Technical complications with tooth-supported fixed dental prostheses (FDPs) of different span lengths: an up to 15-year retrospective study.

BACKGROUNDS: Long-span dental bridges may cause excessive load on abutment teeth and the periodontal area, which may lead to bridge fractures or periodontal problems. However, some reports have revealed that short- and long-span bridges can provide a similar prognosis. This clinical study aimed to investigate the technical complications associated with fixed dental prostheses (FDPs) of different span lengths. METHODS: All patients with previously cemented FDPs were clinically examined during their follow-up visits. Several data related to FDPs were registered, such as design, material type, location, and type of complication. The main clinical factors analyzed were technical complications. Life table survival analyses were performed to calculate the cumulative survival rate of FDPs when technical complications were detected. RESULTS: The study examined 229 patients with a total number of 258 prostheses and an average of 98 months of follow-up. Seventy-four prostheses suffered from technical complications, and the most common complication was ceramic fracture or chipping (n = 66), while loss of retention occurred in 11 prostheses. The long-term evaluation of long-span prostheses revealed a significantly higher technical complication rate compared to short-span prostheses (P = ,003). The cumulative survival rate for short-span FDPs was 91% in year 5, 68% in year 10, and 34% in year 15. For long-span FDPs, the cumulative survival rate was 85% in year 5, 50% in year 10, and 18% in year 15. CONCLUSION: Long-span prostheses (5 units or more) can be associated with a higher technical complication rate compared to short-span prostheses after long-term evaluation.

Uprighting a mesially tilted molar using customized titanium healing abutment of an adjacent osseointegrated implant.

This case report evaluates the use of a customized healing abutment of a dental implant to upright a mesially tilted molar using elastic separating rings. The external surface of the healing abutment was roughened by air particle abrasion, and a flowable composite was applied as a collar around it. The size of the resin collar was increased several times during the molar uprighting treatment by replacing the elastic ring. The uprighting procedure was evaluated after 2 months using radiographic and clinical evaluations. After treatment, the mesiodistal space above the implant was increased from 6 mm to 9 mm as follows: 2 mm by uprighting the second molar and 1 mm by mesial shifting the second premolar, and then a screw-retained zirconia crown was placed to restore the implant. The healing abutment of the implant can be modified by adding a resin collar and used as orthodontic anchorage for uprighting the adjacent tilted molar to facilitate the prosthetic procedure. Neither special instruments nor an orthodontic background are required for this minor tooth movement.

The impact of a 12-hour educational program on nurses' knowledge and attitudes regarding pain management: a quasi-experimental study.

BACKGROUND: Proper pain assessment is fundamental to effective pain management. Training nursing staff is critical for improving pain assessment competence and patient clinical outcomes. However, there is a dearth of research examining interventions that can enhance nurses' knowledge and attitudes toward pain management, especially in Saudi Arabia. Thus, this study aimed to evaluate the effectiveness of a structured education program on nurses' knowledge and attitudes towards pain management. METHODS: A quasi-experimental design was used. The study sample included 124 registered nurses working in intensive care or inpatient units in Saudi Arabia. Data were collected between March and September 2021 using a knowledge and attitudes survey regarding pain, satisfaction with and self-confidence in learning, and the learning self-efficacy scale for clinical skills. RESULTS: Nurses showed moderate levels of knowledge and attitudes regarding pain before (M = 20.3, SD = 4.80) pain management education, which were significantly higher after the intervention (M = 22.2, SD = 5.09, t = 2.87, p < .01). Before the intervention, nurses with a baccalaureate degree had more knowledge and better attitudes regarding pain management than diploma nurses (t = 3.06, p < .01). However, there was no significant difference between the two groups after the intervention (p > .05), indicating that the education was effective in enhancing nurses' knowledge and attitudes, regardless of nursing education level. Nurses in this study had high mean scores for self-confidence in learning (M = 35.6, SD = 4.68, range = 18-40), self-learning efficacy (M = 52.9, SD = 7.70, range = 25-60), and satisfaction with learning (M = 22.2, SD = 3.24, range: 10-25). CONCLUSION: Regular pain education programs can improve nurses' knowledge and attitudes. Increasing the breadth and depth of educational courses, alongside appropriate training, competency-based assessment, and pain education programs, is also recommended. Future research should consider the subjectivity and individualized nature of nursing by including patient satisfaction surveys to measure the improvement in nurses' knowledge and attitudes from the patient perspective.

