Endodontic retreatment –scanning electron microscopy analysis

U slučajevima neuspešne endodontske terapije, neophodno je ponovno lečenje kanala korena. Ortogradni endodontski retretman podrazumeva uklanjanje postojećeg materijala za punjenje iz kanala uz dodatno čišćenje, dezinfekciju i ponovnu finalnu opturaciju kanala. Važan korak u toku retretmana je što potpunije uklanjanje postojećeg kanalnog punjenja kako bi se pristupilo svim delovima kanalnog sistema. Cilj doktorske teze bio je da se ispita kvalitet čisšćenja zidova kanala korena nakon endodontskog retretmana pomoću skening elektronske mikroskopije (SEM). Posmatran je uticaj vrste materijala za opturaciju, uticaj upotrebe rastvarača i uticaj ručnih i mašinskih instrumenata na količinu zaostalog materijala na zidovima kanala. Takođe, ispitan je uticaj ovih faktora na apikalnu transportaciju materijala i na vreme potrebno za retretman, a utvrđena je i učestalost oštećenja korišćenih instrumenata. Materijal i metode: Ukupan uzorak činilo je 125 ekstrahovanih, humanih jednokorenih zuba. Nakon preparacije kanala korena, 120 zuba je podeljeno u dve grupe i napunjeno pomoću dva različita materijala za opturaciju (gutaperkom i resilonom). U zavisnosti od tehnike uklanjanja ovih materijala, grupe su dalje podeljene u odnosu na korišćene instrumente (Hedstrom, ProTaper i Twisted File) i u odnosu na upotrebu rastvarača (sa i bez hloroforma). Preostalih 5 zuba, bez kanalnog punjenja, korišćeni su kao kontrolna grupa. Nakon završenog retretmana, korenovi su uzdužnim cepanjem razdvojeni, a odabrane polovine posmatrane na SEM-u. Mikrofotografije svake trećine kanala načinjene su pri uveličanju od 500x. Količina preostalog materijala za punjenje ocenjivana je pomoću skale. Otvoreni dentinski kanalići prebrojavani su na mikrofotografijama načinjenim pri uveličanju od 1000x, u odnosu na uvek konstantnu površinu. Rezultati: Analiza rezultata ukazala je na postojanje statistički značajne razlike u kvalitetu čišćenja zidova kanala u zavisnosti od uklanjanog materijala za opturaciju. Kvalitet čišćenja zidova kanala bio je veći nakon uklanjanja gutaperke nego nakon uklanjanja resilona. Rotirajućim, mašinskim instrumentima je efikasnije uklanjana gutaperka, a ručnim Hedstrom turpijama je bolje uklanjan resilon. Posmatrajući ceo uzorak, ProTaper instrumenti ostavljali su velike količine materijala na zidovima kanala nakon endodontskog retretmana. Međutim, uklanjanje materijala pomoću ovih instrumenata bilo je najbrže. Primena rastvarača značajno je doprinela bržem uklanjanju materijala, dok uticaj na kvalitet čišćenja zidova kanala nije bio značajan. Posmatrajući kanal korena po trećinama, najveća količina materijala nalazila se u apikalnoj trećini, bez obzira na vrstu uklanjanog materijala i korišćenih instrumenata, i bez obzira na upotrebu rastvarača tokom retretmana. Učestalost oštećenja instrumenata bila je značajno veća prilikom upotrebe Twisted File instrumenata. Apikalna transportacija materijala je bila veća tokom uklanjanja resilon materijala i kada su korišćene ručne Hedstrom turpije. Zaključak: Kvalitet čišćenja zidova kanala nakon uklanjanja gutaperke je veći nego nakon uklanjanja resilona. Dizajn i vrsta instrumenata utiče na kvalitet čišćenja zidova kanala korena. Upotreba rastvarača tokom retretmana ne utiče značajno na smanjenje količine materijala zaostalog na zidovima kanala. Mašinski pokretani instrumenti i upotreba rastvarača značajno skraćuju vreme potrebno za endodontski retretman.In cases when endodontic treatment fails, it is necessary to retreat the root canal. Orthograde endodontic retreatment requires the removal of the existing root filling material with additional cleaning, disinfection and refilling of the canal. An important step during retreatment is complete removal of existing filling materials, to regain access to all parts of the canal system. The aim of the doctoral thesis was to investigate the cleanliness of root canal walls after removal of two different obturation material. The retreatment efficacy was observed depending on the usage of solvent and different hand or rotary instruments. The amount of residual material on the canal walls was assessed using scanning electron microscopy (SEM). Also, apical transportation of the obturation material, working time and frequency of instrument damage during retreatment was recorded. Materials and Methods: The total sample consisted of 125 extracted, single-rooted human teeth. After root canal preparation, 120 teeth were divided in two groups and filled using two different obturation materials (gutta-percha and resilon). Depending on the technique of removing these materials, the groups were further divided, in relation to the used instruments (Hedstrom, ProTaper and Twisted File), as well as in relation to the use of solvent (with or without chloroform). The remaining 5 tooth without canal filling were used as a control group. After root canal desopturation, the longitudinaly splitted root halves were observed on SEM. Microphotography of each third were made at magnification of 500x. The amount of remaining filling material was evaluated by using a scale. Open dentinal tubules were counted on microphotographies made at a magnificiation of 1000x, on a surface that was always constant. Results: Analysis of the results indicated a significant difference in the cleanliness of the canal walls depending on the used obturation material. Cleanliness of the canal walls was higher after gutta-percha removal than after the removal of resilon.  Rotary instruments were more effective in removing gutta-percha and Hedstrom hand files better removed resilon. ProTaper instruments left more residual material on canal walls, however endodontic retreatment with these instruments was the fastest. The application of solvent significantly contributed to faster material removal, while the impact on the increase of canal cleanliness was not significant. The largest amount of material remained in the apical third, regardless of the type of material removed and instruments used, and also regardless whether solvent was used for retreatment. The frequency of instrument deformation and fracture was significantly higher when Twisted File instruments were used. Apical transportation of material had a significantly higher occurrence during resilon removal and when manual Hedstrom files were used. Conclusion: Cleanliness of the canal walls was higher after the removal of gutta-percha than after the removal of resilon. The use of solvent is not significant on the increase of canal wall cleanliness, but significantly shortens the time needed for retreatment. There is a difference in the cleanliness of root canal walls depending on the used instruments. Engine-driven rotary instruments and the use of a solvent significantly shortens the time needed for endodontic retreatment

