Dental Drill Research Articles

Odontogenic foreign bodies of the maxillary sinus

The anatomical proximity of the roots of molars and premolars to the floor of the maxillary sinus creates the risk for the formation of odontogenic sinusitis, which is often initiated by foreign bodies entering the sinus during dental procedures. Odontegenic foreign bodies (FB) of the maxillary sinus are usually represented by fragments of tooth roots, filling material, plastic material used in sinus lifting, dental implants, dental burs, pins and needles. FB causes the development of an inflammatory process in the sinus due to the penetration of highly virulent microbiota of the oral cavity or the formation of a fungal body. In rare cases, small FB can be evacuated into the nasal cavity as a result of the movement of the cilia of the ciliated epithelium. Most odontogenic FB are radiopaque and are detected by computed tomography (CT) of the paranasal sinuses. CT data allows to accurately localize FB and choose a treatment tactics.

DYNAMICS OF BONE MINERAL COMPOSITION OF RABBIT LOWER JAW AFTER BONE-DESTRUCTIVE TRAUMA

The properties of bone tissue, in particular its strength and hardness, depend on the mineral component of the bone. The aim of our work was to study the content of four mineral macronutrients – calcium, phosphorus, magnesium and sodium in the bone tissue of the rabbit lower jaw and to analyze the posttraumatic dynamics. Research was done on 20 adult 6-7-month-old rabbits, having 2.5-3.0 kg weight, which were segregated into experimental (15 animals) and control (5 animals) groups. Animals of the experimental group under combined anesthesia were subjected to bilateral bone-destructive trauma with a dental drill, that disrupted the integrity of the bone tissue of the alveolar part of the lower jaw. 1, 2, and 3 weeks after the injury the animals were taken out of the experiment, and were subjected to lower jaw disarticulation. To determine the mineral composition of the bone tissue, we used the method of atomic absorption spectral analysis. The content of four mineral elements (Ca, P, Mg, Na) was determined. It was found that calcium content more than doubled by the end of the fi rst week after injury, slightly decreased by the end of the second week, and slightly increased again during the third week. Bone phosphorus content increases by the end of the fi rst week after injury, and decreases during the next two weeks. The amount of sodium decreases slightly at the end of the fi rst week after injury, but increases during the next two weeks and exceeds the norm at the end of the third week. The amount of magnesium in the bone tissue decreases during the two weeks after injury, and increases by the end of the third week, almost returning to normal levels. The results of the study allowed us to conclude that within three weeks after surgical bone-destructive trauma, the studied macronutrients in bone tissue have a pronounced dynamic, diff erent and specifi c for each element.

Evaluating Knowledge, Attitudes and Practices of Pakistani Dental Professionals Regarding Silver Diamine Fluoride

Objective: The objective of this study was to evaluate the knowledge and attitude regarding Silver Diamine Fluoride (SDF) among Pakistani Dental Professionals worked at various institutes of Karachi.
 Methodology: This cross-sectional survey-based study was conducted among the house surgeons, general dental practitioners and specialists worked at various institutes of Karachi. Questionnaire was distributed among 375 participants through social media. Questionnaire was kept on google forum and link was sent to all participants through social media including Facebook, WhatsApp by non-probability consecutive sampling. Questionnaire was composed of two portions. Questions in first portion were related to demographic data and in second portion of Questionnaire had 13 closed ended questions regarding Knowledge and Approach towards Silver Diamine Fluoride. Statistical package for social sciences SPSS-25 was used for data entry and analysis with descriptive statistic, which used frequency, percentage, mean, and standard deviation.
 Results: Out of the total 375 participants, 160(43%) were male and 215 (57%) female. Mean age of participants was 33 + 11.8 years. 191(51%) heard about SDF and only 108(29%) attended lectures/discussions about SDF. 189(50.40%) responded that SDF is used in enamel lesion. 251(67%) participants responded that SDF is used in both anterior and posterior teeth. Only 160(42.66%) of participants responded that SDF is used for both dentitions. 122(32.53%) were agreed that SDF is an alternative to removing dental lesion by a dental drill, while only 118 (31.47%) agreed that many patients would not accept treatment of dental caries with SDF due to the permanent black staining of the carious lesion. 240 (64%) of participants were disagree about the SDF require the use of local anesthesia and more than half of participants responded that the silver is an antimicrobial ingredient in SDF. 237(63.2%) of participants responded that SDF is indicated in Children with High caries rate and most of them responded that black staining of tooth is main disadvantage and barrier to the use of SDF. Majority of participants did not know about reapplication interval for use of SDF.
 Conclusion: SDF is an appropriate alternative for restoring dental cavities in children. As it doesn’t require local anesthesia, it is the safest way to limit the progression of lesion in patient with high caries index. But there are some barriers related to the use of SDF in their regular dental practice is that, SDF causes permanent staining of tooth and also practitioners had little knowledge about their application protocols and recall or reapplication intervals.

