Clinical benefits of immediate dentin sealing: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: The clinical complications, success, and survival rates of indirect restorations delivered with the immediate dentin sealing protocol are unclear. PURPOSE: The purpose of this systematic review and meta-analysis was to find and collect evidence on the clinical complication, success, and survival rates of indirect restorations delivered with immediate dentin sealing. MATERIAL AND METHODS: Electronic databases were searched for clinical studies on immediate dentin sealing up to December 2023, without language or time limitations. The records were included if they were clinical trials evaluating the clinical complication and survival rates of indirect restorations bonded to tooth substrate sealed immediately after preparation with suitable resin bonding. The extracted data were analyzed via Review Manager 5.4 for meta-analysis (α=.05). RESULTS: A total of 11 studies were included in this review. The clinical complication rate was lower for immediately sealed dentin than for protocols without dentin sealing. The survival rate of restorations luted with the immediate dentin sealing protocol was higher (96.4% to 100%) than that of immediate dentin sealing (81.8% to 96.7%), negatively correlated with the observation time. The intensity and incidence of postoperative sensitivity were statistically significantly lower for restorations with immediate dentin sealing than for those without dentin sealing or conventionally cemented (P<.05). CONCLUSIONS: Immediate dentin-sealed indirect restorations had fewer clinical complications and higher success and survival rates than those delivered without dentin sealing. To avoid postoperative sensitivity or reduce its intensity, dentin surfaces should be sealed immediately after preparation. More long-term randomized clinical trials are recommended to confirm these evidence-based conclusions.

The Influence of Ferrule Design and Pulpal Extensions on the Accuracy of Fit and the Fracture Resistance of Zirconia-Reinforced Lithium Silicate Endocrowns.

The study aimed to assess the marginal, axial, and internal adaptation, as well as the fracture resistance of zirconia-reinforced lithium silicate (ZLS) endocrowns with varying pulpal inlay extensions and marginal geometry. Sixty extracted maxillary first molar teeth were divided into six groups (n = 10) according to pulpal inlay extension and marginal configuration. The first three groups (J2, J3, and J4) utilized prepared teeth for endocrowns without ferrule design and 2 mm, 3 mm, and 4 mm pulpal extensions, respectively. The second three groups (F2, F3, and F4) utilized prepared teeth with 1 mm shoulder margins and 2 mm, 3 mm, and 4 mm pulpal extensions. The endocrowns were fabricated from ZLS blocks using CAD/CAM milling technology. After cementation, the specimens underwent thermal aging for 5000 cycles and were evaluated for marginal adaptation. Using a universal testing machine, the fracture resistance was tested under quasistatic loading (1 mm/min). Two-way ANOVA and the Tukey's post hoc test were employed for data analysis (p ≤ 0.05). The results of this study revealed that endocrowns without ferrule exhibited superior fracture strength than a 1 mm ferrule design p < 0.05, irrespective of the inlay depth. All designs with and without ferrule and all inlay depths showed clinically acceptable marginal and internal fit. The conventional endocrown design without ferrule and 2 mm inlay depth showed the lowest surface gap. The pulpal surface showed the highest discrepancy among all groups compared to the other surfaces. Endocrowns without ferrule are more conservative and have higher fracture strength than 1 mm ferrule designs; extending the inlay depth showed a significant increase in fracture resistance of the 1 mm ferrule design, but not for the conventional design without ferrule and 2 mm inlay depth. All groups exhibited a high auspicious fracture strength value for molar endocrown restorations.

Evaluation of Implant Placement Risk Levels in Partially Edentulous Patients Using Cone Beam Computed Tomography.

