Master of Dental Surgery / In setting out this thesis, an attempt has been made to give a detailed investigation of the gingival changes which may take place in pregnancy and with particular reference to pregnancy gingivitis or, as it is referred to in this thesis: gingivitis gravidarum. Gingivitis gravidarum is that gingivitis which occurs in the pregnant state and is attributable to, or aggravated by the gravid state. A clinical survey has been carried out and a detailed study of all available literature made. As a result of this study, comparisons are drawn between Australian born and immigrant groups. There are many unsolved problems concerning the condition, and although this investigation does not cover any new ground in the light of world research, it is, to the best of my knowledge, the first time that a survey as comprehensive as this has been made in this country.

Master of Dental Surgery / In setting out this thesis, an attempt has been made to give a detailed investigation of the gingival changes which may take place in pregnancy and with particular reference to pregnancy gingivitis or, as it is referred to in this thesis: gingivitis gravidarum. Gingivitis gravidarum is that gingivitis which occurs in the pregnant state and is attributable to, or aggravated by the gravid state. A clinical survey has been carried out and a detailed study of all available literature made. As a result of this study, comparisons are drawn between Australian born and immigrant groups. There are many unsolved problems concerning the condition, and although this investigation does not cover any new ground in the light of world research, it is, to the best of my knowledge, the first time that a survey as comprehensive as this has been made in this country.

Increased levels of oestrogen and progesterone during pregnancy may lead to periodontal disease. The anaerobic Gram-negative bacteria called red complex (Porphyromonas gingivalis, Tannerella forsythensis and Treponema denticola) are frequently associated with periodontal disease. Periodontopathogens produce toxins and enzymes which can enter the bloodstream and cross the placenta to harm the foetus. The response of the mother&rsquo / s immune system to infection by these periodontopathogens, brings about the release of inflammatory mediators which may trigger preterm labour or result in low birth-weight infants. The purpose of this study was to examine the prevalence of red complex, using BANA and PCR in subginginval plaque samples from pregnant women. Subgingival plaque samples were obtained from pregnant women between the ages of 17 to 45 years attending a Mitchells Plain ante-natal clinic. Plaque samples were analyzed by the enzymatic BANA-test for detection of the presence of red complex and DNA was extracted and analyzed using 16 rDNA-Polymerase Chain Reaction (PCR).<br /> <br /> Seventy-nine percent of pregnant women showed gingival index scores of &ge / 1 of which 74.24% harboured by at least one of the members of the red complex. P.gingivalis was the most prevalent of the three members of the red complex. Findings of this study confirmed a need for dental preventive measures in pregnant women and microbial monitoring of suspected periodontopathogenes. This could be achieved by joint cooperation between Maternity Obstetric Units (MOU), Dentistry and oral microbiology departments. The results of this study revealed that although PCR is more sensitive than BANA in detecting members of the red complex, BANA showed a better association with the indices used to diagnose periodontal disease.

Increased levels of oestrogen and progesterone during pregnancy may lead to periodontal disease. The anaerobic Gram-negative bacteria called red complex (Porphyromonas gingivalis, Tannerella forsythensis and Treponema denticola) are frequently associated with periodontal disease. Periodontopathogens produce toxins and enzymes which can enter the bloodstream and cross the placenta to harm the foetus. The response of the mother&rsquo / s immune system to infection by these periodontopathogens, brings about the release of inflammatory mediators which may trigger preterm labour or result in low birth-weight infants. The purpose of this study was to examine the prevalence of red complex, using BANA and PCR in subginginval plaque samples from pregnant women. Subgingival plaque samples were obtained from pregnant women between the ages of 17 to 45 years attending a Mitchells Plain ante-natal clinic. Plaque samples were analyzed by the enzymatic BANA-test for detection of the presence of red complex and DNA was extracted and analyzed using 16 rDNA-Polymerase Chain Reaction (PCR).<br /> <br /> Seventy-nine percent of pregnant women showed gingival index scores of &ge / 1 of which 74.24% harboured by at least one of the members of the red complex. P.gingivalis was the most prevalent of the three members of the red complex. Findings of this study confirmed a need for dental preventive measures in pregnant women and microbial monitoring of suspected periodontopathogenes. This could be achieved by joint cooperation between Maternity Obstetric Units (MOU), Dentistry and oral microbiology departments. The results of this study revealed that although PCR is more sensitive than BANA in detecting members of the red complex, BANA showed a better association with the indices used to diagnose periodontal disease.

[Truncated abstract] Periodontal disease is a common and underdiagnosed disease in humans that may have adverse effects on pregnancy outcomes. The aim of this thesis was to investigate the effects of periodontal disease in pregnancy by means of two observational human studies and the development of animal models of fetal and uterine exposure to periodontopathic bacteria and lipopolysaccharide. I performed a prospective study examining the rates of preterm birth, small for gestational age neonates and neonatal inflammation in 277 women who had undergone a detailed antenatal periodontal examination and oral health questionnaire. Periodontal disease was associated with small for gestational age neonates, and increased CRP levels in umbilical cord blood, but no effect was seen on the rate of preterm birth. Maternal oral health symptoms predicted both periodontal disease and newborn biometry. In a retrospective case control study, I examined the role of periodontal disease in perinatal mortality. Participants included 53 women who had experienced a perinatal loss for which no cause could be found after thorough investigation, and 111 control women. Women who had experienced a perinatal loss were more than twice as likely as controls to have periodontal disease. The incidence of periodontal disease was even higher in women in whom the perinatal loss was due to extreme prematurity. In contrast to my prospective study, risks to the pregnancy could not be predicted by maternal oral health behaviours or oral health symptoms. In order to better understand the mechanisms regulating the associations described in the human studies, two animal models were developed; one to investigate acute exposure and the second to investigate long-term exposure to periodontal pathogens. The first study examined the effects of administration of a bolus of periodontopathic bacteria and lipopolysaccharide to the pregnant sheep. Injection of bacteria and lipopolysaccharide in the amniotic fluid of the pregnant preterm sheep caused a high rate of fetal lethality, disturbance of fetal acid base status and inflammation of the fetus and membranes. Given the circumstances of exposure to periodontopathic pathogens in human periodontal disease, a model investigating long-term exposure to periodontopathic lipopolysaccharide on pregnancy outcomes was developed. ... Overall, I have demonstrated that maternal periodontal disease is associated with adverse pregnancy outcomes including fetal growth restriction and possibly perinatal loss. Mechanisms regulating these effects are likely to be mediated by fetal adaptations to intrauterine inflammation resulting in altered fetal development, growth or survival. Randomised controlled trials that are currently in progress will provide further information on the effects of periodontal disease in human pregnancy, and the efficacy of treatment to reduce these adverse outcomes.