An in vitro evaluation of surface roughness, color stability and bacterial accumulation of lithium disilicate ceramic after prophylactic periodontal treatment

Objective: to evaluate the effect of scaling procedures using different ultrasonic tips on the surface roughness, color stability and bacterial accumulation of lithium disilicate ceramic. Material and Methods: Scaling procedure was carried out using ultrasonic scaler (Satalec, Acteon, North America) with stainless-steel tip (US), titanium tip (UT) and plastic tip (UP), on disc shaped lithium disilicate samples cemented into a cavity prepared onto the labial surface of freshly extracted bovine teeth (10 samples per group). The samples were stored in coffee solution in an incubator at 37°C for 12 days, which is equivalent to 1 year of coffee consumption. The surface roughness was measured before and after the scaling procedure using a profilometer and atomic force microscopy. The color parameters were measured before and after scaling and staining procedures using VITA Easyshade Advance 4.0 according to the CIE L*a*b* color order system. The samples were then incubated with Streptococcus mutans (S. mutans) suspension. After incubation, the plates with 30 to 300 typical colonies of S. mutans were counted in a colony counter and mean values of colony forming units were obtained (CFU/mL). Results: The titanium scaling tip showed a statistically significant higher mean values of change in surface roughness Ra and bacterial count than the plastic scaling tip. Color changes (E) were not a statistically significant among the groups. The results showed a statistically significant positive (direct) correlation between surface roughness and color change (p = 0.012) and also between surface roughness and bacterial count (p = 0.00). Conclusion: Within the limitations of this study, titanium scaling instruments cause irreversible surface alterations of lithium disilcate ceramics which was in direct correlation to the color changes and bacterial accumulation; therefore, dentists should proceed with caution when scaling lithium disilicate surfaces. The findings of the current study may indicate the need for instruments or equipment that can remove plaque and calculus without causing surface damage. Keywords Surface properties; Color; Bacterial adhesion; Ultrasonics; Dental scaling; Ceramics.

Human variation in gingival inflammation

Oral commensal bacteria actively participate with gingival tissue to maintain healthy neutrophil surveillance and normal tissue and bone turnover processes. Disruption of this homeostatic host–bacteria relationship occurs during experimental gingivitis studies where it has been clearly established that increases in the bacterial burden increase gingival inflammation. Here, we show that experimental gingivitis resulted in three unique clinical inflammatory phenotypes (high, low, and slow) and reveal that interleukin-1β, a reported major gingivitis-associated inflammatory mediator, was not associated with clinical gingival inflammation in the slow response group. In addition, significantly higher levels of Streptococcus spp. were also unique to this group. The low clinical response group was characterized by low concentrations of host mediators, despite similar bacterial accumulation and compositional characteristics as the high clinical response group. Neutrophil and bone activation modulators were down-regulated in all response groups, revealing novel tissue and bone protective responses during gingival inflammation. These alterations in chemokine and microbial composition responses during experimental gingivitis reveal a previously uncharacterized variation in the human host response to a disruption in gingival homeostasis. Understanding this human variation in gingival inflammation may facilitate the identification of periodontitis-susceptible individuals. Overall, this study underscores the variability in host responses in the human population arising from variations in host immune profiles (low responders) and microbial community maturation (slow responders) that may impact clinical outcomes in terms of destructive inflammation.