OBJECTIVE: This study aimed to evaluate the implant placement risk levels in partially edentulous patients using cone beam computed tomography (CBCT) and implant planning software. MATERIALS AND METHODS: A total of 101 CBCT scans of partially edentulous patients were included. Evaluations of jawbone anatomy, vital structures' proximity, and the risk of inferior alveolar nerve injury with esthetic considerations were done on CBCT images using implant surgery software (Blue Sky Plan 4; Blue Sky Bio, Grayslake, IL). RESULTS: A total of 101 patients with 106 edentulous sites were examined. The mean ridge height of the non-esthetic zone was 10 mm and 14.4 mm in the maxilla and mandible, respectively. The period of edentulousness significantly affected the risk of placing implants in the non-esthetic zone (P<.05). The relation between gender and mandibular canal identification was significant (P<.01). A higher risk of implant placement is associated with a more extended period of edentulousness. The preoperative assessment revealed that the mandibular canal could be identified more easily in females than males; thus, nerve injury could be avoided. However, age had no associated effect. CONCLUSION: Age has no associated effect on the implant placement risk levels for partially edentulous patients during dental implant planning. A higher risk of implant placement is associated with a more extended period of edentulousness. Mandibular canal identification during virtual preoperative assessment was higher in females.

SMOKERS MAY BE SUBJECT TO A HIGHER RISK OF SCHNEIDERIAN MEMBRANE PERFORATION THAN NONSMOKERS DURING MAXILLARY SINUS AUGMENTATION.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Association between smoking and Schneiderian membrane perforation during maxillary sinus floor augmentation: A systematic review and meta-analysis. Wang, X., Ma, S., Lin, L., & Yao, Q. Clinical Implant Dentistry and Related Research. 2022., 25.1: 166-176. SOURCE OF FUNDING: National Natural Science Foundation of China, Grant/Award Number: 81801021; Hunan Provincial Health Commission, Grant/Award Number: B202308056991. TYPE OF STUDY/DESIGN: Systematic review and meta-analysis.

Polymeric Denture Base Materials: A Review.

An ideal denture base must have good physical and mechanical properties, biocompatibility, and esthetic properties. Various polymeric materials have been used to construct denture bases. Polymethyl methacrylate (PMMA) is the most used biomaterial for dentures fabrication due to its favorable properties, which include ease of processing and pigmenting, sufficient mechanical properties, economy, and low toxicity. This article aimed to comprehensively review the current knowledge about denture base materials (DBMs) types, properties, modifications, applications, and construction methods. We searched for articles about denture base materials in PubMed, Scopus, and Embase. Journals covering topics including dental materials, prosthodontics, and restorative dentistry were also combed through. Denture base material variations, types, qualities, applications, and fabrication research published in English were considered. Although PMMA has several benefits and gained popularity as a denture base material, it has certain limitations and cannot be classified as an ideal biomaterial for fabricating dental prostheses. Accordingly, several studies have been performed to enhance the physical and mechanical properties of PMMA by chemical modifications and mechanical reinforcement using fibers, nanofillers, and hybrid materials. This review aimed to update the current knowledge about DBMs' types, properties, applications, and recent developments. There is a need for specific research to improve their biological properties due to patient and dental staff adverse reactions to possibly harmful substances produced during their manufacturing and use.

Effectiveness of Virtual Reality and Interactive Simulators on Dental Education Outcomes: Systematic Review.

In recent years, virtual reality and interactive digital simulations have been used in dental education to train dental students before interacting with real patients. Scientific evidence presented the application of virtual technology in dental education and some recent publications suggested that virtual and haptic technologies may have positive effects on dental education outcomes. The aim of this systematic review was to determine whether virtual technologies have positive effects on dental education outcomes and to explore the attitudes of dental students and educators toward these technologies. A thorough search was conducted in PubMed, Scopus, MEDLINE (via EBSCO), The Cochrane Library (via Wiley), Web of Science Core Collection (via Thomson Reuters), and Dentistry and Oral Science source (via EBSCO) using the keywords (student, dental) AND (education, dental) AND (virtual reality) OR (augmented reality) OR (haptics) OR (simulation) AND (dentistry) OR (dental medicine). The quality of the reported information was assessed following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement for systematic reviews. A total of 73 publications were considered for this review. Fifty-two of the selected studies showed significant improvement in educational outcomes and virtual technologies were positively perceived by all the participants. Within the limitations of this review, virtual technology appears to improve education outcomes in dental students. Further studies with larger samples and longer term clinical trials are needed to substantiate this potential positive impact of various virtual technologies on dental education outcomes.

