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Biomedical subjects

B Danielsen

Publications and source records attributed to B Danielsen.

At least 19 recordsLinked to original sources
PubMed2005

Thyroid cancer in pregnancy.

OBJECTIVE: To compare stage at diagnosis, treatment and survival among pregnant women with thyroid cancer to non-pregnant women with thyroid cancer, and to assess the impact of treatment on maternal and perinatal outcomes. METHODS: A database containing maternal and newborn discharge records linked to the California Cancer Registry was queried to obtain information on all thyroid cancers from 1991-1999. Women with thyroid cancer occurring during pregnancy were compared to age-matched non-pregnant women with thyroid cancer. RESULTS: 595 cases of thyroid cancers were identified (129 antepartum and 466 postpartum). About 64% of thyroid cancers were diagnosed at stage 2 among pregnant women versus 58% among non-pregnant controls. The odds of thyroid cancer were 1.5 times higher among Asian/Pacific Islanders than among Non-Hispanic White women. Pregnancy had no significant effect on mortality after diagnosis of thyroid cancer. Thyroidectomy during pregnancy was not associated with adverse maternal or neonatal outcomes. CONCLUSIONS: Thyroid cancer discovered during or after pregnancy does not appear to have a significant impact on the prognosis of the disease.

Adenocarcinoma, Follicular↗
PubMed2001

Obstetrical deliveries associated with maternal malignancy in California, 1992 through 1997.

OBJECTIVE: This study aims to characterize the rate of occurrence and nature of outcomes associated with obstetrical deliveries in women with malignant neoplasms among 3,168,911 women who delivered in California in 1992 through 1997. DESIGN: The study is a population-based retrospective review of infant birth and death certificates and maternal and neonatal discharge records. Cases of malignant neoplasms associated with obstetrical delivery were attributed to 1 of 3 categories, depending on the earliest documented hospital discharge diagnosis, as follows: "prenatal" if the diagnosis was first documented by hospitalization within 9 months preceding delivery, "at delivery" if the diagnosis was established from the delivery hospitalization, or "postpartum" if the diagnosis was first documented by hospitalization within 12 months after delivery. METHODS: Computer-linked infant birth and death certificates and maternal and neonatal discharge records were used to identify cases and outcomes. Cases of malignant neoplasms were identified by using International Classification of Diseases, Ninth Revision codes (140-208). Noninvasive neoplasms and carcinoma in situ neoplasms were excluded. In analysis of outcomes, the Mantel-Haenszel estimate for adjusted odds ratios was used. RESULTS: Among 3,168,911 obstetrical deliveries over the 6-year span, a total of 2247 cases of primary malignancy were identified. The observed rate of occurrence for primary malignant neoplasms was 0.71 per 1000 live singleton births. Most cases (53.3%) were first documented in the postpartum period as follows: prenatal, 587 cases (0.18 per 1000); at delivery, 462 cases (0.15 per 1000); and postpartum, 1198 cases (0.38 per 1000). The most frequently documented primary malignant neoplasms associated with obstetrical delivery were breast cancer (423 cases, 0.13 per 1000), thyroid cancer (389 cases, 0.12 per 1000), cervical cancer (266 cases, 0.08 per 1000), Hodgkin's disease (172 cases, 0.05 per 1000), and ovarian cancer (123 cases, 0.04 per 1000). Odds ratios for a variety of demographic factors identified maternal age as the most significant risk factor for development of malignant neoplasms (age greater than 40 vs 20-25, odds ratio 5.7, CI 4.6-6.9). Age-adjusted odds ratios for maternal cancer of any type suggested significantly elevated risks for cesarean delivery (odds ratio 1.4, CI 1.3-1.6), blood transfusion (odds ratio 6.2, CI 4.5-8.5), hysterectomy (odds ratio 27.4, CI 20.8-36.1), and maternal postpartum hospital stay greater than 5 days (odds ratio 30.6, CI 27.9-33.6), but not for postpartum maternal death (odds ratio 0.8, CI 0.6-1.0). Odds ratios also suggested significantly elevated risks for premature newborn (odds ratio 2.0, CI 1.8-2.2), very low birth weight (odds ratio 2.9, CI 2.2-3.8), and newborn hospital stay longer than 5 days (odds ratio 2.6, CI 2.4-3.0), but not for neonatal death (odds ratio 1.6, CI 0.8-3.1) or infant death (odds ratio 1.2, CI 0.5-3.3). However, several types of malignant neoplasms did confer significant elevations in risk for neonatal death. Hospital charges for both maternal and neonatal care were significantly elevated in the maternal malignant neoplasm group. CONCLUSION: A lower than expected occurrence rate of obstetrical delivery associated with maternal malignancy was seen when compared with previously published hospital-based reports. Malignant neoplasms associated with obstetrical delivery were most frequently first documented in the postpartum period. Maternal and neonatal morbidity were significantly increased, yet the risk of in-hospital maternal death was not significantly elevated. A significant increase in risk of neonatal death for infants of mothers with cervical cancer was found.

