International Journal of Periodontics & Restorative Dentistry, 05/2021

This study involves a group of 168 teeth in 126 patients treated with crown lengthening and tooth reconstruction (experimental group), and a group of 75 teeth from 62 patients that were judged irrational to treat, extracted, and replaced (control group). In the control group, 13 teeth in 12 patients were not replaced; 37 were replaced with an implant-supported crown, 14 with a tooth-supported partial denture, 2 with a Maryland partial denture; and 9 patients requested a removable prosthesis. In the experimental group, 44 teeth in 37 patients received a conservative restoration (24 direct and 20 indirect), while 124 teeth in 94 patients received a full crown. All 168 teeth were surgically treated with minimally invasive crown lengthening. Endodontic treatment and orthodontic extrusion were applied when necessary. Treatment resulted in healthy periodontal and dental/implant conditions at the 1-year follow-up in both groups. Function and esthetics were described from satisfactory to extremely satisfactory by patients of both groups, with the exception of three patients in the control group who received a mobile prosthesis restoration and reported some difficulties in chewing. When comparing treatment cost and duration of the reconstructed teeth (experimental group) to the treatment cost and duration of extracted and replaced teeth (control group), the difference is significantly in favor of the preservation of natural teeth, both monetarily and in terms treatment time. Saving a tooth with a compromised crown is more favorable for the patient than extraction and replacement. This conservative approach is advisable to clinicians whenever the clinical conditions enable treatment.

This retrospective study evaluated 335 hybrid implants placed in edentulous ridges; 167 were placed with an immediate implant protocol (IIP) and 168 were placed with a delayed implant protocol. Radiographic bone level changes were measured 1 to 23 years after loading. The average bone loss between implant placement and second-stage loading was 0.16 mm in the delayed group and 0.12 mm in the IIP group. Average bone loss from implant loading to the final radiograph was 0.26 mm in the IIP group and 0.13 mm in the delayed group. There was statistically significantly more bone loss in the IIP group, in patients taking amoxicillin (vs those taking azithromycin), in sites with splinted implants (vs nonsplinted implants), and in smokers (vs nonsmokers). However, even when statistically significant, bone loss would be considered clinically insignificant by most clinicians over the 1- to 23-year follow-up.

Barrier membranes are critical to the success of guided bone regeneration (GBR). Though not directly involved in bone regeneration, barrier membranes hold bone graft materials at the surgical site during the slow process of bone regeneration and prevent the infiltration of fibrotic gingival tissues that would compromise new bone formation. Many options are available on the market, but membranes derived from placental tissues are gaining rapid adoption due to their unique biologic and handling properties. In this case series, a dehydrated human deepithelialized amnion-chorion membrane (ddACM) was used in combination with freeze-dried bone allograft (FDBA) for two-stage GBR procedures. Data from 1-year and 5-year follow-up appointments are presented, as well as predictable indications for the use of ddACM. Using ddACM with FDBA for GBR cases led to predictable bone regeneration with osseointegrated implants at 5-year postoperative visits.

This study evaluated the influence of different implant types on (1) radiographic marginal bone levels after healing and (2) radiographic and histomorphometric tissue levels and characteristics following ligature-induced peri-implantitis. Four implant types (Standard Plus, Straumann [S]; NobelReplace Tapered, Nobel Biocare [N]; In-Kone Universal, Global D [I]; and twinKon, Global D [T]) were randomly placed in the edentulous healed mandibular ridge of six dogs (T0), for a total of 57 implants placed. After 10 weeks, a peri-implantitis was ligature-induced (T1). After 12 weeks, biopsy samples were processed for histomorphometric analysis (T2). Standardized radiographs were taken at T0, T1, and T2 for imaging analysis. Statistical analysis was performed using mixed-effects linear modeling. After healing (T1), the radiographic marginal bone level was more coronal for implants I, T, and S compared to N. Following peri-implantitis (T2), the histologic marginal bone level was more coronal for implants I, T, and S compared to N, and for implants I and T compared to S. Also at T2, the radiographic marginal bone level was more coronal at implants I, T, and S compared to N. Implant type may influence bone remodeling during healing and bone loss during the early stages of experimental peri-implantitis.

