Osteoporosis and Apical Periodontitis Prevalence: A Systematic Review.

Osteoporosis is a common systemic bone disorder in the elderly, characterized by low bone mineral density and deterioration of bone structure. Apical periodontitis is an inflammatory response to the microbial infection of root canals, typically characterized by apical bone destruction surrounding the tooth's apex. This systematic review aimed to determine if osteoporosis affects the prevalence of apical periodontitis in adults. PRISMA guidelines have been followed. It included randomized clinical trials, cross-sectional, cohort, and case-control studies, and excluded non-relevant investigations and various secondary sources. A comprehensive search was performed in PubMed, Scopus, and Web of Science, until 13 March 2024. The Newcastle-Ottawa Scale was used to assess the quality of the three selected studies: two cross-sectional studies and one case-control study. One investigation only included post-menopausal women recruited at a dental university clinic, the other integrated data from the total hospital patients' population, and the third selected patients referred to the university dental clinic from the university hospital. The findings varied: one study noted a marginal association between low bone mineral density and apical periodontitis, another found a significant association, and the third, with the lowest risk of bias, reported no link. The main limitations were the scarcity of eligible studies and their overall quality. The review was registered in the PROSPERO database (CRD42024523705), applied strict inclusion criteria and thorough searches by experienced and independent reviewers. There is no strong evidence that adult individuals with osteoporosis have a higher probability of developing apical periodontitis. However, clinicians should remain cautious of osteoporosis's potential impact on apical periodontitis development.

Exploring Musculoskeletal Complaints in a Needle Manufacturing Industry: A Cross-Sectional Study.

Musculoskeletal disorders (MSD) encompass a variety of conditions affecting muscles, joints, and nerves. In Portugal, MSDs are the most prevalent occupational health problem in companies. Based on the relevance of work-related MSD (WMSD), this study aims to assess the prevalence of MSD complaints in a needle manufacturing industry in Northern Portugal, following a cross-sectional approach. Thus, 526 workers from five departments (i.e., operator, tuning, maintenance, administration, and logistics) answered a sociodemographic questionnaire and the Nordic Musculoskeletal Questionnaire (NMQ). Within the last 12 months, females exhibited a higher frequency of complaints than males across all body parts except for ankles/feet. The body parts eliciting the most percentage of complaints for both genders include the lower back (54.2%), neck (42.2%), shoulders (39.0%), ankles/feet (38.2%), and wrists/hands (35.7%). No significant association was found between Body Mass Index (BMI) and body part complaints. Tuners reported the highest complaint rate, with occupations as substantial predictors of complaints in certain body parts. Likewise, complaints tend to increase with age. The findings advocate for ergonomic interventions that are gender-, age-, and job-sensitive.

Nanostructured ZnO thin film to enhance gutta-percha's adhesion to endodontic sealers.

BACKGROUND: Gutta-percha (GP) combined with an endodontic sealer is still the core material most widely used for tridimensional obturation. The sealer acts as a bonding agent between the GP and the root dentinal walls. However, one of the main drawbacks of GP core material is the lack of adhesiveness to the sealer. ZnO thin films have many remarkable features due to their considerable bond strength, good optical quality, and excellent piezoelectric, antibacterial, and antifungal properties, offering many potential applications in various fields. This study aimed to explore the influence of GP surface's functionalization with a nanostructured ZnO thin film on its adhesiveness to endodontic sealers. METHODS: Conventional GP samples were divided randomly into three groups: (a) Untreated GP (control); (b) GP treated with argon plasma (PT); (c) Functionalized GP (PT followed by ZnO thin film deposition). GP's surface functionalization encompassed a multi-step process. First, a low-pressure argon PT was applied to modify the GP surface, followed by a ZnO thin film deposition via magnetron sputtering. The surface morphology was assessed using SEM and water contact angle analysis. Further comprehensive testing included tensile bond strength assessment evaluating Endoresin and AH Plus Bioceramic sealers' adhesion to GP. ANOVA procedures were used for data statistical analysis. RESULTS: The ZnO thin film reproduced the underlying surface topography produced by PT. ZnO thin film deposition decreased the water contact angle compared to the control (p < 0.001). Endoresin showed a statistically higher mean bond strength value than AH Plus Bioceramic (p < 0.001). There was a statistically significant difference between the control and the ZnO-functionalized GP (p = 0.006), with the latter presenting the highest mean bond strength value. CONCLUSIONS: The deposition of a nanostructured ZnO thin film on GP surface induced a shift towards hydrophilicity and an increased GP's adhesion to Endoresin and AH Bioceramic sealers.

