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Biomedical subjects

I M Waite

Publications and source records attributed to I M Waite.

16 recordsLinked to original sources

A 4-year controlled clinical study into the use of a ceramic hydroxylapatite implant material for the treatment of periodontal bone defects.

10 patients with chronic adult periodontitis who had greater than 1 tooth with infra-bony pockets were treated at the test defects by periodontal flap procedures with implantation of hydroxylapatite particles; the control defects were treated by the same surgical procedures but without the implant. A total of 58 test defects and 59 control defects were treated. Each defect had measurements carried out at given sites on the involved tooth surfaces, the sites being considered for subsequent tabulation purposes under the category of shallow (less than 3 mm) moderate (3-6 mm) and deep (greater than 6 mm) initial pocket depths. There were 146 and 152 shallow sites, 216 and 241 moderate sites and 140 and 133 deep sites, at test and control sites, respectively. Measurements of recession, probing pocket depths and probing attachment levels were made at 6 months and 1, 2, 3 and 4 years. At all sites over the period of the study, for the moderate and deep initial pockets there was a significant reduction in probing depths and an increase in the probing attachment levels. At the 4th year of assessment for the initially deep pockets, the reduction in probing depths was significantly greater for the sites treated with the implant material. In view of the difficult clinical problem posed by the treatment of teeth with deeper periodontal bone defects, further research using either this type of implant material or similar material should be considered.

Adult

Computerized densitometric analysis of interproximal bone levels in a controlled clinical study into the treatment of periodontal bone defects with ceramic hydroxyapatite implant material.

The aim of this controlled clinical study was to utilize computer-assisted densitometric analysis of radiographs to assess the effectiveness of treating periodontal osseous defects with a sintered hydroxyapatite implant material. It was found that over the 2-year period of the study for the osseous defects treated by the implant material, there was a gain in the height of the hard tissue relative to the cemento-enamel junction; this gain was statistically significant compared with the results for the control sites.

Absorptiometry, Photon

A comparison between measurements made with a conventional periodontal pocket probe, an electronic pressure probe and measurements made at surgery.

This study compared clinical measurements using a manual periodontal probe and an electronic pressure probe using a 0.25 N force, and related them to measurement of the bone levels at the time of surgery. All measurements were taken from the cemento-enamel junction at specified sites. It was found that neither probing technique provided a means for accurately measuring bone level. In the presence of healed tissue, little difference was found between the two instruments; whereas the manual probe more closely approximated the actual level of bone in the presence of inflammation. It was therefore concluded that under the conditions of present study the manual probe depth measurements were the more applicable for routine clinical use.

Alveolar Process

The relationship between the multidimensional health locus of control and the performance of subjects on a preventive periodontal programme.

Criteria have been defined to quantify a personality characteristic-termed locus of control. The criterion at one extreme of this range was referred to as external, indicating a belief that health was determined by a variety of other factors such as powerful other individuals or by chance. The criterion at the other extreme was termed internal, indicating a belief that health might be modified by the behaviour pattern of the individual. Locus of control scales have been used to relate psychological factors to physical disease, and the response of patients to disease. The aim of the present study was to investigate whether locus of control could be used to anticipate the response of subjects to a plaque control programme. A study was carried out on 14 males and 46 females to investigate the relationship between the multidimensional health locus of control (MHLC) and the response of a group of office workers to a plaque control programme. It was found that there was significant correlation between the external MHLC dimension of powerful others and improvement in some of the clinical criteria; a similar result was found for the internal dimension of the MHLC. In contrast, there was minimal correlation between the external dimension of the MHLC termed chance and the clinical results. It was concluded that subjects who perceive their susceptibility to disease being influenced by powerful external factors or who believe that susceptibility can be controlled by their own actions, respond more positively to a plaque control regime than those subjects who consider that susceptibility to disease is an event of chance.

Adult

A comparison of 4 techniques for clinical detection of early plaque formed during different dietary regimes.