Ten patients with a diagnosis of generalized chronic periodontitis underwent nonsurgical periodontal therapy performed with the exclusive use of ultrasonic instrumentation and air polishing with erythritol powder. For each patient, four pockets with probing depths (PDs) of 4 to 10 mm were selected as experimental sites, and air polishing was performed either before (Group A) or after (Group B) ultrasonic scaling. PDs and clinical attachment levels significantly improved over a 12-month observation period. No significant difference was observed between the use of air polishing before or after ultrasonic instrumentation. The present clinical protocols could represent a suitable treatment for cause-related periodontal therapy.

Buccal bone remodeling around immediate implants placed in animals with streptozotocin (STZ)-induced diabetes has not been investigated. The present histologic and microcomputed tomography (μCT) in vivo experiment assessed the buccal bone remodeling around immediate implants, extraction socket healing, and bone-to-implant contact (BIC) in dogs with and without STZ-induced diabetes. Three male beagle dogs with STZ-induced diabetes and three healthy dogs (controls) were included. Fasting blood glucose levels were measured using a glucometer. Under general anesthesia, all animals underwent atraumatic tooth extraction of bilateral maxillary and mandibular second premolar teeth using Piezosurgery and immediate implant placement in the distal root socket. Primary closure was achieved for all implants and adjacent socket sites. After 11 months, all animals were sacrificed, and buccal bone thickness (BBT), marginal bone loss (MBL), BIC, and mesial extraction socket bone volume were assessed in control and diabetic animals using histologic and μCT examination. High-resolution μCT analyses were performed to identify the percentage of osteocytes and blood vessels in bone specimens harvested from a mesial extraction socket in each group. BBT and BIC were significantly higher in control dogs (P < .05), and diabetic dogs demonstrated significantly more MBL than control dogs (P < .05). Compared to healthy subjects, the sockets of induced diabetic dogs lost over 50% of bone horizontally and vertically. Control group had more significant osteocytes (38.85%) and blood vessels (37.87%), whereas the same values for STZ-induced diabetic dogs were 27.92% and 27.76%, respectively. Buccal bone loss and MBL were significantly higher around immediate implants placed in dogs with STZ-induced diabetes and were associated with multiple implant buccal thread exposure. A large percentage of socket space in diabetic dogs healed with nonosseous structure following tooth extraction.

The present prospective case series evaluated the efficacy, the intra- and postsurgical complications, and the patient-related outcomes of a tunnel technique with a subperiosteal bag (TTSB) for horizontal ridge augmentation prior to implant placement. Twenty-five systemically healthy patients searching for implant rehabilitation and presenting with a horizontal ridge deficiency requiring bone augmentation before implant placement were included. Guided bone regeneration (GBR) was performed using the TTSB technique, involving the preparation of a collagen membrane that is perforated, folded, and sutured to form a bag that is then filled with a xenogeneic bone graft material. The bag is then inserted into a subperiosteal tunnel. Horizontal bone gain (HBG) was calculated 6 months after the surgery using CBCT. Healing was uneventful and with minimal morbidity. Average HBG was 3.7 ± 1.8 mm (P < .05), with a vertical component gain of 1.3 ± 1.7 mm (P > .05). In 12 patients, additional bone augmentation was required at the time of implant placement. A higher HBG was achieved in the maxilla than in the mandible (4.3 ± 1.3 mm vs 3.2 ± 1.8 mm, respectively; P < .05), and sites with an initial horizontal ridge width ≤ 3.5 mm were associated with a higher chance of requiring additional bone grafting at the time of implant placement compared to sites with an initial horizontal ridge width > 3.5 mm. The present case series demonstrated that TTSB is an effective approach for ridge augmentation prior to implant placement with minimal intra- and postoperative complications or patient morbidity.

This article evaluated the sealing capacity of single crowns made of a new zirconia (Katana STML, Kuraray Noritake) when cemented with two different cement types and two different marginal preparation types. Forty intact human anterior teeth, extracted for periodontal reasons, were used. Each sample was prepared with two margin preparations: knife-edge (KE) on one half of the tooth and chamfer (CH) on the other half. Based on the type of cement used, abutments were randomly distributed into one of two groups: Group 1 used resin cement (Panavia V5, Kuraray Noritake), and Group 2 used reinforced glass-ionomer cement (FujiCEM 2, GC). A digital workflow was utilized for crown fabrication. After the cementing procedures, samples were processed, and microleakage and scanning electron microscopic observations were made. Microleakage varied significantly depending on the type of cement combination used. Group 1 samples showed less microleakage (medians: 0.76 for CH and 0.51 for KE in Group 1, and 4.1 and 3.45 for Group 2, respectively) than Group 2 specimens; the difference was statistically significant (P < .000). KE preparation showed less microleakage than CH, although no statistically significant differences were found (P < .0558). Under microscopic observations, some samples showed internal fractures within the zirconia material. KE and CH seal the margin of zirconia crowns similarly. The resin cement system ensured better adhesion than reinforced glass-ionomer cement.

