The effects of repeated usage of implant drills on cortical bone temperature, primary/secondary stability and bone healing: A preclinical in vivo micro-CT study.

OBJECTIVE: The aims of the study were to evaluate the effects of new vs. used drills on cortical bone temperature, operation time, and primary/secondary stability and to assess bone healing by micro-CT. MATERIALS AND METHODS: New, 50×-used and 100×-used drills at 800 rpm were used to place implants in the iliac crests of three male sheep in this experimental in vivo animal study. A total of 36 implants (12 in each group) were placed. The temperature of the cortical bone was recorded with an infrared thermometer, and the ISQ values at implant placement (primary stability) and at 4 weeks (secondary stability) were evaluated. The bone volume assessed by micro-CT was used to evaluate bone tissue healing. The results were statistically compared. RESULTS: The results have shown that the operation time and the cortical bone temperature increased by the usage of the drills (p < .05) and the primary/secondary stability (ISQ values) decreased with the number of drill usage (p < .05) The highest 2- and 3-dimensional bone volume (assessed by micro-CT) were noted for new drills group followed by 50×-used drills and 100×-used drills (p < .05 at 4 weeks). CONCLUSION: The number of drill usage seems to be directly affecting the osseointegration process in implant surgery. Therefore, replacing the drills at certain time intervals may increase the success of implant treatment.

Efficiency of dental caries prevention with the use of polymer-based toothpastes modified by the electromagnetic field.

The most important problems of modern dentistry cover not only the early diagnosis but also prevention of dental caries, including the one based on the use of various hygienic products and therapeutic agents. Normally, the processes of re- and demineralization in the oral cavity are in a state of dynamic. However, in the presence of cariogenic factors, the balance is shifted towards demineralization. In the event of initial caries, enamel remineralization is possible only to a certain extent, and specifically, for a reversible degree of carious lesion. There was an idea about structural changes in polymer-based consumable dental materials including toothpastes. The purpose of the study is to increase the efficiency of dental caries prevention based on the activation of metabolic processes in dental hard tissues with the use of R.O.C.S. Active Calcium toothpastes (Russian-Swiss "DRC-Group" company) modified by an electromagnetic field. As a result of the experimental part of the study, certain changes in the properties of the R.O.C.S. Active Calcium toothpastes under the electromagnetic field influence including microstructural transformation of the toothpaste (an increase in the size of the polymer matrix particles and a decrease in the distance between them confirmed by the electron microscopy findings), confirmed by the transmission electron microscopy results. The investigations with the help of X-ray microanalysis made it possible to clarify the chemical composition of the surface layer of the tooth enamel, for the first time to reveal in detail the concentration of micro- and macroelements of organic and inorganic nature, to trace the changes occurring under controlled tooth cleaning with the R.O.C.S. Active Calcium toothpaste treated with an electromagnetic field. The obtained results promote the further studies of laws in change of physical and mechanical properties of treatment-and-prophylactic means under the electromagnetic field influence in respect of dental caries preventive maintenance efficiency increase.

Diode laser for harvesting de-epithelialized palatal graft in the treatment of gingival recession defects: a randomized clinical trial.

AIMS: The aim of present randomized controlled clinical study was to evaluate the effects of the use of diode laser for graft harvesting and palatal wound irradiation on post-operative morbidity and root coverage outcomes after a coronally advanced flap (CAF) with de-epithelialized gingival grafts (DGG). METHODS: Fifty-two patients with isolated recessions were treated. The CTG resulted from the de-epithelialization of a free gingival graft (FGG) with blade (control group:DGG-B) or diode laser (DL) (test group:DGG-L). The DL was used to de-epithelialize the outer part of the FGG and photo-biostimulate the palatal wound area. Post-operative morbidity was evaluated by using Oral Health-related Quality of Life (OHQoL) and Visual Analogue Scale-discomfort (VAS). Root coverage outcomes were also evaluated 6 months after operation. RESULTS: Statistically significant differences were found for OHQoL (p = 0.0001) and VAS (p = 0.0001) at the 7th day post-operatively favouring test sites. Root coverage results did not show a statistically significant difference. CONCLUSIONS: While both techniques were effective with regard to root coverage at 6 months, the DGG-L technique decreased post-operative morbidity associated with palatal donor-site surgery.

The effect of a streptococci containing probiotic in periodontal therapy: a randomized controlled trial.

