Clinical evaluation and comparison of 2 topical anesthetics for pain caused by needle sticks and scaling and root planing.

BACKGROUND: Pain generated by needle sticks (Ns) for the delivery of local anesthetic and/or scaling and root planing (SRP) instrumentation is commonly addressed by the use of topical anesthetics, such as a benzocaine-gel preparation (BGP). Pain suppression following such use has been highly variable. Development of medicine-containing patches and adhesives for intraoral use have led to a new approach for topical anesthesia in the form of a transoral lidocaine delivery system (LDS). The purpose of this double-blind study was to evaluate the efficacy of the LDS and also to compare LDS with BGP for pain suppression to Ns and SRP. METHODS: One group of 20 subjects randomly received in both maxillary and mandibular molar-bicuspid areas LDS or BGP on one side and non-anesthetic control on the other side. A second group of 20 subjects compared the effectiveness of LDS directly with BGP in molar-bicuspid areas of both arches. Random order determined the selection for each anesthetic tested between the arches and bilateral. Pain perception was separately scored to a pain-inducing Ns simulation without anesthetic injection at each area and subsequently also to SRP using both a verbal pain scale (VPS) and a visual analog scale (VAS). RESULTS: VPS and VAS results analyzed by Bonferroni-adjusted Wilcoxon matched-pairs signed-rank tests found pain suppression scores significantly (P < 0.005) reduced for Ns by LDS to controls and to BGP. Comparing LDS directly with BGP, LDS was significantly (P < 0.05) more effective in reducing pain to Ns in both arches, to SRP in the maxillary arch, and equally effective as BGP in the mandibular arch. CONCLUSIONS: LDS is more effective than BGP for topical pain suppression to Ns and SRP in both arches.

Evaluation of a transoral delivery system for topical anesthesia.

BACKGROUND: The development of bioadhesives has allowed for the creation of a novel transoral topical anesthesia delivery system used to alleviate pain by needlestick injections and select dental procedures. METHODS: Sixty subjects evaluated the effectiveness of a lidocaine-containing bioadhesive patch, or L-BP, to alleviate pain caused by needlesticks, or Ns, with or without injection, and with scaling and root planing, or Sc/RP, instrumentation. The authors topically administered a commonly used benzocaine-containing gel, or B-G, preparation to analogous sites for direct comparison. Subjects rated their degree of pain/discomfort using verbal pain score, or VPS, measurements. RESULTS: Paired t tests and signed ranked tests revealed that the subjects' perception of pain was significantly reduced after the application of L-BP with placebo (P < .01) for both Ns and Sc/RP but was not significantly reduced by B-G with placebo. L-BP also significantly reduced the subjects' perception of pain caused by Ns and Sc/RP when compared directly with B-G (P < .01). The resultant tissue anesthesia by L-BP significantly reduced pain to Ns with or without anesthetic injection using 25- and 27-gauge needles. However, Ns in conjunction with anesthetic injections generated significantly greater pain than that caused by Ns alone (P < .01). VPS score differences between 25- and 27-gauge needles were not found. CONCLUSIONS: This study found that a lidocaine-containing bioadhesive system delivering topical anesthesia was highly effective in alleviating pain/discomfort arising from Ns, with and without concomitant injection, and select Sc/RP procedures. CLINICAL IMPLICATIONS: A new topical delivery system that effectively anesthetizes oral tissues may prove highly useful in allaying patient anxieties about and fear of select dental procedures.

Evaluation of floss types for interproximal plaque removal.

PURPOSE: To evaluate the efficacy of four different floss types for interproximal plaque removal on the normal dentition. MATERIALS AND METHODS: 24 dental hygiene students tested each of four different floss types: waxed, unwaxed, woven and shred-resistant. At baseline, all subjects received a prophylaxis to become plaque-free and identical flossing instructions were given. Subjects were then instructed not to brush, floss, or rinse for 3 days to allow for plaque development. On the fourth day, each subject's teeth were disclosed and scored using O'Leary's Plaque Index. Subjects were then randomly assigned one of the four floss types to use throughout the dentition, following which a second plaque record was assessed. Subjects were timed while flossing, and then completed a 10 cm Visual Analogue Scale (VAS) scoring their degree of discomfort/comfort and ease of use for each specific type of floss. This protocol was followed until all four floss types were tested by each subject. Results analyzed reductions in total interproximal plaque score (TIPS), anterior (teeth) interproximal plaque score (AIPS), and posterior (teeth) interproximal plaque score (PIPS). RESULTS: The greatest reduction in TIPS and PIPS was with waxed floss (68.87%, 66.54% respectively) and in AIPS with woven floss (75.15%). Post-hoc testing using Tukey's method revealed no significant differences among the four floss types. VAS scores revealed shred-resistant most comfortable (6.99) while unwaxed was least (4.29). These results indicated minimal differences in the efficacy of different types of floss, their degree of comfort and ease of use.