Morphological aspects in remineralizing potential of Silver Diamine Fluoride.

Objectives: The purpose of this study was to demonstrate the efficacy of Silver Diamine Fluoride (SDF) antibacterial solution in penetrating the demineralized areas of enamel. Materials and Methods: It was considered a group of four extracted teeth (with no color fading, fissures, decay, or demineralization). Each tooth was sectioned in two equal parts, in mesio-distal direction, using a dental handpiece and a special rounded, flat bur. Each specimen was demineralized, for one minute, with 45% orthophosphoric acid, on occlusal and proximal zones. The specimens were then washed and dried with water-air dental syringe. All the probes were inspected with an optical microscope and enamel thickness was digitally measured. Advantage Arrest (Elevate Oral Care, USA), which contains SDF, was applied on the previous demineralized zones. The penetration of the substance was visually inspected with the optical microscope and electronically measured. Results: It was observed an improvement in remineralizing the white spots on enamel surfaces, the optical microscope being able to detect both demineralization and the penetration of SDF through enamel. Conclusions: Based on our in vitro study, SDF (Advantage Arrest) was capable to induce/increase enamel remineralization, through SDF penetration.

Metallic Dental Burr as an Iatrogenic Foreign Body in Maxillary Sinus - A Case Report

The foreign body in the maxillary sinus is quite a rare incidence. It may found in the case of maxillofacial trauma causing displacement of the tooth into maxillary sinus. The metallic foreign body may happen in case of gunshot injury and bullet, or pellet may retain in the maxillary sinus. Very rarely metallic foreign body like a dental burr may get lodged into maxillary sinus during dental procedure. If it happens ENT surgeon may be called upon to deal the foreign body.In this article we will describe a case that was referred to the ENT department, Khulna Medical College Hospital for removal of a dental burr retained in maxillary sinus. The accident happened in Dental department of the same hospital. We reviewed the options for the removal of the foreign body. There are two accepted approaches open and endoscopic for management of such cases. We successfully removed the foreign body through open approach.

Exploration of the role of the subodontoblastic layer in odontoblast-like cell differentiation after tooth drilling using Nestin-enhanced green fluorescent protein transgenic mice

ObjectivesOriginal odontoblasts and regenerated odontoblast-like cells (OBLCs) may differently regulate Nestin expression. This study aimed to investigate the role of the subodontoblastic layer (SOBL) using green fluorescent protein (GFP) reactivity in the process of OBLC differentiation after tooth drilling in Nestin-enhanced GFP transgenic mice. MethodsA groove-shaped cavity was prepared on the mesial surface of the maxillary first molars of 5- or 6-week-old mice under deep anesthesia. Immunohistochemical staining for Nestin and GFP and Nestin in situ hybridization were conducted on the sections obtained at 1–14 days postoperative. ResultsOdontoblasts showed intense endogenous Nestin protein and mRNA expression, whereas the coronal SOBL cells showed a Nestin-GFP–positive reaction in the control groups. The injured odontoblasts had significantly decreased Nestin immunoreactivity as well as decreased expression of Nestin mRNA 1–2 days after the injury; subsequently, newly differentiated OBLCs were arranged along the pulp–dentin border, with significantly increased Nestin expression as well as increased expression of Nestin mRNA on days 3–5 to form reparative dentin. Nestin-GFP–positive cells at the pulp–dentin border significantly increased in number on days 1 and 2. GFP(+)/Nestin(+) and GFP(−)/Nestin(+) cells were intermingled in the newly differentiated OBLCs. ConclusionsThe commitment of Nestin-GFP–positive cells into Nestin-positive OBLCs suggests that the restriction of endogenous Nestin protein and mRNA expression in the static SOBL cells was removed by exogenous stimuli, resulting in their migration along the pulp–dentin border and their differentiation into OBLCs.