Morphometric Comparison of Two Implants with Different Macroscopy Placed Immediate in the Anterior Region of the Maxilla - A Randomized Clinical Trial with 6-Month of Follow Up.

Purpose - Compare the morphometric results of immediate implants (Type 1C) with a cylindrical (conventional) or triangular neck, in the anterior region of the maxilla, during 6 months of osseointegration. Materials and Methods - Prospective randomized clinical trial with a sample of 20 individuals randomly assigned to each group (10 triangular neck implants and 10 cylindrical neck implants). Consecutively direct measurements were performed: before (T-1) and after tooth extraction (T0), after implant placement (T1), after 1 month of the submerged implant healing (T2), when placing the healing abutment (T3), after placing the definitive crown (T3), and after 6 months of osseointegration (T4). Results - A significant difference between T1 and T3 in the buccal cortical thickness was identified (0.49Å}0.86mm). Although there was a significant increase in the buccal cortical thickness in both implants, this increase was greater for the triangular neck implants (cylindrical shape: 0.08Å}0.59 vs. triangular neck 0.90Å}0.91mm). It was also observed that implants placed below the buccal bone crest (í-1mm) promote less vertical buccal bone loss than implants placed Ñ-1mm at crest level (-0.65Å}0.52mm vs. -1.42Å}0.86mm). This observation needs to be further investigated in additional studies. Conclusions - The triangular neck implants present an increase in the cortical buccal thickness compared to the cylindrical implants. However, this increase does not fully compensate the remodulation after tooth loss.

The Effectiveness of Osseodensification Drilling versus the Conventional Surgical Technique on Implant Stability: A Clinical Trial.

Background/Objective: To ensure that implants are able to support prosthetic rehabilitation, a stable and functional union between the bone and the implant surface is crucial to its stability and success. To increase bone volume and density and excel bone-implant contact, a novel drilling method, called osseodensification (OD), was performed. To assess the effectiveness of the osseodensification drilling protocol versus the conventional surgical technique on implant stability. Methods: Bone Level Tapered Straumann implants were placed side-by-side with both OD and subtractive conventional drilling (SD) in 90 patients from CESPU-Famalicão clinical unit. IT was measured using a manual torque wrench, and the Implant stability quotient (ISQ) value was registered using the Osstell® IDX. Results: According to the multifactorial ANOVA, there were statistically significant differences in the mean IT values due to the arch only (F(1.270) = 4.702, p-value = 0.031 < 0.05). Regarding the length of the implant, there were statistically significant differences in the mean IT in the OD group (p = 0.041), with significantly lower mean IT values for the Regular implants compared to the Long. With respect to the arch, the analyses of the overall ISQ values showed an upward trend in both groups in the maxilla and mandible. High levels of IT also showed high ISQ values, which represent good indicators of primary stability. Conclusions: OD does not have a negative influence on osseointegration compared to conventional subtractive osteotomy.

Intracerebral hemorrhage after deep brain stimulation surgery guided with microelectrode recording: analysis of 297 procedures.

