Thyroid Hormones May Influence Cortical Bone Healing Around Titanium Implants: A Histometric Study in Rats

Dental implant considerations in patients with systemic diseases: An updated comprehensive review

BACKGROUND

Various medical conditions and the drugs used to treat them have been shown to impede or complicate dental implant surgery. It is crucial to carefully monitor the medical status and potential post-operative complications of patients with systemic diseases, particularly elderly patients, to minimize the risk of health complications that may arise.

AIM

The purpose of this study was to review the existing evidence on the viability of dental implants in patients with systemic diseases and to provide practical recommendations to achieve the best possible results in the corresponding patient population.

METHODS

The information for our study was compiled using data from PubMed, Scopus, Web of Science and Google Scholar databases and searched separately for each systemic disease included in our work until October 2023. An additional manual search was also performed to increase the search sensitivity. Only English-language publications were included and assessed according to titles, abstracts and full texts.

RESULTS

In total, 6784 studies were found. After checking for duplicates and full-text availability, screening for the inclusion criteria and manually searching reference lists, 570 articles remained to be considered in this study.

CONCLUSION

In treating patients with systemic conditions, the cost-benefit analysis should consider the patient's quality of life and expected lifespan. The success of dental implants depends heavily on ensuring appropriate maintenance therapy, ideal oral hygiene standards, no smoking and avoiding other risk factors. Indications and contraindications for dental implants in cases of systemic diseases are yet to be more understood; broader and hardcore research needs to be done for a guideline foundation.

Hormone and implant osseointegration: Elaboration of the relationship among function, preclinical, and clinical practice

As clusters of peptides or steroids capable of high-efficiency information transmission, hormones have been substantiated to coordinate metabolism, growth, development, and other physiological processes, especially in bone physiology and repair metabolism. In recent years, the application of hormones for implant osseointegration has become a research hotspot. Herein, we provide a comprehensive overview of the relevant reports on endogenous hormones and their corresponding supplementary preparations to explore the association between hormones and the prognosis of implants. We also discuss the effects and mechanisms of insulin, parathyroid hormone, melatonin, vitamin D, and growth hormone on osseointegration at the molecular and body levels to provide a foothold and guide future research on the systemic conditions that affect the implantation process and expand the relative contraindications of the implant, and the pre-and post-operative precautions. This review shows that systemic hormones can regulate the osseointegration of oral implants through endogenous or exogenous drug-delivery methods.

Patients with Thyroid Disorder, a Contraindication for Dental Implants? A Systematic Review

The thyroid gland is composed of the thyroid follicles, considered to be the functional units of the thyroid gland. The synthesis of the thyroid hormones occurs in these follicles. Triiodothyronine (T3) and thyroxine (T4) are the thyroid hormones and affect metabolic processes all through the body. This systematic evaluation was performed to answer the following PICO question: “Can patients with thyroid disorders undergo dental implant rehabilitation with the same survival rate as patients without thyroid disorders?”. A systematic review of the literature was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements to gather available and current evidence of thyroid disorders and its relationship with dental implants. The electronic search, in the PubMed and Cochrane databases, yielded 22 articles. Out of the 22 articles, only 11 fulfilled the inclusion criteria. Manual research of the reference list yielded no additional papers. According to the SORT criteria and answering our PICO question, level B can be established to conclude that patients with thyroid disorders can be rehabilitated with dental implants, with similar survival rates as patients without thyroid disorders. Papers with higher scientific evidence and bigger sample size should be carried out.

Occurrence and severity of spontaneous exposure of cover screw after dental implant placement

Background. Perforation of the soft tissues overlying the dental implant, resulting in early and spontaneous exposure of cover screws between stages I and II of the two-staged implant placement procedure, is a common problem that can disrupt the primary repair and osseointegration process. The present study aimed to investigate the prevalence of spontaneous exposure of cover screws in dental implants and identify the related risk factors.Methods. The present retrospective, descriptive-analytical study enrolled 40 patients with 182 dental implants in the second stage of the implant placement procedure. Data on patient-related and implant-related classified variables were collected, and all the samples were examined for cover screw exposure based on the classification by Tal. First, the overall prevalence of cover screw exposure was calculated. Then, statistical analysis was performed using SPSS 24 to investigate the effect of different variables on this exposure. The chi-squared test was used at the bivariate level, while the logistic regression was used at the multivariate level.Results. Of 40 participants with 182 implants, 17 implants (9.3%) in 9 patients (22.5%) became exposed to the oral cavity. In terms of severity, Class I exposure was the most common with seven implants. Moreover, Class III was the least common with only one implant. Using the logistic regression analysis, we found significant relationships between the dental implant exposure and the variables of overlying mucosal thickness (OR=24.7, P≤0.001), the duration between tooth extraction and implant placement (OR=9.6, P=0.005), and implant location in the jaw (OR=3.8, P=0.033). Moreover, exposure was more common in the maxillary premolar area (22.5%) than in other locations. Also, there was a significant relationship between implant exposure and lateral augmentation (OR=0.20, P=0.044), indicating the higher risk of exposure in implants with lateral augmentation than those without augmentation.Conclusion. Despite the limitations of this retrospective study, its results showed that three factors, including the overlying mucosal thickness of <2 mm, implant placement in fresh extraction sockets, and maxillary implants, especially at the location of maxillary premolars, were strong predictors of spontaneous implant exposure.