Progesterone facilitates the acquisition of avoidance learning and protects against subcortical neuronal death following prefrontal cortex ablation in the rat.

Following a cortical injury, neurons in areas near and connected to the site of injury begin to degenerate. The observed neuronal death may contribute to the severity of the observed behavioral impairments. The purpose of the present study was to examine if progesterone, a hormone known for its effectiveness at reducing cerebral edema, could protect against secondary neuronal death and facilitate the acquisition of an avoidance learning task in an ablation model of cortical injury. Rats served as sham controls or received bilateral ablation of the medial prefrontal cortex followed by a 10-day regimen of progesterone (4 mg/kg) or oil vehicle (1 ml/kg) beginning 1 h after cortical lesions. Progesterone-treated lesion rats showed a significant facilitation of avoidance learning compared to oil-treated lesion controls. In addition, progesterone-treated lesion animals did not differ from either progesterone- or oil-treated sham controls in avoidance learning. Anatomical analysis revealed that progesterone treatment decreased the amount of neuronal death seen in the striatum and the mediodorsal nucleus of the thalamus. The findings are consistent with the notion that progesterone is an effective neuroprotective agent and suggest that the hormone can reduce the behavioral impairments associated with frontal cortical ablation injury.

Medial prefrontal lesion deficits involving or sparing the prelimbic area in the rat.

The rat medial prefrontal cortex (PFC) is believed to play a central role in working memory and selective attention processes. More recently, it has been shown that the effects of large PFC lesions on working memory may be due to the prelimbic area of the PFC. The aim of the present study was to compare the effects of lesions of the prelimbic area with PFC lesions that involved or spared the prelimbic area on shuttlebox avoidance and radial maze learning in rats. The findings indicate that rats with PFC lesions that spared the prelimbic area were impaired at avoidance but not radial arm maze learning, whereas rats with prelimbic lesions or PFC lesions that included this area were impaired on the radial arm maze but not the avoidance learning task. Results support the notion that the medial frontal cortex of the rat is a functionally dissociable region and suggest that the prelimbic area appears to be critical for working memory, but less so for attention processes.

Lack of furcal bone loss following the tunneling procedure.

Treatment of molar teeth with severe furcation involvement allows for differing therapies of which the tunneling procedure has been least studied. While subsequent root caries in furcal exposed teeth was believed a major shortcoming, successful periodontal therapy is primarily dependent upon the stability of the attachment and intrafurcal and interproximal bone. We evaluated in each of 18 subjects (10 female, 8 male) a molar tooth with deep grade II/III furcation involvement at time of presentation (T-0), to 1st post-surgical recall following a tunneling procedure (T-1), to most immediate last recall (T-2; mean time T-0 to T-2, 5.80 +/- 0.83 years). Assessments included O'Leary's plaque index (P1-I), attachment levels (AL), root caries and radiographic bone loss. The mean P1-I from T-0 to T-2 decreased 56.8% with some plaque at T-2 detected in furcations of 7/18 teeth. AL across all time periods were not significantly difference except for palatal/lingual AL which from T-0 to T-2 were significantly different. Root caries was found in only 3 teeth at T-2. Adequate radiographs were available for 8 surgically tunneled mandibular molars for analysis of 5 measurements of osseous levels i.e., the mesial and distal levels of the intrafurcal and the interproximal osseous crests, and the distal interproximal osseous crest of a mesial adjacent single-rooted reference tooth which received osseous surgery at the same time. Mean time change values (T-1 to last radiograph taken, T-2a; mean time 3.0 +/- 0.7 years) showed no significant difference among the 5 points measured.(ABSTRACT TRUNCATED AT 250 WORDS)

The effectiveness of a disposable tooth cleansing device on plaque.