OBJECTIVES: Report the incidence of symptomatic and asymptomatic intracerebral hemorrhage (ICH) in patients submitted to deep brain stimulation (DBS) guided with microelectrode recording (MER) with further analysis of potential risk factors, both inherent to the patient and related to the pathology and surgical technique. METHODS: We performed a retrospective observational study. 297 DBS procedures were concluded in 277 patients in a single hospital centre between January 2010 and December 2020. All surgeries were guided with MER. We analysed the incidence of symptomatic and asymptomatic ICH and its correlation to age, sex, diagnosis, hypertension and perioperative hypertension, diabetes, dyslipidaemia, antiplatelet drugs, anatomic target, and number of MER trajectories. RESULTS: There were a total of 585 electrodes implanted in 277 patients. 16 ICH were observed, of which 6 were symptomatic and 10 asymptomatic, none of which incurred in permanent neurological deficit. The location of the hemorrhage varied between cortical and subcortical plans, always in relation with the trajectory or the final position of the electrode. The incidence of symptomatic ICH per lead-implantation was 1%, and the CT-scan demonstrated asymptomatic ICH in 1.7% more patients. Male patients or with hypertension are 2.7 and 2.2 times more likely to develop ICH, respectively. However, none of these characteristics has been shown to have a statistically significant association with the occurrence of ICH, as well as age, diagnosis, diabetes, dyslipidaemia, antiplatelet drugs, anatomic target, number of MER trajectories and perioperative hypertension. CONCLUSIONS: MER-guided DBS is a safe technique, with low incidence of ICH and no permanent deficits in our study. Hypertension and male sex seem to be risk factors for the development of ICH in this surgery. Nevertheless, no statistically significant factors were found for the occurrence of this complication.

Functionalization of gutta-percha surfaces with argon and oxygen plasma treatments to enhance adhesiveness.

Gutta-percha's lack of adhesion has been presented as a drawback to avoid gaps at sealer/gutta-percha interface. Plasma treatments have been scarcely assessed on gutta-percha surfaces as a method of enhancing adhesiveness. This study aimed to evaluate the effect of low-pressure Argon and Oxygen plasma atmospheres on conventional and bioceramic gutta-percha standardized smooth discs, assessing their roughness, surface free energy, chemical structure, and sealer wettability. A Low-Pressure Plasma Cleaner by Diener Electronic (Zepto Model) was used. Different gases (Argon or Oxygen), powers (25 W, or 50 W), and exposure times (30 s, 60 s, 120 s, or 180 s) were tested in control and experimental groups. Kruskal-Wallis and Student's t-test were used in data analysis. Statistically significant differences were detected when P < 0.05. Both gases showed different behaviors according to the parameters selected. Even though chemical changes were detected, the basic molecular structure was maintained. Argon or Oxygen plasma treatments favoured the wetting of conventional and bioceramic gutta-perchas by Endoresin and AH Plus Bioceramic sealers (P < 0.001). Overall, the functionalization of gutta-percha surfaces with Argon or Oxygen plasma treatments can increase roughness, surface free energy and wettability, which might improve its adhesive properties when compared to non-treated gutta-percha.

A systematic review of the use of bacteriophages for in vitro biofilm control.

Bacteriophages (phages) are very promising biological agents for the prevention and control of bacterial biofilms. However, little is known about the parameters that can influence the efficacy of phages on biofilms. This systematic review provides a summary and analysis of the published data about the use of phages to control pre-formed biofilms in vitro, suggesting recommendations for future experiments in this area. A total of 68 articles, containing data on 605 experiments addressing the efficacy of phages to control biofilms in vitro were included, after a search conducted in Web of Science, Embase, and Medline (PubMed). The data collected from each experiment included information about biofilm growth conditions, phage characteristics, treatment conditions and biofilm reduction. In most cases, biofilms were formed in the surface of microtiter plates (82.5%); the median time for biofilm formation was 24 h, as is the median treatment duration. Quantification of biofilm biomass (52.6%), viable cells (25.5%) and metabolic activity (17.9%) were the most common biofilm assessment methods. Correlation analysis revealed that some phage parameters can influence the treatment outcome: higher phage concentrations were strongly associated with improved biofilm control, leading to higher levels of biofilm reduction, and phages with higher burst sizes and shorter latent periods seem to be the best candidates to control biofilms in vitro. However, the great variability of the methodologies used prompts the need for the development of standardized in vitro methodologies to characterize phage/biofilm interactions and to assess the efficacy of phages to control biofilms.

