Accuracy of digitally planned, guided apicoectomy with a conventional trephine and a custom-made endodontic trephine: An in vitro comparative study.

PURPOSE: Static guided trephine apicoectomy has been developed as a less invasive and more accurate alternative to conventional freehand apicoectomy with drills. Overpenetration is a frequent issue with this procedure, which deteriorates accuracy and raises safety concerns. A safety improvement to address this problem is presented. MATERIALS AND METHODS: Guided apicoectomies were performed in porcine mandibles with either a conventional bone trephine or a custom-made endo-trephine with built-in depth control. The deviation of the apical endpoint of the trephine from the digital surgical plan was analyzed. Overpenetration frequency was recorded. RESULTS: Procedures performed with the custom trephine were significantly more accurate both along the x-axis and globally, but no significant difference was found for the y and z axes. Overpenetration frequency was 70% in the conventional trephine group versus 38% in the stop trephine group. CONCLUSION: The results indicate that the lack of physical depth control can interfere with the accuracy (and safety) of these procedures to a significant extent, as visual cues (such as the depth markings on a conventional trephine) are insufficient to prevent overpenetration. Our results show that custom-made trephines with a built-in stop offer an optimal solution for this problem.

Accuracy of half-guided implant placement with machine-driven or manual insertion: a prospective, randomized clinical study.

OBJECTIVES: To compare the accuracy of implant placement performed with either a surgical motor or a torque wrench as part of a half-guided surgical protocol. MATERIALS AND METHODS: Implant insertion with half-guided surgical protocol was utilized by surgical motor (machine-driven group) or torque wrench (manual group) in the posterior maxilla. After the healing period, accuracy comparison between planned and actual implant positions was performed based on preoperative cone beam computed tomography and postoperative digital intraoral scans. Coronal, apical, and angular deviations, insertion time, and insertion torque were evaluated. RESULTS: Forty patients were treated with 1 implant each; 20 implants were inserted with a surgical motor and 20 implants with a torque wrench. Global coronal and apical deviations were 1.20 ± 0.46 mm and 1.45 ± 0.79 mm in the machine-driven group, and 1.13 ± 0.38 mm and 1.18 ± 0.28 mm in the manual group (respectively). The mean angular deviation was 4.82 ± 2.07° in the machine-driven group and 4.11 ± 1.63° in the manual group. Mean insertion torque was 21.75 ± 9.75 Ncm in the machine-driven group, compared to 18.75 ± 7.05 Ncm in the manual group. Implant placement duration was 9.25 ± 1.86 s in the machine-driven group at a speed of 50 rpm, and 36.40 ± 8.15 s in the manual group. CONCLUSION: No significant difference was found between the two groups in terms of accuracy and mean insertion torque, while machine-driven implant placement was significantly less time-consuming. CLINICAL RELEVANCE: Optimal implant placement accuracy utilized by half-guided surgical protocol can be achieved with both machine-driven and torque wrench insertion. TRIAL REGISTRATION: ID: NCT04854239.

Esthetic and functional reconstruction of large mandibular defects using free fibula flap and implant-retained prosthetics - a case series with long-term follow-up.

BACKGROUND: The reconstructive and rehabilitative management of large mandibular defects with basal continuity is challenging in many respects, especially in the vertical dimension. The free fibula flap is an under-utilised but efficient approach in this indication. The aim of this case series is to demonstrate its use and long-term success. CASE PRESENTATION: Three cases are presented, where the patient had a large bone defect (at least 5 cm in length and 1 cm in the vertical dimension), but the continuity of the mandible was maintained. Two cases were related to pathological fracture and one was a large defect due to oncological surgery. Vertical augmentation with free microvascularised fibula flap was carried out, followed by implant-retained prosthetic therapy. Clinical status has been followed up for 5 to 6 years, with special attention to the condition of the peri-implant tissues and any radiographically detectable alterations or complications. No complications occurred during the follow-up. Function and esthetics have remained unchanged throughout. CONCLUSIONS: Free microvascularised fibula flap reconstruction combined with implant-retained prosthetics allows a lasting functional and esthetic solution in the discussed indication.