A disposable polyester foam sponge on a stick, impregnated with a non-foaming dentifrice, has been widely dispensed to hospitalized and nursing home patients for intraoral cleansing and refreshing. Since no information was found relative to tooth cleansing capabilities, we have evaluated its effectiveness in the removal of accumulated plaque and also in prevention of plaque accumulation. Removal of 72 hours of accumulated plaque was assessed in a cross-over design study comparing the device with a commercially-available toothbrush by two different groups of 13 and 29 adult, healthy subjects who used each instrument for 1 and 3 minutes respectively. No significant differences were found between mean scores assessed by Turesky's modification of the Quigley-Hein plaque index by either group using either instrument at either time period (P > 0.05). Prevention of plaque accumulation was assessed in a third group of 25 subjects who used each instrument an average of 3 times a day for 1 week in a cross-over study. While the toothbrush was found significantly more effective in retarding the accumulation of plaque from a plaque-free baseline on both facial and lingual surfaces (P < 0.02), the tooth cleansing device still retained plaque-preventive capabilities by maintaining plaque formation below 2 mm at the cervical margin of the tooth. Results of this study indicate the tooth cleansing device may be a viable alternative to conventional toothbrushes.

Effects of hormones and cytokines on stimulation of adenylate cyclase and intracellular calcium concentration in human and canine periodontal-ligament fibroblasts.

Adenylate cyclase was stimulated by prostaglandin E2 (PGE2) and parathyroid hormone-related protein (PTHrP) in both these types of fibroblast and by calcitonin gene-related protein (CGRP) in the human fibroblasts in vitro. PGE2 (1 microM), CGRP (1 microM), and PTHrP (1 microM) stimulated adenylate cyclase up to 50-fold, 10-fold and 9-fold, respectively. Calcitonin (CT), substance P (SP), interleukin-1 beta (IL-1 beta), and transforming growth factor-beta 1 (TGF beta 1) had no effect on adenylate cyclase in either fibroblast. Intracellular Ca2+ (iCa2+) was measured in individual fibroblasts from the periodontal ligament using Indo-1 and an adherent cell analysis and sorting interactive laser cytometer. Ionomycin (3 microM) caused a transient rise of iCa2+ in all human and canine fibroblasts tested. The mean percentage increase in iCa2+ in response to ionomycin was 820 and 840% for human and canine fibroblasts, respectively. The human fibroblasts responded to PGE2 (1 microM) by an increased iCa2+ concentration; the mean percentage increase in iCa2+ was 187%. SP caused a less pronounced increase in iCa2+ in the human fibroblasts (56%). CGRP and SP caused a similar response in the canine fibroblasts. The mean percentage increase in iCa2+ in response to SP and CGRP was 95 and 78%, respectively. PTH, PTHrP, platelet-activating factor, CT, and IL-1 beta had no effect on iCa2+ in either type of fibroblast. The data indicate that cAMP and calcium have roles as intracellular secondary messengers in the action of PGE2, SP, CGRP, and PTHrP in fibroblasts of human and canine periodontal ligament.

Parathyroid hormone-related protein production by normal human keratinocytes in vitro.

The role of parathyroid hormone-related protein (PTHrP) and its regulation in normal epidermal physiology is not currently known. Recent evidence suggests that PTHrP production may be related to the degree of differentiation of keratinocytes in vitro. This investigation characterized the production of PTHrP by normal human foreskin keratinocytes (NHFK) during both spontaneously occurring and induced differentiation in vitro. PTHrP production in keratinocyte serum-free conditioned medium was determined using an N-terminal radioimmunoassay for human PTHrP (1-36). Agents known to stimulate (calcium, 1,25-dihydroxyvitamin D3) or inhibit (transforming growth factor-beta) keratinocyte differentiation were examined for their ability to alter production of PTHrP. Measurements of cell number and involucrin content of the cultures were made to confirm the effects of these agents on keratinocyte growth and differentiation. The production of PTHrP in control cultures (under low calcium conditions, 0.08 mM) was decreased and involucrin content increased (P < 0.01) after the cells became confluent. The addition of 1 mM calcium to keratinocyte medium increased cell number and involucrin content of the cultures (P < 0.05) but inhibited production of PTHrP (P < 0.01). The 1,25-dihydroxyvitamin D3 (10 nM) had no significant effect on cell number or PTHrP production, but increased involucrin content (P < 0.05). Transforming growth factor-beta (5 ng/ml) decreased both cell number (P < 0.05) and involucrin content (P < 0.01), but significantly stimulated PTHrP production (P < 0.01). These data indicate that the production of PTHrP by NHFK is inhibited with the onset of both spontaneously occurring and calcium-induced differentiation in vitro, while transforming growth factor-beta inhibited differentiation and upregulated PTHrP production in normal human keratinocytes.

