Biomedical subjects

N Claffey

Publications and source records attributed to N Claffey.

At least 37 records · Page 2Linked to original sources

PubMed1996

Patterns of attachment loss in advanced periodontitis patients monitored following initial periodontal treatment.

2 main concepts seem to exist for the progression of periodontitis: (1) a slow continuous process of attachment loss; (2) periodic bursts of activity followed by quiescence or remission. This study addresses this problem and presents data for 69 sites having experienced a net loss of probing attachment amounting to > or = 3.0 mm over 42 months. The sites originated from 16 adult patients monitored after nonsurgical treatment of advanced chronic periodontitis. Probing attachment level recordings were obtained every 3rd month. The sequential probing attachment level data for each site were smoothed using cubic splines. Subjective evaluation of the raw and the smoothed data from the study sites suggested that the majority of the sites seemed to lose probing attachment in a continuous fashion, and over periods of 12 months or more. The smoothed curves were subjected to principal components analysis, which allowed the 69 sites to be ordered according to curve similarity. Nonparametric runs test failed to show that the shape of the curves for the sites was significantly associated with any of the following characteristics: patient, tooth type, tooth surface, initial probing depth, bleeding frequency, occurrence of suppuration, or a combination of inflammatory characteristics of sites.

Adult↗

PubMed1995

Effects of groove placement on retention/resistance of maxillary anterior resin-bonded retainers.

Debonding of resin-bonded fixed partial dentures has been partly resolved with modification of tooth preparations. Tooth preparations for resin-bonded retainers were completed on a maxillary central incisor, a lateral incisor, and a canine. Fifteen metal replicas were constructed (five of each tooth morphotype). The three tooth morphotypes were then modified with proximal grooves prepared parallel to the long axes, and another 15 metal replicas were prepared. Cast metal retainers were constructed and cemented to the replicas with a resin cement. Tensile shearing dislodging loads were applied at 20 degrees to the long axes of the teeth with a testing machine. The addition of proximal grooves made statistically significant differences in resistance to debonding forces for all three tooth morphotypes (p < 0.01). An increase of 76.7% was seen in dislodging forces for lateral incisors with proximal grooves compared with incisors without grooves.

Cuspid↗

PubMed1995

Comparison of the dimensional accuracy of one- and two-step techniques with the use of putty/wash addition silicone impression materials.

This study compared the putty/wash one-step and two-step techniques for making addition silicone impressions. For each technique 15 impressions were made of a stainless steel base to which three tapered posts were attached. Stone models were made of all impressions. The results indicated that the interabutment distances increased slightly compared with the stainless steel model for both techniques, but the differences between techniques were not considered to be clinically important. The intraabutment measurements for the abutment without undercut increased, whereas abutments with undercuts decreased. These variations from the stainless steel model were also clinically insignificant.

Calcium Sulfate↗

PubMed1995

Clinical indicators of probing attachment loss following initial periodontal treatment in advanced periodontitis patients.

16 advanced periodontitis patients were subjected to initial periodontal treatment and monitored every 3rd month during 42 months. Clinical characteristics at baseline and during the 42-month maintenance period were investigated for their association with probing attachment loss over the 42-month period, both on a patient level and on a site level. On a patient level, averaged full-mouth plaque and bleeding on probing scores over the maintenance interval showed little association with probing attachment loss. Little association was also observed for % sites with depth > or = 6 mm at baseline. However, a notable relationship was seen for % sites > or = 6 mm at 3 months. This finding initiated a separation of the 16 subjects into 2 groups based upon % sites > or = 6 mm at 3 months (groups 'high' and 'low'). Site level analyses for these groups showed little association between frequent presence of plaque at the sites over the maintenance interval and probing attachment loss. Frequent bleeding on probing showed limited relationship with attachment loss for group 'low', but an appreciable association for group 'high'. The findings suggest that advanced periodontitis patients with multiple residual probing depths > or = 6 mm at re-evaluation run a greater risk of developing sites with additional attachment loss than patients with few such residual depths. For such higher risk patients, bleeding on probing at maintenance examinations may be a useful indicator of subsequent deterioration at a site level.

Adult↗

PubMed1994

Clinical characteristics of periodontal sites with probing attachment loss following initial periodontal treatment.

Periodontal sites which had undergone probing attachment loss were identified in 16 advanced periodontitis patients subjected to initial periodontal treatment and monitored every 3rd month for 42 months. Many sites with probing attachment loss showed no increase in probing depth and bled on probing at a few of the examinations during maintenance. Others showed increase in depth, frequent bleeding and suppuration. An arbitrary classification of 'questionable periodontitis' sites was used and included sites with the following characteristics: probing depth at 42 months < or = 3.5 mm + bleeding on probing at no more than 5 of the 14 examinations 3-42 months + no suppuration on probing 3-42 months. The % sites in this category ranged from 21-35%, depending upon method used to determine probing attachment loss. Widely varying characteristics of sites identified with probing attachment loss were evident for all surface locations and all subgroups of initial probing depth. From a traditional viewpoint, a significant proportion of the losing sites might not have been afflicted with periodonitis. On the other hand, deterioration does not necessarily have to be coupled with obvious inflammation, particularly following therapy.