Endodontic retreatment –scanning electron microscopy analysis

U slučajevima neuspešne endodontske terapije, neophodno je ponovno lečenje kanala korena. Ortogradni endodontski retretman podrazumeva uklanjanje postojećeg materijala za punjenje iz kanala uz dodatno čišćenje, dezinfekciju i ponovnu finalnu opturaciju kanala. Važan korak u toku retretmana je što potpunije uklanjanje postojećeg kanalnog punjenja kako bi se pristupilo svim delovima kanalnog sistema. Cilj doktorske teze bio je da se ispita kvalitet čisšćenja zidova kanala korena nakon endodontskog retretmana pomoću skening elektronske mikroskopije (SEM). Posmatran je uticaj vrste materijala za opturaciju, uticaj upotrebe rastvarača i uticaj ručnih i mašinskih instrumenata na količinu zaostalog materijala na zidovima kanala. Takođe, ispitan je uticaj ovih faktora na apikalnu transportaciju materijala i na vreme potrebno za retretman, a utvrđena je i učestalost oštećenja korišćenih instrumenata. Materijal i metode: Ukupan uzorak činilo je 125 ekstrahovanih, humanih jednokorenih zuba. Nakon preparacije kanala korena, 120 zuba je podeljeno u dve grupe i napunjeno pomoću dva različita materijala za opturaciju (gutaperkom i resilonom). U zavisnosti od tehnike uklanjanja ovih materijala, grupe su dalje podeljene u odnosu na korišćene instrumente (Hedstrom, ProTaper i Twisted File) i u odnosu na upotrebu rastvarača (sa i bez hloroforma). Preostalih 5 zuba, bez kanalnog punjenja, korišćeni su kao kontrolna grupa. Nakon završenog retretmana, korenovi su uzdužnim cepanjem razdvojeni, a odabrane polovine posmatrane na SEM-u. Mikrofotografije svake trećine kanala načinjene su pri uveličanju od 500x. Količina preostalog materijala za punjenje ocenjivana je pomoću skale. Otvoreni dentinski kanalići prebrojavani su na mikrofotografijama načinjenim pri uveličanju od 1000x, u odnosu na uvek konstantnu površinu. Rezultati: Analiza rezultata ukazala je na postojanje statistički značajne razlike u kvalitetu čišćenja zidova kanala u zavisnosti od uklanjanog materijala za opturaciju. Kvalitet čišćenja zidova kanala bio je veći nakon uklanjanja gutaperke nego nakon uklanjanja resilona. Rotirajućim, mašinskim instrumentima je efikasnije uklanjana gutaperka, a ručnim Hedstrom turpijama je bolje uklanjan resilon. Posmatrajući ceo uzorak, ProTaper instrumenti ostavljali su velike količine materijala na zidovima kanala nakon endodontskog retretmana. Međutim, uklanjanje materijala pomoću ovih instrumenata bilo je najbrže. Primena rastvarača značajno je doprinela bržem uklanjanju materijala, dok uticaj na kvalitet čišćenja zidova kanala nije bio značajan. Posmatrajući kanal korena po trećinama, najveća količina materijala nalazila se u apikalnoj trećini, bez obzira na vrstu uklanjanog materijala i korišćenih instrumenata, i bez obzira na upotrebu rastvarača tokom retretmana. Učestalost oštećenja instrumenata bila je značajno veća prilikom upotrebe Twisted File instrumenata. Apikalna transportacija materijala je bila veća tokom uklanjanja resilon materijala i kada su korišćene ručne Hedstrom turpije. Zaključak: Kvalitet čišćenja zidova kanala nakon uklanjanja gutaperke je veći nego nakon uklanjanja resilona. Dizajn i vrsta instrumenata utiče na kvalitet čišćenja zidova kanala korena. Upotreba rastvarača tokom retretmana ne utiče značajno na smanjenje količine materijala zaostalog na zidovima kanala. Mašinski pokretani instrumenti i upotreba rastvarača