|Year : 2016 | Volume
| Issue : 1 | Page : 39-44
Nonsurgical periodontal therapy: A review
Jyotsana Tanwar, Shital A Hungund, Kiran Dodani
Department of Periodontics, Darshan Dental College and Hospital, Udaipur, Rajasthan, India
|Date of Web Publication||16-May-2016|
Darshan Dental College and Hospital, Loyara, Udaipur, Rjasthan
Source of Support: None, Conflict of Interest: None
Nonsurgical therapy aims to eliminate both living bacteria in the microbial biofilm and calcified biofilm microorganisms from the tooth surface and adjacent soft tissues. Complete elimination of such pathogenic microorganisms is perhaps over-ambitious. However, a reduction in inflammation of the periodontium due to a lesser bacterial load leads to beneficial clinical changes. In addition, nonsurgical therapy aims to create an environment in which the host can more effectively prevent pathogenic microbial recolonization using personal oral hygiene methods. The concept of critical probing depth was consistently found to be greater for the surgical approach than for the nonsurgical treatment. The various methods used in nonsurgical therapy, such as hand instrumentation, ultrasonic and sonic scalers, and ablative laser therapy.
Keywords: Antibiotics, laser, periodontium, root planing, scaling
|How to cite this article:|
Tanwar J, Hungund SA, Dodani K. Nonsurgical periodontal therapy: A review. J Oral Res Rev 2016;8:39-44
| Introduction|| |
Periodontitis is an inflammatory disease of the supporting tissues of the teeth caused by specific microorganisms or groups of specific microorganisms resulting in progressive destruction of the periodontal ligament and alveolar bone with pocket formation, recession, or both. Ideally, periodontal therapy should eliminate inflammation, arrest progression of periodontal disease, improve esthetics, and create an environment conductive to maintenance of health.
Nonsurgical periodontal therapy (NSPT) is the cornerstone of periodontal therapy and the first recommended approach to the control of periodontal infections. It is also known as “Cause-related therapy,” “Phase I therapy or Etiotrophic phase,” and “Initial therapy.” It is defined as “plaque removal, plaque control, supragingival and subgingival scaling root planing (SRP), and adjunctive use of chemical agents.” Although NSPT has evolved over the years, it is still considered to be the “gold standard” to which other treatment methods are compared.,
However, conventional mechanical debridement procedures do not remove all periodontopathic bacteria from the subgingival environment, especially those in inaccessible areas such as furcations, grooves, concavities, and deep pockets. It appears that the effects of mechanical therapy might be augmented using antimicrobial agents which further suppress the remaining pathogens. A recent advance which is receiving much attention is the application of lasers, photodynamic therapy (PDT), and hyperbaric oxygen therapy (HBOT) in NSPT.
| Scaling and Root Planing|| |
The primary objective of (SRP) is to regain gingival health by completely removing elements that are responsible for the gingival inflammation (i.e., plaque, calculus, and endotoxins) in the oral environment. Both hand instruments and ultrasonic instruments are capable of dramatically reducing the numbers of subgingival microorganisms. The outcome of any treatment method is determined by complete and adequate access to pocket areas, the time devoted by the operator to the procedure, and the thoroughness of the procedure.
Root surface removal by scaling and root planing
According to Horning et al., during SRP the amount of cemental removal with manual scalers with 40 strokes was 57.8 µm. Ultrasonic scaling became an accepted procedure, and it was stated in 1960 that the instruments were an acceptable alternative to hand scalers by Coldiron NB, 1967.
Rosenberg and Ash  Van Volkinburg et al. reported that more amount of root surface was removed with manual scalers, whereas Pameijer et al. reported that ultrasonic scalers do so. It was concluded that the root substance removal with one stroke was 1–20 µm and it varied depending on the site of the tooth, the power of the power-driven scaler, the shape of the tip, and whether the root surface was exposed or not.