Does the facebow affect the outcome of CAD/CAM occlusal splint. Randomized clinical trial.

BACKGROUND: Occlusal appliances can distribute aggressive loads which are generated by bruxism and can reduce their frequency. The facebow record, when used in the construction of occlusal appliances, helps in minimizing occlusal discrepancies. This study aimed to compare the effect of CAD/CAM stabilization occlusal splint made with and without facebow for management of bruxer patients. METHOD: 24 Patients who were diagnosed as bruxers were randomly assigned into two equal groups and obtained maxillary CAD/CAM occlusal stabilizing splint recorded with centric relation either with or without using a facebow. The patient satisfaction using the visual analog scale (VAS) was recorded at baseline, one month and three months' follow-up periods. The adjustment time of both splints, from the start of splint delivery until becoming well-fitted and occlusally adjusted, was calculated using a stopwatch. RESULTS: The CAD/CAM occlusal splints with or without the use of facebow improved the patient's satisfaction with no statistically significant difference between both groups at baseline, one month and three months with p values of 0.73, 0.24 and 0.45 respectively. The comparison between the two modalities regarding the adjustment time showed no statistically significant difference between both groups (P = 0.06). CONCLUSION: According to the results of this study; no difference was detected in patient satisfaction and the time required for adjustment of CAD/CAM occlus.

Effect of various digital cement space settings on the adaptation of CAD/CAM occlusal veneer "micro-ct evaluation".

The aim was to evaluate the adaptation of CAD/CAM occlusal veneer with different cement space settings using micro CT scan. Three groups of IPS e.max-CAD lithium disilicate occlusal veneers with different cement space settings (30, 40, and 50 µm) were produced. A circle with 20 different diameters was centered at the center of the same image position of every scanned specimen using micro CT scan to measure four different locations [Occlusal (OCG), axial (AXG), Marginal (MAG), and absolute marginal discrepancy values (AMD)]. Kruskal-Wallis test revealed that there were no statistical differences between (OCG), (AXG), and (AMD) tested groups (p>0.05), and statistical differences between (MAG) group and other two groups (p<0.05). An increase in the digital cement space significantly improved the marginal fit of IPS e.max-CAD occlusal veneer.

Early detection of oral cancer and potentially malignant disorders: Experiences, practices, and beliefs of prosthodontists practicing in Saudi Arabia.

STATEMENT OF PROBLEM: Data on the oral cancer screening skills and beliefs of prosthodontists practicing in Saudi Arabia are lacking. PURPOSE: The purpose of this survey was to assess the beliefs, experiences, and practices of prosthodontists practicing in Saudi Arabia regarding the early detection of oral cancer and potentially malignant disorders. MATERIAL AND METHODS: A cross-sectional, questionnaire-based survey was conducted on prosthodontists practicing in Saudi Arabia. A 26-item questionnaire was sent to all eligible prosthodontists (N=250). The collected data were analyzed with a statistical software program. RESULTS: The response rate was 57.2% (N=143). The majority of participants (79%) reported that they routinely examined all new patients for mucosal pathologies. However, only 58% reported that they examine their patients at recall visits, and only 61.5% stated that they provide tobacco use or smoking cessation advice. With regard to the respondents' experiences with suspicious mucosal lesions, the majority said that they had detected a suspicious lesion (79.7%) and had referred affected patients (83.2%) during their career. Most prosthodontists (65%) believed that they were able to detect oral cancer on their own, and 40% believed that they could influence their patients to stop smoking. A lack of training, confidence, time, and financial incentives were reported as barriers to oral cancer screening. CONCLUSIONS: Most of the prosthodontists surveyed in this study appeared motivated to perform routine oral mucosal screening. However, more efforts are needed to help improve the attitudes, confidence, and skills of prosthodontists when it comes to identifying and referring suspicious oral mucosal lesions.