Osseointegration Pharmacology: A Systematic Mapping Using Artificial Intelligence

Clinical performance of osseointegrated implants could be compromised by the medications taken by patients. The effect of a specific medication on osseointegration can be easily investigated using traditional systematic reviews. However, assessment of all known medications requires the use of evidence mapping methods. These methods allow assessment of complex questions, but they are very resource intensive when done manually. The objective of this study was to develop a machine learning algorithm to automatically map the literature assessing the effect of medications on osseointegration. Datasets of articles classified manually were used to train a machine-learning algorithm based on Support Vector Machines. The algorithm was then validated and used to screen 599,604 articles identified with an extremely sensitive search strategy. The algorithm included 281 relevant articles that described the effect of 31 different drugs on osseointegration. This approach achieved an accuracy of 95%, and compared to manual screening, it reduced the workload by 93%. The systematic mapping revealed that the treatment outcomes of osseointegrated medical devices could be influenced by drugs affecting homeostasis, inflammation, cell proliferation and bone remodeling. The effect of all known medications on the performance of osseointegrated medical devices can be assessed using evidence mappings executed with highly accurate machine learning algorithms.

The tendency of reduced periodontal destruction in acromegalic patients showing similar inflammatory status with periodontitis patients

PURPOSE

Evaluate periodontal status of acromegalics through clinical and biochemical variables.

METHODS

Demographics, hormone and metabolic variables, periodontal variables, gingival crevicular fluid (GCF) volume, and content data were collected from 30 patients with acromegaly, 30 patients with periodontitis, and 20 healthy subjects and comparatively analyzed.

RESULTS

GH differences between acromegaly (2.56 ± 4.86) and periodontitis (0.53 ± 0.95) (p < 0.001) were statistically significant. IGF-1 was lowest at periodontitis (113.31 ± 45.01) and lower (152.11 ± 45.56) at healthy group compared with acromegalics (220.38 ± 167.62) (p < 0.05). GH and IGF-1 had positive correlation (p < 0.05). IGF-1 and CAL had negative (p < 0.01) correlation except healthy group that showed the same correlation at the opposite direction (p < 0.05). Besides similar plaque and gingival indices with periodontitis, acromegalics showed relatively less CAL and GCF volume but except CAL, all their periodontal variables were higher than healthy subjects. GCF GH and prolactin showed higher values in acromegalics while healthy subjects showed relatively high interleukin-1, -10 and carboxyterminal telopeptide of type I collagen compared with others.

CONCLUSION

Acromegalics have a tendency of slowed periodontal destruction with an influence of GH and IGF-1 to the inflammation- and collage metabolism-related mechanisms rather than bone-associated ones. However, this information must be confirmed with further studies exploring the mechanisms possibly bonded to others.

Periodontal status of hypothyroid patients on thyroxine replacement therapy: A comparative cross-sectional study

Background:

Thyroid hormones play a significant role in bone remodeling. However, there are few studies on the effect of these hormones on periodontium.

Aim:

The aim of this study was to evaluate the periodontal status of hypothyroid patients on thyroxine replacement therapy.

Materials and Methods:

Clinical parameters (plaque index, bleeding index, probing pocket depth [PPD], and clinical attachment level [CAL]) and radiographic parameters (Mandibular cortical width and panoramic mandibular index) were recorded in 52 hypothyroid patients on thyroxine replacement therapy (Study group) and 50 individuals without signs and symptoms of thyroid dysfunction (Control group). The effect of dosage and duration of therapy on clinical and radiographical parameters were also assessed in the study group.

Results:

Statistically significant higher PPD (P = 0.008) and clinical attachment loss (P = 0.032) were observed in the study group in comparison to the control group. However, no significant differences were observed within the hypothyroid group with varying doses and duration of therapy. Furthermore, there was no correlation between the dosage and duration of therapy with periodontal status. Regression analysis showed that hypothyroidism and thyroxine replacement therapy was a significant predictor of PPD and CAL even after controlling for the effect of age in hypothyroid patients.

Conclusion:

Hypothyroid patients on thyroxine replacement therapy may be at increased risk for periodontal destruction. However, this needs to be validated through longitudinal studies.