Clinical laboratory services for primary healthcare centers in urban cities: a pilot ACO model of ten primary healthcare centers.

BACKGROUND: Primary healthcare centers (PHC) ensure that patients receive comprehensive care from promotion and prevention to treatment, rehabilitation, and palliative care in a familiar environment. It is designed to provide first-contact, continuous, comprehensive, and coordinated patient care that will help achieve equity in the specialty healthcare system. The healthcare in Saudi Arabia is undergoing transformation to Accountable Care Organizations (ACO) model. In order for the Kingdom of Saudi Arabia (KSA) to achieve its transformational goals in healthcare, the improvement of PHCs' quality and utilization is crucial. An integral part of this service is the laboratory services. METHODS: This paper presents a pilot model for the laboratory services of PHC's in urban cities. The method was based on the FOCUS-PDCA quality improvement method focusing on the pre-analytical phase of the laboratory testing as well as the Saudi Central Board for Accreditation of Healthcare Institutes (CBAHI) gap analysis and readiness within the ten piloted primary healthcare centers. RESULTS: The Gap analysis, revealed in-consistency in the practice, lead to lower the quality of the service, which was seen in the low performance of the chosen key performance indicators (KPI's) (high rejection rates, lower turn-around times (TAT) for test results) and also in the competency of the staff. Following executing the interventions, and by using some of the ACO Laboratory strategies; the KPI rates were improved, and our results exceeded the targets that we have set to reach during the first year. Also introducing the electronic connectivity improved the TAT KPI and made many of the processes leaner. CONCLUSIONS: Our results revealed that the centralization of PHC's laboratory service to an accredited reference laboratory and implementing the national accreditation standards improved the testing process and lowered the cost, for the mass majority of the routine laboratory testing. Moreover, the model shed the light on how crucial the pre-analytical phase for laboratory quality improvement process, its effect on cost reduction, and the importance of staff competency and utilization.

Power-Efficient Wireless Coverage Using Minimum Number of UAVs.

Unmanned aerial vehicles (UAVs) can be deployed as backup aerial base stations due to cellular outage either during or post natural disaster. In this paper, an approach involving multi-UAV three-dimensional (3D) deployment with power-efficient planning was proposed with the objective of minimizing the number of UAVs used to provide wireless coverage to all outdoor and indoor users that minimizes the required UAV transmit power and satisfies users' required data rate. More specifically, the proposed algorithm iteratively invoked a clustering algorithm and an efficient UAV 3D placement algorithm, which aimed for maximum wireless coverage using the minimum number of UAVs while minimizing the required UAV transmit power. Two scenarios where users are uniformly and non-uniformly distributed were considered. The proposed algorithm that employed a Particle Swarm Optimization (PSO)-based clustering algorithm resulted in a lower number of UAVs needed to serve all users compared with that when a K-means clustering algorithm was employed. Furthermore, the proposed algorithm that iteratively invoked a PSO-based clustering algorithm and PSO-based efficient UAV 3D placement algorithms reduced the execution time by a factor of ≈1/17 and ≈1/79, respectively, compared to that when the Genetic Algorithm (GA)-based and Artificial Bees Colony (ABC)-based efficient UAV 3D placement algorithms were employed. For the uniform distribution scenario, it was observed that the proposed algorithm required six UAVs to ensure 100% user coverage, whilst the benchmarker algorithm that utilized Circle Packing Theory (CPT) required five UAVs but at the expense of 67% of coverage density.

Evaluation of bactericidal effects of ultraviolet light C irradiation on cariogenic bacteria: An in vitro study.