Study of Prevalence, Severity and Risk Factors of Periodontal Disease in a Portuguese Population.

Periodontal disease is a common worldwide oral inflammation/infection affecting tissues that surround and support teeth. This study aims to evaluate the prevalence, extent and severity of periodontal diseases and its risk factors, according to the most recent periodontal classification, in an adult population of Northern Portugal. This observational study collected data from clinical records of patients who attended the University Clinic of Gandra between April 2021 and April 2022. Of a total of 941 patients included, 457 (48.6%) had periodontitis, 253 (26.9%) had gingivitis and the remaining 231 (24.5%) were healthy patients. The prevalence of stage III severe periodontitis was 51.2%, more prevalent in males, and in the age group of 61-70 years. Gingivitis was more prevalent in females, and in the age group of 31-40 years; in both diseases, the most prevalent extension was the generalized one. Using a binary logistic regression, we observe a significant relation of the risk of periodontitis with age (p = 0.019; OR 1.033; 95% CI 1.005-1.062), tooth brushing (p = 0.002; OR 0.25; 95% CI 0.105-0.599) and dental flossing (p = 0.015; OR 0.63; 95% CI 0.09-0.768). This study revealed a high prevalence of periodontitis. Increased age, lack of tooth brushing and flossing were identified as potential risk factors for periodontitis in the investigated Portuguese population.

In Vitro Study of Preload Loss in Different Implant Abutment Connection Designs.

The stability and integrity of the abutment-implant connection, by means of a screw, is fallible from the moment the prosthetic elements are joined and is dependent on the applied preload, wear of the components and function. One of the main causes of screw loosening is the loss of preload. The loosening of the screw-abutment can cause complications such as screw fracture, marginal gap, peri-implantitis, bacterial microleakage, loosening of the crown and discomfort of the patient. It is also reported that loosening of the screw/abutment may lead to a failure of osseointegration. It is necessary to evaluate and quantify, with in vitro studies, the torque loss before and after loading in the different connections. Aim: evaluate the influence of implant- abutment connection design in torque maintenance after single tightening, multiple tightening and multiple tightening followed by mechanical cycling. Materials and Methods: 180 Klockner implants divided in 4 groups: 15 SK2 external connection, 25 Ncm tightening torque; 15 KL external connection, 30 Ncm tightening torque; 15 Vega internal connection, 25 Ncm tightening torque; 15 Essential internal connection, 30 Ncm tightening torque. In each group removal torque values (RTV) were evaluated with a digital torque meter, in 3 distinct phases: after one single tightening, 10 multiple tightenings and 10 multiple tightenings and cyclic loading (500 N × 1000 cycles). Results: After one single tightening, and for all connections, RTV were lower than those of insertion, but only for Essential and Vega internal connections this result was statistically significant. After multiple tightening, RTV were significantly lower in all connections. After repeated tightening followed by cyclic loading, mean RTV were significantly lower, when compared to insertion torque. The multiple tightening technique resulted in higher RTV than the single tightening technique, except for Vega implant. The multiple tightening followed by cyclic load, compared to the other phases, was the one that generated the lowest RTV, for all connections. Conclusions: The connection design, in our study, did not seem to influence the maintenance of preload. Loading influenced the loss of preload, in the sense that significantly decreased the removal torque values. The multiple re-tightening technique resulted in higher removal torque values than the single tightening technique. Clinically, our results recommend to retighten retaining screws, a few minutes after insertion.