Awareness, attitude and ethical concern of dental practitioners about stem cells: a cross-sectional study / Consciência, atitude e preocupação ética dos dentistas sobre as células-tronco: um estudo transversal

Objective: To evaluate the level of awareness and attitude among dental practitioners regarding the use of stem cells in dentistry and to determine their knowledge of ethical concerns related to the recent therapy. Material and Methods: A cross-sectional survey-based study was conducted at Taibah University Dental College and Hospital. Medina and at governmental and private dental clinics at the western region of Saudi Arabia. Responses of dental practitioners who completed the survey were recorded between March 2019 and July 2019 without containing any personal identifiers. Level of awareness and attitude and knowledge about ethical issues in relation to stem cell therapy was established. Results: A total of 214 male and female dental practitioners participated in this study and the majority were registered at the Saudi Commission for Health Specialists 128 (59.8%). Dental consultants reported the highest percentage of awareness about dental stem cells (96%, p= 0.005), whereas general dental practitioners (56.2%, p= 0.005) and specialists (52%, p= 0.005), respectively had a lower percentage. When ethical concerns were determined, dental consultants had the highest percentage of knowledge (56%, p= 0.005), whereas dental practitioners (71.2%, p= 0.005) with < 5 years of experience (69.1, p= 0.002) lacked information about related ethical issues. Conclusion: Ways to increase stem cell awareness among dental practitioners in this study recommended including stem cell topics in the dental curriculum and organizing frequent seminars and conferences on this subject. (AU)

Objetivo: Avaliar o nível de consciência e a atitude dos dentistas em relação ao uso de células-tronco na odontologia, e determinar o conhecimento desses profissionais sobre as questões éticas relacionadas à terapia recente. Material e Métodos: Um estudo transversal baseado em pesquisa foi conduzido na Faculdade e Hospital de Odontologia da Universidade Taibah de Medina e em clínicas odontológicas governamentais e privadas na região oeste da Arábia Saudita. As respostas dos dentistas que responderam à pesquisa foram registradas entre março de 2019 e julho de 2019, sem conter nenhum identificador pessoal. Foi estabelecido o nível de consciência, atitude e conhecimento sobre questões éticas em relação à terapia com células-tronco. Resultados: Um total de 214 dentistas do sexo masculino e feminino participaram deste estudo, sendo 128 (59,8%) desses cadastrada na Comissão Saudita de Especialistas em Saúde. Os consultores em odontologia relataram o maior percentual de conhecimento sobre as células-tronco dentárias (96%, p = 0,005), enquanto os dentistas gerais (56,2%, p = 0,005) e especialistas (52%, p = 0,005) tiveram um percentual menor. Quando as questões éticas foram determinadas, os consultores em odontologia tiveram o maior percentual de conhecimento (56%, p = 0,005), enquanto os dentistas (71,2%, p = 0,005) com menos de 5 anos de experiência (69,1%, p = 0,002) tinham menos informações sobre questões éticas relacionadas. Conclusão: Formas de aumentar a conscientização sobre as células-tronco entre os dentistas deste estudo incluem tópicos sobre células-tronco no currículo de odontologia, além de frequentemente organizar seminários e conferências sobre o assunto. (AU)

Factors Influencing Global Variations in COVID-19 Cases and Fatalities; A Review.

Since the first cases of the novel corona virus disease (COVID-19) were diagnosed in China, outcomes associated with this infection in terms of total numbers of cases and deaths have varied widely between countries. While some countries had minimal rates of infections and deaths, other countries were hit hard by the pandemic. Countries with highest numbers of cases continued to change over time, but at the time of submission of this article they are: USA, Brazil, Russia, UK, India, Spain, Italy, Peru and Chile. This is in contrary to many countries in the Middle East, Far East, and Africa, which had lower cases or deaths/cases rates. This raised many questions pertaining to this variation. This overview explores the potential factors that contribute to spread, transmission and outcomes of the COVID-19 infection. It also uses an evidence-based approach in reviewing the available most recent literature that tackled the various factors that modify the populations' response to COVID-19, namely, factors pertaining to population characteristics, environmental and geographic factors.

COVID-19: Present and Future Challenges for Dental Practice.

