Introduction: Different implant–abutment connections have been developed to reduce mechanical and biological failure. The most frequent complications are loss of preload, screw loosening, abutment or implant fracture, deformations at the different interfaces, and bacterial microleakage. Aim: To review the evidence indicating whether the implant–abutment connection type is significant regarding the following issues: (1) maintenance of the preload in static and dynamic in vitro studies; (2) assessment of possible deformations at the implant–abutment interfaces, after repeated application of the tightening torque; (3) evaluation of the sealing capability of different implant connections against microleakage. Materials and Methods: In June 2020, an electronic literature search was performed in Medline, EBSCO host, and PubMed databases. The search was focused on the ability of different implant connections to maintain preload, resist deformation after tightening and retightening, and prevent microleakage. The related titles and abstracts available in English were screened, and the articles that fulfilled the inclusion criteria were selected for full-text reading. Results: The literature search conducted for this review initially resulted in 68 articles, among which 19 articles and 1 systematic review fulfilled the criteria for inclusion. The studies were divided according to the three proposed objectives, with some studies falling into more than one category (maintenance of preload, surface abutment–implant deformation, and resistance to microleakage). Conclusions: Conical abutment appears to result in fewer mechanical complications, such as screw loosening or fractures, and higher torque preservation. After SEM evaluation, damage was observed in the threads of the abutment screws, before and after loading in internal and external connections. Internal hexagon implants and predominantly internal conical (Morse taper) implants showed less microleakage in dynamic loading conditions. We suggest further studies to guarantee excellence in methodological quality.

To explore severity and progression biomarkers, we examined the clinical relevance of multiple cytokines and mediators involved in the inflammatory response in periodontitis. A cohort of 68 patients was enrolled in the study and periodontal status assessed by the current classification of periodontal diseases. Immune mediators present in saliva, of both patients and healthy controls, were quantified using a Legendplex-13 panel. Clinic parameters were significantly higher in PD patients compared with HC, with a strong significant association with the disease severity (stage) (p < 0.001), but not with progression (grade). The panel of immune mediators evidenced elevated levels of pro-inflammatory cytokines IL-6 and IL-1β as disease established (p < 0.01). IL-1β/IL-1RA ratio was increased in PD patients, being associated with disease stage. An anti-inflammatory response was spotted by higher IL-10. Lower levels of IL-23 and IP-10 were associated with disease severity. No significant statistical differences were found by grade classification. Moreover, salivary IL-1β and IL-6 exhibited significant positive correlations with several clinical measurements (PI, BOP, PPD, CAL), while IP-10 showed a statistical negative correlation with BOP, PPD, and CAL. These insights highlight the complexity of the periodontitis inflammatory network and the potential of cytokines as biomarkers for refined diagnostic and therapeutic strategies.

The objective of this paper is to anatomically describe the bone morphology in the maxillary and mandibular tooth areas, which might help in planning post-extraction implants. CBCT images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The thickness of the facial wall was measured at the crest, point A, 4 mm below, point B, and at the apex, point C. The second parameter was the angle formed between the dental axis and the axis of the basal bone. A total of 403 teeth were measured. In the maxilla, 89.4% of incisors, 93.94% of canines, 78% of premolars and 70.5% of molars had a buccal bone wall thickness less than the ideal 2 mm. In the mandible, 73.5% of incisors, 49% of canines, 64% of premolars and 53% of molars had < 1 mm buccal bone thickness as measured at point B. The mean angulation in the maxilla was 11.67 ± 6.37° for incisors, 16.88 ± 7.93° for canines, 13.93 ± 8.6° for premolars, and 9.89 ± 4.8° for molars. In the mandible, the mean values were 10.63 ± 8.76° for incisors, 10.98 ± 7.36° for canines, 10.54 ± 5.82° for premolars and 16.19 ± 11.22° for molars. The high incidence of a buccal wall thickness of less than 2 mm in over 80% of the assessed sites indicates the need for additional regeneration procedures, and several locations may also require custom abutments to solve the angulation problems for screw-retained crowns.

Gingivitis and periodontitis are chronic inflammatory diseases that affect the supporting tissues of the teeth. Although induced by the presence of bacterial biofilms, other factor, such as tobacco smoking, drugs, and various systemic diseases, are known to influence their pathogenesis. Diabetes mellitus and periodontal diseases correspond to inflammatory diseases that have pathogenic mechanisms in common, with the involvement of pro-inflammatory mediators. A bidirectional relationship between type 2 diabetes and periodontitis has been documented in several studies. Significantly less studies have focused on the association between periodontal disease and type 1 diabetes. The aim of the study is to analyze the association between periodontal status and type 1 diabetes mellitus. The “Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines” was used and registered at PROSPERO. The search strategy included electronic databases from 2012 to 2021 and was performed by two independent reviewers. According to our results, we found one article about the risk of periodontal diseases in type 1 diabetes mellitus subjects; four about glycemic control; two about oral hygiene; and eight about pro-inflammatory cytokines. Most of the studies confirm the association between type 1 diabetes mellitus and periodontal diseases. The prevalence and severity of PD was higher in DM1 patients when compared to healthy subjects.

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.

Post-extractional implants and immediate loading protocols are becoming much more frequent in everyday clinical practice. Given the existing literature about tapered implants, the objective of this paper was to understand whether implant shape had a direct influence on the results of the insertion torque (IT) and implant stability quotient (ISQ). Seven tapered implant prototypes were developed and distributed into three groups and compared with a control cylindrical implant—VEGA by Klockner Implant System. The implants were inserted into bovine bone type III according to Lekholm and Zarb Classification. The sample size was n = 30 for the three groups. Final IT was measured with a torquemeter, and the ISQ was measured with Penguin Resonance Frequency Analysis (RFA). Modifications done to the Prototype I did not reveal higher values of the ISQ and IT when compared to VEGA. In the second group, when comparing the five prototypes (II–VI) with VEGA, it was seen that the values of the ISQ and IT were not always higher, but there were two values of the ISQ that were statistically significantly higher with the 4.0 mm diameter Prototypes II (76.3 ± 6.1) and IV (78 ± 3.7). Prototype VII was the one with higher and significant values of the ISQ and IT. In both diameters and in both variables, all differences were statistically significant enough to achieve the higher values of primary stability values (IT and ISQ). Given the limitations of this study, it can be concluded that when there is an increase of the diameter of the implant and body taper, there is an increase of the ISQ and IT, showing that the diameter of the implant is an important criteria to obtain higher values of primary stability.