značajno skraćuju vreme potrebno za endodontski retretman.In cases when endodontic treatment fails, it is necessary to retreat the root canal. Orthograde endodontic retreatment requires the removal of the existing root filling material with additional cleaning, disinfection and refilling of the canal. An important step during retreatment is complete removal of existing filling materials, to regain access to all parts of the canal system. The aim of the doctoral thesis was to investigate the cleanliness of root canal walls after removal of two different obturation material. The retreatment efficacy was observed depending on the usage of solvent and different hand or rotary instruments. The amount of residual material on the canal walls was assessed using scanning electron microscopy (SEM). Also, apical transportation of the obturation material, working time and frequency of instrument damage during retreatment was recorded. Materials and Methods: The total sample consisted of 125 extracted, single-rooted human teeth. After root canal preparation, 120 teeth were divided in two groups and filled using two different obturation materials (gutta-percha and resilon). Depending on the technique of removing these materials, the groups were further divided, in relation to the used instruments (Hedstrom, ProTaper and Twisted File), as well as in relation to the use of solvent (with or without chloroform). The remaining 5 tooth without canal filling were used as a control group. After root canal desopturation, the longitudinaly splitted root halves were observed on SEM. Microphotography of each third were made at magnification of 500x. The amount of remaining filling material was evaluated by using a scale. Open dentinal tubules were counted on microphotographies made at a magnificiation of 1000x, on a surface that was always constant. Results: Analysis of the results indicated a significant difference in the cleanliness of the canal walls depending on the used obturation material. Cleanliness of the canal walls was higher after gutta-percha removal than after the removal of resilon.  Rotary instruments were more effective in removing gutta-percha and Hedstrom hand files better removed resilon. ProTaper instruments left more residual material on canal walls, however endodontic retreatment with these instruments was the fastest. The application of solvent significantly contributed to faster material removal, while the impact on the increase of canal cleanliness was not significant. The largest amount of material remained in the apical third, regardless of the type of material removed and instruments used, and also regardless whether solvent was used for retreatment. The frequency of instrument deformation and fracture was significantly higher when Twisted File instruments were used. Apical transportation of material had a significantly higher occurrence during resilon removal and when manual Hedstrom files were used. Conclusion: Cleanliness of the canal walls was higher after the removal of gutta-percha than after the removal of resilon. The use of solvent is not significant on the increase of canal wall cleanliness, but significantly shortens the time needed for retreatment. There is a difference in the cleanliness of root canal walls depending on the used instruments. Engine-driven rotary instruments and the use of a solvent significantly shortens the time needed for endodontic retreatment