Microsomal cytochrome P450 1A1 dependent monooxygenase activity in guinea pig heart: induction, inhibition, and increased activity by addition of exogenous NADPH-cytochrome P450 reductase.

Characterization of cytochrome P450 1A1 dependent monooxygenases in guinea pig heart revealed low rates of 7-ethoxyresorufin O-deethylation, which are markedly increased (20-fold) by treatment with beta-naphthoflavone, a polycyclic aromatic hydrocarbon. Both 7-ethoxyresorufin O-deethylation and 7-methoxyresorufin O-demethylation were found to be approximately 4-fold higher in microsomes prepared from the ventricle than the atrium of beta-naphthoflavone-induced guinea pigs. The low rates of 7-ethoxyresorufin O-deethylation in cardiac microsomes were due, at least in part, to a deficiency of the flavoprotein NADPH--cytochrome P450 reductase; addition of exogenous NADPH--cytochrome P450 reductase; addition of exogenous NADPH--cytochrome P450 reductase dramatically increased 7-ethoxyresorufin O-deethylation in cardiac microsomes of guinea pigs, before and after treatment with beta-naphthoflavone. N-Benzyl-1-aminobenzotriazole, a suicide substrate of cytochrome P450 1A1 in guinea pig, was able to inhibit almost all of the 7-ethoxyresorufin O-deethylase and 7-methoxyresorufin O-demethylase activities in polycyclic aromatic hydrocarbon induced guinea pig heart (88 and 71%, respectively), suggesting that cytochrome P450 1A1 coupled to NADPH--cytochrome P450 reductase in these microsomes inactivates itself by a suicidal mechanism. Addition of alpha-naphthoflavone, an inhibitor of cytochrome P450 1A isozymes, to cardiac microsomes from beta-naphthoflavone-induced guinea pigs resulted in greater than 95% inhibition of 7-ethoxyresorufin O-deethylase activity. The biological significance of these low levels of cytochrome P450 1A1 monooxygenase activity in guinea pig heart and their induction by polycyclic aromatic hydrocarbons are not currently understood.

Retained "hopeless" teeth: lack of effect periodontally-treated teeth have on the proximal periodontium of adjacent teeth 8-years later.

We previously reported the lack of effect periodontally-treated teeth prognosed "hopeless" and retained for 3.4 +/- 1.5 years have on the proximal periodontium of adjacent teeth. We now report our findings for the same group of subjects following 8.4 +/- 0.7 years of "hopeless" tooth retention. Of the 17 "hopeless" and adjacent teeth originally measured in 17 subjects, 14 of the subjects were still available for re-evaluation. Measures used to assess the periodontium of proximal surfaces of adjacent teeth included pocket depths (PD), radiographic alveolar bone level (R-BL), and periodontal ligament space width (W-PL). Treatment for the subjects consisted of surgical therapy (N = 15) and scaling and root planing (N = 2). Of the 14 subjects re-examined, 2 were eliminated due to loss of adjacent tooth reference points and 2 due to extraction of the "hopeless" tooth (N = 10). Differences in measurements (i.e., nonadjacent to "hopeless" tooth value minus adjacent to "hopeless" tooth value) were analyzed using a repeated measures ANOVA. There were no significant differences for PD (P = 0.20), R-BL (P = 0.29), or W-PL (P = 0.16). These data confirm our original findings that retained periodontally "hopeless" teeth do not significantly affect the proximal periodontium of adjacent teeth following therapy.

Plaque score changes based primarily on patient performance at specific time intervals.