Evaluation of Aerosol and Splatter Production using Dental Handpieces and Ultrasonic Scalers during Dental Procedures: A Pilot Study

There have been many articles written about aerosols and splatter during dental procedures with the potential for disease transmission. Due to the global COVID-19 pandemic, aerosol production during dental procedures has been considered a potential disease transmission pathway. Since there is no documented cases of dental professionals acquiring SARS-Cov1 or COVID-19, we decided to see how much aerosol is produced by a Dental High speed drill and ultrasonic scaler. Also if the use of high volume suction can eliminate any aerosol transmission. A pilot study using Glo Germ in the water to evaluate under blacklight the aerosol pattern and spread produced by a high speed dental handpiece and an ultrasonic scaler was performed. The results found that high volume suction using an 8mm diameter suction tip eliminated aerosol spray spread with a high speed dental handpiece. Minimal aerosol spread was found with the use of a cavitron scaler.

Патофизиологические аспекты регенерации костной ткани при увеличении ширины тонкого альвеолярного гребня челюстей с применением пьезохирургической техники

One of the main problems that impede dental rehabilitation with the use of dental implants is the limited amount of bone tissue in cases of its pronounced atrophy. According to a number of authors, about 50% of patients need additional osteoplastic operations before or at the stage of dental implantation. Objective. The aim of the paper is to assess the effectiveness of piezosurgical apparatus for splitting the alveolar crest of the jaw in the insertion of dental implants. Materials and methods. Forty adult patients (15 men and 25 women) aged 36 to 49 years who had undergone surgery for partial tooth loss on one and/or both jaws were evaluated. All in all, 48 implants were placed against the narrow alveolar crest of the jaws, which was surgically split using microsaws (Group 1- 11 patients), thin dental drills (Group 2 -15 patients) and piezosurgery apparatus (Group 3, 14 patients). The postoperative follow-up period was 4 to 6 months before the orthopaedic treatment. Results. During crestal splitting, the smallest bone reduction was obtained using piezosurgical technique, which was 0.84±0.22 mm, while with microsaws and dental drills, this figure was slightly higher, 0.93±0.21 mm (p≥0.05) and 1.23±019 mm (p≤0.05), respectively. One of the properties of a piezosurgical instrument is the effect on protein molecules, namely, their denaturation. This reduces the number of postoperative complications. Conclusion. The technique of alveolar crest splitting with a piezosurgical instrument works according to the absolutely natural and unique mechanism of bone healing - the mechanism of fracture repair. This technique uses the local bone resource and avoids or significantly reduces the use of foreign bone grafting materials. There is a tendency to a better rate of restoration of the lost width of the alveolar crest of the jaw when using the piezosurgical apparatus, in contrast to the use of microsaws and dental drills.