Busslinger et al. reported more time consumption by manual instrumentation than the piezoelectric ultrasonic scaler and the magnetostrictive ultrasonic scaler. Although piezoelectric scaler was more efficient than the magnetostrictive scaler in removing calculus, the instrumented area was found to be rougher.
Schwarz JP (1958) demonstrated that ultrasonic scaling causes no injury to the periodontal membrane, alveolar bone, and gingiva.
Effect of supragingival plaque control on subgingival plaque bacteria
Kho et al. reported that with supragingival scaling showed no significant changes in the subgingival bacterial composition of pockets with 7 mm or deeper.
In contrast, McNabb et al. reported that supragingival plaque control by professional tooth cleaning induced significant changes in the composition of subgingival microflora, including a decrease of Porphyromonas gingivalis and spirochetes.
Haffajee et al. reported reduction in gingival redness, bleeding reduction of 40 bacterial species including Aggregatibacter actinomycetemcomitans, P.gingivalis, Prevotella intermedia, and Treponema denticola and mean gain in attachment level.
| Effects of Nonsurgical Therapy on the Periodontal Tissues|| |
Changes in gingival inflammation
Several investigators have demonstrated higher probability of periodontal breakdown and the range of reduction of the occurrence of bleeding after probing after the 1st month was 6–64%, 12–80% at 3 months posttreatment, 12–87% at 6 months and 37–87% at 12 months after completion of the nonsurgical periodontal treatment.
Cercek et al. reported that patients maintaining oral hygiene showed approximate 25% decrease in bleeding tendency, 0.5 mm probing depth (PD) reduction, 0.7 mm of recession and no gain of clinical attachment.
It was concluded that supragingival plaque control can help resolve signs of inflammation associated with gingivitis but does not predictably alter the bacterial composition in pockets <5 mm. Therefore, subgingival debridement is necessary in addition to personal oral hygiene to achieve periodontal health.
Changes in probing pocket depth and clinical attachment level
For nonmolar sites, with initial PD between 1 and 3 mm, the amount of gingival recession was approximately 1 mm, and with moderately deep (4–6 mm) or deep (7 mm or more) PD at baseline, the gingival recession were 1.2 mm and 1.9 mm, respectively. There was significantly less gingival recession at the molar furcation sites than nonmolar sites. No significant changes were seen when hand instruments or ultrasonic instruments were used.
Proye et al. reported reduction in recession after 1 week and a gain of clinical attachment by 3 weeks after a single episode of SRP.
It was concluded the magnitude of recession was related to initial PDs and inflammatory status of the tissues. The most gingival shrinkage occurred interproximally. The greatest gain of clinical attachment occurred at sites which initially had deep pockets. Conversely, at shallow sites, hand instrumentation usually caused a small amount of attachment loss.
Reduced efficacy in molar furcation defects
Nordland et al. reported similar pocket reduction and gain of clinical attachment in molar or nonmolar sites, but there was a tendency to recur in furcation defects within a year. In addition, the reduction of anaerobes was only 2-fold at furcation defects, whereas there was a 100-fold reduction at other sites.
Changes in alveolar bone structures
Renvert and Egelberg  reported that probing bone levels increased by 0.6 mm after surgery and there was virtually no bone fill after root planing. Isidor et al. found that surgery resulted in 0.5 mm coronal growth of bone in angular defects and no changes following root planing.
Isidor et al. observed no changes in the bone height with horizontal bone loss when treated with NSPT.
It was concluded intraosseous defects treated with NSPT showed an increase in bone probing levels of 0.2 mm at 6 months, 0.3 mm at 12 months, and 0.5 mm at 24 months after therapy. After 3 years, the gain in bone probing levels after NSPT was gradually lost, most probably due to the absence of any additional professional subgingival instrumentation during the 5-year follow-up in these studies.
Single versus repeated instrumentation
Badersten et al. reported reduction of approximately 2 mm in mean PDs with singe instrumentation and no further improvement was achieved with repeated instrumentation.
