International Journal of Periodontics & Restorative Dentistry, 01/2021

Vertical bone augmentation (VBA) procedures for dental implant placement are biologically and technically challenging. Systematic reviews and meta-analyses of studies on VBA have failed to identify clinical procedures that provide superior results for treatment of the vertical ridge deficiencies. A decision tree was developed to guide clinicians on selecting treatment options based on reported vertical bone gains (< 5 mm, 5 to 8 mm, > 8 mm). The choice of a particular augmentation technique will also depend on other factors, including the size and morphology of the defect, location, and clinician or patient preferences. Surgeons should consider the advantages and disadvantages of each option for the clinical situation and select an approach with low complications, low cost, and the highest likelihood of success.

MAPA-cision, named after those who first introduced the method, is a novel simplified regenerative technique for periodontal-orthodontic cases that can be used in all circumstances where bone thickening is required. It is an innovative, minimally invasive piezoelectric surgical procedure designed to facilitate orthodontic tooth movement while simultaneously increasing bone thickness with guided bone regeneration principles. A new regenerative device consisting of a resorbable collagen membrane with filling materials (a “bone bundle” or “small sausage”) is inserted through a tunneling procedure to increase the bone envelope width by allowing the teeth to move within an enhanced periodontal support.

The aim of this article is to propose a simplified digital protocol for the treatment of the fully edentulous patient, using an immediate implant and immediate loading protocol to deliver a polymethyl methacrylate metal-reinforced hybrid prosthesis. Ten consecutive patients were treated with this approach. At the end of 1 year, there was an implant survival rate of 97.8% and a prosthetic success rate of 100%. Based on the responses to the quality of life questionnaire, patients had a high acceptance rate for this treatment protocol. Within the limits of this case series, the proposed simplified digital protocol could be utilized for reconstruction in the fully edentulous patient and for delivering an implant-supported prosthesis immediately after implant placement.

There is a need to modify the definition of attached gingiva (AG) as it applies to healthy and diseased teeth and implants. There are two parts to this new definition: Part A is when the biologic width is supracrestal (epithelial attachment and gingival fibers) and is attached to a healthy tooth or tissue-level implant, and the zone of AG is measured from the base of the sulcus to the mucogingival junction (MGJ); Part B is when the biologic width is subcrestal—as with infrabony defects on periodontally involved teeth, periodontally involved tissue-level implants, and bone-level implants placed at or below the bone crest—and the zone of AG is measured from the bone crest (not the base of the sulcus) to the MGJ. Further, what the AG is actually attached to around teeth and different types of implants, and the clinical significance of these differences, are thoroughly discussed.

The purpose of this prospective study was to evaluate the success rates and prosthetic complications of implants with a modified sandblasted and acid-etched (SLA) surface inserted for posterior single-implant crown restorations. Final crowns were placed 3 to 4 weeks after surgery, and patient follow-up spanned 10 years in a private practice setting. A total of 22 patients (8 women, 14 men) with 25 posterior implants placed (16 mandible, 9 maxilla) were selected, including only implants for posterior single-implant crowns with insertion torque values of ≥ 35 Ncm at placement. Twenty-one implants passed the reverse torque test at 3 to 4 weeks after implant placement, and final restorations were placed. Three patients (4 implants) had “spinners,” and there was one patient dropout after completion of the final restoration. All patients were recalled for clinical exams, digital periapical radiographs, and clinical photos at short-term (≤ 5 years) and long-term (> 5 years) follow-up appointments. The Community Periodontal Index of Treatment Needs was also determined at the initial and follow-up visits. Crestal bone level was measured at crown placement (T1), short-term follow-up (T2; mean: 29.4 months), and long-term followup appointments (T3; mean: 114.4 months). Twenty patients (23 implants) returned for examination at T2, and 15 (18 implants) were available at T3. For the 17 implants available at all evaluations, statistically significant bone loss was found from T1 to T2 (0.23 ± 0.30 mm), and the mean crestal bone level appeared stable from T2 to T3. Based on clinical and radiographic findings, the success rate for the implants and restorations at T2 and T3 was graded as 100%. Therefore, it can be stated that an early loading protocol of 3 to 4 weeks using a modified SLA surface at premolar/molar single-tooth locations can result in favorable clinical and radiographic long-term results.

