Institute of Odontology / Institutionen för odontologihttps://hdl.handle.net/2077/2802024-03-28T15:44:21Z2024-03-28T15:44:21ZEndodontic inflammatory disease and myocardial infarctionSebring, Danhttps://hdl.handle.net/2077/790942024-01-15T21:01:47Z2024-01-15T00:00:00ZEndodontic inflammatory disease and myocardial infarction
Sebring, Dan
Atherosclerosis is the underlying cause to suffering an acute myocardial infarction. Disruption of atherosclerotic plaques lead to thrombus formation and occlusion of the coronary arteries which impedes blood supply to the heart. Inflammation plays a role in the pathogenesis. Through spread of pro-inflammatory mediators, oral inflammatory diseases may contribute to the risk of acute coronary events. The PAROKRANK study reported an independent association between marginal periodontitis and the risk of acute myocardial infarction. The main objective of this thesis was to explore if a similar association exists between endodontic inflammatory disease and acute myocardial infarction. Study I addressed observer reliability in assessment of endodontic variables in panoramic radiographs. Calibration improved agreement between three observers and a reference standard in assessment of periapical lesions (from weighted 0.22, 0.30 and 0.60 to 0.59, 0.64 and 0.80 respectively). In Study II, endodontic variables in PAROKRANK patients and controls were compared. Following adjustment for confounders, more missing teeth increased the risk (OR 1.04; 95% CI 1.02-1.06), whilst number of filled teeth reduced the risk (OR 0.98; 95% CI 0.96-1.00), of myocardial infarction. Decayed teeth (OR 1.18; 95% CI 1.02-1.37) and primary apical periodontitis (OR 1.57; 95% CI 1.08-2.29) increased the risk in younger age-groups while root filled teeth (OR 1.18; 95% CI 1.03-1.36) increased risk in older age groups. Study III explored a composite of endodontic inflammatory disease as an indicator of acute myocardial infarction. In a multivariable logistics regression model, the composite, calculated as the sum of seven weighted endodontic variables, best predicted the risk of myocardial infarction (OR 1.97; 95% CI 1.23-3.17). Study IV analysed correlations between endodontic variables and systemic levels of pro-inflammatory markers in blood. In adjusted analyses, presenting ≥1 root filled tooth related to lower levels of several cytokines (IL-1, IL-2, IL-6, and IL-12p70), whilst ≥1 primary apical periodontitis related to higher levels of interleukin-8 (=0.06). In Study V, national registries were assessed for mortality and morbidity data of the PAROKRANK cohort during a follow-up of eight years. Following adjustment for confounders, remaining teeth and non-root filled teeth decreased the risk of future events, whilst higher DMFT-score increased the risk and ≥1 primary apical periodontitis decreased the risk of suffering cardiovascular events. Higher DMFT-score and decayed teeth increased the risk of all-cause mortality.
2024-01-15T00:00:00ZFunctional characteristics of periodontitis and peri-implantitis lesions in humansDionigi, Carlottahttps://hdl.handle.net/2077/788852023-11-14T21:07:16Z2023-11-14T00:00:00ZFunctional characteristics of periodontitis and peri-implantitis lesions in humans
Dionigi, Carlotta
In the current series of studies functional characteristics of periodontitis and peri-implantitis lesions in humans were investigated. Cell markers for antimicrobial activity were used to evaluate differences between periodontitis and peri-implantitis lesions (Study I), while epigenetic and oxidative stress markers were used to compare periodontitis lesions in smokers and non-smokers (Study II). The occurrence and localization of titanium micro-particles were assessed in tissue samples obtained from dental implant sites with and without peri-implantitis and the influence of titanium particles on gene expression profiles was investigated in peri-implantitis lesions (Study III). Gene expression profiles were analyzed in tissue samples obtained from dental implant sites with and without peri-implantitis by integrating spatial transcriptomics and RNA-sequencing data (Study IV).