Magnusson et al. reported reduction in mean PDs after a single scaling episode from 7.2 mm to 6 mm within 16 weeks and a second instrumentation decreased pockets to 4.9 mm.
It was concluded the efficacy of a single course of SRP will be affected by the skill of the clinician, time allocated for procedures, inflammatory status of tissues, anatomy of roots, etc. In general, after a single instrumentation, treated areas need to be re-evaluated for further treatment.
| Chemotherapeutic Agents|| |
The effects of mechanical therapy might be augmented using antimicrobial agents which further suppress the remaining pathogens. Many chemotherapeutic agents are now available treating periodontal diseases. Systemic anti-infective therapy (oral antibiotics) and local anti-infective therapy (placing anti-infective agents directly into the periodontal pocket) can reduce the bacterial challenge to the periodontium.
Four generations of antiseptics that includes:
- I generation: Antibiotics, phenols, quaternary ammonium compounds, and sanguinarine
- II generation: Bisbiguanides, bipyridines, quaternary ammonium compounds, phenolic compounds, metal ions, halogens, enzymes, surfactants, oxygenating agents, natural products, urea, amino alcohols, saliflour, and agents that increases the redox potentials
- III generation: Effective against specific periodontogenic organisms
- IV generation: Probiotics are incorporated in mouthwashes.
| Keyes Technique|| |
In 1978, Keye's  method of oral hygiene was compared to conventional oral hygiene in patients with no SRP who were divided into untreated (no surgery) and treated (surgery) groups by Greenwell et al. This comparison showed that Keye's antimicrobial agents were more effective in reducing clinical indicator values and producing favorable subgingival proportion changes than was conventional oral hygiene alone.
| Antibiotics in Periodontics|| |
Periodontium usually harbors a constellation of putative pathogens rather than a single species. Any effect produced in the sulcus, a systemically administered antibiotic will produce antimicrobial effects in other areas of the oral cavity. This additional effect will reduce bacterial counts on the tongue and other mucosal surfaces, thus potentially aiding to delay in re-colonization of subgingival sites by the offending bacteria. Winkel et al. showed that combination of metronidazole and amoxicillin has been found to produce more pocket depth reduction than control medication. Most commonly used antibiotics for periodontal organisms are metronidazole, amoxicillin, tetracycline, clindamycin, azithromycin, ciprofloxacin, and augmentin.
| Lasers in Nonsurgical Periodontal Therapy|| |
Laser irradiation has been reported to exhibit bactericidal, and detoxification effects without producing a smear layer and root surface treated with laser may, therefore, provide favorable conditions for the attachment of periodontal tissue.
Although there is no clear evidence to date that laser applications improve clinical outcome due to the action of curettage, laser treatment has a potential advantage of accomplishing soft tissue wall treatment effectively along with root surface debridement, and should be further investigated. The different types of lasers used are CO2, neodymium-doped yttrium aluminum garnet (Nd:YAG), erbium-doped yttrium aluminum garnet laser, diode laser, argon laser, an alexandrite laser, and an excimer laser.
Miyazaki et al. reported decreased inflammation and PD after treatment with CO2 laser and improvements regarding clinical parameters and subgingival microflora after Nd:YAG, CO2 and ultrasonic treatments.
Schwarz et al. reported ineffectiveness of laser for calculus removal, and causes alteration of root surfaces such as grooves and crater-like defects in vivo.
Henry et al. reported effectiveness of low dose argon laser in the treatment of clinical infections caused by biofilm-associated species of Prevotella and Porphyromonas.
Improper use of lasers could cause further destruction of the intact attachment apparatus at the bottom of pockets as well as excessive ablation of root surface and gingival walls. Root surface with major thermal damage could render the tissue incompatible for normal cell attachment and healing. Among these, Nd:YAG shows promise for hard tissue and soft tissue wall treatment.
| Hyperbaric Oxygen Therapy|| |
HBOT is a method of administering pure oxygen at greater than atmospheric pressure to a patient to improve or correct conditions. HBOT should be used to compliment conventional therapies and treatments.
