Interventional retrospective prospective randomized clinical trial (RCT) in parallel groups.

The sample size is 384 patients with loss of teeth and vitamin D imbalance. All patients will undergo or underwent dental implantation after additional investigations which reveal vitamin D imbalance (<30 ng/ml or <75 nmol/l).

The 1 group will include 192 patients who will be or were operated on with dental implants after stabilization of vitamin D level with a help of an endocrinologist.

The 2 group will include 192 patients who will be or were operated on during the treatment of vitamin D imbalance prescribed by the endocrinologist.

The possible difference between groups can be considered the change of dental implants survival time and bone resorption level depending on the level of vitamin D and treatment time by the endocrinologist.

A purpose is to increase the efficiency of rehabilitation of patients with loss of teeth and mineral metabolism disorders due to vitamin D3 imbalance using an interdisciplinary approach to dental implantation.

Retrospective prospective RCT in parallel groups includes 384 patients with loss of teeth and vitamin D3 imbalance who will undergo or underwent the dental implantation on the base of Oral Surgery Department of Borovskiy Institute of Dentistry of I.M.Sechenov First Moscow State Medical University (Sechenov University) and private dental clinic 'Society with limited responsibility (SLR) Topaz 2000' from 2010 till the 2021 year: prospective part will include 100 patients, the retrospective part will include 284 patients.

The counted sample size according to loss of teeth prevalence in Russia on the base of Sechenov University and private dental clinic Topaz 2000 is equal to 384 patients.

Randomization will be assured by surgeons blinded to endocrinologic status of patients who underwent or will undergo the dental implantation.

All patients will be included in 2 groups: 1 group will include patients (n=192), 25-50-years-old, with loss of teeth and mineral metabolism disorders due to vitamin D3 imbalance (<30 ng/ml, or <75 nmol/l) who will undergo dental implant placement after stabilization of vitamin D3 levels (>30-60 ng/ml, or 75-150 nmol/l for the process of treatment and monitoring); 2 group will include patients, 25-50-years-old, with the loss of teeth and mineral metabolism disorders due to vitamin D3 imbalance (n=192) who will undergo the dental implantation during treatment by an endocrinologist before the stabilization of vitamin D3 level in the blood.

Group 1

Patients will be directed for lab tests to detect mineral imbalance (vitamin D, ng/ml; parathyroid hormone (PH), thyroperoxidase antibodies (anti-TPO), Thyrotoxin 3 free (TT), Thyrotropic hormone (TH) pg/l) before dental implantation, and according to results, we will discuss further plan treatment with the endocrinologist. If it is needed due to the indications (adults with osteoporotic fractures; adults with a disease or condition accompanied by reduced bone mass or bone loss; all persons in the appointment of drug therapy, iatrogenic in relation to loss of bone mass; all patients receiving anti-osteopathic treatment to monitor its effectiveness; all persons who are not yet receiving treatment, but who may need it in case of bone loss.), Dual-Energy X-Ray Absorptiometry (DEXA) of skeleton mineral bone density will be done. After appropriate systemic treatment with vitamin D3 in 2 months after stabilization (>30 ng/ml, or >75 nmol/l) ) of vitamin D3 level (Aquadetrim (cholecalciferol) 15000 International Units (IU), Medana Pharma S.A., Poland, Registration number P N014088/01 from 21st June 2017; first 2 months taking orally 2-5 drops with a spoon of water depending on the severity of diseases, after 2 months and reaching the reference level of vitamin D its dose will be 1 drop per a day whole period of monitoring) the dental implantation was and will be performed with the further control of bone density and peri-implant tissues in 3 months after the operation. In the case of low bone density (type 3 or 4) the additional bone plasty was and will be performed. we assess the stability of dental implant on the stages of prosthetic rehabilitation according to the force of osteointegration during the inserting of the healing abutment (in Newtons on square centimeter), and each 1 year after treatment in the condition of periodical monitoring of patients with the endocrinologist (after the beginning of treatment after 2 months, then 1 time per 6 months).

Traditional 2-stage dental implantation will be performed according to surgical protocols of dental implant systems (Straumann (Institut Straumann AG, Switzerland, registration in Russia 03/10/2017 No FSZ 2010/06855), Astra Tech (Dentsply Implant Manufacturing GmbH, Germany, registration in Russia 27/09/2018 No FSZ 2008/02570), Xive (FRIADENT GmbH, Germany, registration in Russia 09/09/2008 No FSZ 2008/02568), Alpha Bio (Alpha Bio Tec Ltd., Israel, registration in Russia 26/04/2017 No FSZ 2009/05582), for different types of bone tissue

Group 2

Patients will be directed for lab tests to detect mineral imbalance (vitamin D, ng/ml; PH, anti-TPO, TT, TH, pg / l) before dental implantation, and according to results, we will discuss further plan treatment with the endocrinologist. If it is needed due to the indications (adults with osteoporotic fractures; adults with a disease or condition accompanied by reduced bone mass or bone loss; all persons in the appointment of drug therapy, iatrogenic in relation to loss of bone mass; all patients receiving anti-osteopathic treatment to monitor its effectiveness; all persons who are not yet receiving treatment, but who may need it in case of bone loss.), Dual-Energy X-Ray Absorptiometry (DEXA) of skeleton mineral bone density will be done. Treatment with vitamin D3 for stabilization of its level (>30 ng/ml, or >75 nmol/l) will be provided with Aquadetrim (cholecalciferol) 15000 International Units (IU), Medana Pharma S.A., Poland, Registration number P N014088/01 from 21st June 2017; first 2 months taking orally 2-5 drops with a spoon of water depending on the severity of diseases, after 2 months and reaching the reference level of vitamin D its dose will be 1 drop per a day whole period of monitoring). The dental implantation was and will be performed with the further control of bone density and peri-implant tissues in 3 months after operation at the beginning of treatment by endocrinologist without waiting of reference level of vitamin D. In case of low bone density of jaws (type 3 or 4) the additional bone plasty was or will be performed. We will assess the stability of dental implant on the stages of prosthetic rehabilitation according to the force of osteointegration during the inserting of the healing abutment (in Newtons on square centimeter), and each 1 year after treatment in the condition of periodical monitoring of patients with the endocrinologist (after the beginning of treatment after 2 months, then 1 time per 6 months)

Traditional 2-stage dental implantation according to surgical protocols of dental implant systems (Straumann (Institut Straumann AG, Switzerland, registration in Russia 03/10/2017 No FSZ 2010/06855), Astra Tech (Dentsply Implant Manufacturing GmbH, Germany, registration in Russia 27/09/2018 No FSZ 2008/02570), Xive (FRIADENT GmbH, Germany, registration in Russia 09/09/2008 No FSZ 2008/02568), Alpha Bio (Alpha Bio Tec Ltd., Israel, registration in Russia 26/04/2017 No FSZ 2009/05582), will be performed for different types of bone tissue

Inclusion Criteria:

1. Signing of written informed consent of the patient to participate in a study
2. Age from 25 to 50 years old
3. Established diagnosis: tooth loss (K08.1- ICD 10), vitamin D3 imbalance.
4. Patients who are medically stable

Exclusion Criteria:

1. Refusal of the patient from further participation in the study
2. Pregnancy diagnosed after the inclusion into the trial
3. Non-compliance by the patient with postoperative recommendations.
4. Residence address change

No, according to the rules (SOPs) of the Local Ethics Committee

Surgeons will be blinded to the endocrinologic status of patients who underwent or will undergo the dental implantation