A 60-year-old woman presented with an upper right canine that had a sinus tract with a soft tissue defect measuring 5 mm in diameter at the labial apical area and attachment loss with gingival recession of 3 mm on the labial side. The tooth required apicoectomy and root coverage, which were performed simultaneously in a single surgical procedure for three reasons: (1) with the widespread use of microscopes, established surgical procedures and specialized instruments have been developed, increasing the predictability of each procedure; (2) it has excellent cost and time performance, and can reduce patient anxiety and pain; and (3) in 2019, Nelson et al. reported that, if infection is properly controlled by apicoectomy, it is possible to perform root coverage surgery for gingival recession at the same time. Now, one year after treatment, the apical radiolucency on X-ray has disappeared, the exposed root surface is completely covered by the gums, and the periodontal pocket is within the normal range, showing good results.

Front surface mirrors are commonly used in microscopic dentistry. This is because conventional back surface mirrors produce a ghosting effect in which the reflected image appears doubled, preventing objects from being seen clearly. However, most commercially available front surface mirrors use rare metals for their reflective coatings. They have the advantages of reflecting a clearer image with higher reflectance than back surface mirrors, but they have the disadvantages of high cost and durability issues. The reflectance of various front surface mirrors was compared, and a front surface mirror was successfully developed without using rare metals; it had an excellent average reflectance of 99% in the range of 400 nm to 700 nm, within the visible light spectrum of 380 nm to 780 nm.

Objective: This case report aims to describe the application of real-time telementoring in microendodontic procedures, utilizing a digital microscope system to enhance procedural accuracy and remote guidance.

Case Report: A 30-year-old woman diagnosed with odontogenic maxillary sinusitis originating from a necrotic maxillary right molar. Real-time telementoring was utilized to assist in the endodontic treatment of the patient's maxillary molar. The digital microscope system enabled the operator in Japan and the remote endodontist in Paraguay to share the operative field. Despite initial challenges in locating the MB2 canal, the remote endodontist provided guidance through real-time annotations and review of CBCT images, ultimately leading to successful root canal filling.

Conclusion: Real-time telementoring using digital microscopes offers a valuable tool for enhancing microendodontic procedures. It provides remote expertise, facilitates international collaboration, and optimizes the ergonomic and educational aspects of dental practice. Future research should explore its application in other dental fields to further validate its effectiveness and benefits.

The use of conventional microscopes has been associated with leading to musculoskeletal injuries or chronic pain syndrome. Some surgeons find it difficult to observe subjects through the binocular/monocular tubes of a microscope. Heads-up surgery has been reported as beneficial, but the associated posture does not provide proper ergonomics. Forward Head Posture syndrome is also caused by a looking-up posture. To solve these problems, a 3D digital microscope/exoscope/endoscope with a 3D-Head Mounted Display (3D-HMD) system has been reported. But recently, most manufacturers have suspended production of medical grade 3D-HMDs, and consumer grade 3D monitors. No studies have directly, and objectively, compared the resolution and delay/latency between the seen video image on the HMD’s display and the optical image seen through the eyepieces of the microscope. This study compared the performance of thirteen consumer grade 2D/3D-HMDs to a medical grade 3D-HMD HMM-3000MT, and to an High Definition (HD) video monitor Shogun Flame. No differences were found in resolution when comparing 9 of 13 HMDs, HMM-3000MT, Shogun Flame and the optical image seen through the eyepieces of the microscope. A 3D digital microscope/exoscope/endoscope with one of these HMDs has a possibility solving the problems with conventional microscope usage.

Dens invaginatus is an abnormality in the development of the hard tissues of the tooth. It tends to be found on the maxillary lateral incisors and rarely on the mandibular central incisors.

In this case, we encountered an Oehlers type II dens ivaginatus mandibular central incisor with a chronic apical abscess, which was diagnosed definitively by cone-beam computed tomography (CBCT). Since the tooth had no caries or history of trauma, we thought it was highly likely that the invaginated area was the route of infection. Under an operating microscope, the invaginated area was cut and removed using a diamond-coated ultrasonic tip, and a root canal preparation was performed with a Ni-Ti rotary file. Root canal cleaning was performed using sodium hypochlorite and EDTA, and agitation with a sonic polyamide activation tip attached to an air scaler effectively eliminated infection. Root canal filling was performed using multiple gutta-percha points and a non-shrinking sealer without the use of a spreader. After resin construction with fiber posts, the whole crown was restored with glass ceramics.

We report a case of a Dens invaginatus of Oehlers type II with a complex root canal morphology, in which a good progress was made without excessive cutting of the tooth substance, by using state-of-the-art endodontic treatment instruments.

The treatment of periodontal disease involves the removal of deposits and infected tooth structure. Traditionally, manual instruments and ultrasonic scalers have been used for this purpose. They are mainly operated by inserting the instrument through the pocket opening and applying the blade along the tooth surface. In this case, it is necessary to consider the size and reachability of the applied instrument to reduce contact with the tooth surface and damage to the soft tissue in the pocket. Shimizu (2021)^{1, 2} developed the micro-retraction method, in which the periodontal pocket is widened under a microscope to visualize the treatment target. A micro-ultrasonic tip was developed to be used in conjunction with this method to enable minimally invasive procedures.

This paper introduces the characteristics of the newly developed micro-periotip and reports its clinical use.