The potential effect of instrumentation with different nickel titanium rotary systems on dentinal crack formation-An in vitro study.

The potential mechanical impact of different rotary systems used for root canal preparation has been a matter of debate for long. The aim of this study was to explore the incidence of dentinal cracks after root canal instrumentation with various rotary systems, in vitro. One hundred and eighty intact lower central incisors were selected and randomly divided into fourteen treatment groups (n = 12/group) and a control group (n = 12). After decoronation, the root canals were instrumented with fourteen different rotary systems (E3, E3 azure, NT2, Hyflex CM, Hyflex EDM, 2Shape, OneCurve, ProTaper Next, ProTaper Gold, WaveOne Gold, Mtwo, Reciproc Blue, TF adaptive, K3XF). All roots were horizontally sectioned at 3, 6, and 9 mm from the apex with a low-speed saw under water-cooling. The slices were then examined under stereomicroscope for dentinal cracks. No cracks were found in the control group. Cracks were found in all treatment groups, predominantly in the 3 mm slices. There was no statistically significant difference in the number of cracks when comparing the different systems to each other at any section level. At 3 mm, however, five of the studied systems, namely K3XF (p = 0.004), Protaper Next (p = 0.001), Reciproc Blue (p<0.001), TF adaptive (p = 0.050), and 2Shape (p = 0.009) presented a significantly higher number of cracks than the control group. Within the limitations of this study, instrumented canals presented dentinal cracks, while uninstrumented ones presented no cracks after sectioning. There seems to be no significant difference among the tested systems regarding crack formation in the instrumented root canal wall. Crack formation occurred irrespective of the motion of the rotary system (rotational or reciprocation). Further studies are needed to clarify the factors that contribute to crack formation in the case of each individual rotary system.

Digitally planned root end surgery with static guide and custom trephine burs: A case report.

INTRODUCTION: Apicoectomy is an endodontic surgical intervention that requires high precision. The computer-assisted static guided approach has proven to increase the precision of dental implantation in a significant manner. The authors sought to transfer this precision to root-end resection with the use of custom designed trephine burs manufactured specifically for use in targeted endodontic microsurgery. METHODS: A set of custom bone trephines were designed and manufactured, then their digital models were integrated into an already existing implant surgical planning software, in cooperation with the software developer. Apicoectomy was performed in an actual case with the help of the new system. RESULTS: It has become possible to plan root end removal in the virtual space and to manufacture 3D printed static surgical guides to help the execution of the surgery. A patient with persistent periapical lesion was successfully treated without complication. The 6-month follow-up found uneventful healing. CONCLUSION: The presented system is a step toward a standardized digital system and workflow dedicated to guided endodontic surgery.

Guidance means accuracy: A randomized clinical trial on freehand versus guided dental implantation.

OBJECTIVES: A randomized clinical trial was conducted to compare all three known static guided surgery protocols (pilot, partial, and full) with each other and with freehand surgery in terms of accuracy, under the same conditions. MATERIAL AND METHODS: A total of 207 implants of the same brand and type were placed in 101 partially edentulous volunteers in need of implantation in the mandible or maxilla or both. All cases were digitally planned, and the comparison of the planned and actual implant positions was performed using a medical image analysis software with dedicated algorithms. The primary outcome variable was angular deviation (AD, degrees). The secondary outcome variables were coronal global deviation (CGD, mm), apical global deviation (AGD, mm), and voxel overlap (VO, %). RESULTS: AD showed stepwise improvement in significant steps as the amount of guidance increased. The highest mean AD (7.03° ± 3.44) was obtained by freehand surgery and the lowest by fully guided surgery (3.04° ± 1.51). As for the secondary outcome variables, all guided protocols turned out to be significantly superior to freehand surgery, but they were not always significantly different from each other. CONCLUSIONS: As for the comparison that this study sought to perform, it can be said that the static guided approach significantly improves the accuracy of dental implant surgery as compared to freehand surgery. Furthermore, the results suggest that any degree of guidance yields better results than freehand surgery and that increasing the level of guidance increases accuracy.