Adult↗

PubMed1992

Comparative study of subgingival microbiological sampling techniques.

The presence of specific bacteria in subgingival plaque has been used as an indicator of active periodontal disease. The technique of subgingival sampling may conjecturally influence the identification and enumeration of microorganisms reported. In this study, paper point sampling and scaler sampling are compared. Subgingival samples using both methods were taken from three surfaces in each of 12 patients at the following time points: at each of two appointments one week apart before treatment and at each of two appointments 12 and 13 weeks following treatment. Microbiological analyses were undertaken to determine the total number of colony forming units, the proportions of suspected periodontal pathogens, and the number of spirochetes using phase contrast microscopy. Significantly higher numbers of colony forming units and spirochetes were found for paper point sampling both before and after treatment.

Adult↗

PubMed1992

New attachment and tissue regeneration.

In periodontology, the possibility of stimulating new connective tissue attachment to previously diseased root surfaces, and the regeneration of the supporting periodontal tissues destroyed by periodontitis have been under study for some years. This paper reviews the different experimental methods used to prepare root surfaces for optimal regeneration and attachment of periodontal tissues. The mechanisms of blood clot formation, adhesion to the root surface and wound maturation are considered, as are the future needs for research in this subject.

Epithelial Attachment↗

PubMed1991

Acute necrotizing ulcerative gingivitis is associated with attachment loss.

Acute necrotizing ulcerative gingivitis (ANUG) has been generally considered as a gingivitis. However, clinical impressions suggest that periodontal attachment loss is one of the sequelae of the disease. This study was designed to investigate the extent of probing attachment loss detectable following resolution of the acute phase of the disease. 13 patients (3 male, 10 female) aged on average 22.7 years were studied. The presence of interdental soft tissue cratering was used to determine whether a site was previously affected by ANUG. ANUG sites were compared with other sites using a paired Student t-test (N = 13). Patient mean probing attachment level was greater for ANUG sites (2.2 +/- 0.9) than for the mean of all other sites (0.8 +/- 0.7). It is concluded that greater loss of probing attachment is associated with sites affected by ANUG than with other sites studied.

Acute Disease↗

PubMed1991

Periodontal repair in dogs. Effect of heparin treatment of the root surface.

Studies on periodontal repair to denuded root surfaces have suggested that initial clot adhesion to the root surface may be important for the nature of subsequent healing. To study this hypothesis, circumferential periodontal defects, approximately 5 mm in vertical dimensions, were surgically created and immediately treated around the mandibular premolars in 4 beagle dogs. Prior to wound closure, the root surfaces were treated with either the anticoagulant heparin or with saline. Tissue blocks were obtained at sacrifice 4 weeks after surgery. Histometric analysis showed that connective tissue repair to the root surface averaged 50% of the defect height for heparin-treated teeth as compared to 95% for saline-treated teeth. Junctional epithelium amounted to an average of 33% of the defect height in heparin-treated teeth in contrast to 5% following saline treatment. It can be concluded that heparin treatment of the root surface compromises connective tissue repair, confirming clot adhesion as one prerequisite for connective tissue repair of periodontal defects.

Alveolar Bone Loss↗

PubMed1991

Decision making in periodontal therapy. The re-evaluation.

7 patients completed 2 years of observation following initial therapy. Triplicate probing measurements were used to identify sites with greater than or equal to 1 mm of probing attachment change between any 2 of the following time points; immediately pre-instrumentation; immediately post-instrumentation; 3 months; 12 months and 24 months. 24% of sites lost probing attachment directly due to instrumentation. 12% of sites lost probing attachment at 24 months compared to pre-instrumentation, but over 1/3 of these lost attachment at the time of instrumentation. 47 sites lost probing attachment from post-instrumentation to 24 months. 22 of these sites were shallow buccal or lingual sites and their attachment apparatus may have remodelled. The initially deeper of these sites displayed other clinical features more consistent with inflammatory periodontitis. Sites that initially gained probing attachment due to treatment but which later lost were identified. These sites may have had a reversal of the enhanced epithelial adaption. 17 other patients were monitored over a period of 3 1/2 years and sites losing probing attachment were identified using linear analysis of regression. The diagnostic predictability of clinical signs to reveal probing attachment loss at 3 1/2 years was calculated. In general, predictability values improved with increasing time interval. Increase in probing depth, particularly if combined with a high frequency of bleeding, showed the highest predictability. The effect of therapy on probing attachment levels should be considered in the identification of sites with probing attachment loss. Persistent bleeding, combined with high residual probing depths or increase in probing depth, may be a useful adjunct to probing attachment loss in identifying diseased sites.