Guo and Zhu  showed that HBOT combined with supragingival and subgingival scaling therapy had synergistic action on periodontitis.
Chen et al. showed that HBO had good therapeutic effects on human severe periodontitis, the effects can keep more than 1 year.
| Photodynamic Therapy|| |
Andersen et al. found that SRP combined with photodisinfection leads to significant improvements of the investigated parameters over the use of SRP alone.
de Almeida et al. reported that PDT may be an effective alternative for control of bone loss in furcation areas in periodontitis.
Christodoulides et al. reported failure in additional improvement in terms of PD reduction and clinical attachment level (CAL) gain with a single episode of PDT to SRP, but it resulted in a significantly higher reduction in bleeding scores compared to SRP alone.
| Studies Showing the Effect of Nonsurgical Periodontal Therapy on Periodontitis|| |
From 1980 to 1986 a group of seven studies were done to show the effect of SRP on moderately advanced and advanced periodontitis as follows:
- A study done by Anita Badersten, Rolf Nilveus and Jan Egelberg in 1981 evaluated the effect of NSPT on moderately advanced periodontitis with hand instrument and ultrasonic instrumentation and showed no difference at the time of treatment but more reduction in pocket depth and more attachment gain for surfaces with 6–7.5 mm initial depth than for surfaces with 4–5.5 mm initial depth was seen
- In 1984, they reported marked improvement of gingival conditions not only in periodontal pockets of moderate depth but also in pockets up to 12 mm deep bynon surgical therapy
- In another study in 1984, they compared the effects of single versus repeated instrumentation and demonstrated no difference in results could and suggest that recurrence of disease due to subgingival recolonization by microorganisms during healing phase may not be a major problem 
- In 1985 they demonstrated that deep periodontal pockets may be successfully treated by plaque control with one episode of instrumentation and operator variability may be limited
- Continuing the study in 1985 showed that probing and attachment loss in sites with nonresponsive to initial periodontal therapy follows a gradual, linear course, or approximately a linear pattern for the vast majority of treated sites
- In 1985, they suggested that the majority of sites with attachment loss were found amongst initially shallow or moderately deep a lesion which indicates that the attachment loss is due to trauma associated with therapy rather than loss as a result of a continuing inflammatory disease process
- In 1986 showed that sites with probing attachment loss were more frequent for sites with high scores for plaque, bleeding, residual PD, and suppuration than in sites with low scores.
| Various Studies Comparing Surgical and Nonsurgical Periodontal Therapy|| |
Michigan study I was done by Ramfjord et al. in 1973 found greater gain in probing attachment level by NSPT with no difference in probing attachment level in surgical and nonsurgical treatment after 5 years.
Michigan study II was done in 1975 by Ramfjord et al. found no difference after 1 year in surgical and nonsurgical therapy. However, after 5 years, pocket depth ≥7 mm treated with Modified Widman flap had greater attachment gain than NSPT.
Michigan study III was done by Morrison, Ramfjord, Hill in 1980 found greater reduction in PD by surgery when compared to NSPT and when pocket depth was 4–6 mm there was less loss (greater gain) with NSPT and PD ≥7 mm showed no difference by surgical and nonsurgical therapy. After 5 years, PD reduction was greater by surgery when pocket depth was 4–6 mm before surgery. However, when pocket depth was ≥7 mm there was no difference in PD reduction by surgical and NSPT.
Sweden study I was done by Rosling et al. in 1976 found no difference in PD reduction by flap surgery with osseous and without osseous resection.
Sweden study II was done by Lindhe et al. in 1982 found greater PD reduction and more attachment level gain with surgical therapy than nonsurgical therapy and no difference in surgical and NSPT with pocket depth ≥4 mm.
Sweden study III was done by Lindhe and Nyman in 1985 found no difference in surgical and NSPT in PD reduction and attachment level gain.
