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Most would agree that the etiology of dental implant failure is related to oral biofilm. At present one group of scientists and clinicians feel that biofilm is solely responsible for bone loss around the devices. However, there is strong evidence that particles and ions of titanium released into the surrounding tissues by the action of biofilm and/or mechanical forces, a process termed metallosis, can be responsible for bone loss around some dental implants. These findings are reinforced by similar responses found around failed metal on metal joint prostheses. Both possible etiologies are discussed in detail in this commentary., (© 2020 American Academy of Periodontology.)

Background: During videoscope-assisted minimally invasive surgery which uses a high magnification videoscope to treat periodontal defects, small areas resembling calculus are detected remaining on root surfaces following scaling. These are clinically termed microislands of calculus, which are removed by the use of a chelating agent. This material has not been verified as calculus and the ability of a chelating agent to remove calculus has not been proven. The purpose of this ex vivo study is to verify if the material is calculus and to determine if calculus is removed with a chelating agent., Methods: Extracted teeth (n = 22) with heavy calculus on root surfaces were selected. A 5-mm 2 area containing calculus was scribed on each root. Digital videoscope images were made of the marked areas using only white light and also with only a 655-nm diode laser that causes calculus to fluoresce. The marked areas were root planed until no calculus was visible with 3.5× surgical loupes. Digital images were again made. The test area was then burnished with a chelating agent (EDTA) for 30 seconds and images again made. Using the images, the percentage of the marked root surface containing calculus was calculated., Results: Calculus remained on the roots surfaces after they were judged to be clean using 3.5× loupe magnification. Remaining calculus was reduced after burnishing for 30 seconds with EDTA., Conclusions: Calculus remains on root surfaces judged to be calculus free using surgical loupes for visualization. Small areas of calculus are reduced or eliminated with a chelating agent., (© 2020 American Academy of Periodontology.)

Background: There is growing concern that titanium particles may play a role in peri-implant breakdown. Ultrasonic scalers are routinely used in the debridement of peri-implant lesions. This in vitro study is designed to evaluate if titanium particles are produced when an ultrasonic scaler is used on an implant., Methods: New sandblasted, large grit, acid etched (SLA) coated implants were subjected to ultrasonic scaling with stainless steel, titanium, and PEEK plastic tips. The implants were placed in a holding device and the ultrasonic scaler was positioned on the SLA surface under 25 grams of pressure. The implants were subjected to 30 scaling motions. The ultrasonic coolant water was collected and the number of metallic particles were counted under a light microscope. The particles were confirmed to be titanium via elemental analysis. The implants were visually evaluated for damage to the SLA coating., Results: No metallic particles were detected in the water supplied to the ultrasonic scalers (passive control). Metallic particles were detected when implants were subjected to the ultrasonic coolant water only without the scaler tip touching the implant (active control). All implants that were scaled produced metallic particles and showed easily detectable damage to the SLA layer., Conclusions: All ultrasonic scaling caused the production of titanium particles and caused damage to the SLA coating of the implant. Ultrasonic scalers should be used with great caution in the treatment of peri-implant conditions and care should be taken to not touch the SLA surface of the implant., (© 2018 American Academy of Periodontology.)

Background: Titanium (Ti) dominates as the material of choice for dental implant systems. Recently, titanium-zirconium alloy (TiZr) and zirconia (ZrO ₂ ) have emerged as alternative materials due to higher mechanical strength and lower corrosion susceptibility. Oral pathogenic bacteria can colonize Ti surfaces, leading to surface degradation, which has yet to be investigated on TiZr and ZrO 2 . The aim of this study was to compare in vitro oral bacterial adhesion and subsequent surface degradation on commercial Ti, TiZr, and ZrO 2 implants., Methods: Ti, TiZr, and ZrO 2 implants with sandblasted, acid-etched (SLA) surfaces in addition to modified SLA-treated (modSLA) Ti implants (n = 3) were immersed for 30 consecutive days in Streptococcus polyculture. Post-immersion, adherent bacterial count was quantified. Optical microscopy was used to assess qualitative degradation and score Ti-based implants based on degree of surface damage while electrochemical testing quantified corrosion behavior. Analysis of variance followed by post-hoc Tukey test was used to statistically compare quantitative results (α = 0.05)., Results: Ti-SLA, Ti-modSLA, and TiZr-SLA implants exhibited localized features characteristic of corrosion attack while ZrO 2 -SLA implants experienced minimal changes in surface morphology as compared to non-immersed control. Corrosion features were more numerous on Ti-modSLA implants but smaller in size as compared with those on Ti-SLA and TiZr-SLA implants. No significant differences in corrosion resistance (polarization resistance and corrosion rate) were observed between Ti-SLA, Ti-modSLA, and TiZr-SLA implants., Conclusion: TiZr and ZrO 2 dental implant surfaces were not more susceptible to colonization and surface degradation by oral Streptococcus species than commercially pure Ti implants., (© 2018 American Academy of Periodontology.)