Adult↗

PubMed1991

Periodontal repair in dogs: effect of root surface treatment with stannous fluoride or citric acid on root resorption.

This study evaluated healing, with emphasis on root resorption, following root surface treatment with 1% aqueous stannous fluoride (SnF2), saturated citric acid (CA), or saline control (C) in conjunction with periodontal flap surgery. Supraalveolar periodontal defects were surgically created and immediately treated in the mandibular premolars in 6 beagle dogs. The defect height approximated 5 to 6 mm from the reduced alveolar bone to the cemento-enamel junction. Root treatments were rotated between experimental teeth within jaw quadrants and duplicated in left and right quadrants in the dogs. Flaps were raised to cover most of the crowns of the teeth and sutured. The dogs were sacrificed 12 weeks after surgery and tissue blocks with teeth and adjacent structures were processed for histometric analysis. SnF2-treated teeth healed with significantly longer junctional epithelium, less connective tissue repair to the root surface, and less bone regeneration than CA and C-treated teeth. New cementum formation was limited in all treatment groups. Root resorption was observed in almost all teeth exhibiting connective tissue repair, however to a lesser amount and not as frequent in SnF2 treated teeth due to limited connective tissue repair. No differences were found in amount and frequency of root resorption in CA and C-treated teeth. An inhibitory effect on root resorption of SnF2 could not be disclosed in this experiment, however, it may be concluded that CA treatment of the root surface in conjunction with reconstructive periodontal flap surgery does not seem to enhance root resorption.

Alveolar Process↗

PubMed1991

Fibrous hyperplasia of the gingiva in organ transplant patients.

Recent improvements in immunosuppressive therapy have improved the survival rate of post organ transplant patients. These developments have introduced a new group of medically compromised patients to the general dental practitioner. This paper reviews the medical and dental complications of organ transplant patients with special reference to heart transplant patients. A case report of the management of Cyclosporin A induced gingival hyperplasia in a post heart transplant patient is presented. Guidelines for dental management of heart transplant patients are suggested.

Adult↗

PubMed1990

Diagnostic predictability of scores of plaque, bleeding, suppuration and probing depth for probing attachment loss. 3 1/2 years of observation following initial periodontal therapy.

Recordings of supragingival plaque, bleeding, suppuration and probing depth were obtained for 42 months following initial periodontal therapy. Scores accumulated after various time intervals during monitoring were studied for their predictive value in revealing probing attachment loss as determined by regression analysis during the 0-42 month period. Accumulated plaque scores demonstrated low predictability. Accumulated bleeding scores showed modest predictive values. Suppuration on probing was not a frequent finding during the observation interval and also had modest predictive power. Increase in probing depth compared to baseline and deep residual probing depth had modest predictability after 3 and 12 months, but showed increasing accuracy in revealing probing attachment loss over later time intervals. After a few years of maintenance, increase in probing depth, particularly if combined with high frequency of bleeding on probing, showed the highest predictive value for probing attachment loss of the scores examined.

Adult↗

PubMed1990

Effect of stannous fluoride and tetracycline on repair after delayed replantation of root-planed teeth in dogs.

Mandibular incisors were extracted and allowed to dry in air for 45 min. They were then root-planed extensively, leaving a cervical collar and the apical region uninstrumented, to prevent direct contact between root surface and alveolar bone after replantation while, at the same time, enabling precise and stable reseating of the tooth. Control teeth were replanted either without further treatment or after treatment with citric acid for 3 min. Experimental teeth were treated before replantation with 1% SnF2 for 5 min, 1% tetracycline HCl for 5 min, or 1% SnF2 followed by 1% tetracycline. Histometric analysis of healing in the root-planed areas showed minimal amounts of inflammatory resorption and ankylosis after 21 days in experimental teeth as compared with the control teeth. A persisting inflammatory reaction in the periodontal ligament without root resorption was, however, frequently seen. The observations confirm that the frequency of adverse healing reactions after delayed replantation of teeth from which nonvital soft tissue remnants have been removed can be reduced by demineralizing the root surface and preventing mechanical trauma to the root surface in the postoperative period. Root surface treatment with SnF2 followed by tetracycline resulted in complete absence of inflammatory resorption and ankylosis in this short-term experiment.

Animals↗

PubMed1989

Effect of placement of occlusive membranes on root resorption and bone regeneration during healing of circumferential periodontal defects in dogs.