Accuracy and clinical safety of guided root end resection with a trephine: a case series.

BACKGROUND: Root-end resection is an endodontic surgical intervention that requires high precision so that all ramifications and lateral canals so as infected tissues are eliminated. An exploratory study was conducted to justify the clinical safety and accuracy of guided root-end resection with a trephine. METHODS: Fourteen root-end resections were performed in 11 patients. With the aid of computer tomography and rapid prototyping a stereolithographically fabricated, tooth-supported surgical template was used to guide trephinations. Surgery was performed using the printed surgical stent and a trephine was used not only for the osteotomy but for the root end resection as well. RESULTS: The root end was successfully and completely resected by the trephine in all cases. No intraoperative complications were observed in any of the cases, and the patients were free of symptoms indicating recurrence or complications at the 6-month follow-up. The median angular deviation of the trephination was 3.95° (95% CI: 2.1-5.9), comparable to the angular deviation of guided implant surgery. The mean apex removal error (ARE) was 0.19 mm (95% CI: 0.03-0.07). The mean osteotomy depth error (ODE) was 0.37 mm (95% CI: 0.15-1.35). Overpenetration was a characteristic finding, which indicates the necessity of a stop-trephine. CONCLUSIONS: Within the limitations of this study, we conclude that our results support the use of guided trephination for root-end resection.

Chicken or the Egg: Microbial Alterations in Biopsy Samples of Patients with Oral Potentially Malignant Disorders.

Oral carcinogenesis often leads to the alteration of the microbiota at the site of the tumor, but data are scarce regarding the microbial communities of oral potentially malignant disorders (OPMDs). Punch biopsies were taken from healthy and non-healthy mucosa of OPMD patients to analyze the microbiome using metagenome sequencing. In healthy oral mucosa biopsies the bacterial phyla Firmicutes, Fusobacteria, Proteobacteria, Actinobacteria and Bacteroidetes were detected by Ion Torrent sequencing. The same phyla as well as the phyla Fibrobacteres and Spirochaetes were present in the OPMD biopsies. On the species level, there were 10 bacterial species unique to the healthy tissue and 35 species unique to the OPMD lesions whereas eight species were detected in both samples. We observed that the relative abundance of Streptococcus mitis decreased in the OPMD lesions compared to the uninvolved tissue. In contrast, the relative abundance of Fusobacterium nucleatum, implicated in carcinogenesis, was elevated in OPMD. We detected markedly increased bacterial diversity in the OPMD lesions compared to the healthy oral mucosa. The ratio of S. mitis and F. nucleatum are characteristically altered in the OPMD lesions compared to the healthy mucosa.

An observation on the severity of periodontal disease in past cigarette smokers suffering from rheumatoid arthritis- evidence for a long-term effect of cigarette smoke exposure?

BACKGROUND: Rheumatoid arthritis (RA) and cigarette smoking are both risk factors for periodontal disease (PD). Previous research suggests that systemic inflammatory conditions and cigarette smoking may act in synergy, and their co-occurrence leads to a much higher risk of developing severe stage PD than what the combination of their individual risks would suggest. We originally sought to test this in the case of RA, but it turned out that the majority of our patients were former smokers, who smoked for prolonged periods in the past. For that reason, we decided to shift our focus toward the possible effects of past chronic cigarette smoke exposure. METHODS: The data of 73 RA patients and 77 healthy controls were analyzed. The participants received a full-mouth periodontal examination to determine their periodontal status. Rheumatological indices and data on past tobacco use were also recorded. Both the patient and the control groups were divided into former smoker and non-smoker subgroups for the analyses. Non-smoker controls were used as the reference group. RESULTS: In the control group, smoking in history increased the odds of developing both the moderate and the severe stages of PD, but the change was not statistically significant. RA significantly, increased the odds of developing both stages in itself, but the highest odds were seen in the former smoker RA group. CONCLUSION: Based on this surprising observation of ours, we hypothesize that chronic cigarette smoke might bring about permanent changes in the periodontal tissues, leading to their hypersensitivity to inflammatory challenges.