The syndrome known as posterior bite collapse (PBC) has taken on multiple definitions over the years since its first introduction in 1964 by Morton Amsterdam and Leonard Abrams. In 2017, the World Workshop in the Classification of Periodontal and Peri-implant Diseases and Conditions proposed a staging system for periodontitis, defined by severity and extent of periodontal breakdown. Within this staging system, Stage IV periodontitis can include PBC. However, without a clear delineation regarding the clinical presentation or pathogenesis of PBC, this further obfuscates its definition. It is therefore the goal of this article to reexamine the original definition of PBC as defined by Amsterdam and Abrams, present an updated definition, and propose a clinical grading system of PBC to coincide with the 2017 staging of periodontitis.

In everyday practice, surgeons have to deal with bone atrophy. These rehabilitations are even more complex in the posterior mandible, and it is still unclear in the literature which fixed rehabilitation option is best. The purpose of this article was to help oral surgeons to choose the proper and updated treatment for their atrophic patients. Posterior mandible bone atrophies were divided into four main groups depending on the bone height measured above the inferior alveolar nerve: (1) ≤ 4 mm; (2) > 4 mm ≤ 5 mm; (3) > 5 mm ≤ 6 mm; (4) > 6 mm < 7 mm. Different approaches were proposed for each group, considering patient expectations. If ≤ 4 mm of bone height was available, guided bone regeneration was used as the adequate approach. For bone heights > 4 mm and ≤ 6 mm, the “sandwich” technique and/or short implants were used, depending on esthetics. In cases with > 6 mm and < 7 mm above the mandibular canal, short implants might be the proper option. The authors’ clinical experience and the literature were considered in order to suggest a possible correct treatment decision based on the residual bone height in the posterior mandible.

Implant position and soft tissue thickness have a direct influence on implant abutment design. The goal is to place the implant in the optimal spatial position to maintain the adjacent bone and soft tissues. When the implant is not placed ideally, prosthetic variations to abutments and restorations must be made, which may limit the esthetic appearance of the final restoration or alter the biologic environment of the bone and tissues. This article illustrates and explains the effect of different implant positions on the emergence profile design in order to assist the clinician with treatment planning and selection in various clinical situations.

The aim of the present study was to retrospectively evaluate the longevity of teeth and implants during a long-term period in a cohort of periodontally compromised patients, treated and maintained in a private specialist periodontal practice, and to analyze the associated risk factors. Fifty-eight patients (30 men, 28 women) who had received active periodontal therapy (APT) and regular periodontal maintenance (PM) ≥ 10 years were included and evaluated. The following were evaluated: (1) statistically significant differences of clinical parameters assessed at six tooth or implant sites (plaque scores, bleeding score, periodontal probing depth, bleeding on probing, and gingival recession) and radiographic parameters (mesial and distal bone crest loss) between patients with and without tooth/implant loss during PM; and (2) associations between the number of teeth and implants lost and potential risk factors. During PM, the overall average tooth loss was 0.07 teeth/patient/year (0.04 teeth/patient/year for periodontal reasons), while the overall average implant loss was 0.4 implants/patient/year. The overall implant failure was 10.08%, and the rate of implant failure due to biologic reasons was 9.8%. Incidence of implant failures in patients with vs without recurrent periodontal disease was 83.3% vs 16.7% (P < .05). Results showed that in chronic periodontitis patients, ATP followed by long-term PM is successful in keeping the majority of periodontally compromised teeth. In the same patients, a higher tendency for implant loss than tooth loss was found.