Successful treatment of peri-implantitis requires decontamination of implant surfaces exposed to biofilms and byproducts of tissue inflammation. In this regard, dental lasers may provide a clinical benefit. While the inherent characteristics of specific laser wavelengths may damage titanium implant surfaces, in vitro and animal studies have shown that damage to the target surface can be avoided with the selection of appropriate laser parameters. In this in situ human study, five hopeless implants were irradiated, each by one of the following lasers: Nd:YAG (1,064 nm), Er,Cr:YSGG (2,780 nm), Er:YAG (2,940 nm), CO₂ (9,300 nm), and CO₂ (10,600 nm) at their recommended settings. All implants were then removed and examined under scanning electron microscopy for the presence of residual bacteria and to assess the extent of damage to the implant surface. An additional implant (implant no. six) was irradiated and evaluated by the Limulus Amebocyte Lysate test for the presence of residual lipopolysaccharide endotoxin. The results showed that while there were localized areas of heat-related damage to an implant surface following laser irradiation, residual bacteria were rarely noted. Additionally, the Limulus Amebocyte Lysate test indicated a nearly complete removal of endotoxin. With the use of appropriate settings, all current dental lasers can be utilized for implant surface decontamination in a human.

The gingival thickness (GT) and keratinized tissue width (KTW) constitute the gingival phenotype, a concept that has received a great deal of appreciation in recent years. Gingival phenotype modification has been achieved via different surgical techniques and grafting materials. Despite the superiority of autogenous grafts, their increased patient morbidity and limited recourse has led to the development of graft substitutes. The human dermal matrix is a notable example that, depending on its processing method, can become freeze-dried or solvent-dehydrated acellular dermal matrix (FDADM and SDADM, respectively). This article reports the 9-year outcomes of a randomized clinical trial regarding gingival phenotype modification following root coverage with FDADM and SDADM. Twelve of the original 20 patients were available at the 9-year follow-up. Overall, the outcomes of gingival phenotype modification were maintained in both groups and at all sites after 9 years. For KTW, an incremental increase was observed over time in both groups, and minimal or no changes were noted in GT from the 1-year recall to the 9-year recall. However, the gingival margin level showed an apical shift for both groups.

This case report describes an alternative minimally invasive fixed rehabilitation to approach an impacted maxillary canine (IMC) and the residual deciduous teeth. The patient refused any orthodontic treatment or surgical extraction of the IMC, asking for a fixed and fast option. Considering the available bone was about 5 mm in height, an immediately provisionalized postextractive 4-mm super-short implant was placed. Healing was uneventful. Two years after loading, the result was stable and the patient was fully satisfied. Within all the limitations of this case report, this approach could reduce rehabilitative times, possible complications, and costs.

To improve the adaptation to bone level discrepancies of sloped alveolar crests, an implant with a sloped implant-abutment interface has been developed. In a previously reported international multicenter study, 65 sloped implants replaced single teeth with a buccolingual bone level discrepancy at least 3 months after tooth loss. The present study reports the long-term outcomes of one study center and also evaluates marginal bone and keratinized mucosa alterations around sloped implants in healed, sloped crests in a long-term follow-up. Implant survival, marginal bone levels, and buccal bone dimensions in relation to the implant shoulder level (assessed by periapical radiographs and CBCT), width of keratinized mucosa, and probing depths were observed. Two patients did not present for follow-up examinations. No implants were lost. The remaining 13 implants were followed for a mean period of 123 months. Mean marginal bone levels were maintained slightly coronal to implant shoulder level at the interproximal (0.13 mm) and the buccal aspects (0.57 mm). The width of keratinized mucosa improved significantly from delivery (1.85 mm) to the 1-year follow-up (3.39 mm) and was thereafter unchanged. Placing implants with a sloped shoulder in a healed crest with lingual-buccal bone level discrepancy resulted in circumferential marginal bone maintenance and improved width of the keratinized mucosa.

