Scaling and root planing vs. conservative surgery in the treatment of chronic periodontitis.

A renewed interest in conservative surgical techniques has been fueled by new technology, changes in referral patterns to periodontists and a desire to achieve periodontal health in the least invasive, most cost-efficient manner possible. Trends suggest that an increasing amount of periodontal care is being provided in the offices of general dentists. If true, it is likely that patients receiving care in these offices will be offered simpler surgical treatment modalities that do not require an extensive armamentarium. The purpose of this article was to review the effectiveness of six relatively simple surgical techniques - gingivectomy, flap debridement, modified Widman flap, excisional new attachment procedure, modified excisional new attachment procedure and laser-assisted new attachment procedure - and to compare the results obtained using these procedures with the well-known clinical benefits of scaling and root planing. The intent was to determine whether the benefits of surgical procedures in the hands of most general dentists extend beyond those of conventional nonsurgical therapy.

Subgingival scaling and root planing during minimally invasive periodontal surgery: A randomized controlled split-mouth trial.

BACKGROUND: The purpose of this randomized, controlled split-mouth study was to evaluate a videoscope as a visual adjunct to scaling and root planing when utilized in combination with minimally invasive surgery. METHODS: Twenty-five pairs (89 interproximal surfaces) of periodontally hopeless teeth planned for extraction were scaled and root planed with minimal surgical access using surgical loupes (control) or adjunctive use of a videoscope (test). Teeth were extracted with minimal trauma, stained with methylene blue, and photographed with a digital microscope for analysis. The primary outcome of residual calculus was calculated as a percentage of the total interproximal area of interest. Secondary outcomes included treatment time, as well as residual calculus according to probing depth, tooth location, and treatment date. Data were analyzed using Student's paired t-tests, two-way analyses of variance, and Spearman's correlation tests. RESULTS: Residual calculus area was 2.61% on control and 2.71% on test surfaces with no significant difference between groups. Subgroup analysis showed no difference in residual calculus between groups at moderate or deep sites. Treatment time per surface was significantly longer in the test group compared to the control group. Treatment order, tooth location, and operator experience did not significantly affect the primary outcome. CONCLUSIONS: Though the videoscope provided excellent visual access, it did not improve the efficacy of root planing for flat interproximal surfaces during minimally invasive periodontal surgery. Small amounts of calculus remain after instrumentation even with minimal surgical access and when root surfaces appear visually clean and tactilely smooth.

Donor site wound healing following free gingival graft surgery using platelet rich fibrin: A randomized controlled trial.

BACKGROUND: The primary purpose of this two-arm, parallel design, randomized controlled study is to compare healing of the palatal tissue donor site when platelet-rich fibrin (PRF) is used as a wound dressing compared to the use of a hemostatic agent. Secondary outcomes of patient pain perception and analgesic intake were also evaluated. METHODS: Seventy-four patients receiving free gingival grafts were randomized to receive either PRF (test) or hemostatic agent (control) as a palatal wound dressing by patients selecting a sealed envelope containing their group assignment (initially 37 envelopes for PRF group and 37 for hemostatic agent group). Patient pain assessment and analgesic consumption were documented using a 21-point numerical scale (NMRS-21) at 24, 48, and 72 hours post-surgery. At 1-, 2-, 3-, and 4-week follow-up appointments palatal early healing index (PEHI) scores including wound color, epithelialization, presence or absence of swelling, granulation tissue, and bleeding on gentle palpation were generated by direct intraoral examination by a blinded examiner unaware of the patients' treatment group. RESULTS: NMRS-21 pain scores showed a significant reduction in pain over time in both groups, with no significant difference between groups at any time point. No significant between-group difference was found in the amount of analgesics taken by patients at 24, 48, and 72 hours. There was significant improvement in PEHI scores over the 4-week time period in both groups, but there was no significant difference in PEHI score at each time point (1, 2, 3, 4 weeks) between groups.  CONCLUSIONS: Study findings suggest that there is no difference in early palatal wound healing, patient pain perception, or analgesic consumption between use of PRF or a hemostatic agent as donor-site wound dressings.