The goal of this multicenter randomized controlled study was to evaluate the effectiveness of a newly developed ionic-sonic electric toothbrush in terms of plaque removal and reduction of gingival inflammation. A total of 78 subjects from three dental centers were invited to join the study. They were randomized to receive either a manual toothbrush (control group) or an ionic-sonic electric brush (test group). Full-mouth prophylaxis and oral hygiene instructions based on the stationary bristle technique were provided 1 week prior to the baseline visit. At baseline and at each follow-up appointment, Plaque Index (PI) and Gingival Index (GI) were recorded. In addition, probing depth (PD) and bleeding on probing were recorded at baseline and at the last appointment (week 5). At completion of the study, subjects in the test group were given a questionnaire regarding their satisfaction with the toothbrush. Sixty-four subjects completed the study (control: 28; test: 36). The mean age of the subjects was 36.90 ± 12.19 years. No significant difference between the baseline and 5-week PD was found. Plaque removal efficacy and reduction in gingival inflammation were more significant for the test group at week 2. Both the control and test groups showed statistically significant improvement in PI and GI from baseline to week 5. The ionic-sonic toothbrush was more effective than manual toothbrush after a 1-week application.

Orthodontic therapy could lead to marginal bone resorption in cases where the teeth are moved outside the envelope of bone. The purpose of this case series was to test corticotomy with a guided bone regeneration (GBR) procedure to regenerate bone in the direction of movement outside the original bony housing. Ten adult patients (60 anterior teeth), all presenting with severe anterior crowding, were enrolled in the study. Orthodontic therapy in all investigated sites was associated with selective surgical corticotomies and a simultaneous GBR procedure. CBCT examinations were performed before starting orthodontic treatment (T0) and at the end of treatment (T1; mean: 7 months; range: 6 to 9 months). Pre- and postoperative CBCTs were superimposed with a DICOM viewer (3D Slicer) and studied with an image-processing software (ImageJ, National Institutes of Health) to measure the area of interest of the buccal plate. The average area was found to be 0.58 ± 0.22 mm2 at T0 and 1.76 ± 0.4 mm2 at T1, with a statistically significant difference (P < .05). The combination of corticotomy and a regenerative procedure seems to have the ability to augment the original osseous anatomy when the root is moved outside of the original bony envelope.

Although it is generally accepted that a prosthetic restoration must take into account the gingiva, smile, and patient’s face, it is often difficult to determine precisely what facial references must be considered. The purpose of this study was to determine the correct vertical and horizontal facial reference planes in esthetic prosthetic treatment. Using photographic analysis of 160 individuals, the different facial reference planes (interpupillary, intermeatic, intercommissural, and incisal edge lines; facial midline; and Camper and Frankfort planes) were compared to the ideal prosthetic reconstruction axis. Additional measurements, including the human eye’s ability to perceive parallelism, were recorded. Most participants (64%) exhibited facial asymmetry. Asymmetry was horizontal (difference between widths of the right and left sides; 52.4%), vertical (difference between heights of the right and left sides; 6.9%), or mixed (4.7%). The interpupillary line is the main horizontal reference in 88.4% of situations, with the intercommissural line the second most important. In the profile view, the horizontal plane was on average 6.5 degrees above the Camper plane and 9 degrees below the Frankfort plane. The human eye’s ability to perceive parallelism between two lines was found to be limited to differences of approximately 1 degree. During anterior tooth reconstruction, it is necessary to take into account the right horizontal and vertical esthetic references. Knowledge of the biometric facial parameters in natural dentition is necessary to define the right reconstruction axes based on the facial symmetry or asymmetry.