Scanning electron microscopy investigation of canal cleaning after canal preparation with nickel titanium files

Introduction. Root canal preparation is the most important phase of endodontic procedure and it consists of adequate canal space cleaning and shaping. In recent years, rotary instruments and techniques have gained importance because of the great efficacy, speed and safety of the preparation procedure. Objective. The aim of this research was to investigate the influence of different NiTi files on the canal wall cleaning quality, residual dentine debris and smear layer. Methods. The research was conducted on extracted human teeth in vitro conditions. Teeth were divided in 7 main groups depending on the kind of instruments used for root canal preparation: ProTaper, GT, ProFile, K-3, FlexMaster, hand ProTaper and hand GT. Root canal preparation was accomplished by crown-down technique. Prepared samples were assessed on scanning electron microscopy JEOL, JSM-6460 LV. The evaluation of dentine debris was done with 500x magnification, and the evaluation of smear layer with 1,000 times magnification. Quantitive assessment of dentine debris and smear layer was done according to the criteria of Hulsmann. Results. The least amount of debris and smear layer has been found in canals shaped with ProFile instruments, and the largest amount in canals shaped with FlexMaster instruments. Canal cleaning efficacy of hand GT and ProTaper files has been similar to cleaning efficacy of rotary NiTi files. Statistic analysis has shown a significant difference in amount of dentine debris and smear layer on the canal walls between sample groups shaped with different instruments. Conclusion. Completely clean canals have not been found in any tested group of instruments. The largest amount of debris and smear layer has been found in the apical third of all canals. The design and the type of endodontic instruments influence the efficacy of the canal cleaning.Uvod. Preparacija kanala korena zuba je najvažnija faza u endodontskom postupku, a podrazumeva adekvatno čišćenje i oblikovanje kanalnog prostora. Mašinske tehnike preparacije i mašinski rotirajući instrumenti poslednjih godina dobijaju na značaju zbog brzine preparacije, efikasnosti obrade kanala korena i sigurnosti pri realizaciji ove faze endodontskog lečenja. Cilj rada. Cilj istraživanja je bio da se ispita uticaj različitih vrsta mašinskih i ručnih nikltitanijumskih (NiTi) instrumenata na kvalitet čišćenja zidova kanala korena zuba i analizira količina zaostalog debrisa i razmaznog sloja na zidovima nakon instrumentacije kanala. Metode rada. Istraživanje je izvedeno u uslovima in vitro na ekstrahovanim humanim zubima. Prema vrsti korišćenih NiTi instrumenata, zubi su podeljeni u sedam osnovnih grupa: ProTaper, GT, ProFile, K-3, FlexMaster, ručni ProTaper i ručni GT. Preparacija kanala korena zuba vršena je tehnikom crown-down. Pripremljeni uzorci posmatrani su na skening- elektronskom mikroskopu JEOL, JSM-6460 LV. Procena količine debrisa vršena je pri uveličanju od 500 puta, a razmaznog sloja pri uveličanju od 1000 puta. Za kvantitativnu procenu postojanja debrisa i razmaznog sloja na zidovima kanala korena zuba nakon instrumentacije i irigacije primenjeni su kriterijumi po Hilsmanu (Hülsmann) i saradnicima. Rezultati Najmanje debrisa i razmaznog sloja uočeno je nakon preparacije ProFile instrumentima, a najviše nakon preparacije FlexMaster instrumentima. Kvalitet čišćenja zidova kanala korena zuba ručnim GT i ProTaper instrumentima je vrlo sličan kvalitetu čišćenja nakon primene rotirajućih NiTi instrumenata. Analizom je utvrđeno da postoji statistički značajna razlika u količini zaostalog debrisa i razmaznog sloja na zidovima kanala korena zuba nakon instrumentacije različitim NiTi instrumentima. Zaključak. Nijedna vrsta mašinskih i ručnih NiTi instrumenata nije obezbedila potpuno čišćenje zidova kanala korena zuba. Najviše zaostalog debrisa i razmaznog sloja nađeno je u apeksnoj trećini kanala svih ispitivanih uzoraka zuba. Dizajn i vrsta endodontskih instrumenata utiču na efikasnost čišćenja kanala