AIM: To evaluate the adjunctive effects of a Streptococcus oralis KJ3, Streptococcus uberis KJ2 and Streptococcus rattus JH145 containing probiotic tablet after scaling and root planing (SRP). MATERIALS AND METHODS: Forty-eight periodontitis patients were included in this double-blind, placebo-controlled clinical trial. After root planing, patients used either a placebo or a probiotic tablet twice a day for 12 weeks. The pocket probing depth (primary outcome measure), bleeding on probing and relative attachment levels were measured at baseline, 12 and 24 weeks. At baseline, 4, 8, 12 and 24 weeks, microbiological sampling was performed and plaque and gingival indices were recorded. RESULTS: The primary and secondary outcome measures were significantly (p < 0.05) improved at the 12- and the 24-week evaluation in both groups. However, no significant inter-group differences could be detected at any time point, except from the % of sites with plaque that were significantly lower in the probiotic group than in the control group at the 24-week evaluation. In addition, at the 12-week time point, the salivary Prevotella intermedia counts were significantly lower in the probiotic group. CONCLUSIONS: No differences were detected when comparing the adjunctive use of a placebo or the investigated streptococci containing probiotic tablet after SRP. ClinicalTrials.gov Identifier: NCT02403960.

Effects of decontamination and implant surface characteristics on re-osseointegration following treatment of peri-implantitis.

BACKGROUND: Although considerable bone fill may occur following treatment of peri-implantitis, re-osseointegration appears to be limited and unpredictable. OBJECTIVES: To evaluate the effects of various decontamination techniques and implant surface configurations on re-osseointegration of contaminated dental implants. MATERIAL AND METHODS: Three months after tooth extraction, implants consisting of a basal part and an exchangeable intraosseous implant cylinder (EIIC) were placed in the mandibles of dogs. The EIIC was machined (M), sandblasted and acid-etched (SLA), or titanium plasma sprayed (TPS). Ligature-induced peri-implantitis was initiated 8 weeks post-implantation and lasted until bone loss reached the junction of the two implant parts. Three treatment modalities were applied: (T1) the EIIC was exchanged for a pristine EIIC; (T2) the EIIC was sprayed in situ with saline; and (T3) the EIIC was removed, cleansed outside the mouth by spraying with saline, steam-sterilized, and remounted. A collagen barrier was placed over each fixture, and 3 months later, samples were processed for histology and histomorphometry. RESULTS: T2 revealed the highest bone-to-implant contact (BIC) level (significantly better than T1 and T3). T2 also yielded the highest bone crest level (significantly better than T1), followed by T3 (significantly better than T1). SLA showed the highest BIC level (significantly better than M), followed by TPS. There were no statistically significant differences in bone crest height between implant types. CONCLUSIONS: Both SLA implants and in situ cleansing resulted in the best re-osseointegration and bone fill of previously contaminated implants.

Combined treatment approach of gingivectomy and CO2 laser for cyclosporine-induced gingival overgrowth.

The aim of this report is to present a combined treatment approach with gingivectomy and CO2 laser for the management of cyclosporine-induced gingival overgrowth in 4 cases. Four renal transplant patients were surgically treated for marked gingival overgrowth by means of gingivectomy and CO2 laser. Postoperatively, all patients were followed for bleeding, pain, infection during the early healing period, and recurrence of gingival overgrowth for 12 months. The healing was uneventful, and no signs of bleeding, postoperative pain, or infection were observed in any patient during the early healing period. In the 12th postoperative month, there was evidence of mild recurrence in 1 patient, while no sign of recurrence was observed in the other patients during the follow-up period. The advantages of this combined technique include satisfactory bleeding control and clear visibility during the procedure, as well as reduced postoperative pain and swelling.

New formation of periodontal tissues around titanium implants in a novel dentin chamber model.

Direct bone-to-implant contact, defined as "osseointegration", is considered most optimal for long-term stability and survival of dental implants. However, the possibility of the formation of a tooth-like attachment apparatus around implants has also been demonstrated. The purpose of this study was to explore the formation of periodontal tissues around titanium implants using a novel and unique experimental model. After resection of the crowns of the maxillary canine teeth in nine mongrel dogs, the roots were hollowed to a depth of 5 mm leaving a thin dentinal wall. Slits were prepared in the cavity wall to create passages from the chamber to the periodontal ligament area. A custom-made, titanium implant was placed into the center of each chamber. Machined, titanium plasma sprayed (TPS) and sand blasted with large grit and acid attacked (SLA) surfaces were used. A collagen barrier was placed over the submerged chamber. Following 4 months of healing, jaw sections were processed for histology. Newly formed periodontal ligament, alveolar bone, and root cementum filled the space between the implant and the wall of the chamber. Ingrown bone was neither in contact with dentin nor with the implant. Thus, an interposed soft connective tissue layer was present. Healing by fibrous encapsulation was observed around most implants. However, cellular cementum was deposited on one TPS and one SLA implant and on the dentinal walls of the chamber. This study shows a remarkable capacity for new periodontal tissue formation at a site where no such tissues ever existed. Maintenance of original periodontal tissue domains most likely prevented osseointegration of the implants. The cementum layer deposited on two implants was likely formed through cementoconductivity rather than by differentiation of periodontal ligament cells upon contact with the implant surface.