This study aimed to histologically analyze the bony tissue formed around dental implants after osseointegration. A 58-year-old patient presented with pain and discomfort caused by two dental implants in her maxilla placed 8 months earlier. At clinical and radiographic analysis, the implants appeared well osseointegrated but tilted buccally, emerging in nonkeratinized mucosa. For this reason, the discomfort began right after the prosthetic load, 4 months after implant placement, and the patient felt pain when wearing the implant-supported removable prosthesis. Both implants were made of titanium, airborne-particle abraded with zirconium oxide, and etched with mineral acids. The implants were removed, preserving the bone around the implant threads, and replaced with two new implants, inserted in a prosthetically guided, correct position. The removed implants were histologically observed. Histologic analysis showed good bone-to-implant contact, mature bone with few marrow spaces, presence of direct connecting bridges between the periimplant bone trabeculae and the implant surface, and no inflammatory cells nor connective fibrous tissue ingrowth. This study showed that dental implants coated with a rough surface were properly osseointegrated, with no inflammatory signs nor connective fibrous tissue ingrowth, 8 months after placement.

The objective of this study was to determine the normal values of faciolingual thickness (FLT) of the papilla base, papilla height (PH), and gingival angle (GA) among Chinese adults and the association of FLT with the gingival phenotype. The periodontal phenotypes of 105 volunteers were confirmed by Kan et al’s periodontal probe transmission method and classification. All volunteers received complete supragingival scaling and were recalled after 1 week for clinical examination and for recording various periodontal indices, including Plaque Index, Gingival Index, and periodontal depth. The FLT, PH, and GA of maxillary anterior teeth were measured, and their associations were analyzed. The mean FLT of papilla between the right canine (CA) and lateral incisor (LI) was 8.11 ± 0.64 mm; between the right LI and central incisor (CI) was 7.77 ± 0.64 mm; between the right CI and left CI was 8.49 ± 0.66 mm; between the left CI and LI was 7.62 ± 0.63 mm; and between the left LI and CA was 8.17 ± 0.63 mm. The thin-phenotype group showed a greater PH and FLT than the thick phenotype group. Inversely, the GA of the thick-phenotype group was greater than the corresponding values for the thin-phenotype group. In Chinese residents, the high and thick papilla are associated with the thin phenotype, while the low and thin papilla are associated with the thick phenotype. The GA is negatively correlated with PH. A weak correlation exists between the GA and FLT of papilla.

Conical retention with antirotational features (Acuris abutment) has been recently proposed for restorations of healed single implants. The conometric abutments use the retentive force of the coping-abutment system to retain the prosthetic crown without the use of cement or screws. This retentive force must be overcome to obtain detachment of the relined provisional crown in immediate restorations. The present article describes the use of digital scanning technology to virtually plan computer-guided implant placement and restoration with conical indexed abutments in postextraction sites. Importing the scan data of both matrix and patrix abutments that are seated on the definitive cast into the computer-aided design software provides a workflow to preoperatively mill a crown that perfectly fits the abutment into the postextraction site. This technique simplifies the provisional crown relining onto the conometric indexed abutment and reduces the intraoperative time.

This study aimed to characterize extraction sockets based on indirect digital root analysis. The outcomes of interest were estimated socket volume and dimensions of the socket orifice. A total of 420 extracted teeth, constituting 15 complete sets of permanent teeth (except third molars), were selected. Teeth were scanned to obtain STL files of the root complex for digital analysis. After digitally sectioning each root 2.0 mm apical to the cementoenamel junction (CEJ), root volume was measured in mm3 and converted to cc. Subsequently, a horizontal section plane was drawn at the most zenithal level of the buccal CEJ, and the surface area (in mm2) and buccolingual and mesiodistal linear measurements of the socket orifice (in mm) were computed. Maxillary first molars exhibited the largest mean root volume (0.451 ± 0.096 cc) and mandibular central incisors the smallest (0.106 ± 0.02 cc). Surface area analysis demonstrated that mandibular first molars presented the largest socket orifice area (78.56 ± 10.44 mm2), with mandibular central incisors presenting the smallest area (17.45 ± 1.82 mm2). Maxillary first molars showed the largest mean socket orifice buccolingual dimension (11.08 ± 0.60 mm), and mandibular first molars showed the largest mean mesiodistal dimension (9.73 ± 0.84 mm). Mandibular central incisors exhibited the smallest mean buccolingual (5.87 ± 0.26 mm) and mesiodistal (3.52 ± 0.24 mm) linear dimensions. Findings from this study can be used by clinicians to efficiently plan extraction-site management procedures (such as alveolar ridge preservation via socket grafting and sealing) and implant provisionalization therapy, and by the industry to design products that facilitate site-specific execution of these interventions.