Supplementary solvent irrigation efficacy on filling remnants removal comparing XP-endo Finisher R vs IrriSafe.

This study aimed to compare the efficacy of XP-endo Finisher R and IrriSafe, with a solvent mixture of Methyl ethyl ketone/Tetrachloroethylene (MEK/TCE), in the removal of root filling residues. Twenty-four human mandibular incisors were pair-matched by micro-computed tomography according to volume and aspect ratio. After retreatment, specimens were allocated to two experimental groups (n = 12), according to the supplementary instrument used. The volume of residual filling material after each irrigating step and the time for retreatment was calculated. Statistical analyses were carried out using Mann-Whitney test, with a significance level of 5%. The volume of initial root canal filling material between the groups was similar (p > 0.05). With the final irrigation protocol (NaOCl and EDTA) the volume of the filling remnants decreased significantly (p < 0.05) with no differences between IrriSafe or XP-endo Finisher R (p > 0.05). The additional solvent mixture MEK/TCE increased the efficiency of filling materials reduction, regardless of the agitating instruments employed, IrriSafe or XP-endo Finisher R (p < 0.05). There was no difference between the two groups regarding the time (p = 0.149). Both supplementary instruments were effective in the reduction of filling remnants. The additional step with a solvent mixture of MEK/TCE enabled a total recovery of patency and the achievement of cleaner canals, independently of the agitation instrument.

Adjunctive procedure with solvent mixtures in non-surgical endodontic retreatment: does it affect root dentin hardness?

The aim of this study was to compare the effects of new irrigation solvent mixtures with Methyl ethyl ketone (MEK)/Tetrachloroethylene (TCE) and MEK/Orange oil (OOil), and different agitation techniques on dentin hardness. One hundred forty-four mandibular teeth were prepared and standardized, with each root's middle part transversely sectioned. Initial hardness was measured using a Vickers microhardness tester. Specimens were divided into four groups of agitation techniques (n = 36): no agitation; EndoActivator; IrriSafe; and XP-endo Finisher R. Each group was subdivided into six subgroups of irrigation protocols (n = 6): saline solution; NaOCl + EDTA; NaOCl + EDTA + MEK/TCE; MEK/TCE; NaOCl + EDTA + MEK/OOil; MEK/OOil. Final hardness was measured. The irrigation protocols NaOCl + EDTA, NaOCl + EDTA + MEK/TCE, and NaOCl + EDTA + MEK/OOil significantly decreased dentin hardness, while MEK/OOil increased it (p < 0.05). Comparing to NaOCl + EDTA sequence, dentin hardness increased significantly with the additional exposure to MEK/TCE (3%NaOCl + 17%EDTA + MEK/TCE) or MEK/OOil (3%NaOCl + 17%EDTA + MEK/OOil) (p < 0.05). There were no significant differences regarding agitation effects on dentin hardness decrease. The irrigation protocols affected dentin hardness significantly. However, the additional solvent proposals do not seem to address further concerns on dentin's mechanical properties. Agitation did not show any influence on dentin's hardness reduction.

Effect of Gutta-percha Solvents on the Bond Strength of Sealers to Intraradicular Dentin: A Systematic Review.