Adult↗
PubMed2000

Purification and characterisation of epithiospecifier protein from Brassica napus: enzymic intramolecular sulphur addition within alkenyl thiohydroximates derived from alkenyl glucosinolate hydrolysis.

Epithiospecifier protein (ESP), a ferrous ion dependent protein, has a potential role in regulating the release of elemental sulphur, nitriles, isothiocyanates and cyanoepithioalkanes from glucosinolates. Two classes of ESP polypeptides were purified with molecular masses of 39 and 35 kDa, and we show that the previously reported instability was conditionally dependent. The 39 kDa polypeptide was made up of two distinct isozymes (5.00, 5.14) whilst several were present for the 35 kDa form of ESP (5.40-5.66). An anti-ESP antibody reacted with both the 39 and 35 kDa ESP forms in Brassica napus and strongly with a polypeptide corresponding to the 35 kDa ESP form in Crambe abyssinica, but did not detect any ESP in Sinapis alba or Raphanus sativus. A cytochrome P-450 mediated iron dependent epoxidation type mechanism is suggested for ESP.

Brassica↗
PubMed2000

Newborn discharge timing and readmissions: California, 1992-1995.

CONTEXT: Hospital stays for newborns and their mothers after uncomplicated vaginal delivery have decreased from an average of 4 days in 1970 to 1.1 days in 1995. Despite the lack of population-based research on the quality-of-care implications of this trend, federal legislation passed in 1996 mandated coverage for 48-hour hospital stays after uncomplicated vaginal delivery. OBJECTIVE: To assess the impact of very early discharge (defined as discharge on the day of birth) on the risk of infant readmission during the neonatal period in a California healthy newborn population. DESIGN: Retrospective cohort study, based on a linked dataset consisting of the birth certificate, newborn, and maternal hospitalization record, and linked infant readmission records for all healthy, vaginally delivered, and routinely discharged California newborns from 1992 to 1995. OUTCOME MEASURES: Very early discharge and infant readmission during the first 28 days of life. RESULTS: The percentage of infants discharged very early or early (after a 1-night stay) increased from 71% in 1992 to 85% in 1995. The percentage of infants discharged very early increased from 5.0% in 1992 to 5.7% in 1993 and 7.0% in 1994, then decreased to 6.7% in 1995. Characteristics that have been previously associated with suboptimal pregnancy outcomes were found to decrease the likelihood of very early discharge, eg, maternal complications, primiparity, and Hispanic, African American, South East Asian, or other Asian race/ethnicity. The rate of readmission in the neonatal period initially decreased from 27.6 infants per 1000 in 1992 to 25.67 infants per 1000 in 1994, then increased to 30.2 infants per 1000 in 1995. For infants discharged early, no statistically significant increase in the risk of readmission was observed, compared with infants discharged after a 2+-night stay. The adjusted odds ratio (OR) for readmission was statistically significantly higher for infants who were discharged very early, compared with infants discharged early (OR: 1.27), first order births (OR: 1.21), infants born to mothers who experienced complications (OR: 1.11), infants with Medicaid insurance (OR: 1.23), and infants born to mothers who received adequate plus prenatal care (OR: 1.15). The risk was statistically significantly lower for female infants (OR: 0.75). The proportion of infants rehospitalized for dehydration and low-risk infections over the 4 study years combined was statistically significantly higher in infants discharged very early (4.37 per thousand and 10.30 per thousand, respectively), compared with infants discharged early (3.59 per thousand and 8.16 per thousand, respectively) or after a 2+-night stay (2.91 per thousand and 7.95 per thousand, respectively). The proportion of infants rehospitalized for dehydration increased statistically significantly from 2.89 per thousand in 1992 to 4.52 per thousand in 1995. CONCLUSIONS: One-night stays with adequate antenatal and postnatal care outside the hospital do not increase the risk of readmission for healthy, vaginally delivered infants born in California. However, the decision to discharge infants on the day of birth should be applied conservatively because of the increased risk of infant readmission associated with very early discharge.