Previous studies indicate that root resorption is a frequent sequela to significant amounts of periodontal repair in animal models. A model was developed in labrador dogs to study periodontal wound healing in large circumferential defects in the absence of influence from the oral environment. A polytetrafluorethylene membrane of 1 micron pore size (GORE-TEX) was used to occlude cells from specific tissues from populating the healing dentin-connective tissue wound. 3 modalities were studied: (1) control, in which no membrane and therefore no cell occlusion was used, (2) flap occlusion, in which the internal surface of the flap was lined with the membrane preventing contribution of cells from the flap, (3) bone occlusion, in which the reduced alveolar bone was lined with the membrane preventing contribution from bone cells. Wound closure included total submergence of teeth and membranes. The membranes remained incorporated and no exposure of membranes or teeth occurred during the 3 months healing period. Histology revealed bone regrowth in all 3 treatment modalities. It is suggested that inductive elements in the connective tissue or dentin, or bone cells from periosteum were responsible for bone regrowth in the bone membrane treatment modality. No significant difference was seen for root resorption between the 3 treatment modalities. This study found that physical occlusion of cells from the inside of the surgical flap, or from the pre-existing bone, is not sufficient to prevent root resorption in periodontal wound healing.

Alveolar Process↗

PubMed1989

Placement of a porous membrane underneath the mucoperiosteal flap and its effect on periodontal wound healing in dogs.

This study was designed to investigate the healing of surgically induced, horizontal periodontal defects in dogs following placement of a biocompatible, porous polytetrafluorethylene membrane around the roots of the treated teeth and to compare the healing to that of control teeth without membrane. Mandibular premolar teeth of 5 beagle dogs were used for experimentation. Specimen blocks were removed 3 months postoperatively for histological evaluation of contralateral experimental and control teeth. Mean apical migration of junctional epithelium among the experimental surfaces amounted to 0.1 mm as compared to 1.3 mm for the control surfaces. Accordingly, the amount of connective tissue attachment, defined by the distance from the base of the junctional epithelium to the apical termination of root planing, was greater for experimental than for control surfaces. As this increased amount of connective tissue attachment was associated with more coronal bone apposition, a periodontal ligament space was more prevalent in experimental than in control surfaces. A limited amount of ankylosis was observed for both experimental and control surfaces. Root resorption was more prevalent in control than in experimental surfaces. Conceivable reasons for the differences in healing between experimental and control teeth are discussed.

Alveolar Process↗

PubMed1989

Probing depth at re-evaluation following initial periodontal therapy to indicate the initial response to treatment.

9 adult subjects with severe periodontitis were monitored following oral hygiene instruction and a single episode of crown and root debridement. Baseline recordings for probing attachment level were obtained both immediately pre-instrumentation and immediately post-instrumentation. Sites with gain, no change or loss of probing attachment level at 3 and 12 months compared to both pre- and post-instrumentation were identified. The classification was based upon the use of triplicate recordings at each time point, a site-specific standard deviation for measurement variability, and the requirement of a minimum of 1.0 mm change. The relative frequencies of gain, no change, and loss of probing attachment were then calculated for sites of various residual probing depths at 3 and 12 months. This was performed to evaluate if a given probing depth at re-evaluation, e.g., 7.0-7.5 mm, could be used as an indicator of the need for supplementary treatment following the initial therapy, based upon the observed probing attachment changes compared to baseline. As an example of the results of the present study, 60% of sites with residual probing depths of 7.0-7.5 mm showed probing attachment gain greater than or equal to 1.0 mm compared to the post-instrumentation baseline, and only 2% had undergone probing attachment loss greater than or equal to 1.0 mm. The overall results suggest that a relatively deep residual probing depth at re-evaluation following initial therapy, by itself, provides little evidence of lack of improvement compared to baseline. On this basis, the use of a specific probing depth at 3 or 12 months following treatment as a yardstick for the provision of supplementary treatment may not be justified.

Adult↗

PubMed1989

Clinical effects of root debridement in molar and non-molar teeth. A 2-year follow-up.

12 patients were studied longitudinally to monitor the effects of basic periodontal therapy in molar and non-molar teeth. Periodontal sites were grouped into molar furcation sites, molar flat-surface sites and non-molar sites. Clinical measurements were taken at baseline and directly followed by full mouth root debridement. Subsequently, measurements were taken every 3rd month until 24 months. At each of these appointments, the patients were monitored for their oral hygiene performance and given supragingival prophylaxis. The mean results indicated that initially moderately deep and deep molar furcation sites responded less favorably to therapy compared to non-molar sites and molar flat-surface sites of similar probing depth. Initial improvements in probing measurements for moderately deep and deep molar furcation sites were limited and also tended to revert during the observation interval. Identification of individual sites with probing attachment loss disclosed that 25% of molar furcation sites lost probing attachment as compared to 7% for non-molar sites and 10% for molar flat-surface sites. These results corroborate previous findings and call for additional or alternative treatment regimens for periodontal furcation pockets.

Adult↗