Efektivitas Permen Karet Xylitol dalam Menurunkan Plak

Oral and tooth problem that often occurs is caries worldwide. According to Riset Kesehatan Dasar (Baseline Health Research) in 2018, the largest proportion of oral and tooth problems in Indonesia is caries (45,3%). Caries could be caused inter alia by the presence of bacterial accumulation attached to plaque. One of the ways to control plaque is xylitol chewing gum which is proven to be quite effective in cleaning teeth from debris and plaque, preventing periodontal diseases, increasing salivary pH, and stimulating saliva excretion. This study was aimed to evaluate the effectiveness of xylitol chewing gum in reducing plaque. This was a literature review study using two databases, namely Google Scholar and Indonesia One Search. The results showed that samples used in the literatures were 10-24 years old. The xylitol doses used were 3.4 g/day, 4.05 g/day, 6 g/day, and 45 g/day. Xylitol dose below 3.4 g/day was not effective and dose above 10 g/day was less effective to reduce S. mutans. In conclusion, xylitol chewing gum at a dose of 3.4 g-10 g per day is quite effective in reducing plaque.Keywords: xylitol chewing gum; dental plaque Abstrak: Masalah kesehatan gigi dan mulut khususnya karies merupakan penyakit yang dialami oleh sebagian besar penduduk di dunia. Riset Kesehatan Dasar (RISKESDAS) pada tahun 2018 menyatakan bahwa proporsi terbesar masalah gigi dan mulut di Indonesia ialah karies (45,3%). Penyebab terjadinya karies ialah antara lain adanya kumpulan bakteri yang terikat dalam plak. Salah satu pengendalian plak ialah dengan tindakan mengunyah permen karet xylitol yang terbukti cukup efektif membersihkan gigi dari debris dan plak, mencegah terjadinya penyakit periodontal, meningkatkan pH saliva, dan merangsang pengeluaran saliva. Penelitian ini bertujuan untuk mengulas efektivitas permen karet xylitol dalam menurunkan plak. Jenis penelitian ialah literature review dengan menggunakan dua database yaitu Google Scholar dan Indonesia One Search. Hasil penelitian mendapatkan bahwa kelompok eksperimen penelitian yang dikaji berkisar 10-24 tahun. Dosis xylitol yang dipakai dalam penelitian berkisar 3,4 gr/hari, 4,05 gr, 6 gr/hari, dan 45 gr per hari. Dosis xylitol di bawah 3,4 gr/hari tidak efektif dan dosis yang melebihi 10 gr/hari juga kurang efektif terhadap reduksi S. mutans. Simpulan penelitian ini ialah mengunyah permen karet xylitol dengan dosis 3,4 gr-10 gr per hari cukup efektif dalam menurunkan plak.Kata kunci: permen karet xylitol; plak

SEM and TEM for identification of capsular fibrosis and cellular behavior around breast implants – a descriptive analysis

Background Capsular fibrosis (CF) is the most common long-term complication in implant-based breast augmentation. It is well accepted that the foreign body response (FBR) instigates the development of fibrotic disease. Our study aims to compare murine and human samples of CF and describe the cellular and extracellular matrix (ECM) composition using scanning and transmission electron microscopy (SEM and TEM). Results Miniature microtextured silicone breast implants were implanted in mice and subsequently harvested at days 15, 30, and 90 post-operation. Isolated human capsules with the most aggravated form of CF (Baker IV) were harvested post-operation. Both were analyzed with SEM and TEM to assess cellular infiltration and ECM structure. An architectural shift of collagen fiber arrangement from unidirectional to multidirectional was observed at day 90 when compared to days 15 and 30. Fibrosis was observed with an increase of histiocytic infiltration. Moreover, bacterial accumulation was seen around silicone fragments. These findings were common in both murine and human capsules. Conclusions This murine model accurately recapitulates CF found in humans and can be utilized for future research on cellular invasion in capsular fibrosis. This descriptive study helps to gain a better understanding of cellular mechanisms involved in the FBR. Increases of ECM and cellularity were observed over time with SEM and TEM analysis.

The Influence of Gut Microbiota on the Cardiovascular System Under Conditions of Obesity and Chronic Stress

Purpose of Review Based on the available data, it can be assumed that microbiota is an integral part of the human body. The most heavily colonized area of the human body is the gut, with bacterial accumulation ranging from 101–103 cells/g in the upper intestine to 1011–1012 cells/g in the colon. However, colonization of the gut is not the same throughout, as it was shown that there are differences between the composition of the microbiota in the intestine lumen and in the proximity of the mucus layer. Recent Findings Gut microbiota gradient can be differentially regulated by factors such as obesity and chronic stress. In particular, a high fat diet influences the gut microbial composition. It was also found that chronic stress may cause the development of obesity and thus change the organization of the intestinal barrier. Recent research has shown the significant effect of intestinal microflora on cardiovascular function. Enhanced absorption of bacterial fragments, such as lipopolysaccharide (LPS), promotes the onset of “metabolic endotoxemia,” which could activate toll-like receptors, which mediates an inflammatory response and in severe cases could cause cardiovascular diseases. It is presumed that the intestinal microbiota, and especially its metabolites (LPS and trimethylamine N-oxide (TMAO)), may play an important role in the pathogenesis of arterial hypertension, atherosclerosis, and heart failure. Summary This review focuses on how gut microbiota can change the morphological and functional activity of the cardiovascular system in the course of obesity and in conditions of chronic stress.