A novel dental reconfigurable drilling guide based on standardized drilling sleeves and personalized substrate

Drilling guide that consists of a personalized substrate and additional guide sleeves has been widely used to precisely position the implants in dental surgery. However, the traditional drilling guide cannot be reused or disassembled because the guide sleeves are affixed in the substrate. Additionally, the guide sleeves are not as wearable as they are made of titanium. In this paper, based on standardized drilling sleeves and a personalized substrate, a novel dental reconfigurable drilling guide is proposed, which is beneficial to ensure the accuracy of implant insertion. The drilling sleeves are installed in the substrate through transition fit and can be easily disassembled. First, the three-dimensional model of mandible was reconstructed based on the cone beam computed tomography data. Secondly, according to the implant planning from the dentist, the drilling sleeves were designed based on the diameter of special drills. The drilling sleeves was used in conjunction with the special drill. Thirdly, different substrates were designed through medical image processing software based on the oral cone-beam computed tomographic data. Afterwards, the designed drilling sleeves and substrates were manufactured by means of computer numerical control machining and three-dimensional printing, respectively. Finally, the reconfigurable drilling guide was formed by installing the standardized drilling sleeves in different substrates. The results were demonstrated that the standardized drilling sleeves can be reused in different substrates for different drilling guides. Reusing the reconfigurable drilling sleeves economizes medical materials, reduces the time to prepare the drilling guide, and simultaneously achieves prospective precision in the implant placement.

Comparing the disinfecting efficacy of pomegranate peel extract oil, Garlic oil, Tulsi leaf oil, and Clove leaf oil with standard autoclaving on dental round burs tested against Enterococcus faecalis: An in vitro study.

Background:The study was conducted to compare and evaluate the disinfecting efficacy of four different herbal oils with standard autoclaving against Enterococcus faecalis (E. faecalis). Fifty round burs were infected with E. faecalis and dipped into the chemical test solution for 10 min. The disinfecting efficacy for each test chemical was checked using culture method on blood agar plate and peptone water test to check for turbidity. Clove leaf oil and Tulsi leaf oil have very good antimicrobial efficacy against E. faecalis which are similar and comparable to that of autoclaving.Aim:This stusy aimed to compare the efficacy of pomegranate peel extract (PPE) oil, Garlic oil, Tulsi leaf oil, and Clove leaf oil with standard autoclaving on dental round burs tested against E. faecalis.Settings and Design:The disinfecting capability of four different experimental oils against autoclave was evaluated on 50 round burs exposed to E faecalis in an In-vitro study.Materials and Methods:A total of 50 round dental burs were exposed to E. faecalis and the disinfecting capability of four different experimental oils against autoclave was evaluated by counting colony-forming units (CFUs) and turbidity test.Statistical Analysis:Statistical analysis was performed using SPSS version 20.0 (IBM), Chicago. The CFUs between the five groups (I, II, III, IV, V) were compared using the Chi-square test. The level of significance was kept at 5%.Results:Clove leaf oil showed the best disinfection efficacy comparable to autoclaving, followed by Tulsi leaf oil with no statistically significant difference between them, whereas garlic oil and PPE oil were significantly less effective against E. faecalis.Conclusion:Clove leaf oil and Tulsi leaf oil can be used for disinfecting dental burs, infected with E. faecalis, as alternatives to autoclaving.

Foreign Bodies of Dental Iatrogenic Origin Displaced in the Maxillary Sinus - A Safety and Efficacy Analysis of a Retrospective Study.

Introduction:Foreign bodies (FB) of the paranasal sinuses are an uncommon clinical entities with the maxillary sinuses being those most frequently affected. According to the literature, 60% of paranasal sinus FB are of iatrogenic origin, while 25% are of traumatic origin. This article aims to present an iatrogenic origin series of cases of FB displaced or projecting into the maxillary sinus.Materials and Methods:In this retrospective study, the presence of the foreign body was revealed with radiologic methods and confirmed during the operation with macroscopic or later with histopathologic examination. All cases were treated with osteoplasty with vascularised pedicled bone flap or through minimally invasive intraoral procedure.Results:A total of 27 patients were included in our study, 14 men and 13 women. The age range was 18–65 years with mean age of 46.14 (standard deviation = 10.35) years. Foreign body was displaced fragments of teeth in 11 patients (40.27%), complete teeth in four patients (14.81%), dental implants in five patients (18.51%), dental impression material in 2 cases (7,40%), gutta percha cone in two patients (7.40%), endodontic sealer associated with aspergillosis in two patients (7.40%), and dental burr in one patient (3.7%). The time between dental foreign body displacement and the surgical intervention for its removal was critical for the occurrence of sinusitis. All operated patients remained asymptomatic during a follow-up of at least 1 year.Discussion:Prompt intervention for removal of FB eliminates the risk for chronic inflammation of the affected maxillary sinus and reduces the odds for sequelae.