Sweden study IV and V was done by Westfelt et al. in 1985 found more attachment gain in pocket ≥7 mm with surgery and after 1 year no difference was noticed with surgical and NSPT in PD reduction and attachment level gain.
This study was done by Pihlstrom et al. found greater reduction in PD with surgical therapy as compared to nonsurgical therapy. When initial PD was 1–3, no difference was found in surgical and NSPT. After 5 years, no difference in surgical and NSPT was found with PD 1–6 mm and with PD ≥7 mm greater reduction in probing was found by surgical therapy. In case of attachment level gain after 1 year and 5 years duration, pocket with 4–6 mm there was greater gain in attachment in NSPT and pocket with <7 mm there was no difference in surgical and nonsurgical therapy.
The Denmark study was done by Isidor F, Karring et al. found that there was greater PD reduction after 1 year duration, but there was no difference after 5 years. In case of attachment level gain, there was greater attachment gain by NSPT but after 5 years there was no difference.
Loma Linda study
This study was done by Durwin et al. found greater gain in attachment level by surgical therapy after 1 year. However, after ≥5 years duration there was no difference in surgical and NSPT.
The Nebraska study was done by Kalkwarf et al. in 1988 found greater PD reduction by surgical procedures after 1 year. However, in case of attachment level gain, there was more gain with NSPT when PD was 5–6 mm after 1 year and with PD ≥ 7 mm there was no difference in surgical and NSPT.
This study was done by Becker et al. in 1988 found greater PD reduction with surgical therapy after 1 year and no difference in attachment level gain.
| Conclusion|| |
The causative factors of periodontal disease are mostly eliminated by SRP. In periodontitis patients, mechanical nonsurgical pocket therapy reduces inflammation, pocket depth, and increases CAL. There is no evidence of a difference in efficacy of machine driven (ultrasonic and sonic) and hand instruments (in single rooted teeth). In periodontal maintenance patients, mechanical debridement reduces inflammation and disturbs the bacterial biofilm which has a crucial role in disease causation and recurrence. The effect of mechanical nonsurgical pocket therapy on pocket depth reduction and clinical attachment gain in maintenance patients is unclear; however, maintenance or stability of pocket PD and CAL has been demonstrated and meets the goal of maintenance. Adjunctive therapies used in combination with conventional mechanical treatment have the potential to improve the condition of the periodontal pockets more than mechanical therapy alone. At present, there is no single periodontal therapeutic regimen that will provide a beneficial response for all patients. NSPT still constitutes the first step in controlling periodontal infections. Changing concepts in periodontal microbiology might modify our approach to mechanical therapy, and technologic advances might help us to understand the exact nature of periodontal infections and to perform the treatment more effectively and easily.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Offenbacher S. Periodontal diseases: Pathogenesis. Ann periodontal 1996;1:821-78.
Plessas A. Nonsurgical Periodontal Treatment: Review of the Evidence. OHDM 2014;3:71-80.
Drisko CH. Non surgical periodontal therapy. Periodontol 2000 2001;25:78-9.
Ehizele AO, Akhionbare O. Effect of non surgical periodontal therapy on the concentration of volatile sulphur compund in mouth air of group of nigerian young adults. Ann Med Health Sci Res 2013;3:433-7.
American Academy of Periodontology, Ad Hoc committee on the parameters of care: Phase I therapy, J Periodontal 2000;71(suppl):856.
Dragoo M. A clinical evaluation of hand and ultrasonic instruments on subgingival debridement I. With unmodified and modified ultrasonic inserts, Int J Periodont Restor Dent 1992;12:311.
Ower P. Minimally invasive non periodontal therapy. Dent Update 2013;40:289-95.
Horning GM, Cobb CM, Killoy WJ. Effect of an air-powder abrasive system on root surfaces in periodontal surgery. J Clin Periodontol 1987;14:213-20.
