Impact of CAD-CAM materials and bonding protocol on the bond strength between denture base/artificial teeth: a systematic review and meta-analysis.

PURPOSE: To identify the most effective bonding protocol between the denture base and artificial teeth made with different CAD/CAM materials (milled and 3D printed) compared to conventional heat-cured materials. MATERIALS AND METHODS: This review was performed according to the Preferred Reporting Items for Systematic and Meta-Analysis (PRISMA) criteria and registered in PROSPERO (CRD42021276084). An electronic search was performed independently by two examiners in the MEDLINE/PubMed, Cochrane Library, Scopus, Web of Science, ProQuest, and OpenGrey databases for articles published up to and including December 2021. RESULTS: The electronic search returned 806 articles, and after duplicates were removed, the total was 589 articles. Four articles were selected according to the eligibility criteria. Evaluating the different combinations of denture base materials and artificial teeth, the IvoBase CAD Bond (Ivoclar Vivadent) was effective for bonding the CAD/CAM denture bases to prefabricated acrylic resin denture artificial teeth. There were no differences compared to heat-cured denture base bonding to prefabricated acrylic resin denture artificial teeth (χ2: 68.56; I2: 96%; P < .001). CONCLUSION: IvoBase CAD Bond as a bonding system can be an alternative for using new technologies in the fabrication of α CAD/CAM base with prefabricated acrylic resin denture artificial teeth.

Impact of head and neck radiotherapy on the longevity of dental adhesive restorations: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Established restorative protocols for patients after head and neck radiotherapy are lacking, increasing the failure rates of dental adhesive restorations. PURPOSE: The purpose of this systematic review and meta-analysis was to analyze the evidence regarding the impact of head and neck radiotherapy on the longevity of dental adhesive restorations. MATERIAL AND METHODS: A search was performed using PubMed, Scopus, and Embase in May 2018 (updated in November 2020). Data extraction was performed regarding the percentage of restoration failure among dental adhesive materials, including glass ionomer cements, resin-modified glass ionomer cements, and composite resins. Risk of bias was assessed by the meta-analysis of statistics assessment and review instrument (MAStARI). Confidence in cumulative evidence was evaluated by the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) protocol. RESULTS: Four studies met the inclusion criteria. All included studies were classified as having a moderate risk of bias and reported results regarding class V restorations. Overall, composite resins presented lower failure rates at 2 years (30%) when compared with resin-modified glass ionomer (41%) and glass ionomer cements (57%). Meta-analysis showed that the risk of failure with glass ionomer cements was greater than with resin-modified glass ionomer cements (RR: 1.71, P<.001). Composite resins presented lower risk of failure when compared with glass ionomer (RR: 2.29, P<.001) and resin-modified glass ionomer cements (RR: 1.30, P=.03). Three studies reported results regarding fluoride compliance, which had a negative effect on the survival rates of glass ionomer and resin-modified glass ionomer cements and a positive effect on composite resin restorations. CONCLUSIONS: The results suggest that composite resin restorations associated with fluoride gel compliance seems to be the best alternative for restoring class V lesions in patients after head and neck radiotherapy. However, the results showed moderate certainty of evidence, which justifies the need for more randomized clinical trials regarding this subject.

Casein phosphopeptide-amorphous calcium phosphate nanocomplex (CPP-ACP) in dentistry: state of the art / Nanocomplejo de fosfopéptido de caseína-fosfato de calcio amorfo (CPP-ACP) en Odontología: estado del arte

ABSTRACT Saliva and external agents containing different concentrations of sodium fluoride (NaF) promote the dental remineralization process. However, these resources may not be sufficient to counteract the multiple factors involved in the process of dental caries, especially in high-risk patients. There are alternatives that have been extensively researched, such as casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) which provides essential ions, like phosphate and calcium, acting as an adjuvant in the remineralization process. Manufacturers of CPP-ACP-based products also suggest that it can produce desensitizing effects. This nanocomplex has been used experimentally with some dental cements and adhesive systems, but it is important to clarify the effects of this procedure, and the remineralizing/desensitizing advantages it offers. The objective of this topic review was to present the state of the art on CPP-ACP nanocomplex. In terms of dental caries prevention, this remineralizing option is not better than NaF. CPP-ACP provides a dental desensitizing action, but it is temporary, similar or less effective than other alternatives such as potassium nitrate or NaF. The experimental incorporation of CPP-ACP into dental cements should be controlled for not to compromise the physico-chemical properties of the material. The use of dental products based on this nanocomplex as dental surface pretreatment may decrease the bond strength of adhesive materials, but this effect is material dependent.