Canal wall thickness after preparation with NiTi rotary files

Root canal preparation is the most important phase of endodontic procedure and it consists of adequate canal space cleaning and shaping. In recent years, rotary instruments and techniques have gained importance because of the great efficacy, speed, and safety of the preparation procedure. AIM: The aim of this research was to investigate measurement of maximal and minimal residual dentine thickness (RDT) and canal diameter after the canal preparation with different NiTi rotary files. METHODS: The research has been conducted on extracted human teeth in vitro conditions. The teeth have been divided in seven groups (20 teeth per group) depending on the kind of instruments used for root canal preparation: ProTaper, GT, ProFile, K-3, FlexMaster, hand ProTaper, and hand GT. The canals have been shaped in a crown-down manner and irrigated with 5.25% sodium hypochlorite. The roots of the teeth have been cut 1 and 3 mm from the apex. Apical preparation quality has been assessed under the polarized light microscope. RESULTS: The maximal residual dentine thickness at distance 1 mm from apex, ranged from 1.16 to 1.45 mm, and at distance 3 mm from apex, from 1.44 to 1.84 mm. The minimal dentine thickness at distance 1 mm from apex ranged from 0.52 to 0.73 mm, and at distance 3 mm from apex, from 0.66 to 0.83 mm. The canal diameters after preparation at distance 1 mm from apex ranged from 0.42 to 0.49 mm, and at distance 3 mm from apex, from 0.53 to 0.63 mm. CONCLUSIONS: There was no significant difference neither in maximal and minimal RDT, nor in canal diameters shaped with different NiTi instruments tested. All tested NiTi files have accomplished good quality preparation of apical root canal parts. Microsc. Res. Tech., 2011

Impact of inhalation therapy on the incidence of carious lesions in patients with asthma and COPD

Objective: The aim of this study was to investigate the incidence of carious lesions, the amount of salivary flow rate and pH value in patients with asthma and chronic obstructive pulmonary diseases (COPD), using inhalation therapy. The obtained results were compared with the results of adult healthy subjects, forming a control group. Material and Methods: The study included 80 participants aging between 18 and 65 years. The experimental group (EG) was comprised of 40 participants, previously diagnosed with asthma or COPD undergoing inhalation therapy for more than five years. The control group (CG), comprised of 40 participants, mirrored the same age and gender status of the EG. Dental status was determined by decayed, missing, and filled teeth (DMFT index). Quantity and pH value of saliva were determined in the laboratory. Results: In the EG, the mean value of the salivary flow rate and pH value were statistically significantly lower than in the CG (p<0.001). Patients in the EG had a higher value of DMFT index when compared with the CG, although the difference was not statistically significant (p=0.199). Mean number of decayed teeth, as well as missing teeth, in the EG was statistically significantly higher than in the CG (p<0.001). Mean number of filled teeth in the EG was statistically significantly lower than in the CG (p<0.001). Conclusion: It was found that patients undergoing inhalation therapy face increasing risk of dental caries due to the lower salivary flow rate and pH value along with the inhalation therapy. They should receive intensive preventive care, including oral hygiene instruction and dietary advice