COVID-19 was declared a pandemic by the World Health Organization, with a high fatality rate that may reach 8%. The disease is caused by SARS-CoV-2 which is one of the coronaviruses. Realizing the severity of outcomes associated with this disease and its high rate of transmission, dentists were instructed by regulatory authorities, such as the American Dental Association, to stop providing treatment to dental patients except those who have emergency complaints. This was mainly for protection of dental healthcare personnel, their families, contacts, and their patients from the transmission of virus, and also to preserve the much-needed supplies of personal protective equipment (PPE). Dentists at all times should competently follow cross-infection control protocols, but particularly during this critical time, they should do their best to decide on the emergency cases that are indicated for dental treatment. Dentists should also be updated on how this pandemic is related to their profession in order to be well oriented and prepared. This overview will address several issues concerned with the COVID-19 pandemic that directly relate to dental practice in terms of prevention, treatment, and orofacial clinical manifestations.

Association of Dental Caries, Retained Roots, and Missing Teeth with Physical Status, Diabetes Mellitus and Hypertension in Women of the Reproductive Age.

OBJECTIVES: To investigate in women of reproductive age a possible association between particular dental diseases-dental caries, retained roots, and missing teeth-with some systemic conditions-physical status score- ASA (American Society for Anesthesiologists), diabetes mellitus, and hypertension. METHODS: Dental and medical history were retrieved from the electronic files of dental patients. Statistical analysis was performed using cross tabulation with the Chi-square test to explore the significance of an association between variables pertaining to dental diseases and the investigated systemic conditions. Logistic regression was further used to explore the significance of the above dental diseases as predictors for systemic conditions. RESULTS: A total of 1768 female patients in the age range 18-55 were included, with a mean age of 31.2 ± 10.13 years. A total of 228 (12.9%) patients had a chronic systemic disease within the ASA II category, 66 (3.7%) were diabetic, and 76 (4.3%) were hypertensive. Missing teeth were significantly associated with the ASA II category, diabetes mellitus, and hypertension (p < 0.001, p = 0.009, p = 0.005 respectively), while retained roots were significantly associated with the ASA II category only (p = 0.023). Logistic regression showed a low predictive capacity of models describing the three systemic conditions. CONCLUSIONS: Diabetes mellitus and hypertension were the most common systemic diseases among the study sample. While carious teeth had no significant association with the investigated systemic conditions, retained roots were significantly associated with the ASA II category only, and missing teeth were significantly associated with all investigated systemic conditions. However, oral diseases expressed a low predictive power of these systemic conditions.

Impact of Surface Treatment Methods on Bond Strength of Orthodontic Brackets to Indirect Composite Provisional Restorations.

AIM: To assess the impact of different surface treatment protocols on the shear bond strength (SBS) of metal orthodontic brackets (MOBs) and ceramic orthodontic brackets (CBOs) bonded to provisional crowns via the SBS test. MATERIALS AND METHODS: A total of 120 provisional indirect composite crowns (SR Nexco; Ivoclar Vivadent) for maxillary first premolars were fabricated and evenly allocated into two groups: MOBs and CBOs. According to the surface treatment protocol, each group was divided into three subgroups: group CO, no treatment; group HF, the surface was etched with 10% hydrofluoric acid; and group SA, the surface was sandblasted followed by silanization. After bracket bonding, the samples were subjected to 3,000 thermocycles between 5°C and 55°C. SBS was evaluated using a universal testing machine at a crosshead speed of 1 mm/minute and the adhesive remnant index (ARI) was identified. For statistical analysis, ANOVA and Tukey HSD post hoc tests were performed. RESULTS: Mean bond strength values for CBOs cemented to control, HF-, and SA-treated subgroups before and after thermocycling were (9.6 µ 1.4, 6.2 µ 1.1), (17.8 µ 2.1, 13.8 µ 1.3), and (17.2 µ 1.4, 12.1 µ 1.8) MPa, respectively. For the metallic brackets, the results were (7.7 µ 2.3, 3.9 µ 1.4), (15.5 µ 1.6, 12.8 µ 1.2), and (15 µ 1.2, 11.2 µ 1.6) MPa, respectively. There was a significant difference (p = 0.000) between ceramic and metallic bracket groups. CONCLUSION: Conditioning of indirect composite provisional crowns either with HF or SA was significantly affecting the adhesion to both bracket types. CLINICAL SIGNIFICANCE: Increasing the bond strength between provisional crowns and orthodontic brackets (OBs) may improve the treatment standard provided to patients.