The increasing in operating characteristic of medical rotating cutting tool by introduction abrasive smaller grain size powder into the galvanic bond

The results of studies on strengthening the galvanic bond by introduction an abrasive smaller grain size powder into it are discussed. A comparative analysis of a standard abrasive tool and a tool, the working part of which consists of modified abrasive particles, the size of which is 1/3 of the size of the working abrasive tool, is presented. As indicators wear, cutting ability, and wear resistance are studied. The positive effect of the proposed method is confirmed by the results of comparative tests of a medical rotating cutting tool made with the introduction of fine diamond powder into a metal bond of a dental bur and electrocorundum of a similar fraction into the working part of a podology bur.

An Economical Innovative Use of a Dental Burr to Sharpen and Reuse Follicular Unit Extraction (FUE) Punches for Hair Transplantation.

A simple technique of using a dental burr to sharpen a follicular unit extraction (FUE) punch for hair transplant surgery is used. During the process of extraction in FUE, the sharpness of a punch plays a vital role in reducing transection rates and thus increasing the yield of harvested grafts. Every time a sharp punch loses its sharpness, its expensive to replace it, hence we have described an ingenious technique to reuse a punch innumerable times, thus reducing the financial burden for the surgeon and the patient.

Additive manufacturing of PLA to mimic the thrust force of mandibular bone during drilling

Edentulism is a condition that results in the partial or total loss of teeth. It may lead to problems during chewing and be a cause of self-isolation and low self-esteem. Edentulism can be resolved both with removable prostheses (dentures) and fixed implants, with the latter being more efficient. The installation of a fixed implant involves a real surgical operation in which the jaw/mandibular bone is drilled through a special drill. One of the main cautions the surgeon must have during the operation is not to sever the nerves during the drilling. Given the composition of the bone is different in each person, the drilling thrust force is variable and controlling its movement can sometimes be complicated. Therefore, being able to test the operation on a dummy may reduce the number of errors. Additive manufacturing with its high degree of customization and ability to produce objects with almost no geometrical limitations could provide the required features to realize the dummy. In this work, the drilling properties of samples made in PLA through Fused Filament Fabrication (FFF) were studied. The samples were designed to mimic the composition of the bone. Specifically, a thin, hard, and denser outer layer and a 25% internal filling were adopted. The samples were drilled with a dental drill properly connected to a collaborative robot.

Finite element analysis of dental implant surgical guides

Dental drill guide is one of the most widely used devices to perform the dental implant surgery. The use of drill guides can increase the bone temperature while performing surgery because of the restriction introduced by the small clearance between the drill bit and the internal diameter of the guiding cylinders/bush/sleeve. This restriction can severely limit the required amount of irrigant flow to the drilling site, lea1829ding to increase in bone temperature. The rise in temperature can result in thermal necrosis and may induce many complications like bone cell death, longer healing times and weak bond between the implant and the jaw bone. In order to overcome this drawback new design has been proposed by providing irrigation channels in the internal diameter of bush. In this paper FEM analysis of proposed design is performed and it’s compared with the conventional dental drill guide. Fluent and transient thermal modules of finite element methods (ANSYS) are used to perform this analysis. Results of this study show that, with the use of new design of drill guides irrigant flow is better, which further results in better heat dissipation and lower bone temperature.

Effect of Dental Anxiety on Oral Health among the First-Time Dental Visitors: A Hospital-based Study.