Introduction: The aim of our systematic review was to assess the impact of gutta-percha solvents on the bond strength of endodontic sealers to intraradicular dentin using the push-out bond test. Methods and Materials: The literature was searched in databases (PubMed, Web of Science and Scopus) up to September 2020, using the following search terms: (bond strength AND solvent* AND sealer* AND (tooth root OR dentin OR retreatment OR root canal). No date limits were implemented, and English languages were included. The question research was constructed based on the PICO (Population, Intervention, Comparison, and Outcome) strategy: "Does gutta-percha solvents effect the bond strength of sealers to intraradicular dentin?". The studies were analyzed by two reviewers and were included if they utilized extracted permanent human teeth with completely formed apices, as well as assessed the influence of gutta-percha solvents on the bond strength of sealers to intraradicular dentin using push-out bond test. Review articles, case reports and studies that included immature, bovine or artificial teeth were excluded. The risk of bias was evaluated based on the Cochrane criteria adopted to in vitro studies. Results: Thirty-two papers were analyzed, seven accomplished the eligibility criteria and were selected for our systematic review. The global risk of bias was high. Due to variations in the methodological variables, a meta-analysis could not be performed. Conclusion: Our systematic review highlighted the adverse effect of chloroform, which decreased the bond strength of different sealers, and the generally higher bond strength of epoxy resin-based sealers, detected with the push-out bond test. We recommend the standardization of methods in future studies to obtain a more definitive conclusion about the influence of solvents on the bond strength of sealers to intraradicular dentin.

Obesity effects on muscular activity during lifting and lowering tasks.

Obesity is an emerging health problem and its incidence has been increasing throughout the workforce. In industrial workstations, vertical handling tasks (VHT), including lifting and lowering, are very common and can cause a significant muscular overload for the involved workers. During these tasks, muscular activity may be considerably affected by workers' body conditions. This study aims to analyze and compare the muscular activity in subjects with different obesity levels, using surface electromyography (EMG), during predefined VHT. Six different VHT (combining 5, 10 and 15-kg loads with two task styles) were performed. EMG data normalization was based on the percentage of maximum contraction during each task (MCT%). The results show that obesity influences the MCT%, which in turn increases the muscular effort during VHT. The current investigation demonstrates that obesity is a relevant musculoskeletal risk factor regarding VHT. The engineering analysis and design implications of this work can thus be perceived.

Simulated root canals preparation time, comparing ProTaper Next and WaveOne Gold systems, performed by an undergraduate student.

BACKGROUND: The aim of this study was to compare the WaveOne Gold and ProTaper Next systems regarding the time spent preparing simulated canals performed by an inexperienced student. MATERIAL AND METHODS: 0 simulated L-shaped canals were randomly divided into two groups (n = 40) and numbered in order of instrumentation. Canals were instrumented with WaveOne Gold (group 1) and ProTaper Next (group 2) systems. The effective instrumentation time and the number of instrumentation cycles were recorded. All procedures were performed by the same operator. Statistical analysis was obtained by the Mann - Whitney, Kruskal - Wallis test with significance of p<0.05. RESULTS: There were no statistically significant differences regarding the mean instrumentation time between the two instrumentation systems. The instrumentation time decreased over the experimental period, regardless of the technique used. CONCLUSIONS: Through a short learning curve, an inexperienced operator can prepare simulated canals in a very predictable time. Time spent was similar in a multi-file instrument system (ProTaper Next) and a single-file system (WaveOne Gold). Key words:Dental education, endodontics, preclinical, root canal preparation, undergraduate.

Effect of Sonic Agitation of a Binary Mixture of Solvents on Filling Remnants Removal as an Alternative to Apical Enlargement-A Micro-CT Study.

BACKGROUND: This work aimed to evaluate the efficacy of sonic agitation of a binary mixture of solvents (methyl ethyl ketone/tetrachloroethylene) on filling remnants removal and compare the effects of solvent agitation with the enlargement to the next instrument size. METHODS: Twenty-four mandibular incisors were prepared with ProTaper Next (X1, X2) and obturated with the single-cone technique and AH Plus sealer. The teeth were retreated with ProTaper Universal Retreatment and ProTaper Next and divided into two groups (n = 12) according to the final instrument (X3 or X4). All canals were submitted to a supplementary procedure consisting of a mixture of solvents-methyl ethyl ketone/tetrachloroethylene, agitated with EndoActivator. The volume of filling remnants was assessed through micro-computed tomography in the apical 5 mm. Statistical analysis was performed with a significance level of 5%. RESULTS: The supplementary procedure of agitation of the solvent mixture was beneficial in both groups (p < 0.05). There were no statistically significant differences between canals re-prepared until X4 and canals re-prepared until X3 plus solvent (p > 0.05). CONCLUSIONS: An additional step with a two-solvent solution potentiated by EndoActivator showed to be very effective for the removal of gutta-percha and resinous sealer remnants from apical root canals of mandibular incisors, avoiding further enlargement.