A randomized controlled trial evaluating the effect of epithelial removal on free soft tissue autograft healing.

BACKGROUND: The purpose of this study is to determine if there is a difference in dimensional change of a free soft tissue autograft (FSTA) with epithelium compared to without epithelium. The secondary aim is to determine the patient and professional evaluation of color match and graft texture between the two groups. METHODS: Patients with ≤2 mm keratinized tissue indicated for a FSTA were randomly assigned to control group (FSTA with epithelium) or test group (de-epithelialized FSTA). The vertical and horizontal measurements of the grafts were taken at surgery, and 1, 3, and 6 months postoperatively. Patients were asked to evaluate the color match at each postoperative time point on a 21-step Numeric Rating Scale (NRS-21). Professional assessment of color match and graft texture were evaluated on images at the same time points. RESULTS: Forty-six patients and 55 grafts were included in the study. For change in graft height, width, and area, there were no significant differences between the treatment groups at any time point. Graft height and area in both groups decreased significantly from baseline to month 1 (p < .001), but no other difference was significant over time. When patients and professionals used the NRS-21 for evaluation of color match between the graft site and the surrounding soft tissue, there was no significant difference between the treatment groups. Similarly, evaluation of texture match on color images and black-and-white images revealed no significant differences between or within groups. CONCLUSION: De-epithelialized FSTA showed no difference in dimensional change or color and texture match compared to FSTA with epithelium.

Effect of intravenous dexamethasone on postoperative pain and swelling following periodontal flap surgery: A randomized controlled trial of patient-centered outcomes.

BACKGROUND: This randomized, crossover trial sought to determine if a preoperative intravenous (IV) dose of dexamethasone reduces pain, swelling, and analgesic usage following periodontal surgery. METHODS: Thirty-seven patients planned for two similar periodontal flap surgeries under IV sedation were enrolled. Patients were randomized to receive either 2 mL (8 mg) dexamethasone sodium phosphate or 2 mL of IV solution (placebo) before the first surgery, and 2 mL of the other solution before the second surgery. Postoperative discomfort was managed with a standardized regimen of 600 mg ibuprofen and 325 mg acetaminophen. A smartphone application was used to record self-assessed pain and swelling scores using 21-point numerical (NRS-21) and 4-point verbal (VRS-4) rating scales as well as the number of analgesic medications taken at 12-, 24-, 48-, 72-, 168-, and 336-hours following each surgery. RESULTS: IV dexamethasone was associated with a significant reduction in pain at 12, 24, 48, and 72 hours (P <0.05), and swelling at 12, 24, 48, and 168 hours (P < 0.05) postoperatively when compared with placebo based on NRS-21 responses. VRS-4 data showed significant reductions in pain at 12, 72, and 168 hours and swelling at 12, 24, and 168 hours postoperatively with dexamethasone. No significant differences were found in the number of tablets of ibuprofen or acetaminophen between dexamethasone and placebo surgeries. CONCLUSIONS: Preoperative, intravenously administered dexamethasone reduces pain and swelling within the first postoperative week following periodontal flap surgery and should be considered a useful adjunct for perioperative management.

An alternative donor site for an epithelialized-free soft-tissue autograft.

Typically, epithelialized-free soft-tissue autografts are harvested from the palate, while alternative sites include edentulous ridges and wide zones of gingival tissue. This case report documents the use of the operculum over an erupting molar as an additional harvest site, a technique that may offer certain advantages in younger patients.

Necrotizing ulcerative gingivitis: a discussion of four dissimilar presentations.