Background: Peri-implantitis is an inflammatory condition that can lead to implant loss. The aim of this descriptive retrospective study is to describe the histopathologic findings in soft tissue biopsies of implants with peri-implantitis., Methods: Thirty-six human peri-implantitis biopsies were analyzed using light microscopy (LM) and scanning electron microscopy (SEM). The composition of foreign materials found in the tissues was assessed using an energy dispersive x-ray spectrometer., Results: At the LM level, the inflammatory lesion of peri-implantitis was in most cases a mixture of subacute and chronic inflammation dominated by plasma cells. At the SEM level, radiopaque foreign bodies were identified in 34 of the 36 biopsies. The predominant foreign bodies found were titanium and dental cement. These foreign materials were surrounded by inflammatory cells., Conclusions: At present, the exact mechanism for introduction of these materials and their role in peri-implantitis is unknown. Further research is warranted to determine their etiology and potential role in pathogenesis.

The large majority of dental implants are successful over the long term. Failure is usually associated with infection, trauma, inflammation, or a combination of these factors. Early identification and appropriate treatment can identify and eliminate these problems in the majority of cases. Thus routine implant maintenance structured along the guidelines for patients with periodontal diseases is recommended.

Background: Minimally invasive surgery (MIS) is a surgical technique using very small incisions indicated for performing regenerative therapy in periodontal defects. The 11-month results from a prospective study of MIS were previously published. This article presents the 6-year results of that prospective study., Methods: Patients from two private periodontal practices with advanced periodontitis who, after non-surgical therapy, had one or more sites with probing depths >or=6 mm were included in the study. An MIS surgical approach was used for all sites >or=6 mm. After surgical debridement, enamel matrix derivative (EMD) was placed into the bony defect. The surgical sites were reevaluated after >or=6 years., Results: Six-year data were available on 142 sites in 13 patients. No significant differences were noted in the results between the two offices, and the data were combined. Probing depths (mean: 3.18 mm; SD: 0.59 mm) and attachment levels (mean: 3.93 mm; SD: 0.19) at 6 years were unchanged from the 11-month measurements. No recession from preoperative levels was noted. All sites continued to be considered clinically successful., Conclusions: The combination of MIS and EMD yielded significant reductions in probing depths and improvements in attachment levels while producing no detectable recession. The 11-month results remained stable at 6 years.

Background: Cement-retained restorations are commonly used on dental implants. Residual excess cement after placement of fixed partial dentures has been associated with clinical and radiographic signs of peri-implant disease. The purpose of this study was to explore the relationship between excess dental cement and peri-implant disease using the dental endoscope., Methods: Thirty-nine consecutive patients with implants exhibiting clinical and/or radiographic signs of peri-implant disease were studied. Patients were enrolled in the study during a 5-year period in a private periodontal practice. Twelve of these patients had similar implants without signs of inflammation; these implants served as controls. There were 20 controls and 42 test implants. All were evaluated using a dental endoscope initially, and all but one implant was evaluated at a 30-day follow-up. Results from both groups were assessed by two trained operators and recorded., Results: None of the controls and all 42 of the test implants had clinical signs of peri-implant disease at initial treatment. Excess cement was found in none of the controls and 34 of the test sites. Thirty days after cement removal, 25 of 33 test sites from which the cement was removed had no clinical or endoscopic signs of inflammation., Conclusions: Excess dental cement was associated with signs of peri-implant disease in the majority (81%) of the cases. Clinical and endoscopic signs of peri-implant disease were absent in 74% of the test implants after the removal of excess cement.