TiO2/Ag-TiO2 Nanohybrid Films are Cytocompatible with Primary Epithelial Cells of Human Origin: An In Vitro Study.

Failure of dental implants is caused mainly by peri-implant infections resulting in loss of supporting bone. Since there is no ideal therapy of peri-implantitis, the focus of research has been shifted toward better prevention and the development of antibacterial surfaces. In our study we examined the attachment and proliferation of primary epithelial and MG-63 osteosarcoma cells on Ti dental implants coated with photocatalytic nanohybrid films. Two polyacrylate resin based layers were investigated on commercially pure (CP4) Ti discs: 60 wt% TiO2/40 wt% copolymer and 60 wt% Ag-TiO2/40 wt% copolymer ([Ag] = 0,001 wt%). Surface properties were examined by scanning electron microscopy (SEM) and profilometry. Cell responses were investigated via dimethylthiazol-diphenyl tetrazolium bromide (MTT) and visualized with fluorescence microscopy. Profilometry revealed significant changes in surface roughness of TiO2 (Ra = 1.79 µm) and Ag-TiO2 layers (Ra = 5.76 µm) compared to the polished (Ra(P) = 0.13 µm) and sandblasted, acid-etched control surfaces (Ra(SA) = 1.26 µm). MTT results demonstrated that the attachment (24 h) of epithelial cells was significantly higher on the Ag-TiO2 coated samples (OD540 = 0.079) than on the polished control surfaces (OD540 = 0.046), whereas MG-63 cells did not show any difference in attachment between the groups. After one week, epithelial cells showed slightly increased survival as compared to MG-63 cells. The results suggest that the tested coatings are cytocompatible with epithelial cells, which means that they are not only antibacterial, but they also appear to be promising candidates for implantological use.

Prasugrel Versus Clopidogrel: A Comparative Examination of Local Bleeding After Dental Extraction in Patients Receiving Dual Antiplatelet Therapy.

PURPOSE: To study the effects of various parameters on local hemostasis after dental extraction in patients receiving different combinations of medications who had previously confirmed effective dual inhibition of platelet aggregation. MATERIALS AND METHODS: A total of 129 patients were enrolled. They underwent acute or planned percutaneous coronary intervention and their stomatological examination disclosed teeth that could have acted as foci and thus had to be removed. All patients took acetylsalicylic acid 100 mg and clopidogrel or prasugrel. Lidocaine with or without epinephrine was used for local anesthesia, and a gauze swab or suture was applied to help hemostasis. RESULTS: Bleeding time was significantly longer by an average of 10 minutes (+21%) in patients taking prasugrel (P < .05) compared with those taking clopidogrel. Use of a suture resulted in a significantly shorter bleeding time after anesthesia with or without epinephrine (P < .05). A considerably longer bleeding time was observed when anesthesia with no epinephrine was combined with gauze. In smokers, the bleeding time was shorter by 15% on average. CONCLUSION: This study is the first to analyze differences in bleeding times between clopidogrel and prasugrel treatments during dental extraction. In general, prasugrel is associated with a considerably longer bleeding time; nevertheless, dental extraction can be performed safely with either combination.

Volatile sulphur compound measurement with OralChroma(TM): a methodological improvement.