Efficacy and Cytotoxicity of Binary Mixtures as Root Canal Filling Solvents.

OBJECTIVES: This study reports the efficacy of two solvent mixtures on the dissolution of gutta-percha and AH Plus sealer, together with the cytotoxicity. METHODS: Methyl ethyl ketone (MEK), orange oil, tetrachloroethylene, MEK/tetrachloroethylene (1:1), MEK/orange oil (1:1), and chloroform (control) were tested. Twelve groups (n = 15) of standardized stainless-steel molds filled with softened gutta-percha cones and twelve (n = 15) filled with AH Plus were immersed in the corresponding mixture or individual solvent, in an ultrasonic bath, for either 2 or 5 min. The effect of the solvents was assessed qualitatively by a topographical analysis (scanning electron microscopy) and chemical analysis (Fourier transform infrared spectroscopy), and quantitatively by a weight loss and viscoelastic property (dynamic mechanical analysis) evaluation. The cytotoxicity was assessed on MG63 human osteoblastic cells. RESULTS: The mixtures did not show the formation of new compounds. Both presented significantly higher efficacies compared to their individual solvents, suggesting a synergistic effect. Their dissolution efficacy was similar to that of chloroform, showing high cytocompatibility. CONCLUSIONS: The proposed strategy, incorporating ultrasound agitation and profiting from the synergy of adequate solvents, might enhance root canal cleanliness allowing a single-step procedure to dissolve gutta-percha and the sealer remnants, while assuring cytocompatibility with the periapical tissues.

Measurements in First-Trimester Abortion Products: A Pathologic Study.

CONTEXT.­: Related to the advances in prenatal diagnosis and the emergence of medically challenging situations, there has been an increased interest in conducting a pathologic study of first-trimester abortion products. OBJECTIVE.­: To evaluate measurements across a large group of first-trimester spontaneous abortion specimens. Potential goals include a validation of prenatal embryo and gestational-sac measurements as a function of gestational age (GA). DESIGN.­: A retrospective case study of first-trimester spontaneous abortions between June 2015 and April 2017 in Centro de Genética Clínica Embryo-Fetal Pathology Laboratory, Porto, Portugal. Considering the inclusion criteria, 585 complete gestational sacs, 182 embryos, and 116 umbilical cords were selected. We recorded the weight of the gestational sacs and embryos and measurements of gestational sacs, umbilical cords, and embryo crown-rump length. Models were computed using regression techniques. RESULTS.­: Gestational-sac diameter percentiles 5, 25, 50, 75 and 95 were calculated according to GA, and at each 1-week interval the diameter increased an average of 3 mm. Umbilical cord length percentiles 5, 25, 50, 75 and 95 were calculated according to GA, and at each 1-week interval, the length increased an average of 1.35 mm. Embryo crown-rump length estimated mean ± SD values were GA 6 weeks, 5.3 ± 2.3 mm; GA 7 weeks, 9.4 ± 4.8 mm; GA 8 weeks, 13.7 ± 8.2 mm; GA 9 weeks, 20.8 ± 9.1 mm; GA 10 weeks, 22.6 ± 13.4 mm; GA 11 weeks, 29.4 ± 12.9 mm; and GA 12 weeks, 52 mm. CONCLUSIONS.­: Pathologic measurements obtained should be compared to expected measurements and correlated with ultrasound findings, clinical information, and microscopic findings. Deviations from expected values could lead to an understanding of early pregnancy loss.