BACKGROUND: Necrotizing ulcerative gingivitis (NUG) is a periodontal disease characterized by pain, bleeding, and necrosis of interdental papillae. This series details treatment of four cases, followed by a discussion of the disease. CASE DESCRIPTION: Four patients presented to four practitioners for treatment of severe gingival pain, each eventually being diagnosed with NUG. All patients in this series were successfully treated using accepted protocols, and though each was different with regard to presenting signs and symptoms, all responded similarly to treatment. Similar to the patients described in this series, NUG cases in general can present with varying degrees of involvement from barely-noticeable to starkly severe. CLINICAL IMPLICATIONS: The most severe cases of NUG are often more destructive in appearance than those most commonly seen in textbooks, while in the mildest cases the appearance can almost be mistaken for health.

Impact of different surgical protocols on dimensional changes of free soft tissue autografts: A randomized controlled trial.

BACKGROUND: To determine if there is a difference in the amount of shrinkage during healing of free soft tissue autografts (FSTAs) using different surgical techniques-suturing the vestibular flap margin apically to the base of the recipient bed versus leaving the flap margin free and unsutured. METHODS: Twenty-eight patients with mucogingival defects requiring FSTAs were recruited and enrolled in the study. Patients were randomized into test and control groups (14 per group) and received ≥1 FSTAs on non-molar mandibular teeth. In the test group the mucosal flap margin was sutured apically to the periosteum at the base of the graft; whereas, the mucosal flap margin in the control group was left free. Graft dimensional measurements were taken at time of surgery, then at 1, 3, and 6 months post-surgery. RESULTS: Thirty-five grafts were performed (15 test, 20 control). All FSTAs experienced vertical shrinkage after 6 months, but there was no significant difference (P = 0.51) in the mean amount of shrinkage after 6 months between the test (23.20% ± 20.88%) and control (21.10% ± 21.88%) groups. There was significantly greater horizontal shrinkage in the test (loss of 7.59% ± 10.20%) compared with the control (small gain of 0.32% ± 4.20%) group (P = 0.01). CONCLUSIONS: The findings suggest that there is similar vertical shrinkage when performing FSTA surgery when the mucosal flap margin is left free and unsutured when compared with leaving the flap margin free.

Accuracy of dental calculus detection using digital radiography and image manipulation.

BACKGROUND: The aim of this study was to determine if image enhancement improves a clinician's ability to identify the presence of calculus on digital radiographs. METHODS: Seventy-one hopeless teeth were collected from 34 patients. Teeth were stained with 1% methylene blue, the largest interproximal calculus deposit was scored, and photographs of each interproximal root surface were taken. The surface area of calculus deposit was determined as a percentage of the total interproximal root surface area. Digital radiographs of teeth taken before extraction were modified using the following enhancements: auto-contrast, emboss, invert, and sharpen. Radiographic presence of calculus was determined by two examiners. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each examiner and enhancement. A receiver operating characteristic curve was used to compare differences between the image enhancements in the detection of dental calculus. The kappa statistic was used to compare ratings between examiners. RESULTS: None of the enhanced images were statistically superior to original images in identifying radiographic calculus (P > 0.05). The average sensitivity of digital radiography was 50%, average specificity was 82.2%, PPV was 94%, and NPV 23.2%. A threshold of >30% of interproximal root surface covered with calculus and increasing size of deposits were associated with improved detection (P < 0.05). CONCLUSIONS: Digital enhancements do not significantly improve radiographic detection of dental calculus. As area of calculus on the root surface and size of calculus deposits increased, sensitivity of detection also increased.

Response of chronic and aggressive periodontitis to treatment.

Patients with aggressive periodontitis can be both rewarding and frustrating to treat in clinical practice. Interindividual variation in response to therapy can be widespread, and we do not clearly understand the reasons for this variable response. It is possible that new research into the resolution of inflammation may reveal basic differences between patients with chronic periodontitis and those with aggressive disease. In addition, future research involving modulation of host inflammatory responses may clarify the reasons for the differences in clinical outcomes between patients. We think it likely that this research could result in further alterations to the classification of periodontal diseases, as with more knowledge of the mechanisms of disease it is possible that patients currently classified as having aggressive periodontitis may be found not to represent a single diagnostic entity. Better understanding of the true nature of patients currently identified as having aggressive periodontitis may therefore lead to more effective treatment approaches.