It was demonstrated that:
- Peri-implantitis lesions were larger and presented with significantly larger densities of cells with antimicrobial activity than periodontitis lesions. In both lesions, cellular densities were higher in the inner zone, lateral to the pocket epithelium, than in the outer compartment of the lesion. The non-infiltrated connective tissue in peri-implantitis specimens showed significantly higher densities of cells with antimicrobial activity than that in periodontitis specimens (Study I).
- Although periodontitis lesions did not differ in size between smokers and non-smokers, differences in cellular functions were observed. Periodontitis lesions in smokers presented with diminished antimicrobial activity and lower levels of epigenetic markers than lesions in non-smokers (Study II).
- Densities of titanium micro-particles in peri-implant tissues varied across patients but not between dental implant sites with and without peri-implantitis within the same individual. The titanium micro-particles were of similar size and morphology and mainly located in a 2-mm wide tissue zone close to the implant, in samples with and without peri-implantitis. Out of >36000 analyzed genes, only 14 were differentially expressed when comparing peri-implantitis specimens with high and low densities of titanium micro-particles (Study III).
- A clear association was observed between distinct gene clusters and specific compartments in peri-implant tissues. Peri-implantitis specimens showed overall higher levels of gene activity than specimens from reference implant sites. Several pathways specific for the activation of the host response towards bacterial insults were clearly dysregulated in peri-implantitis specimens (Study IV).
2023-11-14T00:00:00ZThe Oral Hygiene Ability Instrument-OHAI Development and evaluation of an instrument measuring the cause of poor oral hygiene self-care in older adultsGrönbeck-Lindén, Ingelahttps://hdl.handle.net/2077/777722023-11-02T21:01:14Z2023-11-02T00:00:00ZThe Oral Hygiene Ability Instrument-OHAI Development and evaluation of an instrument measuring the cause of poor oral hygiene self-care in older adults
Grönbeck-Lindén, Ingela
Oral hygiene is an important preventive measure to maintain good oral health in the growing group of older adults. Oral hygiene often deteriorates with age, but the causes of this at the individual level are rarely investigated. One reason of several may be that a multifactorial assessment instrument is missing. The aim of this thesis was therefore to develop and evaluate an instrument to assess the cause of any inability for older adults to manage daily oral care. The qualitative Study I aimed to identify factors that affect older adults’ ability to manage oral hygiene. Focus group interviews (n = 4) were conducted with dental hygienists, occupational therapists, assistant nurses, and older adults. Data were analysed using content analysis. The results were formulated into the core category “Oral hygiene is a complex activity” that is influenced by psycho-logical, functional, and environmental factors. Inclusion criteria for Studies II-IV were: 1) age ≥ 65 years, 2) at least one natural tooth or osseointegrated implant, and 3) ability to manage oral hygiene independently. Study II describes the development process of the Oral Hygiene Ability Instrument (OHAI), which comprised three phases: planning, construction, and evaluation. The construction phase was based largely on the results of Study I. The evaluation phase resulted in the reduction of OHAI from 47 to 33 items. OHAI came to consist of three parts: Part I – interview, Part II – clinical examination, and Part III – observation of the oral hygiene activity. Based on the results of Parts I-III, the rater (a dental staff member) conducts a summary assessment of the impact of ten factors (cognitive function, frailty, motivation, vision, fine motor skills, coordination knowledge of oral hygiene, spatial ability, oral clearance, and balance) on the individual’s oral hygiene ability. Study III concerned the reliability of OHAI. Part I (interview) was tested for test–retest reliability on 37 older adults. Parts II and III were tested for intra-/interrater reliability. Four dental professionals assessed 15 films and intraoral photos of older adults undergoing OHAI assessment. Parts I and III were found to have acceptable-to-good test-retest and intra-/interrater reliability, respectively; however, five items in Part II displayed limited reliability. In Study IV, the OHAI was tested for criterion and construct validity in a stroke group (n = 50), a group with cognitive impairment (n = 49), and a group of general dental patients (n = 50). Criterion validity was analysed, with sensitivity/ specificity showing acceptable-to-good agreement. To test for construct validity, known-group validity analysis, factor analysis, and Rasch analysis were used. In general, OHAI demonstrated good criterion and construct validity. However, Study IV, like Study III, showed potential for improvement for some items, which meant that some minor changes were implemented in the OHAI to obtain a more robust and easier-to-use instrument. In conclusion, oral hygiene was found to be a complex activity that needs to be supported in different ways depending on the cause of the lack of ability. The development of the OHAI means that there now is a valid and reliable instrument for the assessment of the cause of an older adult’s inability to manage oral hygiene.