This study compares the mechanical strengths of bulk-fill composite resin and amalgam material to investigate the stress distribution and capacity to mitigate stress of restored Class I and Class II teeth under chewing loads, using finite element analysis. A 3D model of a human mandibular first molar and four Class I (C1) and Class II (C2) caries, including 95-degree cavity-margin angles, were created. Different material combinations were simulated: model C1-A and C2-A, with an amalgam material; and model C1-C and C2-C, with a bulk-fill composite resin. Solid 3D elements with four grid points were employed for modeling the tooth. A vertical occlusal load of 600 N was applied, and nodal displacements on the bottom cutting surfaces were constrained in all directions. All materials were assumed to be isotropic and elastic, and a static linear analysis was performed. The highest maximum principal stress was observed in C2-C, followed by C1-C, C2-A, and C1-A, respectively. The maximum principal stress load on the lingual cusp was recorded at the junction of the lingual margin (C1-C and C2-C), and stress was recorded on the line of restoration and enamel (C1-A and C2-A). Restoration materials and cavity preparations influence the stress distribution at the restoration-tooth interface and, consequently, the measured bond strength.

This prospective longitudinal clinical trial aimed to evaluate the success of a bone-level implant with an integrated platform-switched connection by assessing peri-implant soft tissue and marginal bone level. Twenty-six patients were treated in two different centers with implants placed in healed partially edentulous ridges. Implant success rate and marginal bone level were evaluated with photographs, radiographs, and clinical measurements, with a 6-month postloading follow-up. The esthetic appearance of the photographed periimplant soft tissue was evaluated at 6 months via the Pink Esthetic Score applied by two calibrated operators. All of the implants except for one placed in the mandible demonstrated successful osseointegration, resulting in a success rate of 97.8% at the 6-month follow-up. Compared to historical controls, no detectable differences in peri-implant marginal bone loss or esthetic outcome were seen.

The purpose of this study was to evaluate the cleaning and surface treatment techniques in the repair of aged and contaminated yttrium oxide-stabilized tetragonal polycrystalline zirconia (Y-TZP). From a total of 80 specimens of Y-TZP, 60 were subjected to aging simulation in a buccal environment with degradation in an autoclave for 24 hours (127ºC/1.5 bar) and contaminated with Streptococcus mutans. The surfaces were cleaned with a triple syringe (air/water jet; n = 20) or isopropyl alcohol (n = 20), or by prophylaxis (n = 20) with pumice and water. The remaining 20 specimens comprised the control group. All specimens were then treated with silicatization (n = 10 per group) or adhesive (n = 10 per group) and repaired with composite resin. Analyses of shear strength, failure mode, and roughness were performed by electron microscopy. Data were analyzed by twoway analysis of variance (ANOVA) and t test (α = .05). Statistical significance was set at P < .05. Two-way ANOVA was significant for aging and surface treatments (P = .049), but was not significant for surface cleaning (P = .05). ANOVA results were statistically significant for surface treatments (P < .0001), with higher resistance for the silicatization groups. The failure mode was mostly adhesive for all specimens. The roughness was not significant for aging and control groups (P > .05). Triple-syringe and prophylaxis cleansing followed by silicatization was the most efficient treatment for the repair of aged and contaminated Y-TZP. There is reduced repair efficiency with the aging of Y-TZP.