Coldiron NB, Yukna RA, Weir J, Caudill RF. A quantitative study of cementum removal with hand curettes. J Periodontol 1990;61:293-9.
Rosenberg RM, Ash MM Jr. The effect of root roughness on plaque accumulation and gingival inflammation. J Periodontol 1974;45:146-50.
Van Volkinburg JW, Green E, Armitage GC. The nature of root surfaces after curette, cavitron and alpha-sonic instrumentation. J Periodontal Res 1976;11:374-81.
Pameijer CH, Stallard RE, Hiep N. Surface characteristics of teeth following periodontal instrumentation: a scanning electron microscope study. J Periodontol 1972;43:628-33.
Busslinger A, Lampe K, Beuchat M, Lehmann B. A comparative in vitro
study of a magnetostrictive and a piezoelectric ultrasonic scaling instrument. J Clin Periodontol 2001;28:642-9.
Schlageter L, Rateitschak-Plüss EM, Schwarz. Root surface smoothness or roughness following open debridement. An in vivo
study. J Clin Periodontol 1996;23:460-4.
Kho P, Smales FC, Hardie J. The effect of supragingival plaque control on the subgingival microflora. J Clin Periodontol 1985;12:676-86.
McNabb H, Mombelli A, Lang N. Supragingival cleaning 3 times a week. The microbiological effects in moderately deep pockets. J Clin Periodontol 1992;19:348-56.
Haffajee AD, Cugini MA, Dibart S, Smith C, Kent RL Jr, Socransky SS. Clinical and microbiological features of subjects with adult periodontitis who responded poorly to and root planing. J Clin Periodontol 1997;24:767-76.
Cercek JF, Kiger RD, Garret S, Egelberg J. Relative effects of plaque control and instrumentation on the clinical parameters of human periodontal disease. J Clin Periodontol 1983;10:46-56.
Proye M, Caton J, Polson A. Initial healing of periodontal pockets after a single episode of root planing monitored by controlled probing force. J Periodontol 1982;53:296-301.
Nordland P, Garrett S, Kiger R, et al
. The effect of plaque control and root debridement in molar teeth. J Clin Periodontol 1987;14:231-6.
Renvert S, Egelberg J. Healing after treatment of periodontal intraosseous defects. II Effect of citric acid conditioning of the root surface. J Clin Periodontol 1981;8:459-65.
Isidor F, Attstrom R, Karring T. Regeneration of alveolar bone following surgical and non-surgical periodontal treatment. J Clin Periodontol 1985;12:687-96.
Hardy JH, Newman HN, Strhan JD. Direct irrigation and subgingival plaque. J Clin Periodontol 1982;9:52.
Badersten A, Nilveus R, Egelberg J. Effect of non-surgical periodontal therapy III. Single versus reapeted instrumentation. J Clin Periodontol 1984;11:114-24.
Magnusson I, Lindhe J, Yoneyama T, Liljenberg B. Recolonization of a subgingival microbiota following scaling in deep pockets. J Clin Periodontol 1984;11:193-207.
The use of antiseptics, enzymes and oxygenating agents as adjuncts in supragingival plaque control in Manson and Eley's Periodontics 5th
edition. United State of America; Elsevier limited. 2004
Keyes P, Wright W. Howard S. The use of phase contrast microscopy and chemotherapy in the diagnosis and treatment of periodontal lesions-an initial report. Quintessence International 1978;9:51-6.
Hibst R, Keller U. Experimental studies of the application of the Er:YAG laser on dental hard substances I. Measurement of the ablation rate. Lasers Surg Med 1989;9:338-44.
Miyazaki A, Yamaguchi T, Nishikata J, Okuda K, Suda S, Orima K, et al
. Effects of Nd: YAG and CO2 laser treatment and ultrasonic scaling on periodontal pockets of chronic periodontitis patients. J Periodontol 2003;74:175-80.