California↗
PubMed1999

Childbearing beyond age 40: pregnancy outcome in 24,032 cases.

OBJECTIVE: To examine pregnancy outcomes in women age 40 or older. METHODS: We used data from the California Health Information for Policy Project, which consists of linked records from the birth certificate and the hospital discharge record of both mother and newborn of all births that occurred in acute care civilian hospitals in California between January 1, 1992, and December 31, 1993. The study population consisted of all women who delivered at age 40 or over. The control population was women who delivered between age 20 and 29 years during this 2-year period. We reviewed gestational age at delivery, birth weight, mode and type of delivery, discharge summary and birth certificate demographics, birth outcome, pregnancy, and delivery data. RESULTS: Approximately 1,160,000 women delivered during the study period, and 24,032 (2%) of these women were age 40 or older. Of this latter group, 4777 (20%) were nulliparous. The cesarean delivery rate for nulliparous women in the study population was 47.0%, and the rate for multiparous patients in this group was 29.6%. The cesarean delivery rate was 22.5% for nulliparous and 17.8% for multiparous women in the control group. In the older group, the operative vaginal delivery rate (forceps and vacuum) was 14.2% for nulliparous women and 6.3% for multiparous women. Rates of birth asphyxia, fetal growth restriction, malpresentation, and gestational diabetes were significantly higher among older nulliparas (6, 2.5, 11, and 7%, respectively) compared with rates among control nulliparas (4, 1.4, 6, and 1.7%, respectively), and there were similar significant increases among older multiparas (3.4, 1.4, 6.9, and 7.8%, respectively), compared with younger multiparous controls (2.4, 1, 3.7, and 1.6%, respectively). Mean (+/- standard error) birth weight of infants delivered by older nulliparous women was 3201+/-10 g, significantly lower than that among nulliparous controls (3317+/-1 g), whereas mean birth weight in the group of older multiparas (3381+/-5 g) was no different than that among younger multiparous controls (3387+/-1 g). Gestational age at delivery was significantly lower among older nulliparas (273.4+/-0.4 days), compared with nulliparous controls (278.5+/-0.05 days), and similarly lower among older multiparous women (274.0+/-0.2 days), compared with multiparous controls (278.3+/-0.05 days). More white women age 40 or over than younger white women were having a first child (64 and 39%, respectively). CONCLUSION: Nulliparous women age 40 or over have a higher risk of operative delivery (cesarean, forceps, and vacuum deliveries: 61%) than do younger nulliparous women (35%). This increase occurs in spite of lower birth weight and gestational age and may be explained largely by the increase in other complications of pregnancy. The increased frequency at which white women are having their first child at age 40 or over may reflect career choices that involve delaying childbirth until the fifth decade of life. These data will allow us better to counsel patients about their pregnancy expectations and possible outcomes.

Adult↗
PubMed1999

Associated factors in 1611 cases of brachial plexus injury.

