 and 6 weeks, all clinical parameters were assessed. Following the baseline assessment, a supragingival prophylaxis was provided. RESULTS One hundred and forty subjects completed the study. The Ctb+R group had lower plaque and bleeding scores than the Ttb and the Ctb group and significantly (p=0.0001) higher stain scores. There were no significant differences in plaque, bleeding and stain scores between the Ttb and the Ctb group. No differences were detected in oral tissue changes, except for discoloration of the tongue. CONCLUSIONS In the present study, no beneficial effect could be demonstrated for the experimental CHX-releasing toothbrush. The use of a 0.2% CHX mouthrinse (in combination with brushing) remains the gold standard for additional chemical plaque control.

Java project on periodontal diseases: causes of tooth loss in a cohort of untreated individuals

OBJECTIVE To assess the relative contribution of caries and periodontal disease to tooth loss over 24 years in a cohort deprived of regular dental care. MATERIAL & METHODS The study population consisted of 98 subjects from a tea estate on West Java, Indonesia, that had been part of a prospective longitudinal study and provided full datasets of clinical assessments between 1987, 1994 and 2002. In 2011, complete sets of dental radiographs were made which was combined with the survey forms and clinical slides from the previous assessments in order to estimate reasons for tooth loss. RESULTS Thirty-seven subjects lost no teeth, whereas 61 subjects lost 185 teeth. In this group, 45.9% lost ≤2 teeth, 32.8% lost 3 to 4 teeth and 19.7% lost ≥5 teeth. The majority of teeth were lost due to caries. In five subjects, tooth loss could be attributed solely to periodontitis, whereas in four subjects teeth were lost due to both caries and periodontits. Analyses of the predictor variables age, gender, smoking, education, presence of caries and severe periodontitis showed that male gender and caries were significantly associated with tooth loss. CONCLUSION The majority of teeth in this population were lost due to caries.

Patterns of bone loss around teeth restored with endodontic posts

OBJECTIVES This retrospective study described the pattern of bone loss around teeth with endodontic posts in periodontitis patients, and compared it with contra-lateral teeth without posts. MATERIAL AND METHODS From full-mouth radiographic surveys of 146 periodontitis patients (> or =35 years), 194 roots with endodontic posts and contra-laterals without posts were selected. Upper molars, pre-molars with two posts and roots of lower molars with two posts were excluded. Technical parameters of the post space preparation, endodontic and restorative status were evaluated. The level of alveolar bone measured in millimetre from the cemento-enamel junction (CEJ)/restoration margin and the pattern of bone loss (angular/horizontal) were evaluated on both mesial and distal aspects of roots with posts and contra-laterals, but not on the furcal areas of lower molars. RESULTS The distance from the bone level to the CEJ/restoration margin was similar for teeth with posts and contra-laterals. However, teeth with posts had more angular defects mesially (18.8%versus 7.3%) as compared with their contra-laterals without posts. The defects around teeth with posts appeared to be typical in the sense that their apical level approximated the tip of the endodontic post. CONCLUSION In periodontitis patients, teeth restored by an endodontic post had angular bony defects on the mesial aspect more frequently in comparison with their contra-laterals.

In vitro evaluation of temperature changes in the root canal induced by ultrasonic scalers

OBJECTIVE To evaluate in vitro the thermal effects induced by four different ultrasonic scalers on the temperature in the root canal during ultrasonic scaling. METHODS An extracted lower central incisor provided with a thermocouple in the root canal and a tube, entering the tooth incisally and exiting it apically to simulate an artificial bloodstream, was placed in a model of the lower jaw with soft artificial gingiva. Tested ultrasonic scaler systems included: EMS PM-600, Satelec P-max, Dürr Vector and Dentsply Cavitron. The tooth was scaled with each system at full water supply of 21°C. Furthermore, the amount of water supply was determined to maintain during scaling a constant temperature in the root canal. Finally, thermal changes due to scaling without water were assessed. RESULTS Except for the Vector all scaler systems showed a temperature decrease in the root canal. The Vector with water/polish suspension showed a trend towards an increase in temperature. To maintain a constant temperature in the root canal the Cavitron needed twice the amount of water compared with PM-600 and P-max. Without water, all scaling systems induced a temperature increase. CONCLUSION For safe ultrasonic scaling, care should be taken that the cooling water has room temperature and that, dependent on the scaler system, the proper amount of water is supplied.

Gingivavergroting als gevolg van medicatie

SamenvattingAlgemeen is bekend dat het anti-epilepticum fenytoine (Diphantoïne) vergroting van de gingiva tot gevolg kan hebben. Al in 1939 werd hiervan de eerste melding gemaakt.

Re: Epidemiology of periodontal diseases (position paper) (1996;67:935-945)

n Editor: My reaction to Paul Cohen’s article in the Spring 1991 issue is quite positive. The research methodology he espouses is one I’ve tried (often unsuccessfully) to elucidate and follow. My hat is off to him for putting in words things I’ve tried to say-he does it quite well and backs it up with evidence. However, while I agree strongly with his analysis that we’ve seen two major (and different) AI methodologies emerge over the past few years, I’m not sure I agree with his main conclusion-that we should all become MAD researchers. Let me attempt a simple elucidation of an alternative-one which I’ve expressed on occasion, but never formally in writing. It’s basically the same as Cohen’s, but instead of focusing on a single methodology (i.e. Cohen’s MAD approach) we need some AI practitioners who pick up this third leg-i.e. a few MAD scientists (pardon the pun). That is, I think Cohen has realized that AI has an “excluded middle.” That is, when the AAAI went to a theory and systems track, people like Cohen and some of the rest of us formed part of an excluded group that focuses on what I’ve called the experimental approach. We are a group of AI researchers who are not developing applications, but are not totally concerned with the formalization of their work-in fact, this is the group that Abelson called “the scruffies” in his 1981 Cognitive Science talk. (Nowadays, some folks use neats and scruffies to differentiate applications builders from theorists. However, I believe that the distinction of “neats” and “scruffies” raised at Cog Sci in ‘81 didn’t define scruffies as people who built expert systems [they didn’t really exist as a “real” part of AI at the time] but those who implemented to test theories vs. those who theorized. Thus, it was like what Cohen called systems vs. models, but the term systems had less of an applications implication than it does today). In short, what I believe is an over-