Biomedical subjects

A G Dijkman

Publications and source records attributed to A G Dijkman.

At least 19 recordsLinked to original sources

PubMed1996

Instruments and methods for the quantitative measurement of factors affecting hygienist/dentist efforts during scaling and root planing of the teeth.

Manual calculus debridement through scaling accounts for a significant proportion of hygienist efforts in dental and periodontal practices. Despite this, little is quantitatively known concerning the effects of instruments, technique and treatments on debridement (scaling) efficiency or efficacy. The total work effort expended by therapists in calculus debridement results from the sum of the efforts associated with each scaling stroke. Each scaling stroke, in turn, is affected by a variety of physical forces, including those in the control of the therapist and those intrinsic to the calculus substrate. The development of procedures and treatments to facilitate easier calculus removal requires consideration of the physical and technique-related factors which contribute to hygienist effort. Instruments have recently been developed which can quantitatively measure force dynamics associated with scaling procedures, including both therapist-applied forces and forces developed due to the extreme hardness and tenacity of supra- and subgingival calculus deposits. The scaling instrument developed to quantitatively record developed forces in scaling, the Quanticalc, can be used for the assessment of techniques and treatments which can soften calculus, facilitating easier debridement. The device can also be used to instruct therapists on factors contributing to surface roughness and tactile response to these factors. The scaling instrument developed to quantitatively measure therapist applied forces in scaling, the Zappa device, can be used for assessment of techniques which can increase the efficiency of calculus removal with minimal damage to sound root substance. In this paper, the force dynamics associated with manual scaling procedures of dental professionals are defined. These force dynamics account for the total work expended by hygienists and other professionals in the important task of calculus removal. Using this as a foundation, the design, use, calibration and clinical applications of these newly developed scaling-force measurement systems are described.

Algorithms↗

PubMed1996

Crest Tartar Control benefits assessed by Quanticalc: clinical method and three-month results.

In this paper, a method is described for applying the Quanticalc (QC) dental scaler to the clinical assessment of tartar control dentifrice effects on supragingival calculus formation and therapist efforts required in subsequent calculus debridement. In a 3-month, randomized cross-over study, subjects using Crest Tartar Control were observed to form 25% less calculus than they formed in a similar period using Crest Regular non-tartar control dentifrice as placebo. QC measurements likewise revealed 25% savings in the developed force used to scale the anterior lingual surfaces, coupled with a 27% reduction in the number of strokes required to clean these surfaces free of supragingival calculus in subjects using tartar control dentifrice. The quantitative savings in professional effort amounted to 3 kg (developed forces saved) per subject using tartar control dentifrice. White subjects using placebo dentifrice for 3 months developed less calculus than shown at baseline (29% less calculus), this was not complemented by decreases in total force and strokes used in cleaning. This supports the hypothesis that the surface area coverage of calculus (e.g., the planimetric "area" of supragingival calculus on the tooth) does not contribute alone to the amount of effort as forces and strokes required in subsequent debridement. These results demonstrate that: 1) the QC dental scaler can be effectively used in the clinical assessment of scaling forces/efforts associated with supragingival calculus debridement; and 2) a tartar control dentifrice containing soluble pyrophosphate is clinically effective in reducing both the surface coverage of calculus and the therapist effort required in subsequent calculus debridement.

Adult↗

PubMed1996

Effects of a scaling gel on forces developed in debridement of supragingival calculus determined by means of a transducer-modified dental scaler: the Quanticalc.

The efficacy of a calculus scaling gel, SofScale (Dentsply, York, PA), has been examined in two protocols by the measurement of scaling forces developed in supragingival calculus debridement from the anterior dentition using hand scaling with a transducer-modified dental scaler, the Quanticalc. In one protocol, the effects of the scaling gel were compared to a placebo gel composed of conventional toothpaste in a double-blind, split-mouth design. In another protocol, the effects of the scaling gel were determined in comparison to non-treated calculus. Results demonstrated that the scaling gel had no apparent effects on the physical forces (work) involved in calculus removal. These results suggest that the application of the scaling gel provides no quantitative benefits in facilitating calculus debridement during manual tooth scaling.

Analysis of Variance↗

PubMed1994

Effect of xylitol and sorbitol in chewing-gums on mutans streptococci, plaque pH and mineral loss of enamel.

Seventeen subjects with more than 3 x 10(5) mutans streptococci per millilitre of saliva completed this randomised, cross-over study. Four different chewing-gums, containing: (1) 70% xylitol, (2) 35% xylitol + 35% sorbitol, (3) 17.5% xylitol + 52.5% sorbitol, and (4) 70% sorbitol, were tested. The participants used 12 pieces of each gum per day for 25 days. During the four experimental periods, they wore a removable palatinal plate containing two demineralised enamel samples, and brushed their teeth with a non-fluoridated toothpaste. The results showed that an increased concentration of xylitol in the gum resulted in a lower number of mutans streptococci in both saliva and dental plaque, although the decreases were only significant in the saliva samples (p < 0.01). The pH drop in plaque, measured in vivo after a 1-min mouthrinse with a 10% sorbitol solution, was least pronounced after the 70% xylitol gum and most pronounced after the 70% sorbitol gum period (p < 0.01). No significant differences were found after a mouthrinse with a 10% sucrose solution. All demineralised enamel samples lost mineral during the experimental periods. However, the lesion depth as well as the mineral loss values, assessed microradiographically, did not differ significantly between the four chewing-gums.

Adult↗

PubMed1992

Rate and mechanism of enamel demineralization in situ.

In this paper, data are presented on the in situ demineralization of human enamel as a function of the demineralization period. To quantify the mineral loss parameters versus time, it is important to obtain information on the kinetics, and thus on the mechanism of dental caries. The results show that for in situ enamel demineralization, the lesion depth as well as the mineral loss parameter both vary linearly with the demineralization time. This is in contrast to in vitro lesion formation where the third power, or the square power of the lesion depth is linearly related to the demineralization time. In in situ demineralization, the rate-determining step of the demineralization process is the inhibitor-controlled dissolution process at the enamel crystallite surfaces, while the inhibitor content (F-, proteins etc.) in the lesion originating from the plaque, saliva and enamel is high. Furthermore, the study indicates that in in situ demineralization, interprismatic mineral loss is very important.

Dental Enamel↗

PubMed1990

Effect of fluoride release from a fluoride-containing composite resin on secondary caries: an in vitro study.

The effect of fluoride, released from a fluoride-containing composite resin, on secondary caries was investigated by quantitative microradiography. In all teeth investigated, less demineralization was found near the composite resin than was found at a distance of a few millimeters from the material after an acid attack. The presence of the fluoride-releasing composite resin reduced the lesion depth measured after an acid attack by about 35%. Therefore, in vivo, a reduction of recurrent caries may be expected around fluoride-containing composite resins.

Adult↗

PubMed1988