Background: The primary goal of periodontal therapy is the reduction or elimination of inflammation. Traditionally, this is accomplished through removal of subgingival tooth-borne accretions using non-surgical and/or surgical treatment modalities. Numerous studies indicated the difficulty in removing these accretions to the point that histologic manifestations of chronic inflammation are eliminated. A companion to the current study demonstrated that subgingival inflammation was associated most often with calculus covered with biofilm, not biofilm alone. This pilot study evaluated the histologic response in humans to removal of calculus and biofilm with the aid of the dental endoscope., Methods: Twelve teeth in six patients were identified as test teeth, and all subgingival deposits visible with the endoscope were removed in a single treatment by an operator experienced in root planing and the use of the dental endoscope. The 12 teeth and the coronal portion of their periodontal attachment apparatus were removed 6 months after a single episode of closed subgingival scaling and root planing. Biopsies were processed for histologic evaluation., Results: There were no histologic signs of chronic inflammation. Deposits of calculus and biofilm were seen on one section of one tooth but apparently were deposited after initial therapy. Bone repair and the growth of a long junctional epithelium were observed on previously diseased root surfaces., Conclusion: Histologic signs of chronic inflammation were absent 6 months after a single course of closed subgingival scaling and root planing using the dental endoscope.

Background: The subepithelial connective tissue graft, traditionally harvested from the patient's palate, is commonly used for root coverage in periodontal recession defects. This study evaluates the safety and effectiveness of a living human fibroblast-derived dermal substitute (HF-DDS) compared to a connective tissue graft (CTG) for root coverage in these situations., Methods: Thirteen patients were selected for this study. Each patient had Miller Class I or II bilateral facial recession defects > or =3 mm on two non-adjacent teeth. The test tooth received an HF-DDS graft, while a CTG was placed on the control site. The 10 test surgeries were performed by one operator and three pilot surgeries were performed by another surgeon. Eight of the HF-DDS sites received a single thickness of material; five received a double thickness. Clinical measurements were taken at baseline; 1 week; and 1, 3, and 6 months following surgery. Parameters measured were plaque index, recession depth, clinical attachment levels, recession width, probing depth, and width of keratinized tissue. All clinical readings were taken by a masked, calibrated examiner., Results: There were no statistically significant differences between the test and control groups. The amount of root coverage was slightly greater for the control group than for the test group, but statistically the difference was insignificant. The width of the recession defect measured at the cemento-enamel junction (CEJ) for the test group was slightly smaller than that of the control group at the conclusion of the study. The amount of keratinized tissue was the same in both groups at 6 months. The probing depth was slightly greater in the control group as was the gain in clinical attachment, but neither was statistically significant. The amount of root coverage obtained when one layer of HF-DDS was used compared to the amount of coverage obtained when two layers were used approached statistical significance, but the small sample size may have been responsible for the difference., Conclusion: Within the limits of this study, the human fibroblast-derived dermal substitute may offer potential as a substitute to the connective tissue graft for covering areas of facial Miller Class I or Class II gingival recession in humans.

Background: Osseointegration has been shown to occur around implants placed immediately after tooth extraction in humans. To date, such osseointegration has been achieved only with titanium plasma-sprayed (TPS) implants placed in extraction sockets with a bone-to-implant distance of less than 2 mm. In a previous report, when this horizontal defect dimension (HDD) exceeded 2 mm, the resulting percentage of bone-to-implant contact was reduced, indicating that the immediate technique would be limited in most cases to non-molar teeth. In an attempt to improve the bone-to-implant contact and the initial bone-to-implant contact in a vertical dimension, the implant surface, the type of membrane, and the method of membrane placement used in a previous study by our group were modified., Methods: Ten large-grit sandblasted, acid-attacked (SLA) titanium implants were placed into immediate extraction sites in 5 patients. HDDs of 0.0 to 1.5 mm (controls), 1.5 to 4.0 mm, and >4.0 mm were used. Following insertion, implants were completely covered with a connective tissue membrane. This was in contrast to the use of an expanded polytetrafluoroethylene (ePTFE) membrane penetrated by the neck of the implant in our previous report. Primary closure of soft tissue flaps was achieved in each case. Six months after placement, 7 of the implants were histologically examined., Results: Osseointegration occurred across all HDDs, with the percentage of bone-to-implant contact in the 0.0 to 1.5 mm HDDs similar to that seen in the >4.0 mm HDDs. The first bone-to-implant contact measured vertically was similar in both the smaller and larger HDDs., Conclusions: Osseointegration was successful in immediate implant placement sites with horizontal defect dimensions wider than 4 mm in humans when SLA titanium implants were completely covered with connective tissue membranes. It remains undetermined whether the different type of membrane, placement of the membrane, type of implant surface, or a combination of these 3 factors were responsible for the improved osseointegration in HDDs >4 mm. Further study is needed.