Schwarz F, Sculean A, Berakdar M, Georg T, Becker J. In vivo
and in vitro
effects of an Er: YAG laser, a GaAlAs diode laser and scaling and root planing on periodontally diseased root surfaces. A comparative histologic study. Lasers Surg Med 2003;32:359-66.
Henry CA, Dyer B, Wagner M, Judy M, Matthews JL. Phototoxicity of argon laser irradiation on biofilms of Porphyromonas and Prevotella species. J Photochem Photobiol B 1996;34:123-8.
Guo YH, Zhu BL. The clinical effect of hyperbaric oxygen therapy combined with supragingival and subgingival scaling therapy on periodontitis. Shanghai Kou Qiang Yi Xue 2004;13:333-5.
Chen TL, Lin SL, Liu GQ, Liu JC, Song PZ, Xu B, et al
. Effect and holding time of hyperbaric oxygen on human severe periodontitis. Shanghai Kou Qiang Yi Xue 2003;12:403-5.
Andersen R, Loebel N, Hammond D, Wilson M. Treatment of periodontal disease by photodisinfection compared to scaling and root planing. J Clin Dent 2007;18:34-8.
de Almeida JM, Theodoro LH, Bosco AF, Nagata MJ, Oshiiwa M, Garcia VG. In vivo
effect of photodynamic therapy on periodontal bone loss in dental furcations. J Periodontol 2008;79:1081-8.
Christodoulides N, Nikolidakis D, Chondros P, Becker J, Schwarz F, Rössler R, et al
. Photodynamic therapy as an adjunct to non-surgical periodontal treatment: A randomized, controlled clinical trial. J Periodontol 2008;79:1638-44.
Badersten A, Nilveus R, Egelberg J. Effect of non-surgical periodontal therapy IV. Operator variability. J Clin Periodontol 1985;12:190-200.
Badersten A, Nilveus R, Egelberg J. Effect of non-surgical periodontal therapy VII. Bleeding, suppuration and probing depth in sites with probing attachment loss. J Clin Periodontol 1985;12:432-40.
Ramfjord S, Knowles J, Nissle R, Shick R, Burgett F. Longitudinal study of periodontal therapy. J Periodontol 1973;44:66-77.
Ramfjord S, Knowles J, Nissle R, Burgett F, Shick R. Results following three modalities of periodontal therapy. J Periodontol 1975;46:522-6.
Rosling B, Nyman S, Lindhe J, Jern B. The healing potential of the periodontal tissues following different techniques of periodontal surgery in plaque-free dentitions. A 2-year clinical study. J Clin Periodontol 1976;3:233-50.
Lindhe J, Westfelt E, Nyman S, Socransky S, Heijl L, Bratthall G. Healing following surgical/nonsurgical treatment of periodontal disease. A clinical study. J Clin Periodontol 1982;9:115-28.
Lindhe J, Nyman S. Scaling and granulation tissue removal in periodontal therapy. J Clin Periodontol 1985;12:374-88.
Westfelt E, Bragd L, Socransky S, Haffajee A, Nyman S, Lindhe J. Improved periodontal conditions following therapy. J Clin Periodontol 1985;12:283-93.
Pihlstrom B, Oritz-Campos C, McHugh R. Randomized four-year study of periodontal therapy. J Periodontol 1981;52:227-42.
Isidor F, Karring T, Attstrom R. The effect of root planing as compared to that of surgical treatment. J Clin Periodontol 1984;11:669-81.
Chamberlain D, Garrett S, Renvert S, Egelberg J. Healing after treatment of periodontal intraosseous defects IV. Effect of a non-resective versus a partially resective approach. J Clin Periodontol 1985;12:525-39.
Kalkwarf K, Kaldahl W, Patil K. Evaluation of furcation region response to periodontal therapy. J Periodontol 1988;59:794-803.
Becker W, Becker B, Ochsenbein C, et al
. A longitudinal study comparing scaling, osseous surgery and modified Widman procedures. Results after one year. J Periodontol 1988;59:351-65.