The instrumental measurement of volatile sulphur compounds is a common practice to assess halitosis. One of the most widespread devices for that purpose is OralChroma(TM), a combination of a semiconductor gas sensor and a compact gas chromatograph (GC) system. Several lines of evidence indicate that although the hardware of OralChroma(TM) is fit for the precise measurement of volatile sulphur compounds (VSCs), its software needs revision to allow that precision. In this study we sought to develop software to solve this problem, and to test the utility of the new software in a population of patients and controls. The results were also compared with VSC measurements performed with Halimeter(®), another widespread device, so as to assess the correlation. A set of measurements involving volunteers (21 controls and 14 oral cancer patients) were conducted. The analysis of the chromatograms recorded by OralChroma(TM) indicated that the majority of the studied breath samples contained significant amounts of isoprene (the peak was around 100 s) and acetaldehyde (the peak was around 350 s), therefore OralChroma(TM) was also calibrated for both isoprene and acetaldehyde. A linear relationship was found between the concentration (in the range of 80-1400 ppbv for acetaldehyde and 40-560 ppbv for isoprene) and the area under the corresponding peak. In numerous cases the concentrations of VSCs calculated by the software of OralChroma(TM) required revision. In the new software, the concentrations of the VSCs, isoprene and acetaldehyde were determined by fitting the chromatograms with the sum of six Gaussian functions. Based on the findings of the present study we conclude that our new software allows an improved and instantaneous evaluation of OralChroma(TM) chromatograms with the additional possibility of determining the isoprene and acetaldehyde concentrations from breath samples.

Smoking as a permissive factor of periodontal disease in psoriasis.

BACKGROUND: Population-based studies have identified smoking as a pathogenetic factor in chronic periodontitis. At the same time, chronic periodontal disease has also been found to occur more often in persons suffering from psoriasis than in controls with no psoriasis. It is known that smoking aggravates both periodontal disease and psoriasis, but so far it has not been investigated how smoking influences the occurrence and severity of periodontal disease in psoriasis. METHODS: A hospital-based study was conducted to investigate this question. The study population consisted of 82 psoriasis patients and 89 controls. All patients received a full-mouth periodontal examination, and a published classification based on bleeding on probing, clinical attachment level and probing depth was utilized for staging. Both patients and controls were divided into smoker and non-smoker groups, and the resulting groups were compared in terms of periodontal status. Beyond the descriptive statistics, odds ratios were computed. RESULTS: Psoriasis in itself increased the likelihood of severe periodontal disease to 4.373 (OR, as compared to non-smoker controls, p<0.05), while smoking increased it to 24.278 (OR, as compared to non-smoker controls, p<0.001) in the studied population. In other words, the risk of severe periodontal disease in psoriasis turned out to be six times higher in smokers than in non-smokers. CONCLUSIONS: The results of this study corroborate those of other studies regarding the link between psoriasis and periodontal disease, but they also seem to reveal a powerful detrimental effect of smoking on the periodontal health of psoriasis patients, whereby the authors propose that smoking may have a permissive effect on the development of severe periodontal disease in psoriasis.

Quality of life in head and neck cancer patients after tumor therapy and subsequent rehabilitation: an exploratory study.

PURPOSE: The aim of the study was to evaluate patient-reported quality of life effects of post-treatment intraoral and extraoral rehabilitation in head and neck cancer by repeated measures. METHODS: Fifty-nine patients were involved. Basic socio-demographic, oncological and epidemiological data were gathered, and the type of rehabilitation was recorded. For the assessment of quality of life changes, two widely used brief questionnaires, the University of Washington Quality of Life Questionnaire and the Head and Neck module of the European Organization of Research and Treatment for Cancer Quality of Life Questionnaire, were used. The questionnaires were administered to patients two times: the first time after tumor therapy, but before rehabilitation (upon arriving for rehabilitation) and the second time 6 months after the application of any particular method of rehabilitation. Quality of life data were gathered prospectively, while socio-demographic data were gathered from patient files. RESULTS: Quality of life after rehabilitation was significantly enhanced as compared to the post-treatment status, in all domains of both questionnaires (p < 0.05 and p < 0.01, Mann-Whitney U). CONCLUSIONS: The results support the hypothesis that post-treatment maxillofacial rehabilitation in head and neck cancer does not only restore lost physical capabilities, but also brings about profound changes in patients' quality of life in general.