Objective:The objective was to assess dental anxiety and to find its association with oral health status and oral health-related quality of life (OHRQoL) among 20–40-year-old patients visiting Vokkaligara Sangha Dental College and Hospital.Materials and Methods:A single-center, hospital-based cross-sectional study was done among first-time dental visitors in the Department of Oral Medicine and Radiology, Vokkaligara Sangha Dental College and Hospital over a period of 8 months (July 14–February 18). The sample size was determined to be 700. Participants in the age group of 20–40 years were selected based on inclusion and exclusion criteria. Data were collected using Corah's Modified Dental Anxiety Scale, Oral Health Impact Profile-14 (OHIP-14), and clinical examination was done using the WHO oral health assessment form and OHI-S. Data were analyzed using Chi-square test and t-test. The associations found through bivariate analysis were entered as predictor variables into linear and binomial logistic regression models with high dental anxiety as the outcome variable.Results:The results of the study suggested that 56% of the study participants were having dental anxiety. Local anesthetic injection (80%) and fear of tooth drilling (60%) were the most anxiety-provoking stimulus. Analysis of OHIP-14 suggested that respondents perceiving oral health as affecting their life quality (very often/fairly often) in the past year were observed for items such as tension, difficulty to relax, irritability, difficulty in doing usual jobs, and totally unable to function because of oral problems. Dental anxiety was significantly associated with gender (odds ratio [OR] = 1.32), education (OR = 1.43), occupation (OR = 2.07), poor oral hygiene status (OR = 3.15), presence of dental caries (OR = 2.67), bleeding on probing (OR = 1.57), presence of periodontal pockets (OR = 2.64), clinical attachment loss (OR = 1.63), and OHRQoL (OR = 1.76). Stepwise linear regression model of independent variables (<0.05 variables included) explained dental caries as highest predictor (39%), followed by debris (22%), calculus (38%), mean OHIS (27%), mean OHIP-14 (29%), deep pocket (14%), and the least predictor was shallow pocket (9%).Conclusion:Dental anxiety was associated with poor oral health status seeking further attention to modify patients' behavior regarding improvement in oral health status.

Comparison of an Air-Fed Mask System with Hospital-Issued Personal Protection Equipments for Dental Aerosol Protection During the COVID-19 Pandemic

Aim: A pilot study was conducted with the aim of developing a system to protect the eyes, nose, and mouth from the aerosol generated from a high-speed dental handpiece during the COVID-19 pandemic. Background: The SARS-CoV-2 virus is known to be present in the saliva of an infected individual during the contagious viral shedding phase of the disease. The use of rotary dental instruments places oral health practitioners at risk of contracting COVID-19 from infected individuals. In particular, it is very difficult to protect the mucous membranes of the face against the extremely fine aerosol produced from a high-speed dental handpiece. Objectives: This study aimed to develop and test a novel PPE system for use during the COVID-19 pandemic. An air-fed spray-painting mask was used under a plastic hood to protect against the aerosol from a high-speed dental handpiece. This was found to be superior compared to hospital-issued N-95 masks and eye protection in our test model. Methods: Subjects donned various forms of PPE whilst using a high-speed dental handpiece in a confined cubicle. The efficacy of each form of PPE was evaluated by adding fluorescein to the water coolant supply line of a high-speed dental handpiece before checking for facial contamination with an ophthalmology slit lamp. Results: Under our test conditions, the N-95 mask did not prevent nasal and mouth contaminations, but the combination of an air-fed mask with a sealed hood prevented these contaminations. Although goggles worn tightly did prevent contamination, the air-fed mask system was far more comfortable and did not fog up. Discussion: Under the rigorous test conditions of our model, we found hospital-issued PPE ineffective. We also found the single strategy of using positive airflow into a face mask ineffective, even with extremely high levels of airflow. Complete protection was only achieved reliably by the combination of physically sealing off the face from the surrounding airspace and using the air-fed system to provide an external source of air to breathe. We effectively made the clinical equivalent of a dive bell helmet. The air-fed mask is supplied by a standard dental air compressor and is simple to install for someone familiar with the technical aspects of compressors. The compressor does not rely on a filter and proves effective with cheap and easily accessible disposable items. Conclusion: Under rigorous testing conditions, the developed air-fed mask system with a sealed hood on low flow performed better than hospital-issued PPE against high-speed dental aerosol protection. The developed system protects the operators from the air of the room contaminated with aerosol and brings in safe air from the outside for them to breathe.

