Non Surgical Therapy_Teresa 2021+Hoda 2022 Flashcards
What is the rationale for non-Sx mechanical therapy?
1- Eliminate plaque biofilm accumulating surface characteristics (Rough surfaces –> 4x increase in plaque formation - Quirynen 1993)
2- Reduce inflammation
3- To control disease progression:
- Loe 1965 -biofilm is the primary etiology
- Harrell and Nunn 2001 - Px that don’t receiver Perio tx had increased PD at a rate of 0.3 mm/year
What is the tissue response to sterile & sterile calculus?
Allen and Kerr 1965:
Study in Guinea pigs
- Sterile calculus –> mild foreign body reaction
- Non-sterile calculus –> marked inflammatory response with granulation tissue formation
What are the limits of SubG scaling?
Stambaugh 1981:
- Curette efficiency: PD to which tooth surface the tooth can be instrumented to a plaque and calculus free surface = 3.73 mm (Average) & (Maximum = 4.07 mm)
More efficient on M/D than Bucc/Ling)
- Curette limit: Maximum PD to which evidence of instrumentation on the root could be detected = 6.21 mm (Average = 5.52 mm)
However, the curette efficiency maxed out at 4 mm due to resistance of pocket wall to be distended by the instrument shank for proper blade angulation in deeper pockets.
- Average instrumentation time:
- Max. posterior tooth –> 39 min
- Mandibular posterior tooth –> 25 min
According to Heitz-Mayfield & Lang 2013, what is the critical PD for SRP and MWF(Access flap)? What
Critical PD is the PD below which a specific tx approach would result in CALoss and above which it will result in CALgain. Those numbers are based on a longitudinal RCT in 15 patients with advanced PDitis (Lindhe et al 1982)
SRP –> 2.9 mm
MWF (Access flap) –> 4.2 mm
5.4 mm –> is the PD starting from which access flap would result in sig. higher CALgain than SRP. This means that between PD 2.9-5.4 mm, non Sx therapy is preferred
What classical study showed that plaque biofilm is the 1ry etiology of disease?
Loe et al. 1965
Aim:
OH was withdrawn and the changes in the microbial flora and gingiva was observed
* 12 study participants (9 dental students, 1 perio faculty, and 2 laboratory technicians)
* Patients were told not to perform any oral hygiene and inflammatory changes were observed (GI, PI)
Results:
- 3 subjects developed gingivitis in 10 days.
- 9 subjects took 15-21 days.
- different progression rates and models were present among individuals.
- Gingival inflammation was resolved within one week resuming oral hygiene.
What is the effect of PD reduction on the clinical and microbiological changes?
Mombelli and Nyman et al.1995:
Design:
- 7 patients aged 30-60 years with generalized periodontitis.
- OHI + SupraG debridement
- Flaps + osseous of angular bony defects. While the control teeth were carefully debrided and thoroughly root planed, no root instrumentation was performed on the test teeth + APF
Results:
- Similar pattern of response in the test and control sites over a one year post therapy –> PD + CAL were sig. reduced 1 month after surgery and remained at a lower level.
- Sig. decrease in total anaerobic viable bacterial counts and Gram-ve anaerobic rods (Pg, Fusobacterium and C. Rectus) decreased significantly in both groups.
Conclusion:
These findings corroborate the concept that the reduction of selected SubG microorganisms is the key element for the success of periodontal therapy, rather than the removal of tooth substance and mineralized deposits by root instrumentation.
What is the architecture of biofilm on natural teeth?
Ziginge 2010:
3D architecture with Red complex bacteria in the middle and superficial layer
Is attachment possible between calculus and Junctional epithelium?
Listgarten 1973:
Calculus sterilized with CHX allows the attachment of Junctional epith. via hemidesmosomes.
From the abstract:
“Methods: Following SRP of 2 rhesus monkeys, gingiva was maintained by 1x daily intra-oral swabs with 2 % CHX, supplemented by toothbrushing and interdental cleansing with toothpicks 3X/ week.
- 1 monkey maintained for 3 months on this regimen, the 2nd monkey was maintained for only 3 weeks followed by a period of 12 days without oral hygiene.
Results: The JE is able to form an attachment to a calculus mass which contained bacterial cells. Electron microscopy revealed that this attachment was mediated through a dental cuticle, a basement lamina and hemidesmosomes. The ultrastructure of the epithelial attachment to calculus was indistinguishable from that which exists between junctional epithelium and various tooth surfaces. These results may be due to the inhibiting effect of chlorhexidine gluconate on plaque formation and possibly a concomitant lowering of the toxicity of calculus.”