The purpose of this study was to evaluate the sensitivity of 4 clinical techniques used in detecting early plaque during a period of dietary sucrose restriction and during a period of sucrose supplementation. The accumulation of plaque during experimental periods of 3 h, 6 h and 18 h was recorded in a group of 38 dental personnel for the 1st part of the study, and in a group of 32 for the 2nd part. Plaque levels were assessed using a caries probe, a plaque detection probe, erythrosin and a 2-tone disclosing agent. There was a progressive increase in plaque over the period of the study, with significant variation between the detection methods used and the sites being assessed. Plaque formed more rapidly interdentially and on the posterior teeth. 3 h after the teeth had been thoroughly cleaned, plaque was detectable on over 12% of sites for the sucrose-restricted diet and on up to 23% of sites for the sucrose-supplemented diet. After 18 h of plaque formation, the proportion of plaque-covered surfaces had increased to between 52% and 73%. For minimal amounts of plaque, the disclosing solutions were found to be the most sensitive assessment techniques. However, for moderate and abundant plaque deposits, the techniques using the probes resulted in a greater degree of differentiation in the proportional measurements of plaque. Overall, the plaque probe was found to be as sensitive or better than the other techniques under most conditions and was favoured on clinical grounds, as it aided access to the interdental areas and provided a contrasting colour at the tip to enable plaque to be detected with greater ease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

A comparison of postsurgical healing following debridement by ultrasonic or hand instruments.

Subjects for the study were 15 patients requiring periodontal surgery in the maxillary posterior quadrants. A split mouth technique with assignment of quadrants by random alternation was used. Assessments were carried out at given time intervals using the Gingival Index, crevicular fluid measurement, Plaque Index and Retention Index. Pain experience following surgery was also noted. Approximately 8 weeks after the initial assessment, periodontal flap surgery was carried out. On the one side debridement was carried out using an ultrasonic scaler, on the other side, hand instrumentation only was used. On the side receiving ultrasonic debridement during surgery, there was an increased rate of healing as measured by the Gingival Index and crevicular fluid. There was no difference in postoperative pain experience, Plaque Index or Retention Index.

Adult

Effects of tobacco smoking on plaque development and gingivitis.

A study was undertaken to test the hypothesis that patients who smoke tobacco have a more rapid rate of plaque deposition and development of gingivitis than those patients who do not smoke tobacco. Twenty subjects participated in this study, their age range was 17 to 30 years. Ten were smokers and 10 were nonsmokers. After an initial thorough removal of all deposits, oral hygiene measures were stopped for 10 days. On days 3, 7 and 10, plaque levels were evaluated using the Plaque Index and the gingival status was evaluated using the Gingival Index. Samples of plaque were stained by the Gram technique and examined microscopically. Plaque levels appeared to be higher in smokers than nonsmokers but the differences were not statistically significant. No consistent differences were evident in the gingival status of the two groups. Microbiological analysis showed a statistically significant increase in the percentage of Gram-positive bacteria to Gram-negative bacteria in the smokers as compared to the nonsmokers on day 3, however these differences were not maintained in the plaque samples taken after the 3rd day.

Adolescent

A comparison between conventional gingivectomy and a non-surgical regime in the treatment of periodontitis.

The treatment of periodontitis by scaling and oral hygiene instruction was compared with the same regime augmented by conventional gingivectomy. The procedures were allocated randomly to contralateral sides of the maxillary arches of 28 patients. Following both regimes there was significant reduction in Plaque Index, Gingival Index, crevicular fluid and depths of pockets. There was slight gain in attachment on the non-surgical sides, and a minor loss of attachment on the surgical sides. Comparing the two regimes, over the second half of the study there was no significant difference in Plaque Index or crevicular fluid; however, on the surgical sides there was significantly greater reduction in Gingival Index and depths of pockets. Residual pockets after either technique were associated with more inflammation than where sulcus depths were less than 2 mm. Retrospective comparisons of the initial depths of pockets with the final gingival status indicated that, when initial depths of pockets had been 3 mm or over, surgical treatment was more effective than non-surgical in reducing the final values of both depths of pockets and inflammation; this finding was statistically significant for some, but not all of the parameters. Treatment of shallow pockets by either technique was more effective than the treatment of deep pockets. Final Plaque Index values of zero were associated with significantly less inflammation and pocketing than where plaque deposits could be detected.

Adult

The present status of the gingivectomy procedure.

The use of the conventional gingivectomy procedure is indicated to achieve optimum gingival contour and to eliminate supra-alveolar pockets where these do not extend beyond the muco-gingival junction. The instrument of choice for the procedure is a gingivectomy knife. Where a blood-free field is required, electrosurgery may be used provided the instrument is not brought into contact with bone. The maintenance of good oral hygiene is essential.

Animals