Antibiotic Self-Medication for Oral Conditions: Characteristics and Associated Factors

Objective: To investigate the prevalence and contributing factors of antibiotic selfmedication for oral conditions in dental patients. Material and Methods: A questionnaire was distributed to 501 patients attending Taibah University Dental College and Hospital, Al Madinah, Saudi Arabia during late 2016. Questions were on socio-demographic characteristics, and pattern of antibiotic self-medication for oral disease. Statistical analysis was performed using IBM SPSS software version 21. Statistical significance level was set at p ≤.05. Results: Age range was 15-64 years (29.08±9.32 years) with 297 females (59.3%) and 204 males (40.7%). 135 patients (27%) self-medicated with antibiotics for oral disease. This practice was statistically significantly associated with the older adults (p=0.001), lack of medical or dental insurance (p=0.014 and 0.007, respectively), and poor dental attendance (p=0.021). A number of 26 (25.7%) perceived analgesics as antibiotics. Amoxicillin-clavulanic acid was the most commonly cited antibiotic by 18 patients (17.8%). Dental pain was the most frequently reported oral condition. Pharmacists were the most common source for antibiotic prescription cited by 58 (57.4%). Conclusion: Antibiotic self-medication for oral disease is associated with the use of broad-spectrum antibiotics for non-indicated clinical oral conditions. The practice was encouraged by lenient behavior of pharmacists, lack of health insurance, and poor dental attendance.

Arabic Coffee as a Potential Alternative to Black Coffee in the Post- Bleaching Period: An in-vitro Study

Objective: To investigate the effect of Arabic coffee on bleached teeth in comparison to black coffee. Material and Methods: Forty teeth (sound maxillary or mandibular premolars with no carious lesions) were randomly selected into 4 groups (A, B, C and D). One group (A) did not receive bleaching and was incubated in saline. The second group (B) was bleached and then incubated in saline. The last two groups were bleached and were immersed in either Arabic coffee (C) or black coffee (D). Color recording of the samples was always carried out as near to their mid-buccal surfaces as possible using VITA Easyshade Advance System. Color measurements were carried out using a digital spectrophotometer at baseline and after short-term and long-term immersion. Data were subjected to two way ANOVA and T-test. The level of significance was set at was set at 0.05. Results: Results show that immersion in Arabic coffee resulted only in significant reduction in the b* color value upon long-term immersion (i.e. a reduction in the yellow hue). Black coffee on the other hand resulted in significant: reduction in lightness, increased red tint and increased yellow hue altogether. Conclusion: The use of Arabic coffee did not deteriorate color, with the only significant change being the reduction of yellowish hue. Arabic coffee could be an alternative to black coffee after bleaching.

Coronal pulpotomy for cariously exposed permanent posterior teeth with closed apices: A systematic review and meta-analysis.

OBJECTIVES: This systematic review was performed to evaluate the clinical outcome of coronal pulpotomy treatment to manage carious vital pulp exposure in permanent posterior teeth with closed root apices. DATA/SOURCES: PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline was used. A search of articles published between 1960 January and 2015 July was conducted in PubMed, EMBASE, and CENTRAL databases. STUDY SELECTION: Only studies that performed full coronal pulpotomy for carious vital pulp exposure of permanent posterior teeth and had clinical and radiographic assessments during at least one-year follow-up were qualified for data analyses. The weighted mean success rate (WSR) was the primary outcome and estimated using DerSimonian-Laird random effects model. Out of 299 articles, six studies were included for the analysis of one-year WSR, and five studies were included in the analysis of two-year WSR. The one-year and two-year WSR were 94% (95% confidence interval (CI): [90,99]) and 92% (CI: [84,100]) respectively. Differences in pulp capping and restoration materials did not significantly affect success rates (Two-year WSR in the MTA and MTA-like products group vs. the calcium hydroxide group: 92% (CI: [85,99]) vs. 88% (CI: [76,100]); the amalgam group vs. the composite group: 92% (CI: [81,100]) vs. 93% (CI: [81,100])). CONCLUSIONS: Generally, full coronal pulpotomy had a favorable success rate in treating carious vital pulp exposure of permanent mature teeth with closed root apices. More studies with control group of root canal treated teeth and longer follow-up periods are needed. CLINICAL SIGNIFICANCE: Coronal pulpotomy treatment can be considered as an intermediate treatment option in managing carious vital pulp exposures of permanent teeth with closed root apices. This option may also serve as a substitute to extraction when root canal treatment cannot be performed for low income and uninsured patients or in underserved areas.