SEM and TEM for Identification of Capsular Fibrosis and Cellular Behavior Around Breast Implants – a Descriptive Analysis

BackgroundCapsular fibrosis (CF) is the most common long-term complication in implant-based breast augmentation. It is well accepted that the foreign body response (FBR) instigates the development of fibrotic disease. Our study aims to compare murine and human samples of CF and describe the cellular and extracellular matrix (ECM) composition using scanning and transmission electron microscopy (SEM and TEM).ResultsMiniature microtextured silicone breast implants were implanted in mice and subsequently harvested at days 15, 30, and 90 post-operation. Isolated human capsules with the most aggravated form of CF (Baker IV) were harvested post-operation. Both were analyzed with SEM and TEM to assess cellular infiltration and ECM structure.An architectural shift of collagen fiber arrangement from unidirectional to multidirectional was observed at day 90 when compared to days 15 and 30. Fibrosis was observed with an increase of histiocytic infiltration. Moreover, bacterial accumulation was seen around silicone fragments. These findings were common in both murine and human capsules.ConclusionsThis murine model accurately recapitulates CF found in humansand can be utilized for future research on cellular invasion in capsular fibrosisThis descriptive study helps to gain a better understanding of cellular mechanisms involved in the FBR. Increases of ECM and cellularity were observed over time with SEM and TEM analysis.

The influence of motility on bacterial accumulation in a microporous channel

We study the transport of bacteria in a porous media modeled by a square channel containing one cylindrical obstacle via molecular dynamics simulations coupled to a lattice Boltzmann fluid.

Chlorhexidine Coated Polyglactin Sutures In Prevention Of Surgical Site Infection

Surgical Site Infections (SSIs) are one of the most common complications of any intervention in the maxillofacial region. Most of the times sutures used for wound approximation act as a nidus of bacterial accumulation and subsequent infection due to the presence of scores of microbes in and around the oral cavity. This has been attributed to the wicking action associated with braided sutures. Various methods to prevent surgical site infections are reported in literature, the most recent being use of antibacterial coated sutures. Sutures are either coated with triclosan or chlorhexidine or a combination of anti-microbial agents and fatty acids. These sutures are known to have a significant role in the prevention of SSIs elsewhere in the body, but the role in oral cavity remains questionable. This study aims to establish the role of chlorhexidine coated sutures in the prevention of surgical site infections if any. Chlorhexidine-coated and uncoated suture materials were used in 17 patients undergoing third molar extractions. Seven days post-operatively the sutures were removed, and bacteria were isolated. Following which colony-forming units (CFU/ml) were counted. Concerning the total number of oral pathogens, that adhered to suture material, no reduction was demonstrated for Chlorhexidine coated sutures. The use of chlorhexidine-coated suture material offers no advantage in intraoral surgery.

Molecular events in the clinicopathological diagnosis of alveolar osteitis

Alveolar osteitis (AO) is an extremely distressing outcome following extraction of tooth. Its pathophysiology is poorly understood due to varied nature of presentation of the condition. However, a delay in the healing process of bone due to fibrinolysis is believed to be the underlying pathophysiology. This review highlights three major risk factors – trauma, bacterial accumulation due to poor oral hygiene, and smoking – in causing alveolar osteitis, and describes underlying related molecular events. Fibrinolysis results due to traumatic tooth extraction as well as due to accumulation of certain microorganisms which leads to the development of alveolar osteitis. Tumour necrosis factor-alpha (TNF-?), Runt-related transcription factor 2 (Runx 2) and osteocalcin (OCN) can be used as molecular markers for evaluating alveolar osteitis. Assessment assays of such biomarkers can lead to a better understanding of the pathological process in providing a clearer picture to researchers and clinicians. Continuous...

Comparison of Stresses in Monoblock Tilted Implants and Conventional Angled Multiunit Abutment-implant Connection Systems in the All-on-four Procedure

Background: The All-on-four dental implant method is an implantology method designed to provide a comfortable prosthetic treatment option by avoiding advanced surgical procedures. This research aims to compare and evaluate the stress and tension values in conventional angled multiunit abutment-implant connection systems and monoblock dental implants used in the all-on-four procedure with finite element analysis.Methods: Two master models were created by placing four implants connected to multiunit abutments (group A) in the interforaminal region of a completely edentulous mandible and four monoblock implants (group B) in the same region of another completely edentulous mandible. Group A implants were classified according to their diameter as follows: 3.5 mm (M1A), 4.0 mm (M2A), and 4.5 mm (M3A). Similarly, group B implants were classified as M1B, M2B, and M3B. In the six models rehabilitated with acrylic fixed prostheses, a 100 N force was applied to the anterior implant region, and a 250 N force was applied to the posterior cantilever in both axial and 30° oblique directions. Von Mises stresses were analyzed in the bone and implant regions of all models.Results: M1A and M1B, M2A and M2B, and M3A and M3B were compared with each other under axial and oblique forces. The maximum Von Mises stresses in the bone around implants and the prosthesis screws, and the maximum and minimum principal stresses in the cortical and trabecular bone in group A models were significantly higher than those in group B models.Conclusions: This study shows that the use of monoblock implants without abutment-implant connections can prevent bacterial accumulation in micro-gaps, but the biomechanical properties of this implant system should be improved.