RESUMEN La saliva y agentes externos que contienen diferentes concentraciones de fluoruro de sodio (NaF) favorecen el proceso de remineralización dental. No obstante, estos recursos podrían no ser suficientes para contrarrestar los múltiples factores involucrados en el proceso de caries dental, especialmente en pacientes con alto riesgo. Existen alternativas que han sido ampliamente investigadas, como el fosfopéptido de caseína-fosfato de calcio amorfo (CPP-ACP) que aporta iones esenciales como fosfato y calcio, actuando como coadyuvante en el proceso de remineralización. Los fabricantes de productos basados en CPP-ACP también sugieren que este es capaz de generar efectos desensibilizantes. Este nanocomplejo ha sido utilizado de forma experimental con algunos cementos dentales y sistemas adhesivos, pero es importante esclarecer los efectos de dicha incorporación y las ventajas remineralizantes/desensibilizantes que ofrece esta alternativa. El objetivo del presente artículo de revisión de tema consistió en presentar el estado del arte sobre el nanocomplejo CPP-ACP. En términos de prevención de caries dental, esta opción remineralizante no es superior al NaF. El nanocomplejo ejerce acción desensibilizante dental, pero esta es transitoria, similar o inferior a otras alternativas como nitrato de potasio o NaF. La incorporación experimental de CPP-ACP en cementos dentales debe ser controlada para no comprometer las propiedades fisicoquímicas del material. La utilización de productos dentales a base de este nanocomplejo como pretratamiento de la superficie dental puede disminuir la resistencia de unión de materiales adhesivos, pero este efecto es material-dependiente.

Tumor safety and side effects of photobiomodulation therapy used for prevention and management of cancer treatment toxicities. A systematic review.

Photobiomodulation therapy (PBMT), also known as low-level laser therapy (LLLT), has been increasingly used for the treatment of toxicities related to cancer treatment. One of the challenges for the universal acceptance of PBMT use in cancer patients is whether or not there is a potential for the light to stimulate the growth of residual malignant cells that evaded oncologic treatment, increasing the risk for tumor recurrences and development of a second primary tumor. Current science suggests promising effects of PBMT in the prevention and treatment of breast cancer-related lymphedema and oral mucositis, among other cancer treatment toxicities. Nevertheless, this seems to be the first systematic review to analyze the safety of the use of PBMT for the management of cancer-related toxicities. Scopus, MEDLINE/PubMed, and Embase were searched electronically. A total of 27 articles met the search criteria. Selected studies included the use of PBMT for prevention and treatment of oral mucositis, lymphedema, radiodermatitis, and peripheral neuropathy. Most studies showed that no side effects were observed with the use of PBMT. The results of this systematic review, based on current literature, suggest that the use of PBMT in the prevention and management of cancer treatment toxicities does not lead to the development of tumor safety issues.

The performance of digital microscopy for primary diagnosis in human pathology: a systematic review.

Validation studies of whole slide imaging (WSI) systems produce evidence regarding digital microscopy (DM). This systematic review aimed to provide information about the performance of WSI devices by evaluating intraobserver agreement reported in previously published studies as the best evidence to elucidate whether DM is reliable for primary diagnostic purposes. In addition, this review delineates the reasons for the occurrence of discordant diagnoses. Scopus, MEDLINE/PubMed, and Embase were searched electronically. A total of 13 articles were included. The total sample of 2145 had a majority of 695 (32.4%) cases from dermatopathology, followed by 200 (9.3%) cases from gastrointestinal pathology. Intraobserver agreements showed an excellent concordance, with values ranging from 87% to 98.3% (κ coefficient range 0.8-0.98). Ten studies (77%) reported a total of 128 disagreements. The remaining three studies (23%) did not report the exact number and nature of disagreements. Borderline/challenging cases were the most frequently reported reason for disagreements (53.8%). Six authors reported limitations of the equipment and/or limited image resolution as reasons for the discordant diagnoses. Within these articles, the reported pitfalls were as follows: difficulties in the identification of eosinophilic granular bodies in brain biopsies; eosinophils and nucleated red blood cells; and mitotic figures, nuclear details, and chromatin patterns in neuropathology specimens. The lack of image clarity was reported to be associated with difficulties in the identification of microorganisms (e.g., Candida albicans, Helicobacter pylori, and Giardia lamblia). However, authors stated that the intraobserver variances do not derive from technical limitations of WSI. A lack of clinical information was reported by four authors as a source for disagreements. Two studies (15.4%) reported poor quality of the biopsies, specifically small size of the biopsy material or inadequate routine laboratory processes as reasons for disagreements. One author (7.7%) indicated the lack of immunohistochemistry and special stains as a source for discordance. Furthermore, nine studies (69.2%) did not consider the performance of the digital method-limitations of the equipment, insufficient magnification/limited image resolution-as reasons for disagreements. To summarize the pitfalls of digital pathology practice and better address the root cause of the diagnostic discordance, we suggest a Categorization for Digital Pathology Discrepancies to be used in further validations studies. Among 99 discordances, only 37 (37.3%) had preferred diagnosis rendered by means of WSI. The risk of bias and applicability concerns were judged with the QUADAS-2. Two studies (15.4%) presented an unclear risk of bias in the sample selection domain and 2 (15.4%) presented a high risk of bias in the index test domain. Regarding applicability, all studies included were classified as a low concern in all domains. The included studies were optimally designed to validate WSI for general clinical use, providing evidence with confidence. In general, this systematic review showed a high concordance between diagnoses achieved by using WSI and conventional light microscope (CLM), summarizes difficulties related to specific findings of certain areas of pathology-including dermatopathology, pediatric pathology, neuropathology, and gastrointestinal pathology-and demonstrated that WSI can be used to render primary diagnoses in several subspecialties of human pathology.