OBJECTIVE: To identify risk factors associated with brachial plexus injury in a large population. METHODS: A computerized data set containing records from hospital discharge summaries of mothers and infants and birth certificates was examined. The deliveries took place in more than 300 civilian acute care hospitals in California between January 1, 1994, and December 31, 1995. Cases of brachial plexus injury were evaluated for additional diagnoses and procedures of pregnancy, such as mode of delivery, gestational diabetes, and shoulder dystocia. Those complications were stratified by birth weight and analyzed, using bivariate and multivariate techniques to identify specific risk factors. RESULTS: Among 1,094,298 women who delivered during the 2 years, 1611 (0.15%) had diagnoses of brachial plexus injury. The frequency of diagnosis increased with the addition of gestational diabetes (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.7, 2.1), forceps delivery (OR 3.4, 95% CI 2.7, 4.3), vacuum extraction (OR 2.7, 95% CI 2.4, 3.1), and shoulder dystocia (OR 76.1, 95% CI 69, 84). In cases of brachial plexus injury, the frequency of shoulder dystocia increased from 22%, when birth weight ranged between 2.5 and 3.5 kg, to 74%, when birth weight exceeded 4.5 kg. The frequency of diagnosis of other malpresentation (nonbreech) (OR 73.6, 95% CI 66, 83) was increased for all birth weight categories. Severe (OR 13.6, 95% CI 8.3, 22.5) and mild (OR 6.3, 95% CI 3.9, 10.1) birth asphyxia were increased. Prematurity (OR 0.8, 95% CI 0.67, 0.98) and fetal growth restriction (OR 0.1, 95% CI 0.03, 0.40) were protective against brachial plexus injury. CONCLUSION: In macrosomic newborns, shoulder dystocia was associated with brachial plexus injury, but in low- and normal-weight infants, "other malpresentation" was diagnosed more frequently than shoulder dystocia. Our study findings suggest that brachial plexus injury has causes in addition to shoulder dystocia and might result from an abnormality during the antepartum or intrapartum period.

Birth Injuries↗
PubMed1999

Amniotic fluid embolism: decreased mortality in a population-based study.

OBJECTIVE: To examine the risk factors and pregnancy outcomes associated with 53 cases of amniotic fluid embolism that occurred in California during the 2-year period January 1, 1994 to December 31, 1995. METHODS: Data were obtained from a computerized database that contains linked records from the vital statistics birth certificate and hospital discharge summaries of both mother and newborn. This database covered all singleton deliveries that occurred in 328 civilian acute-care hospitals in California, which represented 98% of all deliveries in California. All cases of amniotic fluid embolism were examined for other pregnancy complications. RESULTS: There were 1,094,248 deliveries during that 2-year period. Fifty-three singleton gestations had the diagnosis of amniotic fluid embolism, for a population frequency of one per 20,646 deliveries. Fourteen women with amniotic fluid embolism died, for a maternal mortality rate of 26.4%. There were 35 (66%) diagnoses of disseminated intravascular coagulation (DIC), 38 (72%) diagnoses of hemorrhage, and 25 (47%) diagnoses of obstetric shock. Among the 14 women who died, the frequency of DIC (79%) and hemorrhage (71%) was not different compared with that of the survivors (62% and 72%, respectively), but obstetric shock was higher (86%, P = .02) than in survivors (33%). The average maternal length of stay for survivors was 6.5 days (range 3-27 days, median 5 days). The cesarean rate was 60% and the frequency of fetal distress was 49%. CONCLUSION: In this population-based study of reported cases of amniotic fluid embolism, the maternal mortality rate (26.4%) was significantly less than previously reported and might reflect a more accurate population frequency. In addition, patients who survived and patients who died had similar pregnancy complications, suggesting that amniotic fluid embolism was present in all cases and not limited to those who died.

Adult↗
PubMed1998

Reliability of visual examination, fibre-optic transillumination, and bite-wing radiography, and reproducibility of direct visual examination following tooth separation for the identification of cavitated carious lesions in contacting approximal surfaces.