Background: This study investigated the relationship of the interleukin-1 (IL-1) genotype, smoking status, and the patient's age to the survival of osseointegrated dental implants., Methods: Twenty-seven patients with 33 implants that had been lost or who had at least 50% bone loss on radiographs were compared to a group of 38 patients who had experienced no bone or implant loss. All lost implants in a private practice were included in the data, except those that had fractured with no previous bone loss., Results: Smoking was demonstrated to increase the risk of implant failure by a factor of almost 2.5., Conclusions: Statistical testing failed to provide evidence of an increased risk for implant failure for patients who are positive for the IL-1 genotype. There was no apparent relationship between the patient's age at the time of placement and implant loss. This study raises several questions concerning the etiology of implant loss and the comparative biology of tissues surrounding implants when compared to those surrounding natural teeth.

This paper presents 5-year data pertaining to a subgroup of patients from a previous investigation who were treated with scaling and root planing plus tetracycline fibers. The parent study demonstrated that 6 months after therapy, scaling and root planing plus tetracycline fiber therapy was significantly better at reducing probing depth and gaining clinical attachment than scaling and root planing alone. However, the long-term data presented here show a regression from the original gains in clinical attachment levels in the fiber group. Ultimately, the use of fibers provided no significant advantage with regards to probing depth reduction or clinical attachment gain. Within the power of this study, which would have required 1.78 mm of change in clinical attachment to show a difference, there was no significant difference between the treatments at 5 years. This study underscores the need for additional long-term evaluation of this mode of therapy.

Patients who receive routine supportive periodontal treatment (SPT) tend to keep their teeth longer and enjoy greater periodontal health than those individual who do not receive this therapy. Previous studies have found less than optimal compliance to suggested SPT. The study reported in this paper covered 5 years of patient data and measured the effects of efforts to improve compliance in a private periodontal practice. These efforts included attempts at simplifying compliance, maintaining records of compliance, informing patients of the consequences of noncompliance, and attempting to identify noncompliers before active periodontal therapy was initiated. The results were measured against a similar group studied in previous work within the same office published in 1984. The main finding of the present study was an increase in complete compliance from 16% in 1984 to 32% in 1991. This increase came largely at the expense of the noncompliant group. The reason for the increase in compliance is likely due to efforts to increase compliance carried out in the office. However, other factors such as change in the hygiene practice law, increased public awareness of dental needs, and economic depression may also have affected compliance. This information suggests that noncompliance can be reduced if the problem is recognized and efforts are made to increase compliance.

This paper begins with a review of the literature on compliance. The medical literature suggests that patients with chronic illnesses tend to comply poorly, especially if the disease is not perceived by the patient as particularly threatening. The dental literature covers two principal areas: compliance with oral hygiene regimens and utilization of dental care by the public. These works show that most patients surveyed do not clean their teeth as they have been instructed, and most do not receive routine dental care. The reasons for this noncompliance are highly variable but include lack of pertinent information, fear, economics, and the patient's perception of lack of compassion on the part of the dental therapist. In periodontics the majority of studies have focused on the effectiveness of patient oral hygiene along with its modification and on maintenance therapy. Other work in the periodontal literature is discussed in light of the widespread noncompliance shown by our patients. A number of studies have been undertaken on how best to improve compliance. In general, it has been found that patients comply better when they are informed and positively reinforced, and when barriers to treatment are reduced. Suggestions are made for improving compliance in the periodontal office and for tailoring therapy to predicted compliance levels.

The purpose of this study was to determine patient compliance with suggested maintenance schedules. All patients eligible for maintenance therapy in a private periodontal practice were included. The study covered a period of 8 years. All patients had chronic inflammatory periodontal disease and had been eligible for at least 1 year of maintenance therapy before the close of data collection. A total of 961 patients were studied; only 16% complied with recommended maintenance schedules. Erratic compliance was found in 49% of the patients and 34% never reported for any maintenance therapy.

A group of 162 maintenance patients, previously studied for compliance to suggested maintenance schedules, were surveyed for tooth loss over a 5-year period. The group was divided into those who complied to suggested maintenance schedules and those whose compliance was erratic. It was found that none of the patients who had complied to suggested maintenance schedules lost any teeth. In the erratic group, where all tooth loss occurred, it was found that the more often a patient presented for maintenance, the less likely he was to lose teeth. These findings are discussed in relation to current studies on efficacy of various therapies for periodontal diseases.