Impact of head and neck radiotherapy on the mechanical behavior of composite resins and adhesive systems: A systematic review.

OBJECTIVES: To analyze the evidence regarding the impact of head and neck radiotherapy (HNRT) on the mechanical behavior of composite resins and adhesive systems. METHODS: Searches were conducted on PubMed, Embase, Scopus and ISI Web of Science databases using "Radiotherapy", "Composite resins" and "Adhesive systems" as keywords. Selected studies were written in English and assessed the mechanical behavior of composite resins and/or adhesive systems when bonding procedure was conducted before and/or after a maximum radiation dose ≥50Gy, applied under in vitro or in vivo conditions. RESULTS: In total, 115 studies were found but only 16 were included, from which five evaluated the effect of in vitro HNRT on microhardness, wear resistance, diametral tensile and flexural strength of composite resins, showing no significant negative effect in most of reports. Regarding bond strength of adhesive systems, 11 studies were included from which five reported no meaningful negative effect when bonding procedure was conducted before simulated HNRT. Conversely, five studies showed that bond strength diminished when adhesive procedure was done after in vitro radiation therapy. Only two studies about dental adhesion were conducted after in vivo radiotherapy but the results were not conclusive. SIGNIFICANCE: The mechanical behavior of composite resins and adhesive systems seems not to be affected when in vitro HNRT is applied after bonding procedure. However, bond strength of adhesive systems tends to decrease when simulated radiotherapy is used immediately before bonding procedure. Studies assessing dentin bond strength after in-vivo HNRT were limited and controversial.

La saliva y sistemas adhesivos alternativos para prótesis total / Saliva and alternative adhesive systems for complete dentures

Las prótesis totales pueden presentar problemas biomecánicos relacionados con la retención y estabilidad, que pueden originarse a partir de errores del profesional durante la toma de impresión funcional de los tejidos, diseño y confección de las prótesis; además de errores durante la fase de laboratorio a cargo de los técnicos o simplemente a cambios biológicos que experimentan los tejidos subyacentes como la reabsorción ósea, atrofia de los maxilares y disminución del flujo salival. Esta última circunstancia es de principal preocupación, ya que la saliva tiene un papel importante en la retención de las prótesis como “adhesivo natural”, por lo que durante años se han propuesto diversos métodos alternativos de retención, especialmente sistemas adhesivos complementarios cuyas propiedades se han perfeccionado con la inclusión de otros compuestos como algunos polímeros sintéticos, agentes antimicrobianos, colorantes, aditivitos y preservativos; además se encuentran disponibles en diferentes presentaciones comerciales. El objetivo de esta revisión es exaltar las propiedades de la saliva como adhesivo natural y la posibilidad de mejorar la retención de las prótesis, cuando estas no poseen la capacidad de asegurar resultados deseados mediante sistemas adhesivos complementarios, que son una alternativa segura y efectiva, siempre que el odontólogo asuma la responsabilidad y la competencia de prescribir el tipo de adhesivo en relación con condiciones específicas del paciente para evitar situaciones indeseables como efectos sistémicos por la ingesta excesiva y prolongada de sales de zinc incluidas en algunas presentaciones comerciales de adhesivos para prótesis.

Complete dentures may show biomechanical problems related to retention and stability, which can arise from professional errors during functional tissue impression, as well as during prostheses design and manufacturing, in addition to errors during the laboratory phase by technicians or simply by biological changes of adjacent tissues, such as bone resorption, maxillaries atrophy, and decreased salivary flow. The latter is a circumstance of major concern because saliva plays an important role in prosthesis retention as a “natural adhesive”; therefore, various alternative retention methods have been suggested over time, especially in terms of complementary adhesive systems whose properties have been improved by including other compounds such as synthetic polymers, antimicrobial agents, colorants, additives, and preservatives, which are available in different commercial presentations. The goal of this review is to highlight the properties of saliva as a natural adhesive and the possibility of improving denture retention when it lacks the ability to guarantee the desired results by additional adhesive systems, which are a safe and effective alternative, provided that the dentist is responsible and competent enough to prescribe the right adhesive in relation to specific patient conditions to avoid undesirable situations such as systemic effects due to prolonged and excessive intake of zinc salts included in some commercial presentations of denture adhesives.