BACKGROUNDS: Ultraviolet light C (UVL-C) irradiation has demonstrated an antimicrobial action against various pathogens. This study aimed to evaluate the bactericidal effect of UVL-C irradiation against cariogenic oral bacteria (Streptococcus mutans) in single layers and colonies grown on solid surfaces. METHODS: Two different experiments were performed. In the first experiment, a single layer of Streptococcus mutans bacteria on agar plates was exposed to UVL-C irradiation at energies from 0 to 21 mWs/cm2. The second experiment was conducted to inhibit viability of bacterial colonies on solid surfaces. The samples were derived from saliva from a patient where bacteria were grown on plastic strips and then exposed to UVL-C. The highest energy was 1050 mWs/cm2. RESULTS: Exposure to 21 mWs/cm2 was bactericidal in single layers of Streptococcus mutans. The result for bacterial colonies on solid surfaces indicated only a bacteriostatic effect, even at energies of 1050 mWs/cm2. CONCLUSIONS: Ultraviolet light C exhibits bactericidal effects on single layers of Streptococcus mutans but has a limited effect on bacterial colonies in a biofilm. It is a matter of debate whether these in vitro results would have the same effect in clinical setting.

Osseointegration effects of local release of strontium ranelate from implant surfaces in rats.

BACKGROUND: Numerous studies have reported the beneficial effects of strontium on bone growth, particularly by stimulating osteoblast proliferation and differentiation. Thus, strontium release around implants has been suggested as one possible strategy to enhance implant osseointegration. AIM: This study aimed to evaluate whether the local release of strontium ranelate (Sr-ranelate) from implants coated with mesoporous titania could improve bone formation around implants in an animal model. MATERIALS AND METHODS: Mesoporous titania (MT) thin coatings were formed utilizing the evaporation induced self-assembly (EISA) method using Pluronic (P123) with or without the addition of poly propylene glycol (PPG) to create materials with two different pore sizes. The MT was deposited on disks and mini-screws, both made of cp Ti grade IV. Scanning electron microscopy (SEM) was performed to characterize the MT using a Leo Ultra55 FEG instrument (Zeiss, Oberkochen, Germany). The MT was loaded with Sr-ranelate using soaking and the drug uptake and release kinetics to and from the surfaces were evaluated using quartz crystal microbalance with dissipation monitoring (QCM-D) utilizing a Q-sense E4 instrument. For the in vivo experiment, 24 adult rats were analyzed at two time points of implant healing (2 and 6 weeks). Titanium implants shaped as mini screws were coated with MT films and divided into two groups; supplied with Sr-ranelate (test group) and without Sr-ranelate (control group). Four implants (both test and control) were inserted in the tibia of each rat. The in vivo study was evaluated using histomorphometric analyses of the implant/bone interphase using optical microscopy. RESULTS: SEM images showed the successful formation of evenly distributed MT films covering the entire surface with pore sizes of 6 and 7.2 nm, respectively. The QCM-D analysis revealed an absorption of 3300 ng/cm2 of Sr-ranelate on the 7.2 nm MT, which was about 3 times more than the observed amount on the 6 nm MT (1200 ng/cm2). Both groups showed sustained release of Sr-ranelate from MT coated disks. The histomorphometric analysis revealed no significant differences in bone implant contact (BIC) and bone area (BA) between the implants with Sr-ranelate and implants in the control groups after 2 and 6 weeks of healing (BIC with a p-value of 0.43 after 2 weeks and 0.172 after 6 weeks; BA with a p-value of 0.503 after 2 weeks, and 0.088 after 6 weeks). The mean BIC and BA values within the same group showed significant increase among all groups between 2 and 6 weeks. CONCLUSION: This study could not confirm any positive effects of Sr-ranelate on implant osseointegration.

Work-related stress among nursing staff working in government hospitals and primary health care centres.

AIM: Work-related stress (WRS) in the nursing working environment is prevalent and significantly affects the performance of nurses and organizations. Poor nursing and administrative performance affects the delivery of safety and quality patient care. Thus, this study aims to compare the sources and factors of stress among nurses from hospitals and primary health care centres. METHODS: A cross-sectional study was conducted in five government hospitals and four sectors of primary health care centres in Saudi Arabia. Through a survey, the Nursing Stress Scale was completed by 347 nurses from February to March 2016. RESULTS: Workload is perceived as the most common source of WRS, whereas inadequate preparation is regarded as the least. Other major sources are conflicts with physicians and nurses in primary centres and the lack of support and uncertainty concerning treatment in hospitals. The nurses' age, marital status, nationality, and job position are the significantly identified factors that contribute to stress. CONCLUSION: Overall, the sources and factors of WRS significantly vary with nurses' working environment. Hence, understanding the perception of nurses towards their working environment can be a strategic basis in modifying policies in occupational stress management.