In vitro investigation of erosive effect of carbonated beverages on enamel and dentin

Background/Aim. Excessive consumption of acidic dietary substances, such as carbonated beverages, increased the chances of dental erosion. The aim of this study was to determine influence of carbonated beverages on enamel and dentin, during different intervals. Methods. Sixty samples were obtained from fifteen impacted third molars. Tooth crown was divided into four parts. One part was a control sample, immersed in destilled water and other three parts were the experimental samples, stored in the following tested beverages: carbonated water, Coca-Cola and Schweppes Bitter Lemon. For each beverage, pH was measured before immersion of the samples. The first group of twenty samples were analysed and photographed, using a Scanning Electron Microscope (SEM), after 60 minutes, the second group after 24 hours and the third group after 7 days of exposure to drinks. The enamel was analysed on the outer surface of the cusps and longitudinal section. Dentin was analysed on longitudinal section. An individually adopted scale was used for determination of the degree of erosive changes of these dental tissues. The data were analysed using the analysis of varance (ANOVA). Results. The pH levels of the tested beverages was bellow the critical pH for enamel demineralisation. The SEM images showed different intensity of erosive changes caused by the tested beverages. The analysis by ANOVA revealed a significant difference between all groups of the treated samples, after 60 minutes of exposure to beverages. The highest values of erosive changes showed the samples that were immersed in Schweppes Bitter Lemon. The analysis of the samples after 24 hours and 7 days showed that the samples immersed in Coca-Cola and Schweppes Bitter Lemon can be classified as one group that was statistically significantly different compared with the control samples and samples immersed in carbonated water. Conclusion. Prolonged exposure of dental tissue to carbonated beverages cause erosive changes and a loss of surface profile

Post-treatment periapical status related to the quality of root canal fillings in adults living in Vojvodina

Background/Aim. Apical periodontitis (AP) is an acute or chronic inflammation of the periradicular tissue, usually caused by the presence of microbial irritants in the root canal system. The aim of the study was to radiographically assess the AP prevalence in root-filled teeth (RFT) in adults from an urban area of Vojvodina, Serbia. Methods. Randomly selected digital ortopantomographs of 616 subjects who visited the Clinic of Dentistry of Vojvodina, from January 2019 to December 2020 were examined. Periapical status, root canal filling (RCF) quality, type of coronal restorations, and their relationships were evaluated. The Chisquared (χ2) test was used for statistical analysis. Results. The total number of endodontically treated teeth was 965; 44.25% of them received an adequate RCF score, and 34.9% had AP, which was diagnosed i n 5 7.4% of inadequately s cored RFT. Posterior teeth had significantly worse RCF quality than anterior teeth (p < 0.001). The direct logistic regression results indicated that a technically well-performed RCF reduced the risk of AP almost 21-fold. The prevalence of AP in our cohort was not influenced by the type of restoration (direct or indirect), but statistically significantly, the highest prevalence of AP was found in RFT without any coronal restoration. Conclusion. The results of this study reaffirm that technically high-quality root canal treatment is crucial to ensure a more predictable root canal treatment outcome

Effects of Nonsurgical Periodontal Therapy on Salivary 8-Hydroxy-Deoxyguanosine Levels and Glycemic Control in Diabetes Mellitus Type 2 Patients