The aim of this study was to evaluate the diagnostic accuracy of visual, fibreoptic transillumination (FOTI), and bite-wing radiographic examination performed by 4 observers for the identification of cavitated carious lesions in contacting approximal surfaces, and to assess the inter-observer agreement with these methods and with direct visual examination conducted after tooth separation, the method used as validation for definitive determination of cavitation. A total of 338 unrestored approximal surfaces in 53 students were examined independently by 4 dentists using the diagnostic methods under study. The results from the diagnostic methods were compared with the results from the validation method for each observer. The sensitivities for identification of cavitated lesions using visual examination ranged from 0.12 to 0.50. For FOTI and radiography, the sensitivities ranged from 0.00 to 0.08 and from 0.56 to 0.69, respectively. The specificities exceeded 0.90 for all observers with all methods. Kappa values expressing inter-observer reproducibility were lowest for FOTI, followed by visual and radiographic examination. On the basis of these results, it was concluded that FOTI was the least reliable of the diagnostic methods tested. For the validation method, the inter-observer agreement was only 'substantial'. This implies that the method cannot be used as a validation for other diagnostic methods applied for the identification of cavitated carious lesions in contacting approximal surfaces. However, visual inspection after tooth separation may serve as a supplementary diagnostic tool to conventional visual and radiographic examination for clinical management of aproximal carious lesions.

Adult↗
PubMed1998

The effects of xylitol-containing chewing gums on dental plaque and acidogenic potential.

The aim of this study was to test the hypothesis that the chewing of xylitol- or xylitol/sorbitol-containing chewing gum reduces plaque formation and the acidogenic potential of dental plaque. Thirty healthy volunteers aged from 19 to 28 yrs were randomly allocated to one of three test groups, chewing either xylitol-, xylitol/sorbitol-, or sucrose-sweetened gums. A three-day plaque accumulation period of no oral hygiene was instituted prior to and at the termination of the chewing gum program, which lasted 33 days. Plaque quantity was assessed on the basis of protein content of individual plaque samples collected by a standardized technique. Acidogenic potential of individual baseline and test plaque samples was assessed by the quantity of various organic acids formed from D-(U-14C)glucose. Identification of extracellular and intracellular metabolites was performed by HPLC. Statistical evaluation of data was performed according to paired comparisons of individual baseline and post-chewing data. Plaque formation, acidogenic potential, and glycolytic profiles were similar at baseline and after the gum-chewing periods. Also, there was no intracellular accumulation of glycolytic metabolites within the plaque bacteria to indicate the inhibition of glycolysis. The study thus leads to the conclusion that, in young adults with low caries experience, exposure of the oral cavity to acceptable doses of xylitol or xylitol and sorbitol has no effect on the microbial deposits on the teeth.

Acetic Acid↗
PubMed1997

Calcium-dependent and -independent binding of the pentraxin serum amyloid P component to glycosaminoglycans and amyloid proteins: enhanced binding at slightly acid pH.

Serum amyloid P component (SAP), a member of the pentraxin family of proteins, binds calcium-dependently to several ligands including glycosaminoglycans (GAG's). We have investigated the influence of pH on the Ca2(+)-dependent binding of SAP to solid phase GAG's and amyloid fibril proteins (AA and beta2M) by ELISA. An increase in the dose-dependent binding of SAP to heparan sulfate, AA-protein and beta2M was observed as the pH decreased from 8.0 to 5.0. Furthermore, a lower, but significant Ca2(+)-independent binding of SAP to heparan sulfate, dermatan sulfate, AA protein and the amyloid precursor protein beta2M was observed. This binding was also enhanced at slightly acid pH, most pronounced at pH 5.0. The results of this study indicate that SAP can exhibit both Ca2(+)-dependent and -independent binding to ligands involved in amyloid fibril formation and that the binding is enhanced under conditions of slightly lowered pH.

Amyloid↗
PubMed1996

Binding of complement proteins C1q and C4bp to serum amyloid P component (SAP) in solid contra liquid phase.