Evaluating the Accuracy of Dental Restorations Manufactured by Two CAD/CAM Milling Systems and Their Prototypes Fabricated by 3D Printing Methods: An In Vitro Study

PURPOSE: This in vitro study was conducted to evaluate the marginal accuracy of all-ceramic onlay restorations and prototypes fabricated using additive and subtractive methods. MATERIALS AND METHODS: Ten typodont first molars were prepared and scanned two times using two different scanners: ARCTICA AutoScan (KaVo Dental) and CEREC Omnicam (Dentsply Sirona). The two groups of virtual models were used to design two groups of virtual onlay restorations using two different CAD software (n = 10 each group) and exported in STL files. Each group of STL files was converted to physical onlay restorations and prototypes by using three different methods; these included two additive manufacturing techniques, stereolithography apparatus (SLA) and digital light processing (DLP), and one subtractive technique, e.max milling using the KaVo Everest system and the Dentsply Sirona inLab MC X5. A digital microscope was used to evaluate the marginal fit around the onlay restorations or prototypes on the typodont teeth. RESULTS: All evaluated groups showed mean marginal gaps between 59 and 84 µm. No statistically significant differences were found when comparing the marginal accuracy of onlay restorations fabricated by the subtractive method and onlay prototypes from the two additive methods, SLA (P = .70) and DLP (P = .21). CONCLUSION: All the models evaluated produced marginal gaps within the reported acceptable clinical range. Thus, these subtractive and additive methods may be considered suitable for onlay restoration production.

Management of unusual complications of modified rhomboid/Limberg procedure by interventional radiology guidance; A case report and literature review.

BACKGROUND: Fragmentation of the surgical drain is an unusual negative consequence of using a drainage system postoperatively. Even though it is rare, multiple management approaches were documented in the literature. CASE PRESENTATION: A 19-year-old male patient who had a history of recurrent pilonidal sinus disease that was operated on twice 4 months apart. He presented to our hospital for postoperative follow-up, during which the inserted drain was assessed. While withdrawing the drain, part of it was damaged and missed. The location of the misplaced drain was assessed by a lumbosacral region computed tomography (CT) scan. The decision was made to proceed with less invasive methods using interventional radiology techniques to avoid wide excision and incision reopening complications and prolonged healing time. A fluoroscopy procedure was performed to create three-dimensional anterolateral, frontal posterior views. Then the fragmented drain was retrieved successfully by a minimally invasive technique. The postoperative period was uneventful. DISCUSSION: Drain fragmentation and/or dislodgement is a highly challenging event that requires highly innovative intervention. Multiple treatment options are available as open surgery techniques and endoscopic approaches. CONCLUSION: This case highlights the potential role of fluoroscopy as an outstanding effective choice that could be carried out promptly and safely at the bedside under local anesthetic and reduce the patient's hospital stay.

Sudden unilateral eye pain with vision loss related to carotid stump syndrome; A case report and literature review.

INTRODUCTION AND IMPORTANCE: Carotid stump syndrome (CSS) is a rare cause of recurrent ipsilateral cerebrovascular accidents (CVAs) resulting from completely occluded internal carotid artery (ICA). In this condition, hemodynamic and embolic risks are related to cerebral and retinal ischemic strokes. PRESENTATION OF CASE: A 65-year-old gentleman with multiple comorbidities, presented to our hospital with a sudden painful unilateral vision loss of the right eye. Head CT was done upon arrival, showing no evidence of ischemic or hemorrhagic brain insult and multiple right frontoparietal old infarct lesions were detected. Central retinal artery occlusion diagnosis was confirmed by an ophthalmologist. CT angiogram of the brain and carotids was done and revealed an obliterated, thrombosed, and non-opacified right internal carotid artery from the carotid bifurcation up to intracranial petrous/foramen lacerum. After taking the patient's surgical consent, right carotid stump endarterectomy and ligation of the stump under general anesthesia was done and the postoperative period was uneventful. CLINICAL DISCUSSION: CSS is an uncommon underlying etiology, causing recurrent stroke events. The clinical features of this syndrome include cerebral and ophthalmology symptoms. Diagnosis of CSS relies on imaging modalities. Internal carotid artery stump surgical excision through the ipsilateral ECA endarterectomy is the gold standard for CSS treatment. CONCLUSION: Despite being a rare entity, CSS is a treatable cause of retinal embolic events TIAs. Therefore, it is important to raise awareness of such condition. The presented case demonstrates the diagnosis, management and prognosis of CSS.