Diabetes and periodontitis are complex chronic diseases that are potentially interrelated, as well as associated with oxidative stress. Thus, the aim of the present study was to evaluate the influence of nonsurgical periodontal treatment on salivary 8-hydroxy-deoxyguanosine (8-OHdG) levels and glycemic control in patients suffering from both diabetes mellitus type 2 (DM2) and periodontitis. The study sample included 53 DM2 patients, while 31 systemically healthy patients served as controls. Participants in both groups suffered from periodontitis of comparable severity. Periodontal clinical parameters, namely plaque index (PI), gingival index (GI), papilla bleeding index (PBI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded, along with salivary 8-OHdG levels and glycated hemoglobin (HbA1c). Levels of 8-OHdG were analyzed by ELISA. All aforementioned parameters were evaluated prior to commencing the study and at 90-day follow-up upon nonsurgical periodontal therapy completion. At baseline, salivary levels of 8-OHdG in DM2 patients were significantly higher (1.17 ng/mL) than those measured for the control group (0.75 ng/mL) and showed significant positive correlation with GI and PPD (p &lt; 0.05). Three months after nonsurgical periodontal therapy, the salivary 8-OHdG levels were significantly reduced in DM2 patients (p &lt; 0.05). Analysis results also revealed statistically significant changes in all measured clinical parameters between baseline and three-month follow-up in both groups (p &lt; 0.05). Upon treatment completion, a decline in the HbA1c level was noted in DM group, but it did not reach statistical significance (p &gt; 0.05). It can be concluded that DM2 patients benefit from non-surgical periodontal therapy, as indicated by a marked reduction in their salivary 8-OHdG level and a modest improvement in glycemic control. Short-term clinical benefits noted in the DM group were similar to those observed in the non-diabetic periodontal patients

Influence of Dimethacrylate Monomer on the Polymerization Efficacy of Resin-Based Dental Cements&mdash;FTIR Analysis

The degree of polymerization for dimethacrylate resin-based materials (BisGMA, TEGDMA, UDMA, HEMA) ranges from 55 to 75%. Literature data indicate that polymerization efficacy depends, among other factors, on the type of methacrylate resin comprising the material. The aim of this study was to evaluate the polymerization efficacy of four dental cement materials characterized by different polymerization mechanisms using FTIR analysis. In the present study, the FTIR method was adopted to analyze the degree of polymerization efficacy of four resin-based dental cement materials, two of which were self-cured and two were dual-cured cements. The IR spectral analysis was performed 24 h after the polymerization of the cementitious material. RelyX ARC cement exhibits the lowest polymerization efficacy (61.3%), while that of Variolink II (85.8%) and Maxcem Elite is the highest (90.1%). Although the efficacy of self-cured cements appears to be superior, the difference is not statistically significant (p = 0.280). Polymerization efficacy largely depends on the chemical structure of the material in terms of the presence of a particular methacrylate resin and less on the polymerization mechanism itself, i.e., whether it is a self-cured or dually cured dental cement. Thus, in clinical practice, cementitious materials with a higher proportion of TEGDMA compared with BisGMA are recommended

Impact of inhalation therapy on the incidence of carious lesions in patients with asthma and COPD

Abstract Objective: The aim of this study was to investigate the incidence of carious lesions, the amount of salivary flow rate and pH value in patients with asthma and chronic obstructive pulmonary diseases (COPD), using inhalation therapy. The obtained results were compared with the results of adult healthy subjects, forming a control group. Material and Methods: The study included 80 participants aging between 18 and 65 years. The experimental group (EG) was comprised of 40 participants, previously diagnosed with asthma or COPD undergoing inhalation therapy for more than five years. The control group (CG), comprised of 40 participants, mirrored the same age and gender status of the EG. Dental status was determined by decayed, missing, and filled teeth (DMFT index). Quantity and pH value of saliva were determined in the laboratory. Results: In the EG, the mean value of the salivary flow rate and pH value were statistically significantly lower than in the CG (p<0.001). Patients in the EG had a higher value of DMFT index when compared with the CG, although the difference was not statistically significant (p=0.199). Mean number of decayed teeth, as well as missing teeth, in the EG was statistically significantly higher than in the CG (p<0.001). Mean number of filled teeth in the EG was statistically significantly lower than in the CG (p<0.001). Conclusion: It was found that patients undergoing inhalation therapy face increasing risk of dental caries due to the lower salivary flow rate and pH value along with the inhalation therapy. They should receive intensive preventive care, including oral hygiene instruction and dietary advice