Titanium-zirconium narrow-diameter versus titanium regular-diameter implants for anterior and premolar single crowns: 3-year results of a randomized controlled clinical study.

AIM: To test whether titanium-zirconium (Ti-Zr) 3.3 mm diameter implants perform differently from titanium (Ti) 4.1 mm diameter implants with respect to marginal bone level (MBL) and clinical parameters. MATERIAL AND METHODS: Forty patients in need of a single-implant crown in the anterior or premolar regions were enrolled in two centres. Following random allocation, either a Ti-Zr or a Ti implant was inserted. Porcelain-fused-to-metal crowns were inserted 6 months after implantation. Implant survival, change in MBL, clinical parameters, change in mid-facial mucosa and papilla levels, and the occurrence of biological and technical complications were assessed at the 3-year follow-up. RESULTS: At 3 years, 32 of the 40 included patients were examined (15 Ti and 17 Ti-Zr implants). There were no implant failures. From the implant placement to 3 years, the median change in mean MBL amounted to 0.21 mm (mean: -0.31) in the Ti group and 0.10 mm (mean: -0.40) in the Ti-Zr group. There were no significant differences between the groups with respect to the change in MBL, the change in mucosa levels, and the occurrence of complications. CONCLUSIONS: Ti-Zr implants with 3.3 mm diameter used for the support of single crowns in the anterior and the premolar regions did not differ from Ti implants with 4.1 mm diameter regarding the clinical performance over a 3-year period.

Effects of interim acrylic resins on the expression of cytokines from epithelial cells and on collagen degradation.

STATEMENT OF PROBLEM: Interim acrylic resins release agents that alter cytokine expression in the surrounding tissues, which could alter extracellular matrix degradation. PURPOSE: The purpose of the study was to evaluate the responses of human epidermal keratinocytes to eluates of interim acrylic resins in regards to cytokine expression and cell-mediated collagen degradation. MATERIAL AND METHODS: Specimens of 4 different interim acrylic resins (HI-I, Jet Acrylic, SNAP acrylic, and Protemp Plus) were placed in Epilife medium for 48 hours and the eluates collected. The cells were incubated for 72 hours in nontoxic concentrations of the eluates. Cytotoxicity was evaluated with lactate dehydrogenase assays and cytokine expression with cytokine antibody arrays. Collagen degradation was determined with a collagen type I assay. The experiments were performed 3 times. Data were analyzed with 1-way and mixed-model ANOVA (α=.05). RESULTS: None of the eluates were cytotoxic. Cytokine expression from the heat-activated polymethyl methacrylate resin group was significantly less for interleukin-3, but significantly greater for interlukin-7. Expression for the chemically activated polymethyl methacrylate resin group was significantly less for growth-regulated oncogene-α, interleukin-1α, and interleukin-3. Expression for the chemically activated polyethyl methacrylate resin group was significantly less for interleukin-1α and interleukin-3, but significantly greater for interleukin-13 and monocytes chemoattractant protein-3. The cytokine expression induced by chemically activated bis-acryl composite resin was significantly greater for granulocyte-macrophage colony stimulating factor, interleukin-7, and monocytes chemoattractant protein-3, but significantly less for growth-regulated oncogene-α. Collagen degradation was not significantly different in any of the groups. CONCLUSIONS: The eluates used were not cytotoxic and did not induce cell-mediated collagen degradation. Some significant changes in cytokine expression were noted.