Post-surgical flap placement following osseous surgery: A short-term clinical evaluation.

BACKGROUND: The purpose of this study is to examine the relationship between immediate post-surgical flap position and subsequent probing depth measurements following osseous surgery. METHODS: Twenty-four patients treatment planned for osseous surgery after completion of initial therapy and re-evaluation were enrolled. Pressure molded stents were fabricated to serve as a reference for probing depth and relative attachment level measurements prior to surgery. After osseous recontouring was completed, flaps were sutured and compressed, and bone sounding measurements were made as designated by the stent. Patients returned at 3- and 6 months for repeat measurements of probing depth and attachment level. RESULTS: Twenty-four patients completed surgical treatment and follow-up measurements with a total of 402 treated sites. A statistically significant moderate correlation between immediate post-surgical bone sounding measurements and subsequent probing depth was found at 6 months (R = 0.56, P < 0.001). There was no significant difference between this correlation at 3 and 6 months. The probability of having 6 month probing depth ≤3 mm was 93.5% when the surgical flap was placed within 3 mm of the alveolar crest (286/306 sites) as opposed to 50% when the surgical flap was >3 mm away from the alveolar crest (48/96 sites). Interproximal sites were significantly more likely (P < 0.01) to have probing depths > 3 mm at 3 and 6 months. CONCLUSIONS: Results suggest a statistically significant relationship between immediate post-surgical flap placement and subsequent probing depths. Positioning the surgical flap more closely to the alveolar crest when performing osseous surgery resulted in shallower probing depths at 3 and 6 months.

Removal of an amalgam tattoo using a subepithelial connective tissue graft and laser deepithelialization.

BACKGROUND: A 56-year-old female presented for periodontal treatment with a large amalgam tattoo located in alveolar mucosa on the facial aspect of her maxillary central incisors. The lesion had been present for 42 years since having endodontic surgery at teeth #8 and #9 after a traumatic childhood incident. METHODS: A two-stage surgical approach was used to eliminate the lesion, beginning with a subepithelial connective tissue graft to increase tissue thickness subjacent to the amalgam tattoo. After 6 weeks of healing, the overlying pigmented tissue was removed using laser surgery to expose the underlying grafted connective tissue. RESULTS: After 2 months of healing following laser surgery, the amalgam pigmentation was completely removed, with good color match and an increased width of keratinized tissue at the surgical site. CONCLUSION: A relatively large amalgam tattoo in the esthetic zone can be adequately removed by a two-stage procedure using grafted palatal connective tissue and laser deepithelialization.

Periodontal wound healing with and without platelet-rich plasma: histologic observations and assessment of flap tensile strength.

BACKGROUND: Platelet-rich plasma (PRP) has been promoted as a surgical adjunct to enhance hard and soft tissue wound healing. Although anecdotally reported to be of value, the results of controlled studies examining the added effects of PRP on surgical procedures have been mixed. The purpose of this study was to test the effect of PRP on flap strength at various post-surgical time points in a minipig animal model. METHODS: Twelve Yucatan minipigs provided four sites per animal. PRP was prepared from each animal at the time of surgery. Following reflection of a mucoperiosteal flap in each quadrant, subgingival plaque and calculus were removed. Each surgical site was irrigated with sterile saline; prior to suturing, one randomly selected test quadrant in each arch was treated with PRP. Four animals were euthanized at day 14, and two animals were euthanized at 2, 7, 10, and 28 days. The flap strength in each quadrant was tested by attaching to a loop of 3-0 silk suture through the tissue; the force required to separate the flap from the tooth/bone interface was recorded for each site. A separate portion of each flap site was prepared for descriptive histologic examination, including inflammation, hemorrhage, and new bone growth. RESULTS: Flap strength was significantly less on day 2 compared to later time points, and there were no significant differences between the test and control groups. No histologic differences in healing between test and control sites were seen at any time point. CONCLUSIONS: PRP did not seem to contribute to greater flap strength at any post-surgical time point, nor was it associated with any histologic differences in wound healing in this Yucatan minipig model. The time points chosen for observation post-surgery, as well as the variability in the PRP platelet count, may have contributed to the lack of positive findings in this study.