Effect of Sterilization (Autoclave) on Wear of Tungsten-Carbide Burs Coated With Diamond Particles With Different Thicknesses

Background: Extending the lifespan and improving the physical properties of dental burs as the most extensivly used instruments have been the subject of several studies. One of the proposed methods is using surface coatings for the burs. Since the dental instruments are reused, they require sterilization. One of the possible causes of the damage to dental burs is autoclaving process. This study aimed to investigate sterilization (autoclave) effect on wear of diamond coated tungsten-carbide burs with different thicknesses. Methods: In this in vitro study, 40 tungsten-carbide dental burs (IQ DENT, Poznan, Poland) were selected, out of which 20 burs were coated with 1.5-μm-like diamond particles, and 20 burs were coated with 3.5-μm by PVD method using Swin Plasma Coating Machine. Then, the burs were randomly divided into four groups (n=10) as follow: G1: 1.5 μm thickness coated burs without sterilization; G2: 3.5 μm thickness coated burs without sterilization; G3: 1.5 μm coated with sterilization; and G4: 3.5μm thickness coated burs with sterilization. Their weights were measured before wear test.Wear test was performed and then they were re-weighted. Data were analyzed using SPSS software (version 21) as well as Two-way ANOVA and Tukey HSD supplementary tests (α=0.05). Results: Mean and standard deviation of the burs weights without sterilization in the control groups were 7.31±2.63 and 7.96±1.61 mg, respectively; and mean and standard deviation of the burs weights in the sterilization groups were 7.06±0.98 and 7.12±1.11 mg, respectively. The study results showed that "sterilization application" and "thickness of coated layer" were the main factors and their intraction had no statistically significant difference (P=0.589). Conclusions: The sterilization process had no effect on wear of diamond coated tungsten-carbide burs with different thicknesses.

Quick and environmentally friendly sterilization process of dental instruments by radical vapor reactor

Dental instruments such as dental burs, endodontic files, scalers, and dental vacuum tips require complete sterilization to protect patients from infection. Generally, these instruments are sterilized by autoclaving or using ethylene oxide gas. However, these sterilization methods require a long time, high energy, and the production of hazardous waste. Therefore, a quick, low-energy, and high-sterilization method that generates no hazardous waste is required in the dental field. A radical vapor reactor (RVR) can sterilize bacteria by producing high concentrations of reactive oxygen species. In this study, we found that RVR can sterilize dental instruments effectively (i.e., under 10 min with green technology), and that packed dental instruments can be completely sterilized in 10 min using RVR treatment. Furthermore, we demonstrated that RVR treatment can meet the sterility assurance level. Thus, we propose the use of RVR technology to perform quick sterilization with a low environmental load.

Evaluation of Multidrug-Resistant P. aeruginosa in Healthcare Facility Water Systems.

According to the WHO, P. aeruginosa is one of the antibiotic-resistant bacteria that represent the biggest threat to public health. The aim of the study was to establish the prevalence of antibiotic-resistant P. aeruginosa in the water systems of various healthcare facilities over the course of nine years. A total of 4500 tap water system samples were taken from seventeen healthcare facilities. The culture method was used to detect P. aeruginosa, and the isolates were then tested for antibiotic resistance using the standardised disc diffusion method. Eleven antibiotics from five different classes were tested. P. aeruginosa was found to have contaminated 2.07% (no. 93) of the water samples. The majority of positive samples came from the dental units (30.11%) and the ward kitchens (23.66%). Considering the total isolates, 56.99% (no. 3) were resistant to at least one of the antibiotics tested. A total of 71.43% of P. aeruginosa isolated from water emerging from dental unit handpieces was antibiotic-resistant, with 45% of it resistant to ≥3 classes of antibiotics. Out of the total isolates, 19.35% showed resistance to carbapenems. It would be advisable to systematically screen tap water for opportunistic micro-organisms such as P. aeruginosa, as many countries already do, including this in the Water Safety Plan.