Serum amyloid P component (SAP), a member of the conserved pentraxin family of plasma proteins, binds calcium dependently to its ligands. The authors investigated SAPs interaction with the complement proteins C4b binding protein (C4bp) and C1q by ELISA, immunoelectrophoresis and electron microscopy. Binding of these proteins to SAP was demonstrated when SAP was immobilized using F(ab')2 anti-SAP, but not when SAP reacted with these proteins in liquid phase; thus the binding to human SAP was markedly phase state dependent. Presaturation of solid phase SAP with heparin, which binds SAP with high affinity, did not interfere with the subsequent binding of C4bp or C1q to SAP. In contrast, collagen I and IV showed partial competition with the binding of C1q to SAP. Using fresh serum, immobilized native SAP bound C4bp whereas binding of C1q/C1 could not be demonstrated. Altogether the results indicate that firm binding of C1q and C4bp to SAP requires that SAP is presented on a solid phase, that C1q and C4bp react with sites distinct from the heparin binding site, and that C1q and collagen I share binding sites on SAP. Immobilized native SAP, aggregated SAP and SAP-heparansulphate complexes induced no detectable complement activation.

Animals↗
PubMed1996

The effects of a mouthrinse containing sodium benzoate and alcohol on the quantity and metabolism of dental plaque.

The aim of this study was to investigate the efficacy of a pre-brushing rinse containing sodium benzoate and alcohol, on 2 week old dental plaque. In a double-blind, placebo-controlled crossover study 20 individuals abstained from oral hygiene for periods of 2 weeks. Ten individuals were then assigned to rinse once for 30 seconds with either the test mouthrinse or a placebo mouthrinse. Following this, all individuals had their teeth cleaned and maintained proper oral hygiene for four weeks before the experiment was repeated. This time, the control individuals were assigned to the test rinse and vice versa. Using the Plaque Index on three buccal sites on all teeth, plaque was recorded before and after rinsing, as well as following a subsequent toothbrushing. For metabolic studies plaque from the lingual surfaces on the teeth in one quadrant in the upper and the lower jaw was sampled before rinsing and from the two remaining quadrants following the rinse, and analysed. There was no difference in Plaque Index between the two experimental periods. An oral rinse with the test mouthrinse had no effect on the amount of plaque, nor did it enhance the subsequent plaque removal after brushing. The independent biochemical analysis showed a significant effect of rinsing on the glycolytic potential, but with no effect on the glycolytic profile, which was similar for test and control plaque samples. Thus, a single oral rinse with a mouthrinse containing sodium benzoate and alcohol does not affect removal of plaque nor does it seems to influence the glycolytic potential of the plaque.

Acids↗
PubMed1993

Serum immunoglobulin G antibodies to Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum and Streptococcus sanguis during experimental gingivitis in young adults.

Twenty-eight young, healthy adults completed an experimental gingivitis study in which blood and clinical recordings were obtained at baseline; after a 4-week period of thorough oral hygiene; after a subsequent 3-week period of plaque accumulation; and after another 2 weeks of thorough oral hygiene. Serum immunoglobulin G antibodies against whole cells of Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum and Streptococcus sanguis were determined using enzyme-linked immunosorbent assay. Mean serum immunoglobulin G antibody levels to P. intermedia, F. nucleatum and S. sanguis remained essentially constant during the experiment, whereas the immunoglobulin G antibodies to P. gingivalis declined during the initial period of oral hygiene and the subsequent period of plaque accumulation to an average of 84.5% of the baseline value. This reduction could be attributed to the people who developed marked gingival inflammation during the period of plaque accumulation, indicating that the systemic host response may be associated with local tissue responses to variations in oral hygiene. These people were, however, also characterized by higher initial serum immunoglobulin G responses to P. gingivalis than people who developed less pronounced gingival inflammation during the experiment. The variability and individuality noted in the host response to potential pathogens have important implications for attempts to use such measures for establishing a diagnosis or prognosis for the individual patient.

Adult↗
PubMed1993

Expression of the endothelial leukocyte adhesion molecule-1 (ELAM-1) on endothelial cells in experimental gingivitis in humans.