Clinical reliability of the "furcation arrow" as a diagnostic marker.

BACKGROUND: The radiographic entity known as the "furcation arrow" has long been used in practice even though little is known about its usefulness as a clinical indicator. The definitive study of the furcation arrow suggests that its presence on a radiograph reliably predicts furcation invasion, but this has not been confirmed in an in vivo investigation. The purpose of this study was to evaluate the furcation arrow in a clinical setting, testing the assertion that the furcation arrow image is an accurate predictor of furcation invasion. Specifically, we sought to determine the following. First, what is the prevalence of furcation arrow images in the radiographs of maxillary molars with periodontitis? Second, what is the interexaminer agreement on what constitutes a furcation arrow? Third, how does the presence or absence of a furcation arrow correlate with the true clinical status of the furcation? Fourth, what is the sensitivity and specificity of the furcation arrow as a diagnostic indicator? METHODS: Eighty-nine patients requiring surgical treatment of periodontitis in the maxillary molar regions were included in this study. Before surgery, one of five calibrated examiners viewed periapical and bitewing radiographs of the surgical site and recorded the presence or absence of a furcation arrow at each proximal furcation. Before administering anesthesia, the same examiner recorded a Hamp index value of each proximal furcation, with a second Hamp index taken after flap reflection and debridement. After surgery, each of the four remaining examiners independently reviewed the radiographs for furcation arrows. Descriptive statistical analysis was performed to correlate the appearance of the furcation arrow image to the actual degree of furcation invasion as determined by the intrasurgical Hamp index. RESULTS: A total of 164 maxillary molars were examined, providing 328 interproximal furcations; 111 (33.8%) furcations were determined at surgical debridement to have a furcation invasion of Hamp degree 1 or greater. Of the 111 furcation invasions, 43 (38.7%) were predicted by a furcation arrow image seen by at least three of the five examiners. When comparing the appearance of the radiographic image to the extent of furcation invasion, 20 of 64 (31.3%) Hamp 1 furcation invasions and 23 of 47 (48.9%) Hamp 2 and 3 furcation invasions were predicted by furcation arrows observed by at least three of five examiners. The multirater kappa statistic for interexaminer agreement on the presence or absence of the image was 0.489. The sensitivity of the furcation arrow image as a diagnostic marker was 38.7%, and the specificity was 92.2%; the positive predictive value of the image was 71.7%, and the negative predictive value was 74.6%. Of the 324 furcations used to compare clinical indices, the agreement of preanesthesia and postdebridement Hamp indices was 0% for degree 3, 83.7% for degree 2, and 98.4% for degree 1 furcation lesions. CONCLUSIONS: These data suggest that the furcation arrow has limited usefulness as a diagnostic marker of furcation invasion. The image is difficult to interpret and highly subjective and can correctly predict furcation invasions only approximately 70% of the time when present on the radiograph. In addition, when furcation invasions are truly present, the furcation arrow is seen in <40% of sites.

Palatal neurofibroma associated with localized periodontitis.