Development of Nursing Research in Saudi Arabia: Implications for Policies and Practice.

Background: Nursing research in Saudi Arabia can be evaluated based on productivity as well as the quality of publications. The scope of scientific inquiry in nursing research expands to include clinical, health system, and outcome-based research, education, and administration. Aim: The purpose of this article is to track the development of nursing research in the Kingdom of Saudi Arabia. Design: Systematic review. Methods: This study used keywords, databases including MEDLINE, CINAHL, and PubMed to search for published articles on nursing in Saudi Arabia. The search resulted in the identification of 681 publications, from which 360 articles met the inclusion criteria and were included in the review. Results: The highest percentage of studies (56.7% of articles) focused on nursing clinical practice, and 76.0% of the studies were conducted in a hospital setting, followed by an educational setting. Most of the studies were quantitative and non-funded. More than 50.0% of the studies were first authored by Saudi scholars. Conclusions: This study concluded that nursing research in Saudi Arabia is still in its infancy, with notable improvements in the last 5 years. This correlated with an increasing number of nurses holding postgraduate degrees. With the Saudi government's strong support, the number of scientific research papers published on Saudi nursing has steadily increased over the last year.

Multiple vehicle cooperation and collision avoidance in automated vehicles: survey and an AI-enabled conceptual framework.

Prospective customers are becoming more concerned about safety and comfort as the automobile industry swings toward automated vehicles (AVs). A comprehensive evaluation of recent AVs collision data indicates that modern automated driving systems are prone to rear-end collisions, usually leading to multiple-vehicle collisions. Moreover, most investigations into severe traffic conditions are confined to single-vehicle collisions. This work reviewed diverse techniques of existing literature to provide planning procedures for multiple vehicle cooperation and collision avoidance (MVCCA) strategies in AVs while also considering their performance and social impact viewpoints. Firstly, we investigate and tabulate the existing MVCCA techniques associated with single-vehicle collision avoidance perspectives. Then, current achievements are extensively evaluated, challenges and flows are identified, and remedies are intelligently formed to exploit a taxonomy. This paper also aims to give readers an AI-enabled conceptual framework and a decision-making model with a concrete structure of the training network settings to bridge the gaps between current investigations. These findings are intended to shed insight into the benefits of the greater efficiency of AVs set-up for academics and policymakers. Lastly, the open research issues discussed in this survey will pave the way for the actual implementation of driverless automated traffic systems.

Secondary caries in fixed dental prostheses: Long-term clinical evaluation.

OBJECTIVES: Even with excellent fixed dental prostheses (FDPs), there will be a substantial risk of biological complications, such as caries, if proper oral hygiene is not maintained. This study aimed to evaluate the risks of developing secondary caries with FDPs in relation to the patient oral hygiene status. MATERIAL AND METHODS: Clinical and radiographic examinations were performed for patients to collect data related to their FDP complications and oral hygiene status. The main clinical parameter analyzed was secondary caries. Complications such as a fracture, debonding, or the need for endodontic therapy were also analyzed. The interval survival rate and the cumulative survival rate of FDPs from the time of treatment to the time of follow-up were analyzed. RESULTS: A total of 423 patients (with a total of 1116 FDPs) were examined in this study, with a mean age of 43.7 years and a mean follow-up time of 7 years. Regarding complications, secondary caries was detected in 94 FDPs (8.4%), fracture (or chipping) in 85 (7.6%) cases, need for endodontic treatment in 42 cases (3.7%), and debonding in four (0.3%) cases. Secondary caries was found in nine out of 219 FDPs (4%) in patients with good oral hygiene, 35 out of 634 FDPs (5.5%) in patients with fair oral hygiene, and 50 out of 272 FDPs (18.4%) in patients with poor oral hygiene (p ≤ .001). CONCLUSIONS: Good oral hygiene has a great influence on reducing the risk of secondary caries in patients with FDPs. The occurrence of secondary caries is a common complication in patients with poor oral hygiene.