In inflammatory conditions, mediators such as interleukin-1 (IL-1) are released by resident tissue cells as well as by infiltrating inflammatory cells. IL-1 activates endothelial cells causing them to express an adhesion molecule called endothelial leukocyte adhesion molecule-1 (ELAM-1). IL-1 is produced by macrophages, but can also be produced by activated keratinocytes. Here we present data from a study of experimentally induced gingivitis, showing the expression of ELAM-1 on endothelial cells even in tissue with little or only minor signs of clinical or histological inflammation. These results indicate that ELAM-1 is found on endothelial cells of the gingiva early in the course of experimental gingivitis, before overt clinical or histological evidence of inflammation is apparent.

Cell Adhesion↗
PubMed1990

Effect of cigarette smoking on the transition dynamics in experimental gingivitis.

This paper reports the findings of an experimental gingivitis study conducted in smokers and non-smokers. 33 volunteers were examined and underwent prophylaxis during a period of 4 weeks. 28 subjects who showed a plaque index less than 0.20 on all prophylaxis occasions were permitted to continue in the study. Subjects then had their gingival status recorded, had their teeth polished and were requested to abstain from all oral hygiene measures for the following 21 days. After 5 days, 10 days and 21 days, plaque and gingival status were recorded using the criteria of the plaque index and gingival index. After the examination on day 21, the teeth were polished and oral hygiene was re-instituted. Following 2 weeks of supervised oral hygiene, recordings of plaque and gingival status were performed. At the initial examination, there was no difference between the clinical assessment of plaque and gingival status in smokers and non-smokers. Similar amounts of plaque accumulated in the 2 groups during the period of no oral hygiene, but smokers exhibited less gingival inflammation assessed clinically than non-smokers. This difference occurred as a result of an apparently lowered incidence rate and a markedly higher recovery rate in smokers compared to non-smokers. These findings may indicate that smokers for reasons yet unknown have a reduced capacity to mount and maintain an effective defense reaction to a given plaque challenge.

Adult↗
PubMed1989

Transition dynamics in experimental gingivitis in humans.

This study was conducted in order to investigate the dynamics of the gingival inflammatory status during periods of plaque accumulation and thorough oral hygiene. After a period of prophylaxis, 42 volunteers were asked to abstain from all oral hygiene measures for 2 weeks, whereafter oral hygiene was reinstituted. In the absence of oral hygiene, plaque was found at virtually all sites after 7 days and the number of sites with gingivitis increased simultaneously. A reduction in gingival inflammation occurred subsequent to plaque removal. During phases of both plaque accumulation and thorough oral hygiene, sites were found to convert from non-inflamed to inflamed status concurrently, as in the reverse direction. No association between plaque and gingivitis was revealed. The gingival status of a single site was a poor predictor of its status on the subsequent occasion. The proportion of inflamed sites converting to non-inflamed status was greater than the proportion of non-inflamed sites converting to inflamed status at any time. The estimated incidence rate remained fairly constant during both the plaque accumulation phase and the oral hygiene phase, whereas the estimated recovery rate was considerable lower during the plaque accumulation phase compared to oral hygiene phase. The clinical appearance is the outcome of the dynamics between these rates. The steady-state prevalences derived from the estimated "incidence" and "recovery" rates were quite similar to the actual findings after 14 d of plaque accumulation and the subsequent 10 d of thorough oral hygiene.

Adult↗
PubMed1989

Chewing sticks, toothpaste, and plaque removal.

The aim of the present study was to assess the efficacy of brushing with chewing sticks in removing plaque and to evaluate whether toothpaste has any additional effect on the removal of established dental plaque. Kenyan schoolchildren had their plaque deposits disclosed by means of disclosing tablets and subsequently recorded on four buccal sites of all permanent teeth. The children were then allocated to two groups in a crossover design; in one group the children brushed with chewing sticks and toothpaste; the other group brushed with chewing sticks only. Substantial amounts of plaque were recorded at base line in most children. Brushing with a chewing stick for 5 min resulted in a net reduction of the proportion of plaque deposit sites per child. Toothpaste resulted in no additional effect.

Adolescent↗