Low Normal TSH levels are Associated with Impaired BMD and Hip Geometry in the Elderly

Subclinical hyperthyroidism is known to be associated with the risk of fractures in elderly people. However, there are few studies assessing whether low normal thyroid-stimulating hormone (TSH) levels affect bone density and geometry. Here, we aimed to assess the influence of the TSH level on bone mineral density (BMD) and geometry in elderly euthyroid subjects. This was a cross-sectional cohort study. A total of 343 men and 674 women with euthyroidism were included and analyzed separately. The subjects were divided into tertiles based on the serum TSH level. The BMD and geometry were measured using dual-energy X-ray absorptiometry and a hip structural analysis program. Multiple regression analysis was used to compute the odds ratios of osteoporosis in the lower TSH tertile group and the association between geometry parameters and the TSH level. We found that the femoral neck and total hip BMDs were lower in the lower TSH tertile group. In women, the cross-sectional area and cortical thickness of the femur were negatively associated with the TSH level in all three regions (the narrow neck, intertrochanter, and femoral shaft); however, in men, these geometry parameters were significantly associated with the TSH level only in the intertrochanter region. The buckling ratio, a bone geometry parameter representing cortical instability, was significantly higher in the lower TSH tertile group in all three regions in women, but not in men. Our results indicated that lower TSH levels in the euthyroid range are related to lower BMD and weaker femoral structure in elderly women.

Premature exposure of dental implant cover screws. A retrospective evaluation of risk factors and influence on marginal peri-implant bone level changes

OBJECTIVES

The objectives of this study were to identify risk factors associated with the premature cover screw exposure (pCSE) at dental implants and to evaluate the influence of a pCSE on peri-implant marginal bone level (MBL) change compared to non-exposed implants.

MATERIALS AND METHODS

Retrospective data assessment from 165 patients (mean age = 54.0 ± 14.4 years) who received 395 submerged implants included demographic, health-related, and therapeutic variables which were analyzed for their respective impact. MBL change was detected at digital radiographs obtained from first- and second-stage surgeries.

RESULTS

pCSE were detected in 43 patients (26.1%) and 53 implants (13.4%). An increased frequency of exposure was significantly associated with (I) male gender (p = 0.012) at patient level and (II) the posterior region of the jaws (p = 0.005), implant systems with platform-matching cover screws, and a vertical distance of ≥0.5 mm between bone crest and the implant platform (both p < 0.001) at implant level. The decrease in mesial, distal, and total MBL differed significantly (mean total = 0.8 ± 0.7 vs. 0.3 ± 0.5; mean mesial = 0.8 ± 0.8 vs. 0.3 ± 0.6; mean distal = 0.8 ± 0.8 vs. 0.3 ± 0.6 mm; p < 0.001) between non-exposed and pCSE implants.

CONCLUSIONS

Male patients, implants with platform-matched cover screws, or when placed supracrestally or in posterior sites revealed significantly more pCSE, resulting in significantly decreased peri-implant MBL compared with non-exposed implants.

CLINICAL RELEVANCE

Patients with an enhanced risk of pCSE should follow frequent regular recalls during the healing period to enable for early diagnosis and intervention.

Systematic review of pre-clinical models assessing implant integration in locally compromised sites and/or systemically compromised animals

OBJECTIVE

The aim was to systematically search the dental literature for pre-clinical models assessing implant integration in locally compromised sites (part 1) and systemically compromised animals (part 2), and to evaluate the quality of reporting of included publications.

METHODS

A Medline search (1966-2011) was performed, complimented by additional hand searching. The quality of reporting of the included publications was evaluated using the 20 items of the ARRIVE (Animals in Research In Vivo Experiments) guidelines.

RESULTS

One-hundred and seventy-six (part 1; mean ARRIVE score = 15.6 ± 2.4) and 104 (part 2; 16.2 ± 1.9) studies met the inclusion criteria. The overall mean score for all included studies amounted to 15.8 ± 2.2. Housing (38.3%), allocation of animals (37.9%), numbers analysed (50%) and adverse events (51.4%) of the ARRIVE guidelines were the least reported. Statistically significant differences in mean ARRIVE scores were found depending on the publication date (p < 0.05), with the highest score of 16.7 ± 1.6 for studies published within the last 2 years.

CONCLUSIONS

A large number of studies met the inclusion criteria. The ARRIVE scores revealed heterogeneity and missing information for selected items in more than 50% of the publications. The quality of reporting shifted towards better-reported pre-clinical trials within recent years.

Absence of periodontitis in acromegalic patients

Acromegaly is a metabolic disorder caused by increased growth hormone (GH) secretion. Common oral features are prognatism, increased interdental spaces, macroglosia, and dental mobility. However, not much is known about the periodontal status of acromegalics. The periodontal status of 16 acromegalic subjects was investigated and compared with 20 controls (similar socioeconomic profile and age). Periodontal probing, followed by the assessment of gingival overgrowth, tooth loss and mobility, and malocclusion was performed. Acromegalic patients' did not present periodontitis and all of them had complete absence of periodontal pockets, while 50% of the control group presented periodontitis. All acromegalic patients presented dental mobility degree 1, mainly in the anterior inferior teeth. Malocclusion (100%) and diastemas (93.75%) were also present in these patients. It was concluded that acromegalic patients may be less prone to periodontal diseases than control subjects.