Effect of full arch two scanning techniques on the accuracy of overdenture conventional and CAD/CAM Co-Cr bars.

This work evaluates the internal and marginal adaptation of implant-assisted overdenture cobalt-chromium (Co-Cr) bars manufactured using conventional as well as CAD/CAM subtractive and selective laser melting (SLM) utilizing two scanning techniques. METHODS: An edentulous study model containing four dental implants placed at teeth sites 36, 33, 43, and 46 was used. The study cast was scanned and compared to the virtual casts developed from two scanning techniques, straight and zigzag motion, using the in silico superimposition process. Then, conventional techniques were used to produce full-arch bars that were compared to the bars fabricated using the two scanning techniques and CAD/CAM subtractive and additive techniques. RESULTS: The conventional impression and casting techniques had the smallest marginal gap among the groups (P-value < 0.05). The CAD/CAM subtractive milling techniques in groups II and III had significantly smaller marginal gaps than SLM technique used in groups IV and V (P-value < 0.05). The analysis of the internal gap within each group showed statistically significant differences between different implant sites in all groups (P-value < 0.001), except when using the conventional impression and casting techniques in group I (P-value = 0.20). CONCLUSION: The conventional impression and fabrication techniques were better than the digital impression and CAD/CAM subtractive and additive techniques for the fabrication of full-arch bars. However, both straight and zigzag scanning techniques and the CAD/CAM subtractive technique had marginal and internal gaps that were within clinically accepted ranges, and the SLM was found to be unsuitable for long-span framework fabrication with either scanning technique used.

The impact of dental fear on the dental attendance behaviors: A retrospective study.

Objective: The aim is to investigate the causes of dental fear and its impact on dental attendance behaviors. Materials and Methods: A short questionnaire was distributed to participants at different dental clinics and by emails to evaluate their perceptions of dental fear. The questionnaire contained questions related to gender and age group. The remaining part of the questionnaire investigated the causes of dental fear and its impact on dental visits. Results: A total of 2264 participants aged 18 years and above agreed to complete the questionnaire. There were 1177 (52%) male participants and 1095 (48%) female participants. There was a response rate of approximately 60%. Drilling tooth devices and their sounds was the option that caused the highest dental fear among the participants who had it (n = 248; 37.7%). Pain was the second most frequently chosen option to cause dental fear (n = 165; 25%). Around 70% (n = 1257) of the participants who had dental fear overcame their fear and decided to seek treatment when they experienced annoying pain. At the same time, 18% (n = 323) of them sought the treatment when they experienced slight pain and 10% (n = 180) sought the treatment once they noticed a large carious lesion. Conclusion: People from both genders responded similarly to dental fear, and age was not found to be a significant factor in individuals' reactions to dental treatment. The sounds of teeth-drilling devices and related sounds may be responsible for the dental fear, as reported by many people. People with dental fear are more likely to avoid regular dental visits.

Nurses' Knowledge and Attitudes Regarding Pain Assessment and Management in Saudi Arabia.

Inadequate pain management affects the patient outcome. Pain assessment and management are fundamental in nursing care, and nurses must be equipped with adequate knowledge and a positive attitude toward pain assessment and management. This study aims to evaluate nurses' knowledge and attitudes regarding pain assessment and management at King Fahad Hospital, Al-Madinah, Kingdom of Saudi Arabia. A quantitative, cross-sectional survey, using a self-administered questionnaire, was conducted from January to February 2020 with 660 registered nurses working in the Emergency Department, critical care units, inpatient and outpatient departments at King Fahad Hospital in Al-Medinah, Kingdom of Saudi Arabia. The data were analyzed with descriptive and inferential statistics. Of the 660 nurses, 291 responded, resulting in a response rate of 44.09%. The participants' scores ranged from 17.7% to 100%, with a mean score 45.29%. The majority of the participants (70.1%) had a poor level of knowledge and attitudes (score < 50%). Nurses working in the outpatient department scored significantly higher than the group working in the Emergency Department and inpatient wards. Deficient knowledge and negative attitudes were found and nurses continue to underassess and undertreat pain. Nursing school curricula and in-service continuous education must equip nurses with the required knowledge and attitudes to enable them to manage pain effectively.