BACKGROUND: Neurofibromatosis type 1 (NF1) is the most common form of neurofibromatosis. While typically considered a dermatologic disorder, intraoral signs of neurofibromatosis occur quite commonly. This clinical entity can be confused with periodontitis because of the presence of periodontal pockets. In this report, we present the case of a palatal neurofibroma with radiographic involvement in a patient with NF1. METHODS: A 40-year-old female patient was referred from her general dentist to evaluate advanced periodontitis in the maxillary left quadrant. The patient's medical history was significant for a soft tissue lesion excised from her back 11 years previously and diagnosed as a neurofibroma. Subsequent medical examination at that time confirmed a systemic diagnosis of NF1. A comprehensive periodontal evaluation was performed, and panoramic and periapical radiographs were taken. Teeth were tested for vitality. An incisional biopsy was completed for histopathologic examination. RESULTS: The periodontal evaluation revealed the presence of 6 to 9 mm probing depths adjacent to teeth #14 and #15. Panoramic and periapical radiographs showed a circumscribed 0.8x0.9-cm unilocular radiolucency superimposed over the root of tooth #13 and extensive horizontal bone loss on the distal side of #15. Incisional biopsy confirmed the presence of a neurofibroma, and because of the extent of the lesion, the patient was referred to the Oral and Maxillofacial Surgery service for complete excision. CONCLUSIONS: Neurofibromas can cause extensive destruction of alveolar bone, mimicking periodontitis. Due to the potential systemic and genetic implications, the diagnosis of neurofibroma requires appropriate medical referral.

Combined endodontic-periodontic treatment of a palatal groove: a case report.

The palatal groove is a developmental anomaly that predisposes the tooth involved to a severe periodontal defect. When further complicated by pulp necrosis, these grooves often present a diagnostic and treatment planning challenge that requires an interdisciplinary treatment approach. This case report describes the successful collaborative management of a maxillary lateral incisor with an extensive palatal groove using a combination of nonsurgical endodontic therapy, odontoplasty, and periodontal regenerative techniques.

Post-surgical infections: prevalence associated with various periodontal surgical procedures.

BACKGROUND: Of the various adverse outcomes that may be encountered following periodontal surgery, the risk of infection stands at the forefront of concern to the surgeon, since infection can lead to morbidity and poor healing outcomes. This paper describes a large-scale retrospective study of multiple surgical modalities in a diverse periodontal practice undertaken to explore the prevalence of clinical infections post-surgically and the relationship between diverse treatment variables and infection rates. METHODS: A retrospective review of all available periodontal surgical records of patients treated in the Department of Periodontics at Wilford Hall Medical Center, San Antonio, Texas, was conducted. The sample comprised 395 patients and included 1,053 fully documented surgical procedures. Surgical techniques reviewed included osseous resective surgery, flap curettage, distal wedge procedures, gingivectomy, root resection, guided tissue regeneration, dental implant surgery, epithelialized free soft tissue autografts, subepithelial connective tissue autografts, coronally positioned flaps, sinus augmentations, and ridge preservation or augmentation procedures. Infection was defined as increasing and progressive swelling with the presence of suppuration. The impact of various treatment variables was examined including the use of bone grafts, membranes, soft tissue grafts, post-surgical chlorhexidine rinses, systemic antibiotics, and dressings. Results were analyzed using Fisher's exact test and Pearson's chi-square test. RESULTS: Of the 1,053 surgical procedures evaluated in this study, there were a total of 22 infections for an overall prevalence of 2.09%. Patients who received antibiotics as part of the surgical protocol (pre- and/ or post-surgically) developed eight infections in 281 procedures (2.85%) compared to 14 infections in 772 procedures (1.81%) where antibiotics were not used. Procedures in which chlorhexidine was used during post-surgical care had a lower infection rate (17 infections in 900 procedures, 1.89%) compared to procedures after which chlorhexidine was not used as part of post-surgical care (five infections in 153 procedures, 3.27%). The use of a post-surgical dressing demonstrated a slightly higher rate of infection (eight infections in 300 procedures, 2.67%) than non-use of a dressing (14 infections in 753 procedures, 1.86%). Despite these trends, no statistically significant relationship was found between post-surgical infection and any of the treatment variables examined, including the use of perioperative antibiotics. CONCLUSIONS: The results of this study confirm previous research demonstrating a low rate of postoperative infection following periodontal surgical procedures. Although perioperative antibiotics are commonly used when performing certain regenerative and implant surgical procedures, data from this and other studies suggest that there may be no benefit in using antibiotics for the sole purpose of preventing post-surgical infections. Further large-scale, controlled clinical studies are warranted to determine the role of perioperative antibiotics in the prevention of periodontal post-surgical infections.