Patient plaque removal is a major component of periodontal therapy and should be continuously monitored during and following treatment. There do not appear to be studies which address plaque score changes achieved primarily by patient performance from the time of initial presentation to, during, and following active therapy. We assessed individual tooth surfaces and segment plaque scores for 24 adult subjects presenting with periodontitis, the majority of which was ADA case types III and IV, at 3 time points (initial presentation, post-initial preparation, and at 3 months following active therapy), using the O'Leary Plaque Index. The assessments describing surfaces and segments were made prior to any professional intervention. Analysis of buccal (B), interproximal (I), and lingual (L) plaque retentive surfaces at t-0 indicated the mean plaque index on B and L surfaces (30.7% and 41.9% respectively) was less than that on I surfaces (79.6%). At t-1 and t-2, the mean plaque index on all three surfaces was significantly (P less than 0.05) less than at t-0. Analysis of plaque indices in each of 6 segments at each time point revealed that plaque scores in all segments, except the mandibular right segment, were analogously reduced from t-0 to t-1 and to t-2. Our results indicate that plaque reduction for all subjects based primarily on patient performance consistently approaches or exceeds 50% on all surfaces and that interproximal surfaces present with and retain more plaque than buccal and lingual surfaces. Furthermore, patient plaque performance achieved at the time of post-initial preparation may be a predictor of the plaque control achievable during therapy based on patient performance.

Effect of periodontal dressings on human gingiva fibroblasts in vitro.

In vitro cytotoxicity studies of periodontal dressings have not generally produced a result consistent with in vivo observations. These prior in vitro studies have not used human intraoral cell lines. We tested the effects of two eugenol containing and two non-eugenol periodontal dressings on cultured human gingival fibroblasts (HGF) (ATCC #1292). Replicate HGF cultures grown in microtiter plates were exposed to stock, 1:4 and 1:16 dilutions of extracts made from each of the four periodontal dressings. The HGF cultures were pulse labelled with tritiated thymidine (3HTdR) after 24, 48, and 72 hours. Incorporations of the labelled thymidine were measured using liquid scintillation counting and expressed as counts per minute. The results showed that undiluted extracts from all four periodontal dressings totally inhibited 3HTdR uptake (P less than 0.05). The 1:4 dilution of eugenol dressings inhibited 3HTdR uptake significantly more than non-eugenol dressings (P less than 0.05). Interestingly, at 72 hours the 1:16 dilution of the non-eugenol dressings caused significantly increased 3HTdR uptake which was not observed with the eugenol dressings. The present results suggest that the use of a human fibroblastic cell line for testing the effects of periodontal dressings may provide information about the relative biological effects of these dressings. Using this cell line, we have found that eugenol dressings inhibit fibroblast proliferation to a greater extent than non-eugenol dressings.

Investigations on in vitro bone resorbing activity from athymic (nude) and euthymic mouse splenic leukocytes.

T-lymphocyte dependence of the production of in vitro bone resorbing activity was examined using athymic (nu/nu) and euthymic (nu/+) mouse splenic leukocytes. Conditioned medium (CM) from unstimulated splenic leukocytes of nu/nu mice had greater in vitro bone resorbing activity compared to CM from nu/+ mice (1.7- as compared to 1.2-fold increase of 45Ca release in mouse calvaria). CM from concanavalin A (Con A)-treated nu/nu and nu/+ leukocytes had 1.8-fold and no increase in 45Ca release, respectively. CM from both nu/nu and nu/+ phytohemagglutinin (PHA)-treated leukocytes had a 1.7-fold increase in 45Ca release. Bone resorbing activity from nu/nu CM was inhibited by interferon-tau (10 & 100 IU/mL) and indomethacin (2 x 10(-6) M). CM (untreated or Con A-treated) from nu/nu leukocytes had higher levels of prostaglandin E (PGE) as compared to CM from nu/+ leukocytes, and indomethacin decreased PGE levels in nu/nu CM. Leukocytes from nu/+ mice had increased mitogenesis when stimulated with PHA (1, 3, & 10 micrograms/mL) or Con A (1 and 10 micrograms/mL), whereas leukocytes from nu/nu mice were nonresponsive or had significant inhibition of mitogenesis with PHA and Con A.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of bone turnover in athymic (nude) and euthymic mice: biochemical, histomorphometric, bone ash and in vitro studies.