Conventional crestal and intrasulcular incisions followed by full-thickness flap reflection may inevitably induce surgical trauma, resulting in facial contour reduction, mucosal recession, and interdental papilla loss. Flapless implant surgery is the most conservative approach; however, it might create undetectable bone fenestration/dehiscence and subsequent complications. The present clinical study introduces a modified and minimally invasive approach, the palatal access flap (PAF), for placing implants in the esthetic zone. Preliminary data of 15 consecutive cases demonstrated clinically negligible soft tissue contour changes when pre- and postoperative 3D model scans were compared. The PAF technique could be a surgical solution, especially for patients with a high esthetic risk, to maintain facial and interproximal tissue contours for the implant site and adjacent teeth.

This study aimed to estimate the radiographic outcomes of the alveolar ridge splitting (ARS) technique combined with guided bone regeneration (GBR) and compare its efficacy with GBR alone in maxillary anterior narrow ridges. Forty patients with 51 implants in the ARS group and 40 patients with 49 implants in the GBR group were included. The buccal bone thickness (BBT) at 0 to 4 mm from the implant shoulder immediately and 6 months postoperative were analyzed using cone beam computed tomography. The BBT at both time points had no statistical disparities between the two groups (P > .05). However, BBT changes indicated significant disparities, with more BBT preservation in the ARS group (P < .05). Compared with GBR alone, the ARS technique combined with GBR, despite obvious buccal bone diminution, could be a reliable modality for treating ridge width deficiency in the anterior maxilla.

The morphology and histology of the soft tissue around the implant are different from the periodontal tissue, but the difference in the regulation of blood flow is not known. The aim of the study was to compare the resting blood flow and the vasodilatation capacity of the gingiva between implants and teeth. Twenty-six healthy volunteers with single-tooth implants were involved. The implant-borne crown was retained on either a zirconia or titanium abutment. The vasodilatation capacity of the gingiva was assessed by a postocclusive reactive hyperemia test. Blood flow was measured by a laser speckle contrast imager at the buccal gingiva of the implant-borne crown and an analog natural tooth. No significant differences in baseline gingival blood flow were observed between the different abutments and the teeth in either region. The hyperemia after compression was significantly attenuated at the zirconia abutments in all regions during the entire investigation period (20 minutes) compared to the titanium abutments and the teeth. No differences were observed between titanium abutments and the teeth. The resting microcirculation seems to be the same at implants and teeth. However, the vascular reactivity might be disturbed at the zirconia, but not at the titanium, abutment.

Different techniques have been introduced when replacement with an implant is planned after tooth extraction. The conventional approach consists of waiting 3 to 4 months before implant placement. However, many other options are available for implant placement, including immediate implant placement (IIP), IIP and immediate provisionalization (IIPIP), and early implant placement (EIP). When the ridge is deficient, guided bone regeneration (GBR) with simultaneous implant placement is often performed. However, this procedure has potential for postoperative complications and patient discomfort, as well as an extended treatment time. The recent introduction of the Customized Alveolar Ridge-Splitting (CARS) technique can help avoid many of these problems and treat atrophic ridges that will require two or three GBR surgeries. The purpose of this case report is to demonstrate the step-by-step surgical and restorative procedures for the CARS technique and present histologic data of the new bone generated utilizing this technique.

The paper presents the inferior alveolar nerve transposition as a successful surgical technique when other treatment options are not possible in the severely resorbed posterior mandible. Based on three clinical cases, this technique is presented in conjunction with implant placement and immediate loading. The paper aims to present the mandibular nerve transposition as a therapeutic method and an important approach, engaging clinicians to use it when other opportunities are impossible.

A cemental tear involves complete or incomplete separation of the cementum on the root surface along the cementodentinal junction. Because a cemental tear can lead to periodontal breakdown and mimic endodontic and periodontal lesions, diagnosing clinical cases can be difficult and requires special examinations. A 72-year-old woman presented with a localized periodontal defect on the labial and interproximal surfaces of the mandibular right central incisor. Performing CBCT scans and a biopsy during periodontal surgery allowed definitive diagnosis of a cemental tear and perforation of the site. First, the perforation was repaired with endodontic therapy. Periodontal regenerative therapy using recombinant human fibroblast growth factor-2 (rhFGF-2) was then performed after removing granulomatous tissue and cementum fragments. Examination of the biopsy specimen showed bacterial colonies. This case showed successful clinical and radiographic outcomes at the 18-month follow-up.