Long-Term Survival and Complication Rates of Porcelain Laminate Veneers in Clinical Studies: A Systematic Review.

The presented study aimed to assess the survival rate of porcelain laminate veneers (PLV) based on a systematic review of the literature. An electronic search was last updated in February 2021. Eligibility criteria included clinical series of patients rehabilitated with PLVs published in the last 25 years, with a minimum follow-up of 3 years. Survival analysis methods were applied. Twenty-five studies were included, with 6500 PLVs. The 10-year estimated cumulative survival rate (CSR) of PLVs was 95.5%. The 10-year CSR of PLVs when fracture, debonding, occurrence of secondary caries, and need of endodontic treatment were considered as isolated reasons for failure were 96.3%, 99.2%, 99.3%, and 99.0%, respectively. PLVs without incisal coverage had a higher failure rate than PLVs with incisal coverage. Non-feldspathic PLVs performed better than feldspathic PLVs. As a conclusion, the 10-year CSR of PLVs was 95.5%, when fracture, debonding, occurrence of secondary caries, and need of endodontic treatment were considered as reasons for restoration failure. Fracture seems to be most common complication of PLVs, followed by debonding, with both more commonly happening within the first years after PLV cementation. PLVs with incisal coverage and non-feldspathic PLVs presented lower failure rates than PLVs without incisal coverage and feldspathic PLVs.

Effects of the local administration of antibiotics on bone formation on implant surface in animal models: A systematic review and meta-analysis.

PURPOSE: This review aimed to evaluate the effects of the local delivery of antibiotics incorporated in implant surfaces on some quantitative parameters of bone formation. MATERIALS AND METHODS: An electronic search was undertaken in three databases (PubMed, Scopus, Embase) in addition to hand searching. The search was limited to animal experiments using endosseous implants combined with localized antibiotics release. Meta-analyses were performed for the percentages of bone volume (BV) and bone-to-implant contact (BIC). RESULTS: Nine studies met the inclusion criteria. Several methods were identified for local delivery of antibiotics at the bone-implant interface, but the most commonly used method was by coating (incorporating the implant surface with the antibiotic agents). Different antibiotic agents were used, namely bacitracin, doxycycline, enoxacin, gentamicin, minocycline, tobramycin, and vancomycin. There was no statistically significant difference in the percentage of BIC between implants with or without localized antibiotic release (P = 0.59). The meta-analysis revealed higher BV around implants coated with antibiotics compared to control groups (without antibiotics) (P < 0.01). CONCLUSION: It is suggested that the local administration of antibiotics around implants did not adversely affect the percentage of direct bone contact around implants, with a tendency for a slightly better bone formation around implants when combined with local administration of antibiotics. It is a matter of debate whether these in vivo results will have the same effect in the clinical setting. However, the risk of bias of these studies may, to some extent, question the validity of these results.

Development of a photon induced drug-delivery implant coating.

A thin surface coating intended for medical devices such as implants where local drug release is enabled using near infrared light (NIR) as an external stimulus has been developed. The delivery system consists of a thin Poly (N-isopropylacrylamide)-co-acrylamide (PNIPAAm-AAm) polymer layer with incorporated gold nanorods (GNRs). The aspect ratio of the GNRs were chosen to absorb NIR light, thus fitting the biological window of low tissue absorption, to locally heat the polymeric layer to initiate a drug release. Hence, controlled drug delivery from a surface within tissue orchestrated from outside the body is achievable. Composition of the PNIPAAm-AAm co-polymer was systematically varied to find a suitable phase transition temperature for in vivo applications. Differential scanning calorimetry (DSC) analysis showed that PNIPAAm-AAm containing 10% acrylamide had an appropriate phase transition temperature of 42 °C. As visualized by scanning electron microscopy (SEM), the surface coating consisted of 200 nm uniform polymer layer. Quartz crystal microbalance with dissipation monitoring (QCM-D) analysis coupled with in situ NIR irradiation demonstrated a dramatic shift in frequency that was attributed to mass being released from the surface upon irradiation. This mass release correlated well with the drug release profile as determined using UV/VIS spectroscopy with phenol as a model drug. In addition, proof-of-concept of the drug-delivery system was demonstrated by releasing the antibiotic vancomycin to eradicate Staphylococcus epidermidis bacteria in culture.