Do you think that calculus detection by periodontists is accurate?
Sherman et. al 1990) evaluated the accuracy of clinical detection of calculus by periodontists, he examined 101 teeth (which were deemed for extraction due to perio/pros reasons)
476 surfaces (4 surfaces of non-molar teeth and 6 surfaces for molars) were evaluated before and 1 week after scaling and root planing (hand + US). After 3-month maintenance, extractions done, then microscopic evaluation of remaining calculus.
Microscopically: 57.7% of surfaces had residual calculus. However, clinically only 18.8% were recorded.
What is the difference in calculus removal with and without flap at different PD?
Caff likes to remove calc
Waerhaug evaluated calculus efficiency in relation to diff. PD:
- Shallow: 83%
- Moderate: 38%
- Deep: 11%
Caffessee et al. 1986: compared the calculus-free surfaces when only SRP or Flap/MWF + SRP was done.
SRP only:
- PD 1-3 mm –> 86%
- 4-6 mm –> 43%
- > 6 mm –> 32%
SRP + Flap:
- PD 1-3 mm –> 86%
- 4-6 mm –> 76%
- > 6 mm –> 50%
Ca
What are the limitations of SRP in furcations?
Bower 1979: assessed the width of molar furcations:
- 81% of furcations were =< 1 mm
- 58% of furcation areas were < 0.75 mm.
On the other hand, the width of the commonly used curettes were smaller than the width of furcations, the narrowest curette width is 0.8 mm (Gracey curette)
Bower also measured root concavity in Max and Mand. molars:
- Max: 94% of MB roots had 0.3 mm concavity
- Mand: 100% Mesial root had 0.7 mm concavity, and 99% of distal root had 0.5 mm concavity
- Regardless of the type of instrumentation, it is expected that there will be residual calculus, but when combining open flap debridement WITH US instrumentation it will be more effective especially in narrow furcations (Matia et. al. 1986).
Does PD measurement affect the success of Plaque control?
(Waerhaug 1978b) In 83% of the sites, plaque control was successful (reformation of JE in histo and seen when pocket depths were < 3mm. , and 39% when PD were 3-5mm. However, when pockets were > 5mm the success rate was only 11%.
How long does it take oral flora to recolonize pocket after SRP?
Greenwell and Bissada 1984 –>
* following SRP microflora from diseased sites return to baseline levels after 4-8 weeks (~ 56 days)
*There was an increase in the proportion of nonmotile bacteria in sites with probing depths of ≤4 mm
Sbordone 1990 –> rebound of subG microflora takes 60 days after SRP
Is there a difference in clinical improvement that can be achieved using hand instrumentation vs. US or laser vs. US?
(Badersten 1981) Compared Ultrasonic vs. Hand :
Patients with moderate- advanced periodontitis, split mouth design.
Both methods resulted in improvements of clinical parameters, NSSD between them.
(Sculean et. al. 2004a) Compared Laser vs. Ultrasonic: 20 patients (PD >4mm), split mouth
non-surgical therapy done with either:
1-Er:YAG laser device.
2-Ultrasonic.
They both resulted in comparable results in terms of (PD, BOP, CAL gain, recession
(Sculean et. al. 2004b) Compairing Ultrasonic vs. Hand: 38 patients recruited with moderate – advanced periodontal disease, they were randomly distributed to non-surgical therapy with either:
1- Vector ultrasonic system (working tip movement is parallel to the root).
2- Hand instrumentation.
There were No differences in parameters measured (PD, BOP, GI, CAL gain &recession).
Less working time with the first group.
(Muller et. al. 2014) RCT, split mouth design, compairing Ultrasonic vs. air polishing: 50 patients (with PD> 4mm):
1-air-polishing device.
2-US instruments.
NSSD between the groups.
Significantly less pain reported by patients in sites treated with air-polishing compared to US.
What is the efficacy of endotoxin removal, time and pocket closure with hand vs. US instrumentation?
Nishimine and O’leary showed that US instrumentation results in 8X more endotoxin left behind than root planning
Copulos showed that US is more time efficient in achieving similar clinical outcomes compared to hand instrumentation.
US –> 3.9 min/tooth
Hand –> 5.6 min/tooth
Wesnstrom and Tomasi 2005: assessed the % of pocket closure (PD of =< 4mm) with 4Quads SRP vs. FM US
- 4 Quads SRP –> 66% pocket closure with 8.8 min/closed pocket
- FM US –> 58% with 3.3 min/closed pocket