2023-11-02T00:00:00ZOn biological response and wear particles around oral implants and implant componentsOlander, Juliahttps://hdl.handle.net/2077/788842023-11-01T21:07:23Z2023-11-01T00:00:00ZOn biological response and wear particles around oral implants and implant components
Olander, Julia
ABSTRACT
Wear particles released from implant components are gaining interest in the dental literature. In orthopedic medicine, wear particles are known to cause bone loss around medical implants in an aseptic manner and several in vitro studies have shown proinflammatory responses to titanium particles. In dentistry and medicine, several materials are used for implant constructions, with a variation in material properties such as hardness and surface roughness. Theoretically, dissimilarity in material combination may cause aggravation as the materials wear. Due to aesthetical advantages, ceramic abutments made from zirconia are increasingly used in dentistry. Zirconia is harder than titanium, which could lead to more wear and particle release. It is unknow whether wear particles in tissues around dental implants cause peri-implant bone loss.
This thesis investigates whether the combination of materials in dental implant constructions alters biological responses and release of wear particles. Specifically, the studies included in this thesis compare single implant crowns manufactured with two abutment materials regarding clinical outcomes (Study I), in vitro wear on two implant materials (Study II), inflammatory cell responses (Study III), gene expression and presence of particles in soft tissues (Study IV).
In Study I, we retrospectively analyzed data from patients treated at a specialist clinic with implant-supported crowns manufactured with two abutment types – zirconia and titanium. These analyses focused on clinical outcome variables with respect to function up to five years after prosthetic placement. In Study II, we evaluated experimental dynamic loading to compare wear, corrosion, and wear particle generation when these two abutment materials were used to connect to two types of implant materials. In Study III, we investigated the proinflammatory response to human peripheral blood mononuclear cells (PBMCS) when exposed to two types of disc materials combined with two particle materials. In Study IV, we evaluated mucosa biopsies from patients with single implant supported crowns manufactured on two abutment materials, focusing on gene expression and presence of wear particles.
The following conclusions were drawn from the thesis. Study I show that abutment material type was statistically significantly associated with amount of yearly bone loss and accumulated five-year bone loss in this cohort but did not affect occurrence of technical complications. Implants with zirconia abutment showed an increase in bone loss but a decrease in technical complications compared to titanium. However, limitations in this finding include small sample size and only slight differences in bone loss values, which may not be clinically relevant. Study II shows that all implants had signs of wear irrespective of abutment material. No clear difference was seen comparing material combinations. Particles were released from the implant-abutment junction and the internal connections harbored wear particles inside the implants. More particles were released when using zirconia abutments. Study III shows that titanium particles and discs generated a higher proinflammatory response compared to zirconia. Neutrophils reacted to zirconia particles by releasing neutrophilic extracellular traps (NETs), which was not seen when exposed to titanium particles. In Study IV, we found titanium wear particles in soft tissue samples and zirconia particles on implant heads. More particles were found in mucosa around zirconia abutments. Gene expression showed upregulation of several proinflammatory genes when using zirconia abutment compared to titanium abutment. Wear particles may trigger pro-inflammatory reactions in the peri-implant mucosa.
2023-11-01T00:00:00Z