Osseous surgery for crown lengthening: a 6-month clinical study.

BACKGROUND: Despite the fact that surgical crown lengthening is a commonly performed treatment, little is known about the specific surgical endpoints of the procedure or the stability of the newly attained crown height over time. Recent clinical reports have ranged across a spectrum from significant tissue rebound to remarkable stability using similar surgical techniques. The purpose of this study was to assess the stability of surgical crown lengthening procedures performed by various surgeons using specific guidelines to determine surgical endpoints. Specifically, we sought to determine the following: 1) What is the immediate increase in clinical crown height following surgery? 2) How stable is the established crown length over a 6-month period? 3) How much supporting bone is removed to establish the new crown length? 4) How does the position of the flap margin relative to the alveolar bone at surgical closure relate to the stability of crown height? METHODS: Twenty-five patients requiring crown lengthening of 43 teeth were included in this study. Clinical indices recorded at eight sites on each molar and six sites on each premolar included plaque, bleeding on probing, probing depth, and relative attachment level from a customized probing stent. Surgical measurements at the same sites included the distance from stent to alveolar bone both before and after osseous surgery and the distance from flap margin to alveolar bone after suturing. Clinical measurements were repeated at 1, 3, and 6 months after surgery. Sites were divided into three groups. All sites on teeth targeted for crown lengthening were labeled treated sites (TT). Interproximal sites on neighboring teeth were labeled adjacent (AA) if they shared a proximal surface with a treated tooth and nonadjacent (AN) if they were on the opposite side, away from the treated tooth. RESULTS: Throughout the entire 6-month healing period, descriptive statistics revealed no significant time or group differences in plaque and bleeding scores. At treated sites, the mean gain of crown height at surgery was 2.27 +/- 1.1 mm. This was reduced to 1.91 +/- 1.08 mm at 1 month, 1.69 +/- 1.02 mm at 3 months, and 1.57 +/- 1.01 mm at 6 months. At adjacent sites, the gain of crown length was 2.18 +/- 0.98 mm, 1.61 +/- 0.98 mm, 1.43 +/- 0.96 mm, and 1.30 +/- 0.96 mm at surgery, 1, 3, and 6 months, respectively. At non-adjacent sites the crown height increased 1.06 +/- 1.07 mm, 1.00 +/- 0.93 mm, 0.84 +/- 1.00 mm, and 0.76 +/- 0.85 mm, respectively. These mean measurements were significantly different for each treatment group at each time interval and appeared not to have stabilized between 3 and 6 months. The mean osseous reduction at treated, adjacent, and non-adjacent sites was 1.13 +/- 0.90 mm, 0. 78 +/- 0.75 mm, and 0.065 +/- 0.69 mm, respectively. Frequency distribution of osseous reduction demonstrated that 23.6% of treated sites had 0 mm, 44.3% had 1 mm, 25.4% had 2 mm, 6.2% had 3 mm, and less than I % had > or = 4 mm of bone removed to establish crown height More bone removal was noted at premolar than at molar sites; however, this was not statistically significant. When tissue rebound following surgery was plotted against post-surgical flap position, it was noted that the closer the flap margin was sutured to the alveolar crest, the greater the tissue rebound during the post-surgical period. This rebound ranged from 1.33 +/- 1.02 mm when the flap was sutured < or = 1 mm from the alveolar crest, to -0.16 +/- 1.15 mm when the flap was sutured > or = 4 mm from the alveolar crest. CONCLUSIONS: These data suggest that there is a significant tissue rebound following crown-lengthening surgery that has not fully stabilized by 6 months. The amount of tissue rebound seems related to the position of the flap relative to the alveolar crest at suturing. These findings support the premise that clinicians should establish proper crown height during surgery without overreliance on flap placement at the osseous crest.