Bone turnover in T-cell deficient mice was investigated by comparing parameters of bone physiology in athymic (nude) and euthymic mice. Static and dynamic bone histomorphometry, serum biochemical assays, body weight and tibia length measurements, and bone ash determination were completed in 6- and 12-wk-old athymic (nude) mice (NIH: Swiss nu/nu) and euthymic mice (nu/+) (10 mice/group). In vitro bone resorbing activity stimulated by parathyroid hormone (PTH) or prostaglandin E2 (PGE2) was measured in calvaria of neonatal athymic and euthymic mice. Athymic mice had smaller vertebral tissue area (p less than 0.01), tibia length (p less than 0.001), and less body weight (p less than 0.01) than euthymic mice. The percent double labeled surface (p less than 0.05) and mineralizing perimeter (p less than 0.01) were reduced in athymic as compared to age-matched euthymic mice. Osteoclast number was reduced in the 6-wk athymic mice as compared to 6-wk euthymic mice. Osteoclastic perimeter was reduced in the 12-wk-old mice (athymic and euthymic) as compared to the 6-wk-old mice. Serum calcium was lower at both ages in athymic mice (p less than 0.01) as compared to euthymic mice. Serum alkaline phosphatase levels were reduced (p less than 0.01) in 12-wk-old athymic mice as compared to age-matched euthymic mice, and were greater in 6-wk-old mice than 12-wk-old mice. Athymic mice had greater femur density than euthymic mice (p less than 0.01), and lower (p less than 0.001) percent ash weight of dry bone compared to euthymic mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Retained "hopeless" teeth. Effects on the proximal periodontium of adjacent teeth.

The retention of teeth diagnosed as periodontally "hopeless" may accelerate the destruction of the adjacent proximal periodontium. Studies determining the influence these teeth have on the health status of adjacent teeth appear nonexistent. It was the intent of this retrospective study to assess the status of the periodontium in adjacent teeth proximal to the periodontium of "hopeless" teeth. We evaluated 17 teeth, each being mesially adjacent to one "hopeless" tooth, in 17 subjects treated for periodontal disease. In each case, the "hopeless" and the adjacent teeth received the same treatment. Probing depths (P-D), radiographic alveolar bone level (R-BL) and the width of the periodontal ligament space (W-PL) were measured for both the adjacent interproximal and the nonadjacent interproximal surface for each hopeless tooth. At both pretherapy and posttherapy, there were no significant differences for any of the variables (P-D, R-BL and W-PL) for the adjacent interproximal surfaces with the nonadjacent interproximal surfaces. However, there was a significant reduction in the mean probing depth for the adjacent interproximal surfaces, pretherapy to posttherapy. No other significant changes were found in any of the other variables for either the adjacent or nonadjacent interproximal surfaces. These data suggest that teeth considered periodontally "hopeless" and retained have no effect on the proximal periodontium of adjacent teeth prior to and following therapy.

Periodontal attachment loss associated with proximal tooth restorations.

This study documents that periodontal attachment loss is greater adjacent to restored tooth surfaces than adjacent to unrestored tooth surfaces. This finding emphasizes the importance of the prevention of caries and poor restorations.

Bone loss following periodontal therapy in subjects without frequent periodontal maintenance.

The longitudinal effects of periodontal therapy in patients without a frequent periodontal maintenance program have been minimally documented. In this study we used Duckworth's modification of the Schei Ruler Technique to assess the difference in bone level around individual teeth treated for periodontal disease in subjects receiving infrequent posttherapy maintenance (less than or equal to 1 time/year). Crestal bone height differences were evaluated using the initial presenting series of long cone parallel radiographs of 23 subjects with their subsequent posttherapy analogous radiographic series taken 5.4 +/- 2.9 years later. Bone loss was defined as a reduction in the alveolar crest of greater than 50% of the radiographic crown height which corresponds to approximately 4 mm in posterior and 5 mm in anterior teeth. The loss for each tooth was expressed as a per cent of the measured height of the crown after conversion from millimeters using the mean crown-root ratio for each tooth. We found increased alveolar bone loss and tooth loss in subjects examined posttherapy when compared with conditions present when each subject initially presented for periodontal treatment. Our data suggest that molar teeth are more at risk than incisors and cuspids and that a lack of periodontal maintenance care and inadequate plaque control contribute to progressive bone loss following treatment.